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Sample records for hybrid nanocomposites based

  1. Photonic structures based on hybrid nanocomposites

    Science.gov (United States)

    Husaini, Saima

    In this thesis, photonic structures embedded with two types of nanomaterials, (i) quantum dots and (ii) metal nanoparticles are studied. Both of these exhibit optical and electronic properties different from their bulk counterpart due to their nanoscale physical structure. By integrating these nanomaterials into photonic structures, in which the electromagnetic field can be confined and controlled via modification of geometry and composition, we can enhance their linear and nonlinear optical properties to realize functional photonic structures. Before embedding quantum dots into photonic structures, we study the effect of various host matrices and fabrication techniques on the optical properties of the colloidal quantum dots. The two host matrices of interest are SU8 and PMMA. It is shown that the emission properties of the quantum dots are significantly altered in these host matrices (especially SU8) and this is attributed to a high rate of nonradiative quenching of the dots. Furthermore, the effects of fabrication techniques on the optical properties of quantum dots are also investigated. Finally a microdisk resonator embedded with quantum dots is fabricated using soft lithography and luminescence from the quantum dots in the disk is observed. We investigate the absorption and effective index properties of silver nanocomposite films. It is shown that by varying the fill factor of the metal nanoparticles and fabrication parameters such as heating time, we can manipulate the optical properties of the metal nanocomposite. Optimizing these parameters, a silver nanocomposite film with a 7% fill factor is prepared. A one-dimensional photonic crystal consisting of alternating layers of the silver nanocomposite and a polymer (Polymethyl methacrylate) is fabricated using spin coating and its linear and nonlinear optical properties are investigated. Using reflectivity measurements we demonstrate that the one-dimensional silver-nanocomposite-dielectric photonic crystal

  2. Nanocomposite-Based Bulk Heterojunction Hybrid Solar Cells

    Directory of Open Access Journals (Sweden)

    Bich Phuong Nguyen

    2014-01-01

    Full Text Available Photovoltaic devices based on nanocomposites composed of conjugated polymers and inorganic nanocrystals show promise for the fabrication of low-cost third-generation thin film photovoltaics. In theory, hybrid solar cells can combine the advantages of the two classes of materials to potentially provide high power conversion efficiencies of up to 10%; however, certain limitations on the current within a hybrid solar cell must be overcome. Current limitations arise from incompatibilities among the various intradevice interfaces and the uncontrolled aggregation of nanocrystals during the step in which the nanocrystals are mixed into the polymer matrix. Both effects can lead to charge transfer and transport inefficiencies. This paper highlights potential strategies for resolving these obstacles and presents an outlook on the future directions of this field.

  3. Elastomer Nanocomposites Based on Butadiene Rubber, Nanoclay and Epoxy-Polyester Hybrid: Microstructure and Mechanical Properties

    OpenAIRE

    Sepideh Zoghi; Ghasem Naderi; Gholam Reza Bakhshandeh; Morteza Ehsani; Shirin Shokoohi

    2013-01-01

    Nanocomposites based on butadiene rubber (BR), (0, 3, 5 and 7 phr) organoclay (Cloisite 15A) and (0, 10, 20, 30, 40 phr) powder coating wastes, i.e., epoxypolyester hybrid (EPH) were prepared using a laboratory-scale internal mixer in order to study the effect of organoclay and EPH content on the mechanical and morphological properties of the nanocomposite samples. Cure characteristics of the prepared compounds including optimum cure time (t90) and scorch time (t5) depicted a decrease in both...

  4. Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications

    OpenAIRE

    Asif Khan; Zafar Abas; Heung Soo Kim; Jaehwan Kim

    2016-01-01

    We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active pa...

  5. Development of novel biocompatible hybrid nanocomposites based on polyurethane-silica prepared by sol gel process

    Energy Technology Data Exchange (ETDEWEB)

    Rashti, Ali [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Yahyaei, Hossein [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Firoozi, Saman [Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Ramezani, Sara [Department of Neuroscience, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Rahiminejad, Ali [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Karimi, Roya [Department of Tissue Engineering and Applied Cell Science, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Farzaneh, Khadijeh [Tehran Heart Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mohseni, Mohsen [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Ghanbari, Hossein, E-mail: hghanbari@tums.ac.ir [Department of Medical Nanotechnology, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Tehran Heart Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Medical Biomaterials Research Center, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2016-12-01

    Due to high biocompatibility, polyurethane has found many applications, particularly in development of biomedical devices. A new nanocomposite based on thermoset polyurethane and silica nanoparticles was synthesized using sol-gel method. Sol-gel process was fulfilled in two acidic and basic conditions by using tetraethylorthosilicate (TEOS) and trimethoxyisocyanatesilane as precursors. The hybrid films characterized for mechanical and surface properties using tensile strength, contact angle, ATR-FTIR and scanning electron microscopy. Biocompatibility and cytotoxicity of the hybrids were assessed using standard MTT, LDH and TUNEL assays. The results revealed that incorporation of silica nanoparticles was significantly improved tensile strength and mechanical properties of the hybrids. Based on the contact angle results, silica nanoparticles increased hydrophilicity of the hybrids. Biocompatibility by using human lung epithelial cell line (MRC-5) demonstrated that the hybrids were significantly less cytotoxic compared to pristine polymer as tested by MTT and LDH assays. TUNEL assay revealed no signs of apoptosis in all tested samples. The results of this study demonstrated that incorporation of silica nanoparticles into polyurethane lead to the enhancement of biocompatibility, indicating that these hybrids could potentially be used in biomedical field in particular as a new coating for medical implants. - Highlights: • Nanocomposites based on polyurethane and nanosilica prepared by sol-gel method fabricated • Addition of inorganic phase improved mechanical properties. • Nanosilica prepared by sol-gel method increased hydrophilicity. • By adding nanosilica to polyurethane biocompatibility increased significantly.

  6. Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications.

    Science.gov (United States)

    Khan, Asif; Abas, Zafar; Kim, Heung Soo; Kim, Jaehwan

    2016-07-26

    We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications.

  7. Recent Progress on Cellulose-Based Electro-Active Paper, Its Hybrid Nanocomposites and Applications

    Directory of Open Access Journals (Sweden)

    Asif Khan

    2016-07-01

    Full Text Available We report on the recent progress and development of research into cellulose-based electro-active paper for bending actuators, bioelectronics devices, and electromechanical transducers. The cellulose electro-active paper is characterized in terms of its biodegradability, chirality, ample chemically modifying capacity, light weight, actuation capability, and ability to form hybrid nanocomposites. The mechanical, electrical, and chemical characterizations of the cellulose-based electro-active paper and its hybrid composites such as blends or coatings with synthetic polymers, biopolymers, carbon nanotubes, chitosan, and metal oxides, are explained. In addition, the integration of cellulose electro-active paper is highlighted to form various functional devices including but not limited to bending actuators, flexible speaker, strain sensors, energy harvesting transducers, biosensors, chemical sensors and transistors for electronic applications. The frontiers in cellulose paper devices are reviewed together with the strategies and perspectives of cellulose electro-active paper and cellulose nanocomposite research and applications.

  8. Hybrid nanocomposites based on conducting polymer and silicon nanowires for photovoltaic application

    International Nuclear Information System (INIS)

    Chehata, Nadia; Ltaief, Adnen; Ilahi, Bouraoui; Salem, Bassem; Bouazizi, Abdelaziz; Maaref, Hassen; Baron, Thierry

    2014-01-01

    Hybrid nanocomposites based on a nanoscale combination of organic and inorganic semiconductors are a promising way to enhance the performance of solar cells through a higher aspect ratio of the interface and the good processability of polymers. Nanocomposites are based on a heterojunction network between poly (2-methoxy-5-(2-ethyhexyl-oxy)-p-phenylenevinylene) (MEH-PPV) as an organic electron donor and silicon nanowires (SiNWs) as an inorganic electron acceptor. Nanowires (NWs) seem to be a promising material for this purpose, as they provide a large surface area for contact with the polymer and a designated conducting pathway whilst their volume is low. In this paper, silicon nanowires are introduced by mixing them into the polymer matrix. Hybrid nanocomposites films were deposited onto ITO substrate by spin coating method. Optical properties and photocurrent response were investigated. Charge transfer between the polymer and SiNWs has been demonstrated through photoluminescence measurements. The photocurrent density of ITO/MEH-PPV:SiNWs/Al structures have been obtained by J–V characteristics. The J sc value is about 0.39 µA/cm 2 . - Highlights: • SiNWs synthesis by Vapor–Liquid–Solid (VLS) mechanism. • SiNWs contribution to absorption spectra enhancement of MEH-PPV:SiNWs nanocomposites. • Decrease of PL intensity of MEH-PPV by addition of SiNWs. • Charge transfer process was taken place. • ITO/MEH-PPV:SiNWs/Al structure shows a photovoltaic effect, with a FF of 0.32

  9. Synthesis and properties of fluorescent hybrid nanocomposites based on copolyacrylates with dansyl semicarbazide units

    International Nuclear Information System (INIS)

    Buruiana, Emil C.; Chibac, Andreea L.; Buruiana, Tinca; Musteata, Valentina

    2011-01-01

    Our study examined a series of hybrid composites containing copolyacrylate with semicarbazide-dansyl groups prepared by conventional radical polymerization of monomers in the organic montmorillonite modified with alkyl chains of variable length or using the sol-gel technique. The structure and the chemical composition of the copolymers N-methacryloyloxyethylcarbamoyl-5- (dimethylaminonaphtalene-1-sulfonohydrazine)-co-methyl metahacrylate (DnsSA-co-MMA) and N-methacryloyloxyethylcarbamoyl -5-(dimethylaminonaphtalene-1-sulfonohydrazine)-co-dodecylacrylamide (DnsSA-co-DA) as well as their nanocomposites (HC-P1, HC-P2, HC-P3, HC-P4) were confirmed by spectral analysis ( 1 H NMR, FTIR, UV/vis), thermal methods and atomic force microscopy. To quantify the effect of the inorganic component compared to pure photopolymers we evaluated the properties of hybrid composites, including dielectric characterization. Additionally, these materials have been tested in experiments of fluorescence quenching by acids (HCl, p-toluenesulfonic acid, 1-S-camphorsulfonic acid), metallic cation (Cu 2+ ) and nitrobenzene. The results suggest that such nanocomposites could find applications as fluorescence-based chemosensors in homogeneous organic solutions or thin films. - Highlights: → Dansylated hybrid composites were prepared by polymerization of monomers in organo-MMT or by sol-gel. → Quenching effects by acids, Cu 2+ and nitrobenzene in solution/film were evidenced. → A fluorescence dequenching was observed for the composite with silsesquixane units. → A reversible process occurs in the composite film exposed to nitrobenzene vapors.

  10. Linear electro-optical behavior of hybrid nanocomposites based on silicon carbide nanocrystals and polymer matrices

    Science.gov (United States)

    Bouclé, J.; Kassiba, A.; Makowska-Janusik, M.; Herlin-Boime, N.; Reynaud, C.; Desert, A.; Emery, J.; Bulou, A.; Sanetra, J.; Pud, A. A.; Kodjikian, S.

    2006-11-01

    An electro-optical activity has been recently reported for hybrid nanocomposite thin films where inorganic silicon carbide nanocrystals (ncSiC) are incorporated into polymer matrices. The role of the interface SiC polymer is suggested as the origin of the observed second order nonlinear optical susceptibility in the hybrid materials based on poly-(methylmethacrylate) (PMMA) or poly-( N -vinylcarbazole) matrices. In this work, we report an analysis of the electro-optical response of this hybrid system as a function of the ncSiC content and surface state in order to precise the interface effect in the observed phenomenon. Two specific ncSiC samples with similar morphology and different surface states are incorporated in the PMMA matrix. The effective Pockels parameters of the corresponding hybrid nanocomposites have been estimated up to 7.59±0.74pm/V ( 1wt.% of ncSiC in the matrix). The interfacial region ncSiC polymer is found to play the main role in the observed effect. Particularly, the electronic defects on the ncSiC nanocrystal surface modify the interfacial electrical interactions between the two components. The results are interpreted and discussed on the basis of the strong influence of these active centers in the interfacial region at the nanoscale, which are found to monitor the local hyperpolarizabilities and the macroscopic nonlinear optical susceptibilities. This approach allows us to complete the description and understanding of the electro-optical response in the hybrid SiC /polymer systems.

  11. Energy efficient hybrid nanocomposite-based cool thermal storage air conditioning system for sustainable buildings

    International Nuclear Information System (INIS)

    Parameshwaran, R.; Kalaiselvam, S.

    2013-01-01

    The quest towards energy conservative building design is increasingly popular in recent years, which has triggered greater interests in developing energy efficient systems for space cooling in buildings. In this work, energy efficient silver–titania HiTES (hybrid nanocomposites-based cool thermal energy storage) system combined with building A/C (air conditioning) system was experimentally investigated for summer and winter design conditions. HiNPCM (hybrid nanocomposite particles embedded PCM) used as the heat storage material has exhibited 7.3–58.4% of improved thermal conductivity than at its purest state. The complete freezing time for HiNPCM was reduced by 15% which was attributed to its improved thermophysical characteristics. Experimental results suggest that the effective energy redistribution capability of HiTES system has contributed for reduction in the chiller nominal cooling capacity by 46.3% and 39.6% respectively, under part load and on-peak load operating conditions. The HiTES A/C system achieved 27.3% and 32.5% of on-peak energy savings potential in summer and winter respectively compared to the conventional A/C system. For the same operating conditions, this system yield 8.3%, 12.2% and 7.2% and 10.2% of per day average and yearly energy conservation respectively. This system can be applied for year-round space conditioning application without sacrificing energy efficiency in buildings. - Highlights: • Energy storage is acquired by HiTES (hybrid nanocomposites-thermal storage) system. • Thermal conductivity of HiNPCM (hybrid nanocomposites-PCM) was improved by 58.4%. • Freezing time of HiNPCM was reduced by 15% that enabled improved energy efficiency. • Chiller nominal capacity was reduced by 46.3% and 39.6% in on-peak and part load respectively. • HiTES A/C system achieved appreciable energy savings in the range of 8.3–12.2%

  12. Elastomer Nanocomposites Based on Butadiene Rubber, Nanoclay and Epoxy-Polyester Hybrid: Microstructure and Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Sepideh Zoghi

    2013-08-01

    Full Text Available Nanocomposites based on butadiene rubber (BR, (0, 3, 5 and 7 phr organoclay (Cloisite 15A and (0, 10, 20, 30, 40 phr powder coating wastes, i.e., epoxypolyester hybrid (EPH were prepared using a laboratory-scale internal mixer in order to study the effect of organoclay and EPH content on the mechanical and morphological properties of the nanocomposite samples. Cure characteristics of the prepared compounds including optimum cure time (t90 and scorch time (t5 depicted a decrease in both mentioned factors with increasing nanoclay content and EPH loading.Intercalation of elastomer chains into the silicate layers was determined by d-spacing values calculated according to the results of X-ray diffraction (XRD patterns. X-ray diffraction (XRD results reveal the intercalation of elastomer chains into the clay galleries. This phenomenon was also confirmed according to the scanning electron microscopy (SEM micrographs and mechanical properties of the nanocomposite samples which were observed to be improved with addition of nanoclay and EPH content.

  13. High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites

    Science.gov (United States)

    Li, Zijiong; Zhou, Zhihua; Yun, Gaoqian; Shi, Kai; Lv, Xiaowei; Yang, Baocheng

    2013-11-01

    In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g-1 at a scan rate of 5 mV.s-1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors.

  14. High-performance solid-state supercapacitors based on graphene-ZnO hybrid nanocomposites

    Science.gov (United States)

    2013-01-01

    In this paper, we report a facile low-cost synthesis of the graphene-ZnO hybrid nanocomposites for solid-state supercapacitors. Structural analysis revealed a homogeneous distribution of ZnO nanorods that are inserted in graphene nanosheets, forming a sandwiched architecture. The material exhibited a high specific capacitance of 156 F g−1 at a scan rate of 5 mV.s−1. The fabricated solid-state supercapacitor device using these graphene-ZnO hybrid nanocomposites exhibits good supercapacitive performance and long-term cycle stability. The improved supercapacitance property of these materials could be ascribed to the increased conductivity of ZnO and better utilization of graphene. These results demonstrate the potential of the graphene-ZnO hybrid nanocomposites as an electrode in high-performance supercapacitors. PMID:24215772

  15. Organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides with intercalated phacolysin as ocular delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Qin, Zhiguo; Zhang, Jie; Chi, Huibo; Cao, Feng, E-mail: cpufengc@163.com [China Pharmaceutical University, Department of Pharmaceutics, School of Pharmacy (China)

    2015-12-15

    This study was mainly aimed to evaluate the potential use of a novel ocular drug delivery system, organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides (LDH). Organic polymers of chitosan–glutathione (CG) and pre-activated chitosan–glutathione (CG-2MNA) were successfully synthesized and characterized. LDH with intercalated phacolysin (PCL), including larger hexagonal LDH–PCL (Lh-LDH–PCL), larger spherical LDH–PCL (Ls-LDH–PCL), smaller hexagonal LDH–PCL (Sh-LDH–PCL), CG hybrid LDH–PCL (LDH–PCL-CG), and CG-2MNA hybrid LDH–PCL (LDH–PCL-CG-2MNA), were prepared. The nanocomposites with particle size of 107.2–274.9 nm were characterized by powder X-ray diffraction, Fourier transform infrared, transmission electron micrographs, etc. In vivo precorneal retention studies showed that the detectable time of all nanocomposites was prolonged from 2 to 6 h in comparison to PCL saline. Accordingly, the AUC{sub 0–6h} values of Lh-LDH–PCL, Ls-LDH–PCL, Sh-LDH–PCL, LDH–PCL-CG, and LDH–PCL-CG-2MNA nanocomposites were increased by 2.27-, 2.08-, 3.08-, 4.67-, and 3.36-fold, respectively. The Draize test and hematoxylin and eosin staining demonstrated that modified LDH had no eye irritation after single and repeated administration. These results indicated that chitosan derivatives-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs.Graphical AbstractThiolated chitosan-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs and may facilitate penetration of drugs into tissues of the eyes.

  16. Organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides with intercalated phacolysin as ocular delivery system

    International Nuclear Information System (INIS)

    Qin, Zhiguo; Zhang, Jie; Chi, Huibo; Cao, Feng

    2015-01-01

    This study was mainly aimed to evaluate the potential use of a novel ocular drug delivery system, organic–inorganic hybrid nanocomposites based on chitosan derivatives and layered double hydroxides (LDH). Organic polymers of chitosan–glutathione (CG) and pre-activated chitosan–glutathione (CG-2MNA) were successfully synthesized and characterized. LDH with intercalated phacolysin (PCL), including larger hexagonal LDH–PCL (Lh-LDH–PCL), larger spherical LDH–PCL (Ls-LDH–PCL), smaller hexagonal LDH–PCL (Sh-LDH–PCL), CG hybrid LDH–PCL (LDH–PCL-CG), and CG-2MNA hybrid LDH–PCL (LDH–PCL-CG-2MNA), were prepared. The nanocomposites with particle size of 107.2–274.9 nm were characterized by powder X-ray diffraction, Fourier transform infrared, transmission electron micrographs, etc. In vivo precorneal retention studies showed that the detectable time of all nanocomposites was prolonged from 2 to 6 h in comparison to PCL saline. Accordingly, the AUC 0–6h values of Lh-LDH–PCL, Ls-LDH–PCL, Sh-LDH–PCL, LDH–PCL-CG, and LDH–PCL-CG-2MNA nanocomposites were increased by 2.27-, 2.08-, 3.08-, 4.67-, and 3.36-fold, respectively. The Draize test and hematoxylin and eosin staining demonstrated that modified LDH had no eye irritation after single and repeated administration. These results indicated that chitosan derivatives-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs.Graphical AbstractThiolated chitosan-LDH hybrid nanocomposite dispersion could be a promising ocular drug delivery system to improve precorneal retention time of drugs and may facilitate penetration of drugs into tissues of the eyes

  17. Synthesis and properties of fluorescent hybrid nanocomposites based on copolyacrylates with dansyl semicarbazide units

    Energy Technology Data Exchange (ETDEWEB)

    Buruiana, Emil C., E-mail: emilbur@icmpp.r [' Petru Poni' Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Chibac, Andreea L.; Buruiana, Tinca; Musteata, Valentina [' Petru Poni' Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania)

    2011-07-15

    Our study examined a series of hybrid composites containing copolyacrylate with semicarbazide-dansyl groups prepared by conventional radical polymerization of monomers in the organic montmorillonite modified with alkyl chains of variable length or using the sol-gel technique. The structure and the chemical composition of the copolymers N-methacryloyloxyethylcarbamoyl-5- (dimethylaminonaphtalene-1-sulfonohydrazine)-co-methyl metahacrylate (DnsSA-co-MMA) and N-methacryloyloxyethylcarbamoyl -5-(dimethylaminonaphtalene-1-sulfonohydrazine)-co-dodecylacrylamide (DnsSA-co-DA) as well as their nanocomposites (HC-P1, HC-P2, HC-P3, HC-P4) were confirmed by spectral analysis ({sup 1}H NMR, FTIR, UV/vis), thermal methods and atomic force microscopy. To quantify the effect of the inorganic component compared to pure photopolymers we evaluated the properties of hybrid composites, including dielectric characterization. Additionally, these materials have been tested in experiments of fluorescence quenching by acids (HCl, p-toluenesulfonic acid, 1-S-camphorsulfonic acid), metallic cation (Cu{sup 2+}) and nitrobenzene. The results suggest that such nanocomposites could find applications as fluorescence-based chemosensors in homogeneous organic solutions or thin films. - Highlights: {yields} Dansylated hybrid composites were prepared by polymerization of monomers in organo-MMT or by sol-gel. {yields} Quenching effects by acids, Cu{sup 2+} and nitrobenzene in solution/film were evidenced. {yields} A fluorescence dequenching was observed for the composite with silsesquixane units. {yields} A reversible process occurs in the composite film exposed to nitrobenzene vapors.

  18. Novel electrochemical xanthine biosensor based on chitosan–polypyrrole–gold nanoparticles hybrid bio-nanocomposite platform

    Directory of Open Access Journals (Sweden)

    Muamer Dervisevic

    2017-07-01

    Full Text Available The aim of this study was the electrochemical detection of the adenosine-3-phosphate degradation product, xanthine, using a new xanthine biosensor based on a hybrid bio-nanocomposite platform which has been successfully employed in the evaluation of meat freshness. In the design of the amperometric xanthine biosensor, chitosan–polypyrrole–gold nanoparticles fabricated by an in situ chemical synthesis method on a glassy carbon electrode surface was used to enhance electron transfer and to provide good enzyme affinity. Electrochemical studies were carried out by the modified electrode with immobilized xanthine oxidase on it, after which the biosensor was tested to ascertain the optimization parameters. The Biosensor exhibited a very good linear range of 1–200 μM, low detection limit of 0.25 μM, average response time of 8 seconds, and was not prone to significant interference from uric acid, ascorbic acid, glucose, and sodium benzoate. The resulting bio-nanocomposite xanthine biosensor was tested with fish, beef, and chicken real-sample measurements.

  19. Hybrid nanocomposite based on cellulose and tin oxide: growth, structure, tensile and electrical characteristics

    International Nuclear Information System (INIS)

    Mahadeva, Suresha K; Kim, Jaehwan

    2011-01-01

    A highly flexible nanocomposite was developed by coating a regenerated cellulose film with a thin layer of tin oxide (SnO 2 ) by liquid-phase deposition. Tin oxide was crystallized in solution and formed nanocrystal coatings on regenerated cellulose. The nanocrystalline layers did not exfoliate from cellulose. Transmission electron microscopy and energy dispersive x-ray spectroscopy suggest that SnO 2 was not only deposited over the cellulose surface, but also nucleated and grew inside the cellulose film. Current-voltage characteristics of the nanocomposite revealed that its electrical resistivity decreases with deposition time, with the lowest value obtained for 24 h of deposition. The cellulose-SnO 2 hybrid nanocomposite can be used for biodegradable and disposable chemical, humidity and biosensors.

  20. Multiscale Hybrid Micro-Nanocomposites Based on Carbon Nanotubes and Carbon Fibers

    Directory of Open Access Journals (Sweden)

    Fawad Inam

    2010-01-01

    Full Text Available Amino-modified double wall carbon nanotube (DWCNT-NH2/carbon fiber (CF/epoxy hybrid micro-nanocomposite laminates were prepared by a resin infusion technique. DWCNT-NH2/epoxy nanocomposites and carbon fiber/epoxy microcomposites were made for comparison. Morphological analysis of the hybrid composites was performed using field emission scanning electron microscope. A good dispersion at low loadings of carbon nanotubes (CNTs in epoxy matrix was achieved by a bath ultrasonication method. Mechanical characterization of the hybrid micro-nanocomposites manufactured by a resin infusion process included three-point bending, mode I interlaminar toughness, dynamic mechanical analysis, and drop-weight impact testing. The addition of small amounts of CNTs (0.025, 0.05, and 0.1 wt% to epoxy resins for the fabrication of multiscale carbon fiber composites resulted in a maximum enhancement in flexural modulus by 35%, a 5% improvement in flexural strength, a 6% improvement in absorbed impact energy, and 23% decrease in the mode I interlaminar toughness. Hybridization of carbon fiber-reinforced epoxy using CNTs resulted in a reduction in and dampening characteristics, presumably as a result of the presence of micron-sized agglomerates.

  1. Electrically and Thermally Conductive Low Density Polyethylene-Based Nanocomposites Reinforced by MWCNT or Hybrid MWCNT/Graphene Nanoplatelets with Improved Thermo-Oxidative Stability

    OpenAIRE

    Sandra Paszkiewicz; Anna Szymczyk; Daria Pawlikowska; Jan Subocz; Marek Zenker; Roman Masztak

    2018-01-01

    In this paper, the electrical and thermal conductivity and morphological behavior of low density polyethylene (LDPE)/multi-walled carbon nanotubes (MWCNTs) + graphene nanoplatelets (GNPs) hybrid nanocomposites (HNCs) have been studied. The distribution of MWCNTs and the hybrid of MWCNTs/GNPs within the polymer matrix has been investigated with scanning electron microscopy (SEM). The results showed that the thermal and electrical conductivity of the LDPE-based nanocomposites increased along wi...

  2. Hybrid titanium dioxide/PS-b-PEO block copolymer nanocomposites based on sol-gel synthesis

    International Nuclear Information System (INIS)

    Gutierrez, J; Tercjak, A; Garcia, I; Peponi, L; Mondragon, I

    2008-01-01

    The poly(styrene)-b-poly(ethylene oxide) (SEO) amphiphilic block copolymer, with two different molecular weights, has been used as a structure directing agent for generating nanocomposites of TiO 2 /SEO via the sol-gel process. SEO amphiphilic block copolymers are designed with a hydrophilic PEO-block which can interact with inorganic molecules, as well as a hydrophobic PS-block which builds the matrix. The addition of different amounts of sol-gel provokes strong variations in the self-assembled morphology of TiO 2 /SEO nanocomposites with respect to the neat block copolymer. As confirmed by atomic force microscopy (AFM), TiO 2 /PEO-block micelles get closer, forming well-ordered spherical domains, in which TiO 2 nanoparticles constitute the core surrounded by a corona of PEO-blocks. Moreover, for 20 vol% sol-gel the generated morphology changes to a hexagonally ordered structure for both block copolymers. The cylindrical structure of these nanocomposites has been confirmed by the two-dimensional Fourier transform power spectrum of the corresponding AFM height images. Affinity between titanium dioxide precursor and PEO-block of SEO allows us to generate hybrid inorganic/organic nanocomposites, which retain the optical properties of TiO 2 , as evaluated by UV-vis spectroscopy

  3. Preparation and properties of UV curable organic/inorganic hybrid nanocomposites based on layered double hydroxides

    International Nuclear Information System (INIS)

    Shichang Lv; Wenfang Shi

    2007-01-01

    The organo-modified layered double hydroxides (LDHs), M-LDH and N-LDH, were obtained by the ionic exchange reaction of a magnesium-aluminium nitrate LDH with modifiers. The LDHs/acrylate organic/inorganic hybrid nanocomposites were prepared from organo-modified LDHs, and aliphatic polyurethane acrylate oligomer and an acrylate monomer, through a bulk photopolymerization process at the presence of a photoinitiator. The effects of LDHs content in the resin on the dispersion, and the properties of UV cured nanocomposites film were investigated by using X-ray diffraction, FTIR, thermal analysis, pendulum/pencil hardness measurement. With the good solubility in acrylate resins, the organo-modified LDHs are hopefully to be used in adhesives, coating, inks as toughness modifiers, fire-retardant additives. (Author)

  4. Hybrid nanocomposites based on electroactive hydrogels and cellulose nanocrystals for high-sensitivity electro-mechanical underwater actuation

    Science.gov (United States)

    Santaniello, Tommaso; Migliorini, Lorenzo; Locatelli, Erica; Monaco, Ilaria; Yan, Yunsong; Lenardi, Cristina; Comes Franchini, Mauro; Milani, Paolo

    2017-08-01

    We report the synthesis, fabrication and characterization of a hybrid hydrogel/cellulose nanocomposite, which exhibits high-performance electro-mechanical underwater actuation and high sensitivity in response to electrical stimuli below the standard potential of water electrolysis. The macromolecular structure of the material is constituted by an electroactive hydrogel, obtained through a photo-polymerization reaction with the use of three vinylic co-monomers: Na-4-vinylbenzenesulfonate, 2-hydroxyethylmethacrylate, and acrylonitrile. Different amounts (from 0.1% to 1.4% w/w) of biodegradable cellulose nanocrystals (CNCs) with sulfonate surface groups, obtained through the acidic hydrolysis of sulphite pulp lapsheets, are physically incorporated into the gel matrix during the synthesis step. Freestanding thin films of the nanocomposites are molded, and their swelling, mechanical and responsive properties are fully characterized. We observed that the embedding of the CNCs enhanced both the material Young’s modulus and its sensitivity to the applied electric field in the sub-volt regime (down to 5 mV cm-1). A demonstrator integrating multiple actuators that cooperatively bend together, mimicking the motion of an electro-valve, is also prototyped and tested. The presented nanocomposite is suitable for the development of soft smart components for bio-robotic applications and cells-based and bio-hybrid fluidic devices fabrication.

  5. Highly efficient solid-state neutron scintillators based on hybrid sol-gel nanocomposite materials

    International Nuclear Information System (INIS)

    Kesanli, Banu; Hong, Kunlun; Meyer, Kent; Im, Hee-Jung; Dai, Sheng

    2006-01-01

    This research highlights opportunities in the formulation of neutron scintillators that not only have high scintillation efficiencies but also can be readily cast into two-dimensional detectors. Series of transparent, crack-free monoliths were prepared from hybrid polystyrene-silica nanocomposites in the presence of arene-containing alkoxide precursor through room temperature sol-gel processing. The monoliths also contain lithium-6 salicylate as a target material for neutron-capture reactions and amphiphilic scintillator solution as a fluorescent sensitizer. Polystyrene was functionalized by trimethoxysilyl group in order to enable the covalent incorporation of aromatic functional groups into the inorganic sol-gel matrices for minimizing macroscopic phase segregation and facilitating lithium-6 doping in the sol-gel samples. Neutron and alpha responses of these hybrid polystyrene-silica monoliths were explored

  6. Flexible Pressure Sensor Based on PVDF Nanocomposites Containing Reduced Graphene Oxide-Titania Hybrid Nanolayers

    Directory of Open Access Journals (Sweden)

    Aisha Al-Saygh

    2017-01-01

    Full Text Available A novel flexible nanocomposite pressure sensor with a tensile strength of about 47 MPa is fabricated in this work. Nanolayers of titanium dioxide (titania nanolayers, TNL synthesized by hydrothermal method are used to reinforce the polyvinylidene fluoride (PVDF by simple solution mixing. A hybrid composite is prepared by incorporating the TNL (2.5 wt % with reduced graphene oxide (rGO (2.5 wt % synthesized by improved graphene oxide synthesis to form a PVDF/rGO-TNL composite. A comparison between PVDF, PVDF/rGO (5 wt %, PVDF/TNL (5 wt % and PVDF/rGO-TNL (total additives 5 wt % samples are analyzed for their sensing, thermal and dielectric characteristics. The new shape of additives (with sharp morphology, good interaction and well distributed hybrid additives in the matrix increased the sensitivity by 333.46% at 5 kPa, 200.7% at 10.7 kPa and 246.7% at 17.6 kPa compared to the individual PVDF composite of TNL, confirming its possible application in fabricating low cost and light weight pressure sensing devices and electronic devices with reduced quantity of metal oxides. Increase in the β crystallinity percentage and removal of α phase for PVDF was detected for the hybrid composite and linked to the improvement in the mechanical properties. Tensile strength for the hybrid composite (46.91 MPa was 115% higher than that of the neat polymer matrix. Improvement in the wettability and less roughness in the hybrid composites were observed, which can prevent fouling, a major disadvantage in many sensor applications.

  7. Nanotechnology : emerging applications of cellulose-based green magnetic nanocomposites

    Science.gov (United States)

    Tao Wang; Zhiyong Cai; Lei Liu; Ilker S. Bayer; Abhijit Biswas

    2010-01-01

    In recent years, a new type of nanocomposite – cellulose based hybrid nanocomposites, which adopts cellulose nanofibers as matrices, has been intensively developed. Among these materials, hybrid nanocomposites consisting of cellulosic fibers and magnetic nanoparticles have recently attracted much attention due to their potential novel applications in biomedicine,...

  8. Silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles as antibacterial/antifungal coatings for monumental stones

    Energy Technology Data Exchange (ETDEWEB)

    Aflori, Magdalena [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Simionescu, Bogdana [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); “Costin D. Nenitescu” Centre of Organic Chemistry, 202B Splaiul Independentei, 7114 Bucharest (Romania); Bordianu, Irina-Elena; Sacarescu, Liviu; Varganici, Cristian-Dragos; Doroftei, Florica; Nicolescu, Alina [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania); Olaru, Mihaela, E-mail: olaruma@icmpp.ro [“Petru Poni” Institute of Macromolecular Chemistry, 41A Grigore Ghica Voda Alley, 700487 Iasi (Romania)

    2013-11-20

    Highlights: • Synthesis of nanocomposites with noble metals having high antibacterial efficiency. • Silver nanoparticles antibacterial activity for monumental stone conservation. • A high antibacterial activity while assuring good stone protection. -- Abstract: The present paper reports on the evaluation of two silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles aimed as antibacterial coatings for monumental stones. Sol–gel reaction of titanium isopropoxide and/or 3-(trimethoxysilyl)propyl methacrylate, in the presence of silver nitrate and a primary amine surfactant, yielded new types of hybrid nanocomposites with high antibacterial/antifungal efficacy. Different polymer behaviours regarding a frequently used monumental stone originating from Romania were evidenced through Fourier-transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) technique. Conclusions regarding the stones acid-resistant character and lower influence of salt weathering on its durability, as well as a better protective coating containing titania units were revealed.

  9. Silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles as antibacterial/antifungal coatings for monumental stones

    International Nuclear Information System (INIS)

    Aflori, Magdalena; Simionescu, Bogdana; Bordianu, Irina-Elena; Sacarescu, Liviu; Varganici, Cristian-Dragos; Doroftei, Florica; Nicolescu, Alina; Olaru, Mihaela

    2013-01-01

    Highlights: • Synthesis of nanocomposites with noble metals having high antibacterial efficiency. • Silver nanoparticles antibacterial activity for monumental stone conservation. • A high antibacterial activity while assuring good stone protection. -- Abstract: The present paper reports on the evaluation of two silsesquioxane-based hybrid nanocomposites with methacrylate units containing titania and/or silver nanoparticles aimed as antibacterial coatings for monumental stones. Sol–gel reaction of titanium isopropoxide and/or 3-(trimethoxysilyl)propyl methacrylate, in the presence of silver nitrate and a primary amine surfactant, yielded new types of hybrid nanocomposites with high antibacterial/antifungal efficacy. Different polymer behaviours regarding a frequently used monumental stone originating from Romania were evidenced through Fourier-transform infrared (FTIR) spectroscopy and powder X-ray diffraction (PXRD) technique. Conclusions regarding the stones acid-resistant character and lower influence of salt weathering on its durability, as well as a better protective coating containing titania units were revealed

  10. A novel CuO-N-doped graphene nanocomposite-based hybrid electrode for the electrochemical detection of glucose

    Science.gov (United States)

    Felix, Sathiyanathan; Kollu, Pratap; Jeong, Soon Kwan; Grace, Andrews Nirmala

    2017-10-01

    We report a catalyst of N-doped graphene CuO nanocomposite, for the non-enzymatic electrocatalytic oxidation of glucose. The hybrid nanocomposite was synthesized by copper sulfate, cetyl ammonium bromide and graphite as starting materials. The synthesized composites were characterized with the techniques like X-ray diffraction, field emission scanning electron microscopy, transmission electron microscope to study the crystalline phase and morphological structure. Based on this composite, a non-enzymatic glucose sensor was constructed. Cyclic voltammetry and chronoamperometry methods were done to investigate the electrocatalytic properties of glucose in alkaline medium. For glucose detection, the fabricated sensor showed a linear response over a wide range of concentration from 3 to 1000 µM, with sensitivity of 2365.7 µA mM-1 cm-2 and a fast response time of 5 s. The designed sensor exhibited negligible current response to the normal concentration of common interferents in the presence of glucose. All these favorable advantages of the fabricated glucose sensor suggest that it may have good potential application in biological samples, food and other related areas.

  11. Hybrid Ag-based inks for nanocomposite inkjet printed lines: RF properties

    Energy Technology Data Exchange (ETDEWEB)

    Chiolerio, Alessandro [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Camarchia, Vittorio, E-mail: vittorio.camarchia@polito.it [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Electronics and Telecommunications Department, Politecnico di Torino Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Quaglia, Roberto; Pirola, Marco [Electronics and Telecommunications Department, Politecnico di Torino Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Pandolfi, Paolo [Politronica Inkjet Printing S.r.l., C/O i3p, Corso Castelfidardo 30/A, 10129 Torino (Italy); Pirri, Candido Fabrizio [Center for Space Human Robotics, Istituto Italiano di Tecnologia, Corso Trento 21, 10129 Torino (Italy); Applied Science and Technology Department, Politecnico di Torino Corso Duca degli Abruzzi 24, 10129 Torino (Italy)

    2014-12-05

    Highlights: • Polymer–silver nanocomposite conductive ink for RF fast prototyping. • Reduction of the sintering temperature. • Improved printing resolution. • State-of-the-art electrical conductivity. • Good RF performances. - Abstract: The development of highly conductive Ag nanoparticle (NP)-based inkjet printed (IP) connections is a fundamental process for the success of next-generation digitally printed electronics. This is true both at low frequency and at RF, considering the increasing integration of heterogeneous technologies and the use of flexible substrates. Ink-based technologies provide and form at liquid state the functional material that is then delivered to solid via a sintering process to achieve NP coalescence and electrical percolation. Sintering must be performed at very low temperatures (depending on the substrate choice) to be compatible with previous process steps, to preserve the geometry and fulfill the requirements in term of electrical conductivity, as well as to reduce production costs. While IP, as additive technology, is now well settled for DC or low frequency applications, few results on electrical characterization at RF or microwave frequencies are present due to low conductivity, poor geometry definition and low reproducibility. Hence, a good setup of ink formulation and technological realization is fundamental to enable system performance assessment in the high frequency regime. In this paper we propose a breakthrough: we present a nanocomposite ink, whose thermal and DC electrical properties are extremely interesting and competitive with pure-metallic ink systems. Introducing a copolymer in the formulation, we obtained a reduction of the overall sintering temperature, if compared to the pristine NP suspension, along with improved printing resolution together with very good electrical conductivity. The RF characterization has been performed in the range 1–6 GHz on geometries printed on sintered alumina and on a power

  12. Hybrid Ag-based inks for nanocomposite inkjet printed lines: RF properties

    International Nuclear Information System (INIS)

    Chiolerio, Alessandro; Camarchia, Vittorio; Quaglia, Roberto; Pirola, Marco; Pandolfi, Paolo; Pirri, Candido Fabrizio

    2014-01-01

    Highlights: • Polymer–silver nanocomposite conductive ink for RF fast prototyping. • Reduction of the sintering temperature. • Improved printing resolution. • State-of-the-art electrical conductivity. • Good RF performances. - Abstract: The development of highly conductive Ag nanoparticle (NP)-based inkjet printed (IP) connections is a fundamental process for the success of next-generation digitally printed electronics. This is true both at low frequency and at RF, considering the increasing integration of heterogeneous technologies and the use of flexible substrates. Ink-based technologies provide and form at liquid state the functional material that is then delivered to solid via a sintering process to achieve NP coalescence and electrical percolation. Sintering must be performed at very low temperatures (depending on the substrate choice) to be compatible with previous process steps, to preserve the geometry and fulfill the requirements in term of electrical conductivity, as well as to reduce production costs. While IP, as additive technology, is now well settled for DC or low frequency applications, few results on electrical characterization at RF or microwave frequencies are present due to low conductivity, poor geometry definition and low reproducibility. Hence, a good setup of ink formulation and technological realization is fundamental to enable system performance assessment in the high frequency regime. In this paper we propose a breakthrough: we present a nanocomposite ink, whose thermal and DC electrical properties are extremely interesting and competitive with pure-metallic ink systems. Introducing a copolymer in the formulation, we obtained a reduction of the overall sintering temperature, if compared to the pristine NP suspension, along with improved printing resolution together with very good electrical conductivity. The RF characterization has been performed in the range 1–6 GHz on geometries printed on sintered alumina and on a power

  13. Polyaniline-CuO hybrid nanocomposite with enhanced electrical conductivity

    Science.gov (United States)

    de Souza, Vânia S.; da Frota, Hidembergue O.; Sanches, Edgar A.

    2018-02-01

    A hybrid nanocomposite based on a polymer matrix constituted of Polyaniline Emeraldine-salt form (PANI-ES) reinforced by copper oxide II (CuO) particles was obtained by in situ polymerization. Structural, morphological and electrical properties of the pure materials and nanocomposite form were investigated. The presence of CuO particles in the nanocomposite material affected the natural alignment of the polymer chains. XRD technique allowed the visualization of the polymer amorphization in the nanocomposite form, suggesting an interaction between both phases. The FTIR spectra confirmed this molecular interaction due to the blue shift of the characteristic absorption peaks of PANI-ES in the nanocomposite form. SEM images revealed that the polymer nanofiber morphology was no longer observed in the nanocomposite. The CuO spherical particles are randomly dispersed in the polymer matrix. The density functional theory plus the Coulomb interaction method revealed a charge transfer from PANI to CuO slab. Moreover, the density of states (DOS) has revealed that the nanocomposite behaves as a metal. In agreement, the electrical conductivity showed an increase of 60% in the nanocomposite material.

  14. Characterization of Hybrid Epoxy Nanocomposites

    Science.gov (United States)

    Simcha, Shelly; Dotan, Ana; Kenig, Samuel; Dodiuk, Hanna

    2012-01-01

    This study focused on the effect of Multi Wall Carbon Nanotubes (MWCNT) content and its surface treatment on thermo-mechanical properties of epoxy nanocomposites. MWCNTs were surface treated and incorporated into two epoxy systems. MWCNT's surface treatments were based on: (a) Titania coating obtained by sol-gel process and (b) a nonionic surfactant. Thermo-mechanical properties improvement was obtained following incorporation of treated MWCNT. It was noticed that small amounts of titania coated MWCNT (0.05 wt %) led to an increase in the glass transition temperature and stiffness. The best performance was achieved adding 0.3 wt % titania coated MWCNT where an increase of 10 °C in the glass transition temperature and 30% in storage modulus were obtained. PMID:28348313

  15. Performance comparison of hybrid resistive switching devices based on solution-processable nanocomposites

    Science.gov (United States)

    Rajan, Krishna; Roppolo, Ignazio; Bejtka, Katarzyna; Chiappone, Annalisa; Bocchini, Sergio; Perrone, Denis; Pirri, Candido Fabrizio; Ricciardi, Carlo; Chiolerio, Alessandro

    2018-06-01

    The present work compares the influence of different polymer matrices on the performance of planar asymmetric Resistive Switching Devices (RSDs) based on silver nitrate and Ionic Liquid (IL). PolyVinyliDene Fluoride-HexaFluoroPropylene (PVDF-HFP), PolyEthylene Oxide (PEO), PolyMethyl MethAcrylate (PMMA) and a blend of PVDF-HFP and PEO were used as matrices and compared. RSDs represent perhaps the most promising electron device to back the More than Moore development, and our approach through functional polymers enables low temperature processing and gives compatibility towards flexible/stretchable/wearable equipment. The switching mechanism in all the four sample families is explained by means of a filamentary conduction. A huge difference in the cyclability and the On/Off ratio is experienced when changing the active polymers and explained based on the polymer crystallinity degree and general morphology of the prepared nanocomposite. It is worth noting that all the RSDs discussed here present good switching behaviour with reasonable endurance. The current study displays one of the most cost-effective and effortless ways to produce an RSD based on solution-processable materials.

  16. Multifunctional zirconium oxide doped chitosan based hybrid nanocomposites as bone tissue engineering materials.

    Science.gov (United States)

    Bhowmick, Arundhati; Jana, Piyali; Pramanik, Nilkamal; Mitra, Tapas; Banerjee, Sovan Lal; Gnanamani, Arumugam; Das, Manas; Kundu, Patit Paban

    2016-10-20

    This paper reports the development of multifunctional zirconium oxide (ZrO2) doped nancomposites having chitosan (CTS), organically modified montmorillonite (OMMT) and nano-hydroxyapatite (HAP). Formation of these nanocomposites was confirmed by various characterization techniques such as Fourier transform infrared spectroscopy and powder X-ray diffraction. Scanning electron microscopy images revealed uniform distribution of OMMT and nano-HAP-ZrO2 into CTS matrix. Powder XRD study and TEM study revealed that OMMT has partially exfoliated into the polymer matrix. Enhanced mechanical properties in comparison to the reported literature were obtained after the addition of ZrO2 nanoparticle into the nanocomposites. In rheological measurements, CMZH I-III exhibited greater storage modulus (G') than loss modulus (G″). TGA results showed that these nanocomposites are thermally more stable compare to pure CTS film. Strong antibacterial zone of inhibition and the lowest minimum inhibition concentration (MIC) value of these nanocomposites against bacterial strains proved that these materials have the ability to prevent bacterial infection in orthopedic implants. Compatibility of these nanocomposites with pH and blood of human body was established. It was observed from the swelling study that the swelling percentage was increased with decreasing the hydrophobic OMMT content. Human osteoblastic MG-63 cell proliferations were observed on the nanocomposites and cytocompatibility of these nanocomposites was also established. Moreover, addition of 5wt% OMMT and 5wt% nano-HAP-ZrO2 into 90wt% CTS matrix provides maximum tensile strength, storage modulus, aqueous swelling and cytocompatibility along with strong antibacterial effect, pH and erythrocyte compatibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Electrically and Thermally Conductive Low Density Polyethylene-Based Nanocomposites Reinforced by MWCNT or Hybrid MWCNT/Graphene Nanoplatelets with Improved Thermo-Oxidative Stability

    Directory of Open Access Journals (Sweden)

    Sandra Paszkiewicz

    2018-04-01

    Full Text Available In this paper, the electrical and thermal conductivity and morphological behavior of low density polyethylene (LDPE/multi-walled carbon nanotubes (MWCNTs + graphene nanoplatelets (GNPs hybrid nanocomposites (HNCs have been studied. The distribution of MWCNTs and the hybrid of MWCNTs/GNPs within the polymer matrix has been investigated with scanning electron microscopy (SEM. The results showed that the thermal and electrical conductivity of the LDPE-based nanocomposites increased along with the increasing content of carbon nanofillers. However, one could observe greater improvement in the thermal and electrical conductivity when only MWCNTs have been incorporated. Moreover, the improvement in tensile properties and thermal stability has been observed when carbon nanofillers have been mixed with LDPE. At the same time, the increasing content of MWCNTs and MWCNTs/GNPs caused an increase in the melt viscosity with only little effect on phase transition temperatures.

  18. Electrically and Thermally Conductive Low Density Polyethylene-Based Nanocomposites Reinforced by MWCNT or Hybrid MWCNT/Graphene Nanoplatelets with Improved Thermo-Oxidative Stability.

    Science.gov (United States)

    Paszkiewicz, Sandra; Szymczyk, Anna; Pawlikowska, Daria; Subocz, Jan; Zenker, Marek; Masztak, Roman

    2018-04-22

    In this paper, the electrical and thermal conductivity and morphological behavior of low density polyethylene (LDPE)/multi-walled carbon nanotubes (MWCNTs) + graphene nanoplatelets (GNPs) hybrid nanocomposites (HNCs) have been studied. The distribution of MWCNTs and the hybrid of MWCNTs/GNPs within the polymer matrix has been investigated with scanning electron microscopy (SEM). The results showed that the thermal and electrical conductivity of the LDPE-based nanocomposites increased along with the increasing content of carbon nanofillers. However, one could observe greater improvement in the thermal and electrical conductivity when only MWCNTs have been incorporated. Moreover, the improvement in tensile properties and thermal stability has been observed when carbon nanofillers have been mixed with LDPE. At the same time, the increasing content of MWCNTs and MWCNTs/GNPs caused an increase in the melt viscosity with only little effect on phase transition temperatures.

  19. Nanocomposite organomineral hybrid materials. Part 2

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich

    2016-04-01

    Full Text Available The paper addresses the issues of alkoxide method of sol-gel synthesis and non-hydrolytic method of sol-gel synthesis and colloidal method of sol-gel synthesis. The authors also consider an alternative approach based on the use of soluble silicates as precursors in the sol-gel technology, of nanocomposites. It was shown that nanocomposites can be produced through aerogels. The paper also analyzes the mixing technologies of nanocomposites preparation. It has been demonstrated the possibility to change the types of nano-phase which is used for obtaining nanocomposites in different approaches. Various models of packaging spherical, fibrous and layered nanoparticles, introduced into the structure of the nanocomposite, in the preparation thereof were examined.

  20. Nanocomposite organomineral hybrid materials. Part I

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich

    2016-02-01

    Full Text Available The paper addresses the issues of alkoxide method of sol-gel synthesis and non-hydrolytic method of sol-gel synthesis and colloidal method of sol-gel synthesis. The authors also consider an alternative approach based on the use of soluble silicates as precursors in the sol-gel technology, of nanocomposites. It was shown that nanocomposites can be produced through aerogels. The paper also analyzes the mixing technologies of nanocomposites preparation. It has been demonstrated the possibility to change the types of nano-phase which is used for obtaining nanocomposites in different approaches. Various models of packaging spherical, fibrous and layered nanoparticles, introduced into the structure of the nanocomposite, in the preparation thereof were examined.

  1. Nanocomposite organomineral hybrid materials. Part 3

    Directory of Open Access Journals (Sweden)

    KUDRYAVTSEV Pavel Gennadievich

    2016-06-01

    Full Text Available The paper addresses the issues of alkoxide method of sol-gel synthesis and non-hydrolytic method of sol-gel synthesis and colloidal method of sol-gel synthesis. The authors also consider an alternative approach based on the use of soluble silicates as precursors in the sol-gel technology, of nanocomposites. It was shown that nanocomposites can be produced through aerogels. The paper also analyzes the mixing technologies of nanocomposites preparation. It has been demonstrated the possibility to change the types of nano-phase which is used for obtaining nanocomposites in different approaches. Various models of packaging spherical, fibrous and layered nanoparticles, introduced into the structure of the nanocomposite, in the preparation thereof were examined.

  2. Label-free amino acid detection based on nanocomposites of graphene oxide hybridized with gold nanoparticles.

    Science.gov (United States)

    Zhang, Qian; Zhang, Diming; Lu, Yanli; Xu, Gang; Yao, Yao; Li, Shuang; Liu, Qingjun

    2016-03-15

    Nanocomposites of graphene oxide and gold nanoparticles (GO/GNPs) were synthesized for label-free detections of amino acids. Interactions between the composites and amino acids were investigated by both naked-eye observation and optical absorption spectroscopy. The GO/GNPs composites displayed apparent color changes and absorption spectra changes in presences of amino acids including glutamate, aspartate, and cysteine. The interaction mechanisms of the composites and amino acids were discussed and explored with sulfhydryl groups and non-α-carboxylic groups on the amino acids. Sensing properties of the composites were tested, while pure gold particles were used as the control. The results suggested that the GO/GNPs composites had better linearity and stability in dose-dependent responses to the amino acids than those of the particles, especially in detections for acidic amino acids. Therefore, the nanocomposites platform can provide a convenient and efficient approach for label-free optical detections of important molecules such as amino acids. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Synthesis of hybrid organic–inorganic nanocomposite materials based on CdS nanocrystals for energy conversion applications

    International Nuclear Information System (INIS)

    Laera, A. M.; Resta, V.; Ferrara, M. C.; Schioppa, M.; Piscopiello, E.; Tapfer, L.

    2011-01-01

    Efficient solar energy conversion is strongly related to the development of new materials with enhanced functional properties. In this context, a wide variety of inorganic, organic, or hybrid nanostructured materials have been investigated. In particular, in hybrid organic–inorganic nanocomposites are combined the convenient properties of organic polymers, such as easy manipulation and mechanical flexibility, and the unique size-dependent properties of nanocrystals (NCs). However, applications of hybrid nanocomposites in photovoltaic devices require a homogeneous and highly dense dispersion of NCs in polymer in order to guarantee not only an efficient charge separation, but also an efficient transport of the carriers to the electrodes without recombination. In previous works, we demonstrated that cadmium thiolate complexes are suitable precursors for the in situ synthesis of nanocrystalline CdS. Here, we show that the soluble [Cd(SBz) 2 ] 2 ·(1-methyl imidazole) complex can be efficiently annealed in a conjugated polymer obtaining a nanocomposite with a regular and compact network of NCs. The proposed synthetic strategies require annealing temperatures well below 200 °C and short time for the thermal treatment, i.e., less than 30 min. We also show that the same complex can be used to synthesize CdS NCs in mesoporous TiO 2 . The adsorption of cadmium thiolate molecule in TiO 2 matrix can be obtained by using chemical bath deposition technique and subsequent thermal annealing. The use of NCs, quantum dots, as sensitizers of TiO 2 matrices represents a very promising alternative to common dye-sensitized solar cells and an interesting solution for heterogeneous photocatalysis.

  4. Thermal properties of oil palm nano filler/kenaf reinforced epoxy hybrid nanocomposites

    Science.gov (United States)

    Saba, N.; Paridah, M. T.; Abdan, K.; Ibrahim, N. A.

    2016-11-01

    The aim of this research study was to fabricate nano oil palm empty fruit bunch (OPEFB)/kenaf/epoxy hybrid nanocomposites and to make comparative study on the thermal properties of nano OPEFB/kenaf/epoxy hybrid nanocomposites with the montmorillonite (MMT)/kenaf/epoxy hybrid nanocomposites and organically modified MMT (OMMT)/kenaf/epoxy hybrid nanocomposites. Epoxy based kenaf hybrid nanocomposites was prepared by dispersing the nano filler (nano OPEFB filler, MMT, OMMT) at 3% loading through high speed mechanical stirrer followed by hand lay-up technique. Thermal properties of hybrid nanocomposites were analyzed through thermogravimetry analyzer (TGA), and differential scanning calorimetry (DSC). Obtained results specified that addition of nano OPEFB filler improves the thermal stability and char yield of kenaf/epoxy composites. Furthermore, the increase in decomposition temperature by the nano OPEFB filler was quite comparable to the MMT/kenaf/epoxy but relatively less than OMMT/kenaf/epoxy hybrid nanocomposites. We concluded from overall consequences that the nano OPEFB filler can be used as the promising and innovative alternative of existing expensive nano filler, with relatively lesser impact on the environment having marked pronounced impact on the construction, automotive, aerospace, electronics and semiconducting sectors as future industries based on bio-wastes with satisfactory light weight and thermal stability on other side.

  5. Chitosan-based nanocomposites

    CSIR Research Space (South Africa)

    Kesavan Pillai, Sreejarani

    2012-08-01

    Full Text Available , and hygiene devices. They thus represent a strong and emerging answer for improved and eco-friendly materials. This chapter reviews the recent developments in the area of chitosan-based nanocomposites, with a special emphasis on clay-containing nanocomposites...-sized mineral fillers like silica, talc, and clay are added to reduce the cost and improve chitosan’s performance in some way. However, the mechanical properties such as elongation at break and tensile strength of these composites decrease with the incorporation...

  6. Ultra-sensitive determination of epinephrine based on TiO{sub 2}-Au nanoclusters supported on reduced graphene oxide and carbon nanotube hybrid nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jianbo, E-mail: chm_lijianbo@yeah.net; Wang, Xiaojiao; Duan, Huimin; Wang, Yanhui; Luo, Chuannan, E-mail: chm_lijianbo@yeah.net

    2016-07-01

    A highly efficient and sensitive electrochemical sensor for EP based on reduced graphene and multi-walled carbon nanotube hybrid nanocomposites loaded TiO{sub 2}-Au nano-clusters modified glassy carbon electrode was developed. The surface nature and morphology of the nanocomposite film and the electrochemical properties of the sensor were characterized by Raman spectra, X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectra (EDX), Fourier transform infrared spectroscopy (FT-IR), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), respectively. Carbon nanomaterials were widely used in sensing due to its large electroactive surface area, fast electron transport and strong adsorption capacity. Meanwhile, TiO{sub 2}-Au nano-clusters could accelerate the electron transfer, increase reactive site and extend electrochemical response window. The nanocomposite film could greatly enhance the response sensitivity and decrease the overpotential. The resulting sensor showed an excellent electrocatalytic activity toward EP. Under the optimum conditions (i.e. pH 6.0, 0.1 M PBS, preconcentration for 110 s), Differential pulse voltammetry was employed to detect ultra-trace amounts of EP. The result of a wide linear range of 1.0–300 nM and limited of detection 0.34 nM (S/N = 3) were obtained. The constructed sensor exhibited excellent accuracy and precision, the relative standard deviation (RSD) was less than 5%. The nanocomposite film sensor was successfully used to accurately detect the content of EP in practical samples, and the recoveries for the standards added are 97%–105%. - Highlights: • The three dimensional composite materials rGO/CNTs were successful synthesized. • High conductivity and catalytic activity of TiO{sub 2}-Au nanoclusters were synthesized. • The sensor displays a wide linear range, low detection limit and good stability.

  7. MWCNT/CdS hybrid nanocomposite for enhanced photocatalytic activity

    International Nuclear Information System (INIS)

    Chaudhary, Deepti; Khare, Neeraj; Vankar, V. D.

    2016-01-01

    Multi-walled carbon nanotubes (MWCNT)/CdS hybrid nanocomposite were synthesized by one step hydrothermal method. MWCNTs were used as a substrate for the growth of CdS nanoparticles. MWCNT/CdS nanocomposite and pure CdS were characterized by XRD, TEM, UV-vis and photoluminescence spectroscopy. HRTEM study confirms the intimate contact of CdS with MWCNT. The photocatalytic activity of nanocomposite was studied for the degradation of methylene blue dye under UV irradiation. The enhanced photocatalytic activity of MWCNT/CdS nanocomposite as compared to pure CdS has been attributed to reduced recombination of photogenerated charge carriers due to interfacial electron transfer from CdS to MWCNT.

  8. Hybrid Organic/Inorganic Nanocomposites for Photovoltaic Cells

    Science.gov (United States)

    Liu, Ruchuan

    2014-01-01

    Inorganic/organic hybrid solar cells have attracted a lot of interest due to their potential in combining the advantages of both components. To understand the key issues in association with photoinduced charge separation/transportation processes and to improve overall power conversion efficiency, various combinations with nanostructures of hybrid systems have been investigated. Here, we briefly review the structures of hybrid nanocomposites studied so far, and attempt to associate the power conversion efficiency with these nanostructures. Subsequently, we are then able to summarize the factors for optimizing the performance of inorganic/organic hybrid solar cells. PMID:28788591

  9. Investigation of the mechanical properties of GNP/MWCNT reinforced PA66 hybrid nanocomposites

    DEFF Research Database (Denmark)

    Doagou Rad, Saeed; Islam, Aminul; Søndergaard Jensen, Jacob

    nanocomposites reinforced with two prominent nanofillers namely Multi Walled Carbon Nanotubes (MWCNT) and Graphene NanoPlatelets (GNP) manufactured through industrially viable methods. Three main groups of Polyamide (PA 66) based nano- and hybrid composite specimens namely PA 66/MWCNT, PA 66/GNP, and PA 66/MWCNT...

  10. Chitosan-doped-hybrid/TiO2 nanocomposite based sol-gel coating for the corrosion resistance of aluminum metal in 3.5% NaCl medium.

    Science.gov (United States)

    J, Balaji; M G, Sethuraman

    2017-11-01

    The study outlines the role of chitosan, a biopolymer on corrosion behavior of Hy/nano-TiO 2 based sol-gel coating over aluminum metal. In this study organic-inorganic hybrid sols were synthesized through hydrolysis and condensation of 3-glycidoxypropyltrimethoxy silane (GPTMS), tetraethoxysilane (TEOS) and titanium (IV) isopropoxide (TIP) in acidic solution. Chitosan was doped into sol-gel matrix and self-assembled over aluminum substrate. The resultant chitosan-doped-Hy/nano-TiO 2 sol-gel coating was characterized by Fourier Transform Infrared (FT-IR) spectra, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and Energy-Dispersive X-ray Spectroscopy (EDX) analyses. The as-tailored aluminum substrate was evaluated for corrosion resistance in neutral medium. The protection ability of these coatings was evaluated by electrochemical impedance studies (EIS) and potentiodynamic polarization (PP) measurements in 3.5% NaCl medium. The EIS and PP results showed that chitosan-doped- Hy/nano-TiO 2 sol-gel coating exhibited better protection from corrosion than the undoped Hy/TiO 2 nanocomposite coating. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Synthesis of hybrid cellulose nanocomposite bonded with dopamine SiO2/TiO2 and its antimicrobial activity

    Science.gov (United States)

    Ramesh, Sivalingam; Kim, Gwang-Hoon; Kim, Jaehwan; Kim, Joo-Hyung

    2015-04-01

    Organic-inorganic hybrid material based cellulose was synthesized by the sol-gel approach. The explosion of activity in this area in the past decade has made tremendous progress in industry or academic both fundamental understanding of sol-gel process and applications of new functionalized hybrid materials. In this present research work, we focused on cellulose-dopamine functionalized SiO2/TiO2 hybrid nanocomposite by sol-gel process. The cellulose-dopamine hybrid nanocomposite was synthesized via γ-aminopropyltriethoxysilane (γ-APTES) coupling agent by in-situ sol-gel process. The chemical structure of cellulose-amine functionalized dopamine bonding to cellulose structure with covalent cross linking hybrids was confirmed by FTIR spectral analysis. The morphological analysis of cellulose-dopamine nanoSiO2/TiO2 hybrid nanocomposite materials was characterized by XRD, SEM and TEM. From this different analysis results indicate that the optical transparency, thermal stability, control morphology of cellulose-dopamine-SiO2/TiO2 hybrid nanocomposite. Furthermore cellulose-dopamine-SiO2/TiO2 hybrid nanocomposite was tested against pathogenic bacteria for antimicrobial activity.

  12. Light tuning DC and AC electrical properties of ZnO-rGO based hybrid nanocomposite film

    Science.gov (United States)

    Nath, Debarati; Mandal, S. K.; Deb, Debajit; Rakshit, J. K.; Dey, P.; Roy, J. N.

    2018-03-01

    We have investigated the electrical and optoelectrical properties of a zinc oxide (ZnO):reduced graphene oxide (rGO) nanocomposite film prepared through the sol gel process on a glass substrate under dark and illumination conditions of light. The bandgap of the composite film is decreased from the pure ZnO nanofilm due to the formation of a Zn-O-C bond in the composite film. The linear behavior in the Current-Voltage curve is attributed to Ohmic contact between ZnO and rGO grains. The photocurrent of the composite film is found to increase with an increase in light intensity having two different slopes, indicating an enhancement of the mobility of carriers and dissociation rate of excitons. The observed decrement of the impedance value with the intensity of light may be due to the flow of charge carriers and the presence of the light dependent relaxation process in the system. Nyquist plots have been fitted using a parallel combination of grain boundary resistances and grain boundary capacitance at different intensities of light. The relaxation frequency is observed to shift towards the high frequency regime. Carrier transit time has been calculated from relaxation frequency showing opposite behavior with the intensity of light. These results indicate the higher generations of photogenerated carriers at the interface between rGO and ZnO grains and an enhancement of the charge transport process due to the increment of the mobility of charge carriers in the system.

  13. Nanocomposites Based on Biodegradable Polymers

    Directory of Open Access Journals (Sweden)

    Ilaria Armentano

    2018-05-01

    Full Text Available In the present review paper, our main results on nanocomposites based on biodegradable polymers (on a time scale from 2010 to 2018 are reported. We mainly focused our attention on commercial biodegradable polymers, which we mixed with different nanofillers and/or additives with the final aim of developing new materials with tunable specific properties. A wide list of nanofillers have been considered according to their shape, properties, and functionalization routes, and the results have been discussed looking at their roles on the basis of different adopted processing routes (solvent-based or melt-mixing processes. Two main application fields of nanocomposite based on biodegradable polymers have been considered: the specific interaction with stem cells in the regenerative medicine applications or as antimicrobial materials and the active role of selected nanofillers in food packaging applications have been critically revised, with the main aim of providing an overview of the authors’ contribution to the state of the art in the field of biodegradable polymeric nanocomposites.

  14. RIR-MAPLE deposition of conjugated polymers and hybrid nanocomposites for application to optoelectronic devices

    International Nuclear Information System (INIS)

    Stiff-Roberts, Adrienne D.; Pate, Ryan; McCormick, Ryan; Lantz, Kevin R.

    2012-01-01

    Resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) is a variation of pulsed laser deposition that is useful for organic-based thin films because it reduces material degradation by selective absorption of infrared radiation in the host matrix. A unique emulsion-based RIR-MAPLE approach has been developed that reduces substrate exposure to solvents and provides controlled and repeatable organic thin film deposition. In order to establish emulsion-based RIR-MAPLE as a preferred deposition technique for conjugated polymer or hybrid nanocomposite optoelectronic devices, studies have been conducted to demonstrate the value added by the approach in comparison to traditional solution-based deposition techniques, and this work will be reviewed. The control of hybrid nanocomposite thin film deposition, and the photoconductivity in such materials deposited using emulsion-based RIR-MAPLE, will also be reviewed. The overall result of these studies is the demonstration of emulsion-based RIR-MAPLE as a viable option for the fabrication of conjugated polymer and hybrid nanocomposite optoelectronic devices that could yield improved device performance.

  15. Flexible nonvolatile memory devices based on Au/PMMA nanocomposites deposited on PEDOT:PSS/Ag nanowire hybrid electrodes

    International Nuclear Information System (INIS)

    Sung, Sihyun; Kim, Tae Whan

    2017-01-01

    Highlights: • Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a PMMA layer were fabricated. • The insertion of the PEDOT:PSS layer enhanced the surface uniformity of the AgNW bottom electrode, resulting in improved device performances. • Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices showed clockwise current hysteresis behaviors. • ON/OFF ratio of 1 × 10 3 was maintained for retention times longer than 1 × 10 4 s. • Memory characteristics of the NVM devices before and after bending were similar. - Abstract: Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a poly(methylmethacrylate) (PMMA) layer were fabricated on a silver nanowire (AgNW) or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/AgNW coated on poly(ethylene terephthalate) (PET) substrates. The transmittance and the sheet resistance of the PEDOT:PSS/AgNW hybrid layer were approximately 89% and 50 Ω/sq, respectively, which were comparable to the values for commercial indium-tin-oxide (ITO) electrodes. Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices at 300 K showed clockwise current hysteresis behaviors due to the existence of the AuNPs. The endurance number of ON/OFF switching for the NVM devices was above 30 cycles. An ON/OFF ratio of 1 × 10 3 was maintained for retention times longer than 1 × 10 4 s. The maximum memory margins of the NVM devices before and after bending were approximately 3.4 × 10 3 and 1.4 × 10 3 , respectively. The retention times of the devices before and after bending remained same 1 × 10 4 s. The memory margin and the stability of flexible NVMs fabricated on AgNW electrodes were enhanced due to the embedded PEDOT:PSS buffer layer.

  16. Flexible nonvolatile memory devices based on Au/PMMA nanocomposites deposited on PEDOT:PSS/Ag nanowire hybrid electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Sihyun; Kim, Tae Whan, E-mail: twk@hanyang.ac.kr

    2017-07-31

    Highlights: • Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a PMMA layer were fabricated. • The insertion of the PEDOT:PSS layer enhanced the surface uniformity of the AgNW bottom electrode, resulting in improved device performances. • Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices showed clockwise current hysteresis behaviors. • ON/OFF ratio of 1 × 10{sup 3} was maintained for retention times longer than 1 × 10{sup 4} s. • Memory characteristics of the NVM devices before and after bending were similar. - Abstract: Flexible nonvolatile memory (NVM) devices fabricated utilizing Au nanoparticles (AuNPs) embedded in a poly(methylmethacrylate) (PMMA) layer were fabricated on a silver nanowire (AgNW) or a poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/AgNW coated on poly(ethylene terephthalate) (PET) substrates. The transmittance and the sheet resistance of the PEDOT:PSS/AgNW hybrid layer were approximately 89% and 50 Ω/sq, respectively, which were comparable to the values for commercial indium-tin-oxide (ITO) electrodes. Current-voltage curves for the Al/PMMA:AuNP/PEDOT:PSS/AgNW/PET devices at 300 K showed clockwise current hysteresis behaviors due to the existence of the AuNPs. The endurance number of ON/OFF switching for the NVM devices was above 30 cycles. An ON/OFF ratio of 1 × 10{sup 3} was maintained for retention times longer than 1 × 10{sup 4} s. The maximum memory margins of the NVM devices before and after bending were approximately 3.4 × 10{sup 3} and 1.4 × 10{sup 3}, respectively. The retention times of the devices before and after bending remained same 1 × 10{sup 4} s. The memory margin and the stability of flexible NVMs fabricated on AgNW electrodes were enhanced due to the embedded PEDOT:PSS buffer layer.

  17. Titanium dioxide–cellulose hybrid nanocomposite and its glucose biosensor application

    International Nuclear Information System (INIS)

    Maniruzzaman, Mohammad; Jang, Sang-Dong; Kim, Jaehwan

    2012-01-01

    Highlights: ► An organic–inorganic hybrid nanocomposite was fabricated by blending TiO 2 nanoparticles and cellulose solution. ► The hybrid nanocomposite has advantages of biodegradability and bio-compatibility of cellulose and physical properties of TiO 2 . ► Enzyme glucose oxidase (GOx) was immobilized into the hybrid nanocomposite and covalent bonding between TiO 2 and GOx was confirmed by X-ray photoelectron analysis. ► Linear response of the glucose biosensor was obtained in the range of 1–10 mM. - Abstract: This paper investigates the fabrication of titanium dioxide (TiO 2 )–cellulose hybrid nanocomposite and its possibility for a conductometric glucose biosensor. TiO 2 nanoparticles were blended with cellulose solution prepared by dissolving cotton pulp with lithium chloride/N,N-dimethylacetamide solvent to fabricate TiO 2 –cellulose hybrid nanocomposite. The enzyme, glucose oxidase (GOx) was immobilized into this hybrid nanocomposite by physical adsorption method. The successful immobilization of glucose oxidase into TiO 2 –cellulose hybrid nanocomposite via covalent bonding between TiO 2 and GOx was confirmed by X-ray photoelectron analysis. The linear response of the glucose biosensor is obtained in the range of 1–10 mM. This study demonstrates that TiO 2 –cellulose hybrid nanocomposite can be a potential candidate for an inexpensive, flexible and disposable glucose biosensor.

  18. Physical, structural and thermomechanical properties of oil palm nano filler/kenaf/epoxy hybrid nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Saba, N., E-mail: naheedchem@gmail.com [Laboratory of Biocomposite Technology, Institute of Tropical Forestry and Forest Products(INTROP), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Paridah, M.T. [Laboratory of Biocomposite Technology, Institute of Tropical Forestry and Forest Products(INTROP), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Abdan, K. [Department of Biological and Agricultural Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM Serdang Selangor (Malaysia); Ibrahim, N.A. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia)

    2016-12-01

    The present research study deals with the fabrication of kenaf/epoxy hybrid nanocomposites by the incorporation of oil palm nano filler, montmorillonite (MMT) and organically modified montmorillonite (OMMT) at 3% loading, through hand lay-up technique. Effect of adding different nano fillers on the physical (density), structural [X-ray diffraction (XRD)] and thermomechanical analysis (TMA) of kenaf/epoxy composites were carried out. Density results revealed that the incorporation of nano filler in the kenaf/epoxy composites increases the density which in turn increases the hardness of the hybrid nanocomposites. XRD analysis confirmed the presence of nano fillers in the structure of their respective fabricated hybrid nanocomposites. All hybrid nanocomposites displayed lower coefficient of thermal expansion (CTE) with respect to kenaf/epoxy composites. Overall results predicted that the properties improvement in nano OPEFB/kenaf/epoxy was quite comparable to MMT/kenaf/epoxy but relatively lesser to OMMT/kenaf/epoxy hybrid nanocomposites and higher with respect to kenaf/epoxy composites. The improvement ascribed due to improved interfacial bonding or cross linking between kenaf fibers and epoxy matrix by addition of nano filler. - Highlights: • Nano OPEFB/kenaf/epoxy hybrid nanocomposites were fabricated by hand lay-up. • Effect of nano OPEFB on density & structure of kenaf/epoxy were investigated. • Thermal expansion coefficients of kenaf/epoxy and hybrid nanocomposites evaluated. • Comparative studies were made with MMT and OMMT kenaf/epoxy hybrid nanocomposites.

  19. Physical, structural and thermomechanical properties of oil palm nano filler/kenaf/epoxy hybrid nanocomposites

    International Nuclear Information System (INIS)

    Saba, N.; Paridah, M.T.; Abdan, K.; Ibrahim, N.A.

    2016-01-01

    The present research study deals with the fabrication of kenaf/epoxy hybrid nanocomposites by the incorporation of oil palm nano filler, montmorillonite (MMT) and organically modified montmorillonite (OMMT) at 3% loading, through hand lay-up technique. Effect of adding different nano fillers on the physical (density), structural [X-ray diffraction (XRD)] and thermomechanical analysis (TMA) of kenaf/epoxy composites were carried out. Density results revealed that the incorporation of nano filler in the kenaf/epoxy composites increases the density which in turn increases the hardness of the hybrid nanocomposites. XRD analysis confirmed the presence of nano fillers in the structure of their respective fabricated hybrid nanocomposites. All hybrid nanocomposites displayed lower coefficient of thermal expansion (CTE) with respect to kenaf/epoxy composites. Overall results predicted that the properties improvement in nano OPEFB/kenaf/epoxy was quite comparable to MMT/kenaf/epoxy but relatively lesser to OMMT/kenaf/epoxy hybrid nanocomposites and higher with respect to kenaf/epoxy composites. The improvement ascribed due to improved interfacial bonding or cross linking between kenaf fibers and epoxy matrix by addition of nano filler. - Highlights: • Nano OPEFB/kenaf/epoxy hybrid nanocomposites were fabricated by hand lay-up. • Effect of nano OPEFB on density & structure of kenaf/epoxy were investigated. • Thermal expansion coefficients of kenaf/epoxy and hybrid nanocomposites evaluated. • Comparative studies were made with MMT and OMMT kenaf/epoxy hybrid nanocomposites.

  20. Palygorskite Hybridized Carbon Nanocomposite as a High ...

    African Journals Online (AJOL)

    NICO

    Pd nanoparticles were deposited on the hybrid support as an electrocatalyst for formic acid oxida- tion. .... synthetic procedure using conventional borohydride reduction .... as Al2O3, CaO and MgO, which may exist in both the tetrahedral.

  1. Analysis of sulphone based organic–inorganic hybrid epoxy nanocomposites for advanced engineering applications—Study of the mechanical, thermomechanical, XRD, EDS and physical properties

    International Nuclear Information System (INIS)

    Shree Meenakshi, K.; Pradeep Jaya Sudhan, E.; Menon, Prathibha G.

    2012-01-01

    Highlights: ► Novel sulphone based tetraglycidyl epoxy nanocomposites were developed for aerospace applications. ► Nano-reinforcements were incorporated and curing was done. ► Excellent results were obtained in the mechanical studies. The nanocomposites developed were flame retardant and hydrophobic. - Abstract: A study was made in the present investigation on sulphone containing tetraglycidyl epoxy nanocomposites to find its suitability for use in high performance applications. The synthesis and characterization of the sulphone tetraglycidyl epoxy resin denoted as ‘B’ was done as reported in our previous study. Nanoclay and POSS-amine nano-reinforcements denoted as N1 and N2 were incorporated into the synthesized epoxy resin. Curing was done with diaminodiphenylmethane (DDM) and bis(3-aminophenyl) phenylphosphine oxide (BAPPO) curing agents denoted as X and Y respectively. In our current research, we continue this research and study the mechanical, thermo-mechanical, X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), viscosity, epoxy equivalent weight (EEW) and gel permeation chromatography (GPC) studies.

  2. Nature-Inspired Green Procedure for Improving Performance of Protein-Based Nanocomposites via Introduction of Nanofibrillated Cellulose-Stablized Graphene/Carbon Nanotubes Hybrid

    Directory of Open Access Journals (Sweden)

    Shicun Jin

    2018-03-01

    Full Text Available Soy protein isolate (SPI provides a potential alternative biopolymer source to fossil fuels, but improving the mechanical properties and water resistance of SPI composites remains a huge challenge. Inspired by the synergistic effect of natural nacre, we developed a novel approach to fabricate high-performance SPI nanocomposite films based on 2D graphene (G nanosheets and 1D carbon nanotubes (CNTs and nanofibrillated cellulose (NFC using a casting method. The introduction of web-like NFC promoted the uniform dispersion of graphene/CNTs in the biopolymer matrix, as well as a high extent of cross-linkage combination between the fillers and SPI matrix. The laminated and cross-linked structures of the different nanocomposite films were observed by field-emission scanning electron microscope (FE-SEM images. Due to the synergistic interactions of π–π stacking and hydrogen bonding between the nanofillers and SPI chains, the tensile strength of SPI/G/CNT/NFC film significantly increased by 78.9% and the water vapor permeability decreased by 31.76% in comparison to neat SPI film. In addition, the ultraviolet-visible (UV-vis light barrier performance, thermal stability, and hydrophobicity of the films were significantly improved as well. This bioinspired synergistic reinforcing strategy opens a new path for constructing high-performance nanocomposites.

  3. Comparative study on the mechanical and microstructural characterisation of AA 7075 nano and hybrid nanocomposites produced by stir and squeeze casting.

    Science.gov (United States)

    Kannan, C; Ramanujam, R

    2017-07-01

    In this research work, a comparative evaluation on the mechanical and microstructural characteristics of aluminium based single and hybrid reinforced nanocomposites was carried out. The manufacture of a single reinforced nanocomposite was conducted with the distribution of 2 wt.% nano alumina particles (avg. particle size 30-50 nm) in the molten aluminium alloy of grade AA 7075; while the hybrid reinforced nanocomposites were produced with of 4 wt.% silicon carbide (avg. particle size 5-10 µm) and 2 wt.%, 4 wt.% nano alumina particles. Three numbers of single reinforced nanocomposites were manufactured through stir casting with reinforcements preheated to different temperatures viz. 400 °C, 500 °C, and 600 °C. The stir cast procedure was extended to fabricate two hybrid reinforced nanocomposites with reinforcements preheated to 500 °C prior to their inclusion. A single reinforced nanocomposite was also developed by squeeze casting with a pressure of 101 MPa. Mechanical and physical properties such as density, hardness, ultimate tensile strength, and impact strength were evaluated on all the developed composites. The microstructural observation was carried out using optical and scanning electron microscopy. On comparison with base alloy, an improvement of 63.7% and 81.1% in brinell hardness was observed for single and hybrid reinforced nanocomposites respectively. About 16% higher ultimate tensile strength was noticed with the squeeze cast single reinforced nanocomposite over the stir cast.

  4. Fabrication of Mesoporous Silica/Alumina Hybrid Membrane Film Nanocomposites using Template Sol-Gel Synthesis of Amphiphilic Triphenylene

    Science.gov (United States)

    Lintang, H. O.; Jalani, M. A.; Yuliati, L.; Salleh, M. M.

    2017-05-01

    Herein we reported that by introducing a one-dimensional (1D) substrate with a porous structure such as anodic aluminum oxide (AAO) membrane, mesoporous silica/alumina hybrid nanocomposites were successfully fabricated by using amphiphilic triphenylene (TPC10TEG) as a template in sol-gel synthesis (TPC10TEG/silicahex). For the optical study of the nanocomposites, TPC10TEG/silicahex showed absorption peak at 264 nm due to the ordered and long-range π-π stacking of the disc-like aromatic triphenylene core. Moreover, the hexagonal arrangement of TPC10TEG/silicahex was proven based on their diffraction peaks of d 100 and d 200 at 2θ = 2.52° and 5.04° and images of transmission electron microscopy (TEM), respectively. For fabrication of mesoporous silica/alumina hybrid membrane, TPC10TEG/silicahex was drop-casted onto AAO membrane for penetration into the porous structure via gravity. X-ray diffraction (XRD) analysis on the resulted hybrid nanocomposites showed that the diffraction peaks of d 100 and d 200 of TPC10TEG/silicahex were still preserved, indicating that the hexagonal arrangements of mesoporous silica were maintained even on AAO substrate. The morphology study on the hybrid nanocomposites using TEM, scanning electron microscope (SEM) and field emission scanning electron microscope (FE-SEM) showed the successful filling of most AAO channels with the TPC10TEG/silicahex nanocomposites.

  5. Characteristic of Hybrid Cellulose-Amino Functionalized POSS-Silica Nanocomposite and Antimicrobial Activity

    Directory of Open Access Journals (Sweden)

    Sivalingam Ramesh

    2015-01-01

    Full Text Available Recently, cellulose has much attention as an emerging renewable nanomaterial which holds promising properties having unique piezoelectricity, insulating, and biodegradable nature for various applications. Also, the modified properties of cellulose by appropriate chemical modifications in various functional groups with outstanding properties or significantly improved physical, chemical, biological, and electronic properties will widen the way for it to be utilized in different usages. Therefore, in this paper, cellulose-functionalized polyhedral oligomeric silsesquioxanes (POSS based materials were considered an important class of high-performance hybrid nanocomposite materials. To functionalize the regenerated cellulose, amino functionalized POSS material was synthesized via sol-gel covalent crosslinking process in presence of amino coupling agent. In this reaction, tetraethoxsilane (TEOS and γ-aminopropyltriethoxy silane (γ-APTES as coupling agent for metal precursors were selected. The chemical structure of cellulose-amine functionalized bonding and covalent crosslinking hybrids was confirmed by FTIR and 1H NMR spectral analysis. From the TEM results, well-dispersed hybrid cellulose-functionalized POSS-silica composites are observed. The resulting cellulose-POSS-silica hybrid nanocomposites materials provided significantly improved the optical transparency, and thermal and morphological properties to compare the cellulose-silica hybrid materials. Further, antimicrobial test against pathogenic bacteria was carried out.

  6. Photothermal and biodegradable polyaniline/porous silicon hybrid nanocomposites as drug carriers for combined chemo-photothermal therapy of cancer.

    Science.gov (United States)

    Xia, Bing; Wang, Bin; Shi, Jisen; Zhang, Yu; Zhang, Qi; Chen, Zhenyu; Li, Jiachen

    2017-03-15

    To develop photothermal and biodegradable nanocarriers for combined chemo-photothermal therapy of cancer, polyaniline/porous silicon hybrid nanocomposites had been successfully fabricated via surface initiated polymerization of aniline onto porous silicon nanoparticles in our experiments. As-prepared polyaniline/porous silicon nanocomposites could be well dispersed in aqueous solution without any extra hydrophilic surface coatings, and showed a robust photothermal effect under near-infrared (NIR) laser irradiation. Especially, after an intravenous injection into mice, these biodegradable porous silicon-based nanocomposites as non-toxic agents could be completely cleared in body. Moreover, these polyaniline/porous silicon nanocomposites as drug carriers also exhibited an efficient loading and dual pH/NIR light-triggered release of doxorubicin hydrochloride (DOX, a model anticancer drug). Most importantly, assisted with NIR laser irradiation, polyaniline/PSiNPs nanocomposites with loading DOX showed a remarkable synergistic anticancer effect combining chemotherapy with photothermal therapy, whether in vitro or in vivo. Therefore, based on biodegradable PSiNPs-based nanocomposites, this combination approach of chemo-photothermal therapy would have enormous potential on clinical cancer treatments in the future. Considering the non-biodegradable nature and potential long-term toxicity concerns of photothermal nanoagents, it is of great interest and importance to develop biodegradable and photothermal nanoparticles with an excellent biocompatibility for their future clinical applications. In our experiments, we fabricated porous silicon-based hybrid nanocomposites via surface initiated polymerization of aniline, which showed an excellent photothermal effect, aqueous dispersibility, biodegradability and biocompatibility. Furthermore, after an efficient loading of DOX molecules, polyaniline/porous silicon nanocomposites exhibited the remarkable synergistic anticancer

  7. Novel hybrid light-emitting devices based on MAPbBr3 nanoplatelets:PVK nanocomposites and zinc oxide nanorod arrays

    Science.gov (United States)

    Wang, Szu-Ping; Chang, Chun-Kai; Yang, Sheng-Hsiung; Chang, Che-Yu; Chao, Yu-Chiang

    2018-01-01

    In this research, we demonstrate inverted perovskite light-emitting devices (PeLEDs) based on zinc oxide nanorod arrays (ZnO NAs) as the electron transport layer and methylammonium lead bromide nanoplatelets (MAPbBr3 NPLs) as the emissive material for the first time. The polyethyleneimine ethoxylated (PEIE) was inserted between the ZnO NAs and the MAPbBr3 NPLs layer to reduce the energy barrier and improve the electron injection efficiency. Besides, different weight ratios of poly(N-vinylcarbazole) (PVK) were blended with MAPbBr3 NPLs to make evenly dispersed nanocomposite films, thereby enhancing the performance of devices. Meanwhile, the photoluminescence of MAPbBr3 NPLs:PVK nanocomposite film was increased due to reduced self-quenching and prolonged carrier lifetime. Inverted PeLEDs with the configuration of ITO/PEIE-modified ZnO NAs/MAPbBr3 NPLs:PVK/TFB/Au were fabricated and evaluated, using TFB as the hole transport layer. The current density of the devices containing PVK matrix was significantly suppressed compared to those without PVK. Herein, the best device revealed a max brightness of 495 cd m-2 and a low turn-on voltage of 3.1 V that shows potential use in light-emitting applications.

  8. Synergistic effect of cellulose nanocrystals/graphene oxide nanosheets as functional hybrid nanofiller for enhancing properties of PVA nanocomposites.

    Science.gov (United States)

    El Miri, Nassima; El Achaby, Mounir; Fihri, Aziz; Larzek, Mohamed; Zahouily, Mohamed; Abdelouahdi, Karima; Barakat, Abdellatif; Solhy, Abderrahim

    2016-02-10

    Novel functional hybrid nanofillers composed of cellulose nanocrystals (CNC) and graphene oxide nanosheets (GON), at different weight ratios (2:1, 1:1 and 1:2), were successfully prepared and characterized, and their synergistic effect in enhancing the properties of poly(vinyl alcohol) (PVA) nanocomposites was investigated. Due to the synergistic reinforcement, it was found that the Young's modulus, tensile strength and toughness of the PVA nanocomposite containing 5 wt% hybrid nanofiller (1:2) were significantly improved by 320%, 124% and 159%, respectively; and the elongation at break basically remained compared to the neat PVA matrix. In addition, the glass and melting temperatures as well as the moisture sorption of nanocomposites were also enhanced. This synergistic effect improved the dispersion homogeneity by avoiding the agglomeration phenomenon of nanofillers within the polymer matrix, resulting in nanocomposites with largely enhanced properties compared to those prepared from single nanofiller (CNC or GON). The preparation of these hybrid nanofillers and their incorporation into a polymer provided a novel method for the development of novel multifunctional nanocomposites based on the combination of existing nanomaterials. Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Improvement of the titanium implant biological properties by coating with poly (ε-caprolactone)-based hybrid nanocomposites synthesized via sol-gel

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, Michelina; Bollino, Flavia; Papale, Ferdinando [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 21, 81031 Aversa (Italy)

    2016-05-18

    When bioactive coatings are applied to medical implants by means of sol-gel dip coating technique, the biological proprieties of the implant surface can be modified to match the properties of the surrounding tissues. In this study organo-inorganic nanocomposites materials were synthesized via sol-gel. They consisted of an inorganic zirconium-based and silica-based matrix, in which a biodegradable polymer (the poly-ε-caprolactone, PCL) was incorporated in different weight percentages. The synthesized materials, in sol phase, were used to dip-coat a substrate of commercially pure titanium grade 4 (CP Ti gr. 4) in order to improve its biological properties. A microstructural analysis of the obtained films was carried out by scanning electron microscopy (SEM) and attenuated total reflectance (ATR) Fourier transform infrared spectroscopy (FT-IR). Biological proprieties of the coated substrates were investigated by means of in vitro tests.

  10. Role of hybrid ratio in microstructural, mechanical and sliding wear properties of the Al5083/Graphitep/Al2O3p a surface hybrid nanocomposite fabricated via friction stir processing method

    International Nuclear Information System (INIS)

    Mostafapour Asl, A.; Khandani, S.T.

    2013-01-01

    Hybrid ratio of each reinforcement phase in hybrid composite can be defined as proportion of its volume to total reinforcement volume of the composite. The hybrid ratio is an important factor which controls the participation extent of each reinforcement phase in overall properties of hybrid composites. Hence, in the present work, surface hybrid nanocomposites of Al5083/Graphite p /Al 2 O 3p with different hybrid ratios were fabricated by friction stir processing method. Subsequently, effect of hybrid ratio on microstructural, mechanical and tribological properties of the nanocomposite was investigated. Optical microscopy and scanning electron microscopy were utilized to perform microstructural observation on the samples. Hardness value measurements, tensile and pin on disk dry sliding wear tests were carried out to investigate effect of hybrid ratio on mechanical and tribological properties of the nanocomposites. Microstructural investigations displayed better distribution with less agglomeration of reinforcement for lower volume fraction of reinforcement for both alumina and graphite particles. Hardness value, yield strength, ultimate tensile strength and wear rate of the nanocomposites revealed a two stage form along with hybrid ratio variation. The results are discussed based on microstructural observations of the nanocomposites and worn surface analyses.

  11. Nanocomposite polymer electrolyte based on whisker or microfibrils polyoxyethylene nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Alloin, Fannie, E-mail: fannie.alloin@lepmi.grenoble-inp.f [LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, Grenoble-INP-UJF-CNRS, UMR 5631, BP 75, 38041 Grenoble Cedex 9 (France); D' Aprea, Alessandra [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France); LEPMI, Laboratoire d' Electrochimie et de Physicochimie des Materiaux et des Interfaces, Grenoble-INP-UJF-CNRS, UMR 5631, BP 75, 38041 Grenoble Cedex 9 (France); Ecole Internationale du Papier, de la communication imprimee et des Biomateriaux, PAGORA- Grenoble-INP, BP 65, 38402 Saint Martin d' Heres Cedex (France); Kissi, Nadia El [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France); Dufresne, Alain [Ecole Internationale du Papier, de la communication imprimee et des Biomateriaux, PAGORA- Grenoble-INP, BP 65, 38402 Saint Martin d' Heres Cedex (France); Bossard, Frederic [Laboratoire de Rheologie, Grenoble-INP-UJF, UMR 5520, BP 53, 38041 Grenoble Cedex 9 (France)

    2010-07-15

    Nanocomposite polymer electrolytes composed of high molecular weight poly(oxyethylene) PEO as a matrix, LiTFSI as lithium salt and ramie, cotton and sisal whiskers with high aspect ratio and sisal microfibrils (MF), as reinforcing phase were prepared by casting-evaporation. The morphology of the composite electrolytes was investigated by scanning electron microscopy and their thermal behavior (characteristic temperatures, degradation temperature) were investigated by thermogravimetric analysis and differential scanning calorimetry. Nanocomposite electrolytes based on PEO reinforced by whiskers and MF sisal exhibited very high mechanical performance with a storage modulus of 160 MPa at high temperature. A weak decrease of the ionic conductivity was observed with the incorporation of 6 wt% of whiskers. The addition of microfibrils involved a larger decrease of the conductivity. This difference may be associated to the more restricted PEO mobility due to the addition of entangled nanofibers.

  12. Microstructural, mechanical, and thermal characteristics of recycled cellulose fiber-halloysite-epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.; Low, I. M.

    2012-01-01

    Epoxy hybrid-nanocomposites reinforced with recycled cellulose fibers (RCF) and halloysite nanotubes (HNTs) have been fabricated and investigated. The dispersion of HNTs was studied by synchrotron radiation diffraction (SRD) and transmission

  13. Fatigue-free PZT-based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, H J; Sando, M [Nat. Ind. Res. Inst., Nagoya (Japan); Tajima, K [Synergy Ceramics Lab., Fine Ceramics Research Association, Nagoya (Japan); Niihara, K [ISIR, Osaka Univ., Mihogaoka, Ibaraki (Japan)

    1999-03-01

    The goal of this study is to fabricate fatigue-free piezoelectrics-based nanocomposites. Lead zirconate titanate (PZT) and metallic platinum (Pt) were selected as a matrix and secondary phase dispersoid. Fine Pt particles were homogeneously dispersed in the PZT matrix. Fatigue properties of the unpoled PZT-based nanocomposite under electrical cyclic loading were investigated. The electrical-field-induced crack growth was monitored by an optical microscope, and it depended on the number of cycles the sample was subjected to. Resistance to fatigue was significantly enhanced in the nanocomposite. The excellent fatigue behavior of the PZT/Pt nanocomposites may result from the grain boundary strenghtening due to the interaction between the matrix and Pt particles. (orig.) 8 refs.

  14. Interfacial characteristics of hybrid nanocomposite under thermomechanical loading

    Science.gov (United States)

    Choyal, Vijay; Kundalwal, Shailesh I.

    2017-12-01

    In this work, an improved shear lag model was developed to investigate the interfacial characteristics of three-phase hybrid nanocomposite which is reinforced with microscale fibers augmented with carbon nanotubes on their circumferential surfaces. The shear lag model accounts for (i) radial and axial deformations of different transversely isotropic constituents, (ii) thermomechanical loads on the representative volume element (RVE), and (iii) staggering effect of adjacent RVEs. The results from the current newly developed shear lag model are validated with the finite element simulations and found to be in good agreement. This study reveals that the reduction in the maximum value of the axial stress in the fiber and the interfacial shear stress along its length become more pronounced in the presence of applied thermomechanical loads on the staggered RVEs. The existence of shear tractions along the RVE length plays a significant role in the interfacial characteristics and cannot be ignored.

  15. Titanium dioxide-cellulose hybrid nanocomposite and its glucose biosensor application

    Energy Technology Data Exchange (ETDEWEB)

    Maniruzzaman, Mohammad; Jang, Sang-Dong [Center for EAPap Actuator, Department of Mechanical Engineering, INHA University, Incheon 402-751 (Korea, Republic of); Kim, Jaehwan, E-mail: jaehwan@inha.ac.kr [Center for EAPap Actuator, Department of Mechanical Engineering, INHA University, Incheon 402-751 (Korea, Republic of)

    2012-06-25

    Highlights: Black-Right-Pointing-Pointer An organic-inorganic hybrid nanocomposite was fabricated by blending TiO{sub 2} nanoparticles and cellulose solution. Black-Right-Pointing-Pointer The hybrid nanocomposite has advantages of biodegradability and bio-compatibility of cellulose and physical properties of TiO{sub 2}. Black-Right-Pointing-Pointer Enzyme glucose oxidase (GOx) was immobilized into the hybrid nanocomposite and covalent bonding between TiO{sub 2} and GOx was confirmed by X-ray photoelectron analysis. Black-Right-Pointing-Pointer Linear response of the glucose biosensor was obtained in the range of 1-10 mM. - Abstract: This paper investigates the fabrication of titanium dioxide (TiO{sub 2})-cellulose hybrid nanocomposite and its possibility for a conductometric glucose biosensor. TiO{sub 2} nanoparticles were blended with cellulose solution prepared by dissolving cotton pulp with lithium chloride/N,N-dimethylacetamide solvent to fabricate TiO{sub 2}-cellulose hybrid nanocomposite. The enzyme, glucose oxidase (GOx) was immobilized into this hybrid nanocomposite by physical adsorption method. The successful immobilization of glucose oxidase into TiO{sub 2}-cellulose hybrid nanocomposite via covalent bonding between TiO{sub 2} and GOx was confirmed by X-ray photoelectron analysis. The linear response of the glucose biosensor is obtained in the range of 1-10 mM. This study demonstrates that TiO{sub 2}-cellulose hybrid nanocomposite can be a potential candidate for an inexpensive, flexible and disposable glucose biosensor.

  16. New approaches to the development of hybrid nanocomposites: from structural materials to high-tech applications

    International Nuclear Information System (INIS)

    Gerasin, V A; Antipov, Evgenii M; Karbushev, V V; Kulichikhin, Valerii G; Karpacheva, Galina P; Talroze, Raisa V; Kudryavtsev, Y V

    2013-01-01

    Current challenges in the development of various polymer nanocomposites and in the study of their properties are considered. Results of studying hybrid structural (polymer–layered silicates, polymer–nanodiamonds) and functional (based on conducting or liquid-crystalline polymers) nanomaterials are presented. Methods of modification of nanoparticles and their dispersion in a polymer matrix, and the role of interactions between a polymer matrix and fillers, as well as of nanoparticle morphology realized in the course of processing, are discussed. The bibliography includes 453 references.

  17. Silver Nanowire/MnO2 Nanowire Hybrid Polymer Nanocomposites: Materials with High Dielectric Permittivity and Low Dielectric Loss.

    Science.gov (United States)

    Zeraati, Ali Shayesteh; Arjmand, Mohammad; Sundararaj, Uttandaraman

    2017-04-26

    This study reports the fabrication of hybrid nanocomposites based on silver nanowire/manganese dioxide nanowire/poly(methyl methacrylate) (AgNW/MnO 2 NW/PMMA), using a solution casting technique, with outstanding dielectric permittivity and low dielectric loss. AgNW was synthesized using the hard-template technique, and MnO 2 NW was synthesized employing a hydrothermal method. The prepared AgNW:MnO 2 NW (2.0:1.0 vol %) hybrid nanocomposite showed a high dielectric permittivity (64 at 8.2 GHz) and low dielectric loss (0.31 at 8.2 GHz), which are among the best reported values in the literature in the X-band frequency range (8.2-12.4 GHz). The superior dielectric properties of the hybrid nanocomposites were attributed to (i) dimensionality match between the nanofillers, which increased their synergy, (ii) better dispersion state of AgNW in the presence of MnO 2 NW, (iii) positioning of ferroelectric MnO 2 NW in between AgNWs, which increased the dielectric permittivity of nanodielectrics, thereby increasing dielectric permittivity of the hybrid nanocomposites, (iv) barrier role of MnO 2 NW, i.e., cutting off the contact spots of AgNWs and leading to lower dielectric loss, and (v) AgNW aligned structure, which increased the effective surface area of AgNWs, as nanoelectrodes. Comparison of the dielectric properties of the developed hybrid nanocomposites with the literature highlights their great potential for flexible capacitors.

  18. Electrochemical study of nitrobenzene reduction using novel Pt nanoparticles/macroporous carbon hybrid nanocomposites

    International Nuclear Information System (INIS)

    Zhang Yufan; Zeng Lijun; Bo Xiangjie; Wang Huan; Guo Liping

    2012-01-01

    Graphical abstract: A one-step microwave-assisted route for rapidly synthesizing Pt nanoparticles ensemble on macroporous carbon hybrid nanocomposites (PNMPC) has been reported. As a novel electrode material, the excellent electrochemical behavior of nitrobenzene was investigated thoroughly at the PNMPC modified glassy carbon electrode. And moreover, the modified electrode was successfully applied to the determination of nitrobenzene in real samples. Highlights: ► One-step microwave-assisted heating synthesis Pt nanoparticles/macroporous carbon hybrid nanocomposites (PNMPC). ► Catalytic rate constant being 3.14 × 10 4 M −1 s −1 for NB in pH 7.0. ► Sensitive electrochemical detection of NB at the PNMPC/Nafion/GC electrode. ► The electrode showing excellent anti-interference ability and good stability for NB. - Abstract: Novel Pt nanoparticles (PN) ensemble on macroporous carbon (MPC) hybrid nanocomposites (PNMPC) were prepared through a rapidly and simple one-step microwave-assisted heating procedure. The obtained PNMPC was characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and electrochemical methods. The electrochemical reduction of nitrobenzene (NB) was thoroughly investigated at the PNMPC modified glassy carbon (GC) electrode, and the catalytic rate constant was calculated to be 3.14 × 10 4 M −1 s −1 for NB. A sensitive NB sensor was developed based on the PNMPC/GC electrode, which showed a wide linear range (1–200 μM), low detection limit (50 nM), high sensitivity (6.93 μA μM −1 ), excellent anti-interference ability and good stability. And moreover, the electrode was successfully applied to the determination of NB in real samples.

  19. Facile Fabrication of MoS2-Modified SnO2 Hybrid Nanocomposite for Ultrasensitive Humidity Sensing.

    Science.gov (United States)

    Zhang, Dongzhi; Sun, Yan'e; Li, Peng; Zhang, Yong

    2016-06-08

    An ultrasensitive humidity sensor based on molybdenum-disulfide- (MoS2)-modified tin oxide (SnO2) nanocomposite has been demonstrated in this work. The nanostructural, morphological, and compositional properties of an as-prepared MoS2/SnO2 nanocomposite were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), energy dispersive spectrometry (EDS), nitrogen sorption analysis, and Raman spectroscopy, which confirmed its successful preparation and rationality. The sensing characteristics of the MoS2/SnO2 hybrid film device against relative humidity (RH) were investigated at room temperature. The RH sensing results revealed an unprecedented response, ultrafast response/recovery behaviors, and outstanding repeatability. To our knowledge, the sensor response yielded in this work was tens of times higher than that of the existing humidity sensors. Moreover, the MoS2/SnO2 hybrid nanocomposite film sensor exhibited great enhancement in humidity sensing performances as compared to the pure MoS2, SnO2, and graphene counterparts. Furthermore, complex impedance spectroscopy and bode plots were employed to understand the underlying sensing mechanisms of the MoS2/SnO2 nanocomposite toward humidity. The synthesized MoS2/SnO2 hybrid composite was proved to be an excellent candidate for constructing ultrahigh-performance humidity sensor toward various applications.

  20. Enhanced Capacitance of Hybrid Layered Graphene/Nickel Nanocomposite for Supercapacitors

    Science.gov (United States)

    Mohd Zaid, Norsaadatul Akmal; Idris, Nurul Hayati

    2016-08-01

    In this work, Ni nanoparticles were directly decorated on graphene (G) nanosheets via mechanical ball milling. Based on transmission electron microscopy observations, the Ni nanoparticles were well dispersed and attached to the G nanosheet without any agglomerations. Electrochemical results showed that the capacitance of a G/Ni nanocomposite was 275 F g-1 at a current density of 2 A g-1, which is higher than the capacitance of bare G (145 F g-1) and bare Ni (3 F g-1). The G/Ni electrode also showed superior performance at a high current density, exhibiting a capacitance of 190 F g-1 at a current density of 5 A g-1 and a capacitance of 144 F g-1 at a current density of 10 A g-1. The equivalent series resistance for G/Ni nanocomposites also decreased. The enhanced performance of this hybrid supercapacitor is best described by the synergistic effect, i.e. dual charge-storage mechanism, which is demonstrated by electrical double layer and pseudocapacitance materials. Moreover, a high specific surface area and electrical conductivity of the materials enhanced the capacitance. These results indicate that the G/Ni nanocomposite is a potential supercapacitor.

  1. PFE: ZnO hybrid nanocomposites for OLED applications: Fabrication and photophysical properties

    Energy Technology Data Exchange (ETDEWEB)

    Belhaj, M. [Université de Monastir, Faculté des sciences de Monastir, Département de physique, Laboratoire des Interfaces et des Matériaux Avancés, 5019 Monastir (Tunisia); Dridi, C., E-mail: cherif.Dridi@issatso.rnu.tn [Université de Monastir, Faculté des sciences de Monastir, Département de physique, Laboratoire des Interfaces et des Matériaux Avancés, 5019 Monastir (Tunisia); Université de Sousse, Institut Supérieur des Sciences Appliquées et de Technologie de Sousse, Cité Ettafala, 4003 Ibn Khaldoun Sousse (Tunisia); Elhouichet, H. [Centre National de Recherches en Sciences des Matériaux, Laboratoire de physico-Chimie des Matériaux Minéreaux et leurs applications, B.P. 95 Hammam-Lif 2050 (Tunisia)

    2015-01-15

    In this work, ZnO nanoparticles (n-ZnO) and poly (9, 9-dioctyl-fluorenyl-2, 7-yleneethynylene) (PFE): n-ZnO based thin films were spin-coated onto glass substrates. Structural, morphological and optical properties of ZnO, PFE and the PFE: n-ZnO hybrid films with different n-ZnO mass ratios were investigated. n-ZnO films obtained by sol–gel technique are polycrystalline with a hexagonal wurtzite structure. They are also homogenous with an average grain size of about 35 nm. For polymer nanocomposite, the optical properties are closely related to the ZnO content in the mixture. Among the tested active layers, the best performance is observed for that containing 2 wt% of ZnO nanoparticles. - Highlights: • We have analyzed the optical properties of PFE: ZnO nanocomposites . • We have optimized the best PFE: ZnO nanocomposite for the OLED application. • We have demonstrated the feasibility of white OLED devices.

  2. PFE: ZnO hybrid nanocomposites for OLED applications: Fabrication and photophysical properties

    International Nuclear Information System (INIS)

    Belhaj, M.; Dridi, C.; Elhouichet, H.

    2015-01-01

    In this work, ZnO nanoparticles (n-ZnO) and poly (9, 9-dioctyl-fluorenyl-2, 7-yleneethynylene) (PFE): n-ZnO based thin films were spin-coated onto glass substrates. Structural, morphological and optical properties of ZnO, PFE and the PFE: n-ZnO hybrid films with different n-ZnO mass ratios were investigated. n-ZnO films obtained by sol–gel technique are polycrystalline with a hexagonal wurtzite structure. They are also homogenous with an average grain size of about 35 nm. For polymer nanocomposite, the optical properties are closely related to the ZnO content in the mixture. Among the tested active layers, the best performance is observed for that containing 2 wt% of ZnO nanoparticles. - Highlights: • We have analyzed the optical properties of PFE: ZnO nanocomposites . • We have optimized the best PFE: ZnO nanocomposite for the OLED application. • We have demonstrated the feasibility of white OLED devices

  3. Third-order nonlinear optical response of Ag-CdSe/PVA hybrid nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, S.K.; Kaur, Ramneek; Kaur, Jaspreet; Sharma, Mamta [Panjab University, Department of Physics, Center of Advanced Study in Physics, Chandigarh (India)

    2015-09-15

    Hybrid nanocomposites of II-VI semiconductor nanoparticles are gaining great interest in nonlinear optoelectronic devices. Present work includes the characterization of CdSe polymer nanocomposite prepared by chemical in situ technique. From X-ray diffraction, the hexagonal wurtzite structure of nanoparticles has been confirmed with spherical morphology from transmission electron microscopy. Ag-CdSe hybrid polymer nanocomposite has been prepared chemically at different Ag concentrations. The presence of Ag in hybrid nanocomposite has been confirmed with energy-dispersive X-ray spectroscopy. The effect of varying Ag concentration on the linear and nonlinear optical properties of the nanocomposites has been studied. In linear optical parameters, the linear absorption coefficient, refractive index, extinction coefficient and optical conductivity have been calculated. The third-order nonlinear optical properties have been observed with open- and closed-aperture Z-scan technique. The large nonlinear refractive index ∝10{sup -5} cm{sup 2}/W with self-focusing behaviour is due to the combined effect of quantum confinement and thermo-optical effects. The enhanced nonlinearity with increasing Ag content is due to the surface plasmon resonance, which enhances the local electric field near the nanoparticle surface. Thus, Ag-CdSe hybrid polymer nanocomposite has favourable nonlinear optical properties for various optoelectronic applications. (orig.)

  4. Third-order nonlinear optical response of Ag-CdSe/PVA hybrid nanocomposite

    International Nuclear Information System (INIS)

    Tripathi, S.K.; Kaur, Ramneek; Kaur, Jaspreet; Sharma, Mamta

    2015-01-01

    Hybrid nanocomposites of II-VI semiconductor nanoparticles are gaining great interest in nonlinear optoelectronic devices. Present work includes the characterization of CdSe polymer nanocomposite prepared by chemical in situ technique. From X-ray diffraction, the hexagonal wurtzite structure of nanoparticles has been confirmed with spherical morphology from transmission electron microscopy. Ag-CdSe hybrid polymer nanocomposite has been prepared chemically at different Ag concentrations. The presence of Ag in hybrid nanocomposite has been confirmed with energy-dispersive X-ray spectroscopy. The effect of varying Ag concentration on the linear and nonlinear optical properties of the nanocomposites has been studied. In linear optical parameters, the linear absorption coefficient, refractive index, extinction coefficient and optical conductivity have been calculated. The third-order nonlinear optical properties have been observed with open- and closed-aperture Z-scan technique. The large nonlinear refractive index ∝10 -5 cm 2 /W with self-focusing behaviour is due to the combined effect of quantum confinement and thermo-optical effects. The enhanced nonlinearity with increasing Ag content is due to the surface plasmon resonance, which enhances the local electric field near the nanoparticle surface. Thus, Ag-CdSe hybrid polymer nanocomposite has favourable nonlinear optical properties for various optoelectronic applications. (orig.)

  5. Tuning the Structure and Ionic Interactions in a Thermochemically Stable Hybrid Layered Titanate-Based Nanocomposite for High Temperature Solid Lubrication

    NARCIS (Netherlands)

    Gonzalez Rodriguez, P.; Lubbers, Roy; Veldhuis, Sjoerd; Narygina, Olga; Lette, Walter; Schipper, Dirk J.; ten Elshof, Johan E.

    2017-01-01

    Solid inorganic lubricants are thermally stable but they are often limited by their lack of deformability, while organic lubricants have limitations in terms of thermal stability. In this study, a novel solid organic–inorganic nanocomposite lubricant that synergistically combines the

  6. Hybrid ternary rice paper-manganese oxide-carbon nanotube nanocomposites for flexible supercapacitors

    Science.gov (United States)

    Jiang, Wenchao; Zhang, Kaixi; Wei, Li; Yu, Dingshan; Wei, Jun; Chen, Yuan

    2013-10-01

    Modern portable electronic devices create a strong demand for flexible energy storage devices. Paper based nanocomposites are attractive as sustainable materials for such applications. Here, we directly explored the hydroxyl chemistry of cellulose fibers to synthesize hybrid ternary nanocomposites, comprised of rice paper, single-walled carbon nanotubes (SWCNTs) and manganese oxide nanoparticles. The functional groups on cellulose fibers can react with adsorbed permanganate ions, resulting in uniform deposition of manganese oxide nanoparticles. SWCNTs coated on top of manganese oxide nanoparticles form a highly conductive network connecting individual manganese oxide particles. By using the hybrid ternary composites as electrodes, the assembled two-electrode supercapacitors demonstrated high capacitance (260.2 F g-1), energy (9.0 W h kg-1), power (59.7 kW kg-1), and cycle stability (12% drop after 3000 cycles). In addition, the nanocomposites show good strength and excellent mechanical flexibility, and their capacitance shows negligible changes after bending more than 100 times. These findings suggest that opportunities exist to further explore the rich chemistry of cellulose fibers for innovative energy applications.Modern portable electronic devices create a strong demand for flexible energy storage devices. Paper based nanocomposites are attractive as sustainable materials for such applications. Here, we directly explored the hydroxyl chemistry of cellulose fibers to synthesize hybrid ternary nanocomposites, comprised of rice paper, single-walled carbon nanotubes (SWCNTs) and manganese oxide nanoparticles. The functional groups on cellulose fibers can react with adsorbed permanganate ions, resulting in uniform deposition of manganese oxide nanoparticles. SWCNTs coated on top of manganese oxide nanoparticles form a highly conductive network connecting individual manganese oxide particles. By using the hybrid ternary composites as electrodes, the assembled two

  7. Graphene-Based Polymer Nanocomposites

    Science.gov (United States)

    2015-03-31

    polymerize in-situ around the fillers or even graft to them [71], thus it overcomes the problem of dramatically increased viscosity of the polymer...filler dispersion, increased polymer viscosity during processing and filler damage due to thermal degradation or strong shear forces [3, 82]. At...123, 124]. Figure 1.12 (a) SEM image of the fracture surface of GO/PVA nanocomposite film [85]. (b) TEM image of a clay reinforced Nylon-6

  8. Simultaneous immobilization of cadmium and lead in contaminated soils by hybrid bio-nanocomposites of fungal hyphae and nano-hydroxyapatites.

    Science.gov (United States)

    Yang, Zhihui; Liang, Lifen; Yang, Weichun; Shi, Wei; Tong, Yunping; Chai, Liyuan; Gao, Shikang; Liao, Qi

    2018-04-01

    Self-aggregation of bulk nano-hydroxyapatites (n-HAPs) undermines their immobilization efficiencies of heavy metals in the contaminated soils. Here, the low-cost, easily obtained, and environment-friendly filamentous fungi have been introduced for the bio-matrices of the hybrid bio-nanocomposites to potentially solve such problem of n-HAPs. According to SEM, TEM, XRD, and FT-IR analyses, n-HAPs were successfully coated onto the fungal hyphae and their self-aggregation was improved. The immobilization efficiencies of diethylene-triamine-pentaacetic acid (DTPA)-extractable Cd and Pb in the contaminated soils by the bio-nanocomposites were individually one to four times of that by n-HAPs or the fungal hyphae. Moreover, the Aspergillus niger-based bio-nanocomposite (ANHP) was superior to the Penicillium Chrysogenum F1-based bio-nanocomposite (PCHP) in immobilization of Cd and Pb in the contaminated soils. In addition, the results of XRD showed that one of the potential mechanisms of metal immobilization by the hybrid bio-nanocomposites was dissolution of n-HAPs followed by precipitation of new metal phosphate minerals. Our results suggest that the hybrid bio-nanocomposite (ANHP) can be recognized as a promising soil amendment candidate for effective remediation on the soils simultaneously contaminated by Cd and Pb.

  9. Au Based Nanocomposites Towards Plasmonic Applications

    Science.gov (United States)

    Panniello, A.; Curri, M. L.; Placido, T.; Reboud, V.; Kehagias, N.; Sotomayor Torres, C. M.; Mecerreyes, D.; Agostiano, A.; Striccoli, M.

    2010-06-01

    Incorporation of nano-sized metals in polymers can transfer their unique features to the host matrix, providing nanocomposite materials with improved optical, electric, magnetic and mechanical properties. In this work, colloidal Au nanorods have been incorporated into PMMA based random co-polymer, properly functionalized with amino groups and the optical and morphological properties of the resulting nanocomposite have been investigated by spectroscopic and AFM measurements. Au nanorods have demonstrated to preserve the plasmon absorption and to retain morphological features upon the incorporation, thus making the final metal modified polymer composite exploitable for the fabrication of plasmonic devices. The prepared nanocomposites have been then patterned by Nano Imprint Lithography technique in order to demonstrate the viability of the materials towards optical applications.

  10. Novel porous graphene oxide and hydroxyapatite nanosheets-reinforced sodium alginate hybrid nanocomposites for medical applications

    International Nuclear Information System (INIS)

    Xiong, Guangyao; Luo, Honglin; Zuo, Guifu; Ren, Kaijing; Wan, Yizao

    2015-01-01

    Graphene oxide (GO) and hydroxyapatite (HAp) are frequently used as reinforcements in polymers to improve mechanical and biological properties. In this work, novel porous hybrid nanocomposites consisting of GO, HAp, and sodium alginate (SA) have been prepared by facile solution mixing and freeze drying in an attempt to obtain a scaffold with desirable mechanical and biological properties. The as-prepared porous GO/HAp/SA hybrid nanocomposites were characterized by SEM, XRD, FTIR, TGA, and mechanical testing. In addition, preliminary cell behavior was assessed by CCK8 assay. It is found that the GO/HAp/SA nanocomposites show improved compressive strength and modulus over neat SA and HAp/SA nanocomposites. CCK8 results reveal that the GO/HAp/SA nanocomposites show enhanced cell proliferation over neat SA and GO/SA nanocomposite. It has been demonstrated that GO/HAp20/SA holds promise in bone tissue engineering. - Graphical abstract: Display Omitted - Highlights: • Graphene oxide (GO), hydroxyapatite (HAp), and alginate (SA) nanocomposites were fabricated. • The novel porous composites were prepared by solution mixture and freeze drying. • The GO/HAp/SA had porous structure with porosity > 85% and pore size > 150 μm. • The GO/HAp/SA exhibited improved mechanical properties over HAp/SA counterparts. • The GO/HAp/SA showed enhanced cell proliferation over GO/SA counterparts

  11. Novel porous graphene oxide and hydroxyapatite nanosheets-reinforced sodium alginate hybrid nanocomposites for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Guangyao [School of Mechanical and Electrical Engineering, East China Jiaotong University, Nanchang 330013 (China); Luo, Honglin [Research Institute of Biomaterials and Transportation, East China Jiaotong University, Nanchang 330013 (China); School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin University, Tianjin 300072 (China); Zuo, Guifu [Hebei Provincial Key Laboratory of Inorganic Nonmetallic Materials, College of Materials Science and Engineering, Hebei United University, Tangshan 063009 (China); Ren, Kaijing [Department of Joint Surgery, Tianjin Hospital, Tianjin 300211 (China); Wan, Yizao, E-mail: yzwantju@126.com [Research Institute of Biomaterials and Transportation, East China Jiaotong University, Nanchang 330013 (China); School of Materials Science and Engineering, Tianjin Key Laboratory of Composite and Functional Materials, Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, Tianjin University, Tianjin 300072 (China)

    2015-09-15

    Graphene oxide (GO) and hydroxyapatite (HAp) are frequently used as reinforcements in polymers to improve mechanical and biological properties. In this work, novel porous hybrid nanocomposites consisting of GO, HAp, and sodium alginate (SA) have been prepared by facile solution mixing and freeze drying in an attempt to obtain a scaffold with desirable mechanical and biological properties. The as-prepared porous GO/HAp/SA hybrid nanocomposites were characterized by SEM, XRD, FTIR, TGA, and mechanical testing. In addition, preliminary cell behavior was assessed by CCK8 assay. It is found that the GO/HAp/SA nanocomposites show improved compressive strength and modulus over neat SA and HAp/SA nanocomposites. CCK8 results reveal that the GO/HAp/SA nanocomposites show enhanced cell proliferation over neat SA and GO/SA nanocomposite. It has been demonstrated that GO/HAp20/SA holds promise in bone tissue engineering. - Graphical abstract: Display Omitted - Highlights: • Graphene oxide (GO), hydroxyapatite (HAp), and alginate (SA) nanocomposites were fabricated. • The novel porous composites were prepared by solution mixture and freeze drying. • The GO/HAp/SA had porous structure with porosity > 85% and pore size > 150 μm. • The GO/HAp/SA exhibited improved mechanical properties over HAp/SA counterparts. • The GO/HAp/SA showed enhanced cell proliferation over GO/SA counterparts.

  12. Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation Of Inorganic Nanoparticles And Organic/Inorganic Hybrid Nanocomposites

    Science.gov (United States)

    Pate, Ryan; Lantz, Kevin R.; Dhawan, Anuj; Vo-Dinh, Tuan; Stiff-Roberts, Adrienne D.

    2010-10-01

    In this research, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been used to deposit different classes of inorganic nanoparticles, including bare, un-encapsulated ZnO and Au nanoparticles, as well as ligand-encapsulated CdSe colloidal quantum dots (CQDs). RIR-MAPLE has been used for thin-film deposition of different organic/inorganic hybrid nanocomposites using some of these inorganic nanoparticles, including CdSe CQD-poly[2-methoxy-5-(2'-ethylhexyloxy)-1,4-(1-cyanovinylene)phenylene] (MEH-CN-PPV) nanocomposites and Au nanoparticle-poly(methyl methacrylate) (PMMA) nanocomposites. The unique contribution of this research is that a technique is demonstrated for the deposition of organic-based thin-films requiring solvents with bond energies that do not have to be resonant with the laser energy. By creating an emulsion of solvent and ice in the target, RIR-MAPLE using a 2.94 μm laser can deposit most material systems because the hydroxyl bonds in the ice component of the emulsion matrix are strongly resonant with the 2.94 μm laser. In this way, the types of materials that can be deposited using RIR-MAPLE has been significantly expanded. Furthermore, materials with different solvent bond energies can be co-deposited without concern for material degradation and without the need to specifically tune the laser energy to each material solvent bond energy, thereby facilitating the realization of organic/inorganic hybrid nanocomposite thin-films. In addition to the structural characterization of the inorganic nanoparticle and hybrid nanocomposite thin-films deposited using this RIR-MAPLE technique, optical characterization is presented to demonstrate the potential of such films for optoelectronic device applications.

  13. Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation Of Inorganic Nanoparticles And Organic/Inorganic Hybrid Nanocomposites

    International Nuclear Information System (INIS)

    Pate, Ryan; Lantz, Kevin R.; Stiff-Roberts, Adrienne D.; Dhawan, Anuj; Vo-Dinh, Tuan

    2010-01-01

    In this research, resonant infrared matrix-assisted pulsed laser evaporation (RIR-MAPLE) has been used to deposit different classes of inorganic nanoparticles, including bare, un-encapsulated ZnO and Au nanoparticles, as well as ligand-encapsulated CdSe colloidal quantum dots (CQDs). RIR-MAPLE has been used for thin-film deposition of different organic/inorganic hybrid nanocomposites using some of these inorganic nanoparticles, including CdSe CQD-poly[2-methoxy-5-(2'-ethylhexyloxy )-1,4-(1-cyanovinylene)phenylene](MEH-CN-PPV) nanocomposites and Au nanoparticle-poly(methyl methacrylate)(PMMA) nanocomposites. The unique contribution of this research is that a technique is demonstrated for the deposition of organic-based thin-films requiring solvents with bond energies that do not have to be resonant with the laser energy. By creating an emulsion of solvent and ice in the target, RIR-MAPLE using a 2.94 μm laser can deposit most material systems because the hydroxyl bonds in the ice component of the emulsion matrix are strongly resonant with the 2.94 μm laser. In this way, the types of materials that can be deposited using RIR-MAPLE has been significantly expanded. Furthermore, materials with different solvent bond energies can be co-deposited without concern for material degradation and without the need to specifically tune the laser energy to each material solvent bond energy, thereby facilitating the realization of organic/inorganic hybrid nanocomposite thin-films. In addition to the structural characterization of the inorganic nanoparticle and hybrid nanocomposite thin-films deposited using this RIR-MAPLE technique, optical characterization is presented to demonstrate the potential of such films for optoelectronic device applications.

  14. Preparation and properties of hybrid monodispersed magnetic α-Fe2O3 based chitosan nanocomposite film for industrial and biomedical applications.

    Science.gov (United States)

    Singh, Jay; Srivastava, M; Dutta, Joydeep; Dutta, P K

    2011-01-01

    In this study, hydrothermally prepared magnetic α-Fe2O3 nanoparticles were dispersed in chitosan (CH) solution to fabricate nanocomposite film. X-ray diffraction (XRD) patterns indicated that the α-Fe2O3 nanoparticles were pure α-Fe2O3 with rhombohedral structures, and the fabrication of CH did not result in a phase change. The scanning electron microscopy (SEM) and transmission electron microscope (TEM) results showed that the hexagonal and spherical monodispersed α-Fe2O3 nanoparticles were encapsulated into the spherical dumb shaped CH-α-Fe2O3 nanocomposite film with a mean diameter of ∼87 and ∼110 nm respectively. The α-Fe2O3 nanoparticles and CH-α-Fe2O3 nanocomposite film were also characterized by Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and vibrating sample magnetometer (VSM). Magnetic measurements revealed that the saturated magnetization (Ms) and remanent magnetization (Mr) of the pure α-Fe2O3 nanoparticles reached 0.573 emu/g and 0.100 emu/g respectively and the nanoparticles showed the characteristics of weak ferromagnetic before and after coating with CH. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Boron nitride-MWCNT/epoxy hybrid nanocomposites: Preparation and mechanical properties

    International Nuclear Information System (INIS)

    Ulus, Hasan; Üstün, Tugay; Eskizeybek, Volkan; Şahin, Ömer Sinan; Avcı, Ahmet; Ekrem, Mürsel

    2014-01-01

    Highlights: • We studied the effects of BN nanoplatelets on tensile strength and elasticity modulus for polymer composites. • We investigated the synergetic effects of BN nanoplatelets and MWCNTs on tensile strength and elasticity modulus for polymer composites. • Fracture surfaces were examined by SEM analysis. - Abstract: In this study, production and mechanical properties of hybrid nanocomposites have been investigated. Hybrid nanocomposites are consisting of boron nitride nanoplatelets (BN) and multiwall carbon nanotubes (MWCNT) embedded in epoxy resin. The BN and MWCNT were mixed to epoxy resin in different weight fractions and mixtures were utilized for tensile test specimen production. The synthesized BN and produced hybrid nanocomposites were characterized by SEM, TEM, XRD, FT-IR and TGA analyses. The elasticity modulus and tensile strength values were obtained via tensile tests. The fracture morphologies were investigated after tensile test by means of scanning electron microscopy

  16. A highly sensitive NADH sensor based on a mycelium-like nanocomposite using graphene oxide and multi-walled carbon nanotubes to co-immobilize poly(luminol) and poly(neutral red) hybrid films.

    Science.gov (United States)

    Chiang Lin, Kuo; Yu Lai, Szu; Ming Chen, Shen

    2014-08-21

    Hybridization of poly(luminol) (PLM) and poly(neutral red) (PNR) has been successfully performed and further enhanced by a conductive and steric hybrid nanotemplate using graphene oxide (GO) and multi-walled carbon nanotubes (MWCNTs). The morphology of the PLM-PNR-MWCNT-GO mycelium-like nanocomposite is studied by SEM and AFM and it is found to be electroactive, pH-dependent, and stable in the electrochemical system. It shows electrocatalytic activity towards NADH with a high current response and low overpotential. Using amperometry, it has been shown to have a high sensitivity of 288.9 μA mM(-1) cm(-2) to NADH (Eapp. = +0.1 V). Linearity is estimated in a concentration range of 1.33 × 10(-8) to 1.95 × 10(-4) M with a detection limit of 1.33 × 10(-8) M (S/N = 3). Particularly, it also shows another linear range of 2.08 × 10(-4) to 5.81 × 10(-4) M with a sensitivity of 151.3 μA mM(-1) cm(-2). The hybridization and activity of PLM and PNR can be effectively enhanced by MWCNTs and GO, resulting in an active hybrid nanocomposite for determination of NADH.

  17. Some fundamental and applicative properties of [polymer/nano-SiC] hybrid nanocomposites

    International Nuclear Information System (INIS)

    Kassiba, A; Boucle, J; Makowska-Janusik, M; Errien, N

    2007-01-01

    Hybrid nanocomposites which combine polymer as host matrix and nanocrystals as active elements are promising functional materials for electronics, optics or photonics. In these systems, the physical response is governed by the nanocrystal features (size, surface and defect states), the polymer properties and the polymer-nanocrystal interface. This work reviews some selective nanostructured architectures based on active elements such as silicon carbide (SiC) nanocrystals and polymer host matrices. Beyond an overview of some key properties of the nanocrystals, a main part will be devoted to the electro-optical (EO) properties of SiC based hybrid systems where SiC nanocrystals are embedded in polymer matrices of different chemical nature such as poly-(methylmethacrylate) (PMMA), poly-vinylcarbazole (PVK) or polycarbonate. Using this approach, the organic-inorganic interface effects are emphasised with regard to the dielectric or hole transporting behaviour of PMMA and PVK respectively. These effects are illustrated through different EO responses associated with hybrid composites based on PMMA or PVK

  18. Some fundamental and applicative properties of [polymer/nano-SiC] hybrid nanocomposites

    Science.gov (United States)

    Kassiba, A.; Bouclé, J.; Makowska-Janusik, M.; Errien, N.

    2007-08-01

    Hybrid nanocomposites which combine polymer as host matrix and nanocrystals as active elements are promising functional materials for electronics, optics or photonics. In these systems, the physical response is governed by the nanocrystal features (size, surface and defect states), the polymer properties and the polymer-nanocrystal interface. This work reviews some selective nanostructured architectures based on active elements such as silicon carbide (SiC) nanocrystals and polymer host matrices. Beyond an overview of some key properties of the nanocrystals, a main part will be devoted to the electro-optical (EO) properties of SiC based hybrid systems where SiC nanocrystals are embedded in polymer matrices of different chemical nature such as poly-(methylmethacrylate) (PMMA), poly-vinylcarbazole (PVK) or polycarbonate. Using this approach, the organic-inorganic interface effects are emphasised with regard to the dielectric or hole transporting behaviour of PMMA and PVK respectively. These effects are illustrated through different EO responses associated with hybrid composites based on PMMA or PVK.

  19. Magnetic graphene based nanocomposite for uranium scavenging

    Energy Technology Data Exchange (ETDEWEB)

    El-Maghrabi, Heba H. [Egyptian Petroleum Research Institute, 11727, Cairo (Egypt); Abdelmaged, Shaimaa M. [Nuclear Materials Authority, 6530 P.O. Box Maadi, Cairo (Egypt); Nada, Amr A. [Egyptian Petroleum Research Institute, 11727, Cairo (Egypt); Zahran, Fouad, E-mail: f.zahran@quim.ucm.es [Faculty of Science, Helwan University, 11795, Cairo (Egypt); El-Wahab, Saad Abd; Yahea, Dena [Faculty of Science, Ain shams University, Cairo (Egypt); Hussein, G.M.; Atrees, M.S. [Nuclear Materials Authority, 6530 P.O. Box Maadi, Cairo (Egypt)

    2017-01-15

    Graphical abstract: Graphical representation of U{sup 6+} adsorption on Magnetic Ferberite-Graphene Nanocomposite. - Highlights: • Synthesis of new magnetic wolframite bimetallic nanostructure on graphene. • A promising adsorption capacity of 455 mg/g was recorded for FG-20 within 60 min at room temperature. • The uranium removal was followed pseudo-second order kinetics and Langmuir isotherm. - Abstract: Magnetic graphene based ferberite nanocomposite was tailored by simple, green, low cost and industrial effective method. The microstructure and morphology of the designed nanomaterials were examined via XRD, Raman, FTIR, TEM, EDX and VSM. The prepared nanocomposites were introduced as a novel adsorbent for uranium ions scavenging from aqueous solution. Different operating conditions of time, pH, initial uranium concentration, adsorbent amount and temperature were investigated. The experimental data shows a promising adsorption capacity. In particular, a maximum value of 455 mg/g was obtained within 60 min at room temperature with adsorption efficiency of 90.5%. The kinetics and isotherms adsorption data were fitted with the pseudo-second order model and Langmuir equation, respectively. Finally, the designed nanocomposites were found to have a great degree of sustainability (above 5 times of profiteering) with a complete maintenance of their parental morphology and adsorption capacity.

  20. Development of multifunctional fluoroelastomers based on nanocomposites

    International Nuclear Information System (INIS)

    Zen, Heloisa Augusto

    2015-01-01

    The fluoropolymers are known for their great mechanical properties, high thermal stability and resistance to aggressive chemical environment, and because of those properties they are widely used in industries, such as automobile, petroleum, chemistry, manufacturing, among others. To improve the thermal properties and gases barrier of the polymeric matrix, the incorporation of nanoparticle is used, this process permits the polymer to maintain their own characteristics and acquire new properties of nanoparticle. Because of those properties, the structural and morphological modification of fluoropolymers are very hard to be obtained through traditional techniques, in order to surmount this difficulty, the ionizing radiation is a well-known and effective method to modify fluoropolymers structures. In this thesis a nanocomposite polymeric based on fluoroelastomer (FKM) was developed and incorporated with four different configurations of nanoparticles: clay Cloisite 15A, POSS 1159, POSS 1160 and POSS 1163. After the nanocomposites films were obtained, a radiation induced grafting process was carried out, followed by sulfonation in order to obtain a ionic exchanged membrane. The effect of nanoparticle incorporation and the ionizing radiation onto films were characterized by X-ray diffraction, thermal and mechanical analysis, scanning electron microscopy and swelling; and the membranes were evaluated by degree of grafting, ionic exchange capacity and swelling. After the films were characterized, the crosslinking effect was observed to be predominant for the nanocomposites irradiated before the vulcanization, whereas the degradation was the predominant effect in the nanocomposites irradiated after vulcanization. (author)

  1. Mechanical properties of hybrid SiC/CNT filled toughened epoxy nanocomposite

    Science.gov (United States)

    Ratim, S.; Ahmad, S.; Bonnia, N. N.; Yahaya, Sabrina M.

    2018-01-01

    Mechanical properties of epoxy nanocomposites filled single filler have been extensively studied by various researchers. However, there are not much discovery on the behavior of hybrid nanocomposite. In this study, single and hybrid nanocomposites of toughened epoxy filled CNT/SiC nanoparticles were investigated. The hybrid nanocomposites samples were prepared by combining CNT and SiC nanoparticles in toughened epoxy matrix via mechanical stirring method assisted with ultrasonic cavitations. Epoxy resin and liquid epoxidized natural rubber (LENR) mixture were first blend prior to the addition of nanofillers. Then, the curing process of the nanocomposite samples were conducted by compression molding technique at 130°C for 2 hours. The purpose of this study is to investigate the hybridization effect of CNT and SiC nanoparticles on mechanical properties toughened epoxy matrix. The total loading of single and hybrid nanofillers were fixed to 4% volume are 0, 4C, 4S, 3S1C, 2S2C, and 1S3C. Mechanical properties of hybrid composites show that the highest value of tensile strength achieved by 3S1C sample at about 7% increment and falls between their single composite values. Meanwhile, the stiffness of the same sample is significantly increased at about 31% of the matrix. On the other hand, a highest flexural property is obtained by 1S3C sample at about 20% increment dominated by CNT content. However, the impact strength shows reduction trend with the addition of SiC and CNT into the matrix. The hybridization of SiC and CNT show highest value in sample 1S3C at about 3.37 kJ/m2 of impact energy absorbed. FESEM micrograph have confirmed that better distributions and interaction observed between SiC nanoparticles and matrix compared to CNT, which contributed to higher tensile strength and modulus.

  2. Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications

    Science.gov (United States)

    Kádár, Roland; Abbasi, Mahdi; Figuli, Roxana; Rigdahl, Mikael; Wilhelm, Manfred

    2017-01-01

    The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate) (EBA) nanocomposite hybrids containing graphite nanoplatelets (GnP) and carbon black (CB). The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests. PMID:28336857

  3. Graphitic carbon nitride based nanocomposites: a review

    Science.gov (United States)

    Zhao, Zaiwang; Sun, Yanjuan; Dong, Fan

    2014-11-01

    Graphitic carbon nitride (g-C3N4), as an intriguing earth-abundant visible light photocatalyst, possesses a unique two-dimensional structure, excellent chemical stability and tunable electronic structure. Pure g-C3N4 suffers from rapid recombination of photo-generated electron-hole pairs resulting in low photocatalytic activity. Because of the unique electronic structure, the g-C3N4 could act as an eminent candidate for coupling with various functional materials to enhance the performance. According to the discrepancies in the photocatalytic mechanism and process, six primary systems of g-C3N4-based nanocomposites can be classified and summarized: namely, the g-C3N4 based metal-free heterojunction, the g-C3N4/single metal oxide (metal sulfide) heterojunction, g-C3N4/composite oxide, the g-C3N4/halide heterojunction, g-C3N4/noble metal heterostructures, and the g-C3N4 based complex system. Apart from the depiction of the fabrication methods, heterojunction structure and multifunctional application of the g-C3N4-based nanocomposites, we emphasize and elaborate on the underlying mechanisms in the photocatalytic activity enhancement of g-C3N4-based nanocomposites. The unique functions of the p-n junction (semiconductor/semiconductor heterostructures), the Schottky junction (metal/semiconductor heterostructures), the surface plasmon resonance (SPR) effect, photosensitization, superconductivity, etc. are utilized in the photocatalytic processes. Furthermore, the enhanced performance of g-C3N4-based nanocomposites has been widely employed in environmental and energetic applications such as photocatalytic degradation of pollutants, photocatalytic hydrogen generation, carbon dioxide reduction, disinfection, and supercapacitors. This critical review ends with a summary and some perspectives on the challenges and new directions in exploring g-C3N4-based advanced nanomaterials.

  4. Nanostructured SnO{sub 2} encapsulated guar-gum hybrid nanocomposites for electrocatalytic determination of hydrazine

    Energy Technology Data Exchange (ETDEWEB)

    Malik, Priya [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India); Srivastava, Manish [Department of Physics & Astrophysics, University of Delhi, Delhi 110007 (India); Verma, Ranjana [Solar Energy Material Laboratory, Department of Energy, Tezpur University, Tezpur, Assam 784 028 (India); Kumar, Manish [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India); Kumar, D., E-mail: dkumar@dce.ac.in [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India); Singh, Jay, E-mail: jay_singh143@yahoo.co.in [Department of Applied Chemistry & Polymer Technology, Delhi Technological University, Shahbad Daulatpur, Main Bawana Road, Delhi 110042 (India)

    2016-01-01

    The present article deals with synthesis of sol–gel derived tin dioxide (SnO{sub 2}) nanoparticles encapsulated in to guar gum (GG) biopolymer as the organic–inorganic hybrid materials for the determination of hydrazine. The organic–inorganic hybrid combines the perfunctory strength offered by the inorganic SnO{sub 2} nanoparticles with flexible binding sites provided by the organic biopolymer (GG) solution by the ultrasonication. The phase identification, crystalline size, surface morphology and optical properties of prepared SnO{sub 2} and SnO{sub 2}-GG nanocomposites has been investigated through FT-IR, XRD, SEM, AFM, TEM, UV–Vis, and PL techniques. The colloidal solution of SnO{sub 2} and GG is electrophoretically deposited (EPD) onto the indium tin-oxide (ITO) glass substrate and studied for the electrooxidation of hydrazine. Under the optimized experimental conditions, the linearity between the current response and the hydrazine concentration has been obtained in the range of 2–22 mM, with a low detection limit of 2.76 mM and a high sensitivity of 5.72 μA cm{sup −2}. Based on the linear increase in amperometric current, a sensitive hydrazine electrochemical sensor is constructed. The proposed SnO{sub 2}-GG/ITO electrode shows a good response time (35 s), reproducibility, and long-term stability. The obtained results suggest that SnO{sub 2}-GG nanocomposites electrode provides a favorable sensing platform for the electrochemical studies. In addition, the cyclic voltammetry (CV) studies are used to evaluate the kinetic parameters. - Graphical abstract: Synthesis of sol–gel derived tin dioxide (SnO{sub 2}) nanoparticles grafted in to gaur gum (GG) organic–inorganic hybrid nanocomposite for determination of hydrazine (HZ). Under optimized experimental conditions, SnO{sub 2}-GG/ITO electrode shows, linearity 2–22 mM, and detection limit 2.769 mM with high sensitivity of 5.72 μA cm{sup −2}. The results clearly suggest that SnO{sub 2}-GG

  5. Structure–property relationships in hybrid dental nanocomposite resins containing monofunctional and multifunctional polyhedral oligomeric silsesquioxanes

    Directory of Open Access Journals (Sweden)

    Wang WG

    2014-02-01

    Full Text Available Weiguo Wang,1,* Xiang Sun,1,* Li Huang,2,* Yu Gao,1 Jinghao Ban,1 Lijuan Shen,1 Jihua Chen1 1Department of Prosthodontics, 2Department of General Dentistry and Emergency, School of Stomatology, Fourth Military Medical University, Xi'an, People's Republic of China*These authors contributed equally to this workAbstract: Organic-inorganic hybrid materials, such as polyhedral oligomeric silsesquioxanes (POSS, have the potential to improve the mechanical properties of the methacrylate-based composites and resins used in dentistry. In this article, nanocomposites of methacryl isobutyl POSS (MI-POSS [bears only one methacrylate functional group] and methacryl POSS (MA-POSS [bears eight methacrylate functional groups] were investigated to determine the effect of structures on the properties of dental resin. The structures of the POSS-containing networks were determined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy. Monofunctional POSS showed a strong tendency toward aggregation and crystallization, while multifunctional POSS showed higher miscibility with the dimethacrylate monomer. The mechanical properties and wear resistance decreased with increasing amounts of MI-POSS, indicating that the MI-POSS agglomerates act as the mechanical weak point in the dental resins. The addition of small amounts of MA-POSS improved the mechanical and shrinkage properties. However, samples with a higher MA-POSS concentration showed lower flexural strength and flexural modulus, indicating that there is a limited range in which the reinforcement properties of MA-POSS can operate. This concentration dependence is attributed to phase separation at higher concentrations of POSS, which affects the structural integrity, and thus, the mechanical and shrinkage properties of the dental resin. Our results show that resin with 3% MA-POSS is a potential candidate for resin-based dental materials

  6. Preparation and Characterization of Hybrid Nanocomposite of Polyacrylamide/Silica-Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ahmad Rabiee

    2013-01-01

    Full Text Available Polyacrylamides are water soluble macromolecules. These polymers are widely used for flocculation, separation and treatment of solid-liquid phase materials. In this research, organic-inorganic hybrid of polyacrylamide/silica nanoparticle is prepared via radical polymerization. First, the silica nanoparticle surfaces were modified by 3-methacryloxypropyltrimethoxysilane as coupling agent using a sol-gel technique in aqueous media in acidic condition. Afterwards, the modified nanoparticles are copolymerized by acrylamide monomer in presence of a peroxide initiator during a free radical polymerization. The chemical structure of the prepared modified nano-silica as well as polyacrylamide nanocomposite was studied and confirmed by FTIR spectroscopy technique. The morphology of nanocomposite was investigated by scanning electron microscopy. The SEM micrograph showed that the surface of the composite did not display any phase separation. Nanoparticles distribution was investigated by SEM-EDX technique. The results showed a uniform distribution of particles throughout the polymer bulk. TEM analysis showed the presence of silica nanoparticles in bulk of polymer which is an indicative of suitable dispersion of nanoparticles. The thermal stability of hybrid nanocomosite with that of polyacrylamide was compared by TGA technique. The higher thermal stability of hybrid nanocomposite with respect to homopolymer is indicative of a reaction between the modified nanoparticles and polyacrylamide chain. The presence of silica particles in copolymer was also confirmed with EDX analysis in ash content of hybrid nanocomposite.

  7. The Effect of Clay/Multiwall Carbon Nanotube Hybrid Fillers on the Properties of Elastomer Nanocomposites

    Directory of Open Access Journals (Sweden)

    Sung Ho Song

    2018-01-01

    Full Text Available The hybrid fillers of 1D multiwalled carbon nanotubes (MWNT and 2D montmorillonite (MMT have led to excellent physical and chemical properties in high performance elastomer nanocomposites. In this study, the hybridization of PDDA (polydiallyldimethylammonium chloride functionalized MWNT (P-MWNT and hydroxyl-functionalized MMT (H-MMT was prepared by the electrostatic interaction between the positive charge on the MWNT and the negative charge on the MMT using a simple solution mixing process. Also, a styrene-butadiene rubber (SBR nanocomposite containing the hybrid nanofillers was prepared to improve the dispersion of nanofillers with SBR latex. The SBR nanocomposites with the hybrid nanofillers exhibited outstanding mechanical properties including modulus, tensile strength, and elongation at break, due to the enhanced interfacial bonding with the elastomer matrix. Furthermore, the hybrid nanofillers in the SBR matrix showed superior thermal and electrical properties and gas barrier performance at low loadings. The synergistic effects of the SBR produced by the hybridized nanofillers will open up new opportunities for elastomer composites with high performance.

  8. Characterization of SWNT based Polystyrene Nanocomposites

    Science.gov (United States)

    Mitchell, Cynthia; Bahr, Jeffrey; Tour, James; Arepalli, Sivaram; Krishnamoorti, Ramanan

    2003-03-01

    Polystyrene nanocomposites with functionalized single walled carbon nanotubes (SWNTs), prepared by the in-situ generation and addition of organic diazonium compounds, were characterized using a range of structural and dynamic methods. These were contrasted to the properties of polystyrene composites prepared with unfunctionalized SWNTs at the same loadings. The functionalized nanocomposites demonstrated a percolated SWNT network structure at concentrations of 1 vol SWNT based composites at similar loadings of SWNT exhibited behavior comparable to that of the unfilled polymer. This formation of the SWNT network structure is because of the improved compatibility between the SWNTs and the polymer matrix due to the functionalization. Further structural evidence for the compatibility of the modified SWNTs and the polymer matrix will be discussed in the presentation.

  9. Helix-sense-selective co-precipitation for preparing optically active helical polymer nanoparticles/graphene oxide hybrid nanocomposites.

    Science.gov (United States)

    Huang, Huajun; Li, Weifei; Shi, Yan; Deng, Jianping

    2017-05-25

    Constructing optically active helical polymer based nanomaterials without using expensive and limited chirally helical polymers has become an extremely attractive research topic in both chemical and materials science. In this study, we prepared a series of optically active helical polymer nanoparticles/graphene oxide (OAHPNs/GO) hybrid nanocomposites through an unprecedented strategy-the co-precipitation of optically inactive helical polymers and chirally modified GO. This approach is named helix-sense-selective co-precipitation (HSSCP), in which the chirally modified GO acted as a chiral source for inducing and further stabilizing the predominantly one-handed helicity in the optically inactive helical polymers. SEM and TEM images show quite similar morphologies of all the obtained OAHPNs/GO nanocomposites; specifically, the chirally modified GO sheets were uniformly decorated with spherical polymer nanoparticles. Circular dichroism (CD) and UV-vis absorption spectra confirmed the preferentially induced helicity in the helical polymers and the optical activity of the nanocomposites. The established HSSCP strategy is thus proven to be widely applicable and is expected to produce numerous functional OAHPNs/GO nanocomposites and even the analogues.

  10. Developing the photovoltaic performance of dye-sensitized solar cells (DSSCs) using a SnO2-doped graphene oxide hybrid nanocomposite as a photo-anode

    Science.gov (United States)

    Sasikumar, Ragu; Chen, Tse-Wei; Chen, Shen-Ming; Rwei, Syang-Peng; Ramaraj, Sayee Kannan

    2018-05-01

    Tin(IV) oxide nanoparticles (SnO2 NPs) doped on the surface of graphene oxide (GO) sheets for application in Dye-Sensitized Solar Cells (DSSCs). The effective incorporation of SnO2 on the surface of GO sheets were confirmed by powder X-ray diffraction (PXRD), Fourier transform infra-red spectroscopy (FT-IR), thermogravimetric analysis (TGA), electrochemical impedance spectroscopy (EIS), and Raman spectroscopy. The morphology of the GO/SnO2 hybrid nanocomposite was confirmed by field emission scanning electron microscopy (FE-SEM) analysis. This current study involvement with the effect of different photo-anodes such as GO, SnO2, and GO/SnO2 hybrid nanocomposite on the power conversion efficiency (PCE) of the triiodide electrolyte based DSSCs. Remarkably, GO/SnO2 hybrid nanocomposite based photo-anode for DSSC observed PCE of 8.3% and it is about 12% higher than that of un-doped TiO2 photo-anode. The equivalent short-circuit photocurrent density (Jsc) of 16.67 mA cm-2, open circuit voltage (Voc) of 0.77 V, and fill factor (FF) of 0.65 respectively. The achieved results propose that the hybrid nanocomposite is an appropriate photo-anodic material for DSSCs applications.

  11. Solution-based colloidal synthesis of hybrid P3HT: Ternary CuInSe2 nanocomposites using a novel combination of capping agents for low-cost photovoltaics

    Science.gov (United States)

    Sharma, Shailesh Narain; Chawla, Parul; Akanksha; Srivastava, A. K.

    2016-06-01

    In this work, ternary CuInSe2 (CISe) chalcopyrite nanocrystallites efficiently passivated by a novel combination of capping agents viz: aniline and 1-octadecene during chemical route synthesis were dispersed in conducting polymer matrix poly(3-hexylthiophene) (P3HT). By varying the composition and concentration of the ligands, the properties of the resulting CISe nanocrystallites and its corresponding polymer nanocomposites thus could be tailored. The structural, morphological and optical studies accomplished by various complimentary techniques viz. Transmission Electron Microscopy (TEM), Contact angle, Photoluminescence (PL) and Raman have enabled us to compare the different hybrid organic (polymer)-inorganic nanocomposites. On the basis of aniline-octadecene equilibrium phase diagram, the polydispersity of the CISe nanocrystals could be tuned by using controlled variations in the reaction conditions of nucleation and growth such as composition of the solvent and temperature. To the best of author's knowledge, the beneficial effects of both the capping agents; aniline and octadecene contributing well in tandem in the development of large-sized (100-125 nm) high quality, sterically- and photo-oxidative stable polycrystalline CISe and its corresponding polymer (P3HT):CISe composites with enhanced charge transfer efficiency has been reported for the first time. The low-cost synthesis and ease of preparation renders this method of great potential for its possible application in low-cost hybrid organic-inorganic photovoltaics. The figure shows the Temperature vs Mole fraction graph of two different phases (aniline and 1-octadecene) in equilibrium.

  12. Low temperature superparamagnetic nanocomposites obtained by Fe(acac3-SiO2-PVA hybrid xerogel thermolysis

    Directory of Open Access Journals (Sweden)

    Catalin Ianasi

    2016-12-01

    Full Text Available Fe(acac3/silica/PVA hybrid xerogel nanocomposite was obtained by one pot acid catalysed sol-gel synthesis using the homogeneous mixture of iron(III acetylacetonate (Fe(acac3, tetraethylorthosilicate (TEOS, and polyvinyl alcohol (PVA. Nominal composition ratio of iron oxide/silica was 15/85 (weight percent. Nitric acid was used as catalyst. Another sample of Fe(acac3/silica xerogel without PVA addition was prepared in the similar processing conditions. Based on thermal analysis studies, the thermal behaviour of both xerogel samples was unveiled and it allowed choosing the optimal calcination temperatures in order to obtain iron oxide silica magnetic nanocomposite samples. The two xerogel (with and without PVA samples were thermally treated, in air, at 220, 260 and 300 °C and characterized by different techniques. XRD investigations revealed phase composition evolution with calcination temperature, from cubic spinel phase (maghemite to hexagonal stable hematite containing nanocomposite of 10–20 nm average crystallite size. These findings were confirmed by Mössbauer spectroscopy. Up to 300 °C, the surface area and total pores volume increased with temperature for all samples. By calcination at the same temperature, the hybrid xerogel containing PVA resulted in significantly higher magnetization and free volume values in comparison with the sample without PVA.

  13. Crafting semiconductor organic-inorganic nanocomposites via placing conjugated polymers in intimate contact with nanocrystals for hybrid solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lei; Lin, Zhiqun [School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA (United States)

    2012-08-22

    Semiconductor organic-inorganic hybrid solar cells incorporating conjugated polymers (CPs) and nanocrystals (NCs) offer the potential to deliver efficient energy conversion with low-cost fabrication. The CP-based photovoltaic devices are complimented by an extensive set of advantageous characteristics from CPs and NCs, such as lightweight, flexibility, and solution-processability of CPs, combined with high electron mobility and size-dependent optical properties of NCs. Recent research has witnessed rapid advances in an emerging field of directly tethering CPs on the NC surface to yield an intimately contacted CP-NC nanocomposite possessing a well-defined interface that markedly promotes the dispersion of NCs within the CP matrix, facilitates the photoinduced charge transfer between these two semiconductor components, and provides an effective platform for studying the interfacial charge separation and transport. In this Review, we aim to highlight the recent developments in CP-NC nanocomposite materials, critically examine the viable preparative strategies geared to craft intimate CP-NC nanocomposites and their photovoltaic performance in hybrid solar cells, and finally provide an outlook for future directions of this extraordinarily rich field. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    Directory of Open Access Journals (Sweden)

    Minh-Tai Le

    2015-08-01

    Full Text Available In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA and thermogravimetric analysis (TGA are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg, as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs.

  15. Thermal and Mechanical Behavior of Hybrid Polymer Nanocomposite Reinforced with Graphene Nanoplatelets

    Science.gov (United States)

    Le, Minh-Tai; Huang, Shyh-Chour

    2015-01-01

    In the present investigation, we successfully fabricate a hybrid polymer nanocomposite containing epoxy/polyester blend resin and graphene nanoplatelets (GNPs) by a novel technique. A high intensity ultrasonicator is used to obtain a homogeneous mixture of epoxy/polyester resin and graphene nanoplatelets. This mixture is then mixed with a hardener using a high-speed mechanical stirrer. The trapped air and reaction volatiles are removed from the mixture using high vacuum. The hot press casting method is used to make the nanocomposite specimens. Tensile tests, dynamic mechanical analysis (DMA) and thermogravimetric analysis (TGA) are performed on neat, 0.2 wt %, 0.5 wt %, 1 wt %, 1.5 wt % and 2 wt % GNP-reinforced epoxy/polyester blend resin to investigate the reinforcement effect on the thermal and mechanical properties of the nanocomposites. The results of this research indicate that the tensile strength of the novel nanocomposite material increases to 86.8% with the addition of a ratio of graphene nanoplatelets as low as 0.2 wt %. DMA results indicate that the 1 wt % GNP-reinforced epoxy/polyester nanocomposite possesses the highest storage modulus and glass transition temperature (Tg), as compared to neat epoxy/polyester or the other nanocomposite specimens. In addition, TGA results verify thethermal stability of the experimental specimens, regardless of the weight percentage of GNPs. PMID:28793521

  16. Graphene oxide - Polyvinyl alcohol nanocomposite based electrode material for supercapacitors

    Science.gov (United States)

    Pawar, Pranav Bhagwan; Shukla, Shobha; Saxena, Sumit

    2016-07-01

    Supercapacitors are high capacitive energy storage devices and find applications where rapid bursts of power are required. Thus materials offering high specific capacitance are of fundamental interest in development of these electrochemical devices. Graphene oxide based nanocomposites are mechanically robust and have interesting electronic properties. These form potential electrode materials efficient for charge storage in supercapacitors. In this perspective, we investigate low cost graphene oxide based nanocomposites as electrode material for supercapacitor. Nanocomposites of graphene oxide and polyvinyl alcohol were synthesized in solution phase by integrating graphene oxide as filler in polyvinyl alcohol matrix. Structural and optical characterizations suggest the formation of graphene oxide and polyvinyl alcohol nanocomposites. These nanocomposites were found to have high specific capacitance, were cyclable, ecofriendly and economical. Our studies suggest that nanocomposites prepared by adding 0.5% wt/wt of graphene oxide in polyvinyl alcohol can be used an efficient electrode material for supercapacitors.

  17. Improvement of Fracture Toughness in Epoxy Nanocomposites through Chemical Hybridization of Carbon Nanotubes and Alumina.

    Science.gov (United States)

    Zakaria, Muhammad Razlan; Abdul Kudus, Muhammad Helmi; Md Akil, Hazizan; Zamri, Mohd Hafiz

    2017-03-16

    The current study investigated the effect of adding a carbon nanotube-alumina (CNT-Al₂O₃) hybrid on the fracture toughness of epoxy nanocomposites. The CNT-Al₂O₃ hybrid was synthesised by growing CNTs on Al₂O₃ particles via the chemical vapour deposition method. The CNTs were strongly attached onto the Al₂O₃ particles, which served to transport and disperse the CNTs homogenously, and to prevent agglomeration in the CNTs. The experimental results demonstrated that the CNT-Al₂O₃ hybrid-filled epoxy nanocomposites showed improvement in terms of the fracture toughness, as indicated by an increase of up to 26% in the critical stress intensity factor, K 1 C , compared to neat epoxy.

  18. Preparation and properties of poly(vinylidene fluoride nanocomposites blended with graphene oxide coated silica hybrids

    Directory of Open Access Journals (Sweden)

    Q. Fu

    2012-04-01

    Full Text Available Graphene oxide coated silica hybirds (SiO2-GO were fabricated through electrostatic assembly in this work, then blended with poly(vinylidene fluoride (PVDF by solution mixing to make PVDF nanocomposites. The interfacial interaction was investigated by scanning electron microscopy (SEM, polarized optical microscopy (POM and Fourier transform infrared spectroscopy (FTIR. The results showed that the interfacial interaction was enhanced by adding of SiO2-GO and strong hydrogen bonds were observed. The as-made nanocomposites were investigated using standard tensile test and dynamic mechanical analysis (DMA measurements, mechanical properties of PVDF with SiO2-GO hybrids showed limited improvement.

  19. HybridSil Icephobic Nanocomposites for Next Generation Aircraft In-Flight Icing Measurement and Mitigation, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this SBIR program is to adapt NanoSonic's HybridSil® nanocomposites and combine high erosion resistance, low ice adhesion, and passive anti-icing...

  20. Biopolymer based nanocomposites reinforced with graphene nanoplatelets

    Energy Technology Data Exchange (ETDEWEB)

    Botta, L.; Scaffaro, R.; Mistretta, M. C.; La Mantia, F. P. [Dipartimento di Ingegneria Civile, Ambientale, Aerospaziale, dei Materiali, Università di Palermo, UdR INSTM di Palermo, Viale delle Scienze, 90128 Palermo (Italy)

    2016-05-18

    In this work, biopolymer based nanocomposites filled with graphene nanoplatelets (GnP) were prepared by melt compounding in a batch mixer. The polymer used as matrix was a commercial biodegradable polymer-blend of PLA and a copolyester (BioFlex®). The prepared materials were characterized by scanning electron microscopy (SEM), rheological and mechanical measurements. Moreover, the effect of the GnP amount on the investigated properties was evaluated. The results indicated that the incorporation of GnP increased the stiffness of the biopolymeric matrix.

  1. Atomistic simulation of graphene-based polymer nanocomposites

    International Nuclear Information System (INIS)

    Rissanou, Anastassia N.; Bačová, Petra; Harmandaris, Vagelis

    2016-01-01

    Polymer/graphene nanostructured systems are hybrid materials which have attracted great attention the last years both for scientific and technological reasons. In the present work atomistic Molecular Dynamics simulations are performed for the study of graphene-based polymer nanocomposites composed of pristine, hydrogenated and carboxylated graphene sheets dispersed in polar (PEO) and nonpolar (PE) short polymer matrices (i.e., matrices containing chains of low molecular weight). Our focus is twofold; the one is the study of the structural and dynamical properties of short polymer chains and the way that they are affected by functionalized graphene sheets while the other is the effect of the polymer matrices on the behavior of graphene sheets.

  2. Linear and Nonlinear Rheology Combined with Dielectric Spectroscopy of Hybrid Polymer Nanocomposites for Semiconductive Applications

    Directory of Open Access Journals (Sweden)

    Roland Kádár

    2017-01-01

    Full Text Available The linear and nonlinear oscillatory shear, extensional and combined rheology-dielectric spectroscopy of hybrid polymer nanocomposites for semiconductive applications were investigated in this study. The main focus was the influence of processing conditions on percolated poly(ethylene-butyl acrylate (EBA nanocomposite hybrids containing graphite nanoplatelets (GnP and carbon black (CB. The rheological response of the samples was interpreted in terms of dispersion properties, filler distortion from processing, filler percolation, as well as the filler orientation and distribution dynamics inside the matrix. Evidence of the influence of dispersion properties was found in linear viscoelastic dynamic frequency sweeps, while the percolation of the nanocomposites was detected in nonlinearities developed in dynamic strain sweeps. Using extensional rheology, hybrid samples with better dispersion properties lead to a more pronounced strain hardening behavior, while samples with a higher volume percentage of fillers caused a drastic reduction in strain hardening. The rheo-dielectric time-dependent response showed that in the case of nanocomposites containing only GnP, the orientation dynamics leads to non-conductive samples. However, in the case of hybrids, the orientation of the GnP could be offset by the dispersing of the CB to bridge the nanoplatelets. The results were interpreted in the framework of a dual PE-BA model, where the fillers would be concentrated mainly in the BA regions. Furthermore, better dispersed hybrids obtained using mixing screws at the expense of filler distortion via extrusion processing history were emphasized through the rheo-dielectric tests.

  3. Theoretical studies on the possible sensitizers of DSSC: Nanocomposites of graphene quantum dot hybrid phthalocyanine/tetrabenzoporphyrin/tetrabenzotriazaporphyrins/cis-tetrabenzodiazaporphyrins/tetrabenzomonoazaporphyrins and their Cu-metallated macrocycles

    Science.gov (United States)

    Gao, Feng; Yang, Chuan-Lu; Wang, Mei-Shan; Ma, Xiao-Guang; Liu, Wen-Wang

    2018-04-01

    The feasibility of nanocomposites of cir-coronene graphene quantum dot (GQD) with phthalocyanine, tetrabenzoporphyrin, tetrabenzotriazaporphyrins, cis-tetrabenzodiazaporphyrins, tetrabenzomonoazaporphyrins and their Cu-metallated macrocycles as a sensitizer of dye-sensitized solar cells (DSSC) are investigated. Based on the first principles density functional theory (DFT), the geometrical structures of the separate GQD and 10 macrocycles, and their hybridized nanocomposites are fully optimized. The energy stabilities of the obtained structures are confirmed by harmonic frequency analysis. The optical absorptions of the optimized structures are calculated with time-dependent DFT. The feasibility of the nanocomposites as the sensitizer of DSSC is examined by the charge spatial separation, the electron transfer, the molecular orbital energy levels of the nanocomposites and the electrolyte, and the conduction band minimum of TiO2 electrode. The results demonstrate that all the nanocomposites have enhanced absorptions in the visible light range, and their molecular orbital energies satisfy the requirement of sensitizers. However, only two of the ten considered nanocomposites demonstrate significantly charge spatial separation. The GQD-Cu-TBP is identified as the most favorable candidate sensitizer of DSSC by the most enhanced in optical absorption, obvious charge spatial separation, suitable LUMO energy levels and driving force for electron transfer, and low recombination rate of electron and hole.

  4. Synthesis and Investigation of Carbon-Based Nanocomposites for Supercapacitors

    OpenAIRE

    LI WAN

    2018-01-01

    Carbon-based nanocomposites were synthesized for high-performance supercapacitors. The coalition between each of the constituent in the nanocomposites and the performance was investigated. Continuous efforts have been put to improve the supercapacitor assembly techniques from conventional supercapacitor to all-solid-state supercapacitor and to binder-free supercapacitor.

  5. Silicon nanowires in polymer nanocomposites for photovoltaic hybrid thin films

    International Nuclear Information System (INIS)

    Ben Dkhil, S.; Bourguiga, R.; Davenas, J.; Cornu, D.

    2012-01-01

    Highlights: ► Hybrid solar cells based on blends of poly(N-vinylcarbazole) and silicon nanowires have been fabricated. ► We have investigated the charge transfer between PVK and SiNWs by the way of the quenching of the PVK photoluminescence. ► The relation between the morphology of the composite thin films and the charge transfer between SiNWs and PVK has been examined. ► We have investigated the effects of SiNWs concentration on the photovoltaic characteristics leading to the optimization of a critical SiNWs concentration. - Abstract: Hybrid thin films combining the high optical absorption of a semiconducting polymer film and the electronic properties of silicon fillers have been investigated in the perspective of the development of low cost solar cells. Bulk heterojunction photovoltaic materials based on blends of a semiconductor polymer poly(N-vinylcarbazole) (PVK) as electron donor and silicon nanowires (SiNWs) as electron acceptor have been studied. Composite PVK/SiNWs films were cast from a common solvent mixture. UV–visible spectrometry and photoluminescence of the composites have been studied as a function of the SiNWs concentration. Photoluminescence spectroscopy (PL) shows the existence of a critical SiNWs concentration of about 10 wt % for PL quenching corresponding to the most efficient charge pair separation. The photovoltaic (PV) effect has been studied under illumination. The optimum open-circuit voltage V oc and short-circuit current density J sc are obtained for 10 wt % SiNWs whereas a degradation of these parameters is observed at higher SiNWs concentrations. These results are correlated to the formation of aggregates in the composite leading to recombination of the photogenerated charge pairs competing with the dissociation mechanism.

  6. New type of protective hybrid and nanocomposite hybrid coatings containing silver and copper with an excellent antibacterial effect especially against MRSA

    Energy Technology Data Exchange (ETDEWEB)

    Slamborova, Irena [Centre for Nanomaterials, Advanced Technologies and Innovations, Studentska 1402/2, 461 17 Liberec 1 (Czech Republic); Zajicova, Veronika, E-mail: veronika.zajicova@tul.cz [Centre for Nanomaterials, Advanced Technologies and Innovations, Studentska 1402/2, 461 17 Liberec 1 (Czech Republic); Karpiskova, Jana [Institute of Novel Technologies and Applied Informatics, Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Studentska 2, 461 17 Liberec 1 (Czech Republic); Exnar, Petr; Stibor, Ivan [Centre for Nanomaterials, Advanced Technologies and Innovations, Studentska 1402/2, 461 17 Liberec 1 (Czech Republic)

    2013-01-01

    Epidemics spread many types of pathogenic bacterial strains, especially strains of MRSA (Methicillin-resistant Staphylococcus aureus), which are being increasingly reported in many geographical areas [1]. This is becoming to be a serious global problem, particularly in hospitals. Not only are antibiotics proving to be increasingly ineffective but also the bacteria responsible for more than 70% of hospital-acquired bacterial infections are resistant to at least one of the drugs commonly used to treat them. In this study, hybrid coating A1 and nanocomposite hybrid coating A2 based on TMSPM (3-(trimethoxysilyl)propyl methacrylate, MMA (methyl methacrylate), TEOS (tetraethyl orthosilicate) and IPTI (titanium isopropoxide) containing silver and copper ions with or without nanoparticles of titanium dioxide were prepared by the sol-gel method. They were deposited on glass, poly(methyl methacrylate) and cotton using dip-coating or spin-coating, and then cured at 150 Degree-Sign C for 3 h or, in the case of poly(methyl methacrylate), at 100 Degree-Sign C for 4.5 h. The morphology and microstructure of these hybrid coatings were examined by SEM. The abrasion resistance was tested using a washability tester and found to depend heavily on the curing temperature. Seven types of bacterial strains were used to determine the profile of antibacterial activity, namely Escherichia coli, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus - MRSA (CCM 4223), MRSA-2 (CCM 7112), Acinetobacter baumanii, Pseudomonas aeruginosa, and Proteus vulgaris (according to ALE-G18, CSNI). All the samples were tested by irradiating with either a UV-A or a daylight fluorescent lamp. All types of hybrid coating A1 and nanocomposite hybrid coating A2 were found to possess an excellent antibacterial effect, including against the pathogenic bacterial strains of MRSA, which present a dangerous threat on a global scale.

  7. New type of protective hybrid and nanocomposite hybrid coatings containing silver and copper with an excellent antibacterial effect especially against MRSA

    International Nuclear Information System (INIS)

    Šlamborová, Irena; Zajícová, Veronika; Karpíšková, Jana; Exnar, Petr; Stibor, Ivan

    2013-01-01

    Epidemics spread many types of pathogenic bacterial strains, especially strains of MRSA (Methicillin-resistant Staphylococcus aureus), which are being increasingly reported in many geographical areas [1]. This is becoming to be a serious global problem, particularly in hospitals. Not only are antibiotics proving to be increasingly ineffective but also the bacteria responsible for more than 70% of hospital-acquired bacterial infections are resistant to at least one of the drugs commonly used to treat them. In this study, hybrid coating A1 and nanocomposite hybrid coating A2 based on TMSPM (3-(trimethoxysilyl)propyl methacrylate, MMA (methyl methacrylate), TEOS (tetraethyl orthosilicate) and IPTI (titanium isopropoxide) containing silver and copper ions with or without nanoparticles of titanium dioxide were prepared by the sol–gel method. They were deposited on glass, poly(methyl methacrylate) and cotton using dip-coating or spin-coating, and then cured at 150 °C for 3 h or, in the case of poly(methyl methacrylate), at 100 °C for 4.5 h. The morphology and microstructure of these hybrid coatings were examined by SEM. The abrasion resistance was tested using a washability tester and found to depend heavily on the curing temperature. Seven types of bacterial strains were used to determine the profile of antibacterial activity, namely Escherichia coli, Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus — MRSA (CCM 4223), MRSA-2 (CCM 7112), Acinetobacter baumanii, Pseudomonas aeruginosa, and Proteus vulgaris (according to ALE-G18, CSNI). All the samples were tested by irradiating with either a UV-A or a daylight fluorescent lamp. All types of hybrid coating A1 and nanocomposite hybrid coating A2 were found to possess an excellent antibacterial effect, including against the pathogenic bacterial strains of MRSA, which present a dangerous threat on a global scale.

  8. Graphene/CuS/ZnO hybrid nanocomposites for high performance photocatalytic applications

    International Nuclear Information System (INIS)

    Varghese, Jini; Varghese, K.T.

    2015-01-01

    We herein report a novel, high performance ternary nanocomposite composed of Graphene doped with nano Copper Sulphide and Zinc Oxide nanotubes (GCZ) for photodegradation of organic pollutants. Investigations were made to estimate and compare the Methyl Orange dye (MO) degradation using GCZ, synthesized pristine Graphene (Gr) and Graphene–ZnO hybrid nanocomposite (GZ) under UV light irradiations. The synthesis of nanocomposites involves the simple ultra-sonication and mixing methods. The nanocomposites were characterized using transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Raman spectroscopy, UV–vis absorption spectroscopy and Brunauer–Emmett–Teller (BET) surface area method. The as synthesized GCZ shows better surface area, porosity and band gap energy than as synthesized Gr and GZ. The photocatalytic degradation of methyl orange dye follows as Gr  > GZ due to the stronger adsorbability, large number of photo induced electrons and highest inhibition of charge carrier's recombination of GCZ. The kinetic investigation demonstrates that dye degradation exhibit the pseudo first order kinetic model with rate constant 0.1322, 0.049 and0.0109 min"−"1 corresponding to GCZ, GZ and Gr. The mechanism of dye degradation in presence of photocatalyst is also discussed. This study confirms that GCZ is a more promising material for high performance catalytic applications especially in the dye waste water purification. - Highlights: • Graphene–CuS–ZnO hybrid composites show better surface area, porosity and adsorbability. • CuS–ZnO hybrid nanostructure highly enhanced the photocatalytic activity of Graphene. • Graphene–CuS–ZnO hybrid composites show superior photocatalytic efficiency, rate constant and quantum yield.

  9. Graphene/CuS/ZnO hybrid nanocomposites for high performance photocatalytic applications

    Energy Technology Data Exchange (ETDEWEB)

    Varghese, Jini, E-mail: jini.nano@gmail.com; Varghese, K.T., E-mail: ktvscs@gmail.com

    2015-11-01

    We herein report a novel, high performance ternary nanocomposite composed of Graphene doped with nano Copper Sulphide and Zinc Oxide nanotubes (GCZ) for photodegradation of organic pollutants. Investigations were made to estimate and compare the Methyl Orange dye (MO) degradation using GCZ, synthesized pristine Graphene (Gr) and Graphene–ZnO hybrid nanocomposite (GZ) under UV light irradiations. The synthesis of nanocomposites involves the simple ultra-sonication and mixing methods. The nanocomposites were characterized using transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Raman spectroscopy, UV–vis absorption spectroscopy and Brunauer–Emmett–Teller (BET) surface area method. The as synthesized GCZ shows better surface area, porosity and band gap energy than as synthesized Gr and GZ. The photocatalytic degradation of methyl orange dye follows as Gr <<< GCZ >> GZ due to the stronger adsorbability, large number of photo induced electrons and highest inhibition of charge carrier's recombination of GCZ. The kinetic investigation demonstrates that dye degradation exhibit the pseudo first order kinetic model with rate constant 0.1322, 0.049 and0.0109 min{sup −1} corresponding to GCZ, GZ and Gr. The mechanism of dye degradation in presence of photocatalyst is also discussed. This study confirms that GCZ is a more promising material for high performance catalytic applications especially in the dye waste water purification. - Highlights: • Graphene–CuS–ZnO hybrid composites show better surface area, porosity and adsorbability. • CuS–ZnO hybrid nanostructure highly enhanced the photocatalytic activity of Graphene. • Graphene–CuS–ZnO hybrid composites show superior photocatalytic efficiency, rate constant and quantum yield.

  10. Hybrid metallic nanocomposites for extra wear-resistant diamond machining tools

    DEFF Research Database (Denmark)

    Loginov, P.A.; Sidorenko, D.A.; Levashov, E.A.

    2018-01-01

    The applicability of metallic nanocomposites as binder for diamond machining tools is demonstrated. The various nanoreinforcements (carbon nanotubes, boron nitride hBN, nanoparticles of tungsten carbide/WC) and their combinations are embedded into metallic matrices and their mechanical properties...... are determined in experiments. The wear resistance of diamond tools with metallic binders modified by various nanoreinforcements was estimated. 3D hierarchical computational finite element model of the tool binder with hybrid nanoscale reinforcements is developed, and applied for the structure...

  11. Nanocomposite metal amorphous-carbon thin films deposited by hybrid PVD and PECVD technique.

    Science.gov (United States)

    Teixeira, V; Soares, P; Martins, A J; Carneiro, J; Cerqueira, F

    2009-07-01

    Carbon based films can combine the properties of solid lubricating graphite structure and hard diamond crystal structure, i.e., high hardness, chemical inertness, high thermal conductivity and optical transparency without the crystalline structure of diamond. Issues of fundamental importance associated with nanocarbon coatings are reducing stress, improving adhesion and compatibility with substrates. In this work new nanocomposite coatings with improved toughness based in nanocrystalline phases of metals and ceramics embedded in amorphous carbon matrix are being developed within the frame of a research project: nc-MeNxCy/a-C(Me) with Me = Mo, Si, Al, Ti, etc. Carbide forming metal/carbon (Me/C) composite films with Me = Mo, W or Ti possess appropriate properties to overcome the limitation of pure DLC films. These novel coating architectures will be adopted with the objective to decrease residual stress, improve adherence and fracture toughness, obtain low friction coefficient and high wear-resistance. Nanocomposite DLC's films were deposited by hybrid technique using a PVD-Physically Vapor Deposition (magnetron sputtering) and Plasma Enhanced Chemical Vapor Deposition (PECVD), by the use of CH4 gas. The parameters varied were: deposition time, substrate temperature (180 degrees C) and dopant (Si + Mo) of the amorphous carbon matrix. All the depositions were made on silicon wafers and steel substrates precoated with a silicon inter-layer. The characterisation of the film's physico-mechanical properties will be presented in order to understand the influence of the deposition parameters and metal content used within the a-C matrix in the thin film properties. Film microstructure and film hybridization state was characterized by Raman Spectroscopy. In order to characterize morphology SEM and AFM will be used. Film composition was measured by Energy-Dispersive X-ray analysis (EDS) and by X-ray photoelectron spectroscopy (XPS). The contact angle for the produced DLC's on

  12. Bioinspired Nanocellulose Based Hybrid Materials With Novel Interfacial Properties

    Science.gov (United States)

    Keten, Sinan

    This talk will overview a simulation-based approach to enhancing the mechanical properties of nanocomposites by utilizing cellulose - the most abundant and renewable structural biopolymer found on our planet. Cellulose nanocrystals (CNCs) exhibit outstanding mechanical properties exceeding that of Kevlar, serving as reinforcing domains in nature's toughest hierarchical nanocomposites such as wood. Yet, weak interfaces at the surfaces of CNCs have so far made it impossible to scale these inherent properties to macroscopic systems. In this work, I will discuss how surface functionalization of CNCs influences their properties in their self-assembled films and nanocomposites with engineered polymer matrices . Specifically, the role of ion exchange based surface modifications and polymer conjugation will be discussed, where atomistic and coarse-grained simulations will reveal new insights into how superior mechanical properties can potentially be attained by hybrid constructs.

  13. Evaluation of clay hybrid nanocomposites of different chain length as reinforcing agent for natural and synthetic rubbers

    International Nuclear Information System (INIS)

    Yehia, A.A.; Akelah, A.M.; Rehab, A.; El-Sabbagh, S.H.; El Nashar, D.E.; Koriem, A.A.

    2012-01-01

    Highlights: → The modified organo-clay (MMT-ATBN) markedly reinforce natural and synthetic rubbers. → The reinforcing efficiency of the organo-clay is much higher than HAF carbon black. → The reinforcing efficiency of MMT modified with different alkylamines greatly depend on the chain length. → The good compatibility of modified organo-clay with NBR can be attributed to the chemical nature. -- Abstract: Polymer nanocomposites are one of the highly discussed research topics in recent time. It has been reported in the present paper the preparation and the properties of different nanoclays based on sodium montmorillonite (bentonite) and some organic amines of varying chain lengths (dodecylamine, hexadecylamine and octadecylamine) beside amine-terminated butadiene-acrylonitrile copolymer (ATBN). The hybrid clays have been characterized with the help of Fourier Transform Infrared spectroscopy (FTIR). Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), Wide angle X-ray diffractions (WXRD), and Thermogravimetric analysis (TGA). X-ray results showed that the intergallery distance of the clay is increased as a result of the intercalation of the amines and ATBN. The nanocomposite clays were incorporated in natural and synthetic rubbers (NR, SBR and NBR). The physico-mechanical properties are greatly improved with loading low concentrations of the nanocomposite clays compared with carbon black.

  14. Hybrid Nanocomposites for Efficient Aerospace Structures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA's Advanced Air Vehicles program seeks to improve safety and efficiency through exploration of the value of hybrid composites, guiding utilization of the...

  15. Organic–inorganic hybrid nanocomposite for enhanced photo-sensing of PFO-DBT:MEH-PPV:PC{sub 71}BM blend-based photodetector

    Energy Technology Data Exchange (ETDEWEB)

    Zafar, Qayyum, E-mail: qayyumzafar@siswa.um.edu.my; Najeeb, Mansoor Ani, E-mail: animansoor@um.edu.my [University of Malaya, Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science (Malaysia); Ahmad, Zubair, E-mail: zubairtarar@qu.edu.qa [Qatar University, Department of Electrical Engineering, College of Engineering (Qatar); Sulaiman, Khaulah, E-mail: khaulah@um.edu.my [University of Malaya, Low Dimensional Materials Research Centre (LDMRC), Department of Physics, Faculty of Science (Malaysia)

    2015-09-15

    The sensing parameters of previously reported PFO-DBT:MEH-PPV:PC{sub 71}BM ternary blend-based organic photodetector have been improved in the present study. Improvement has been successfully demonstrated by doping TiO{sub 2} nanoparticles in the PEDOT:PSS thin film. TiO{sub 2} nanoparticles of 50, 100 and 250 nm diameters have initially been dispersed in PEDOT:PSS, and the resulting suspension has been spun coated on glass substrates and subjected to UV/vis and PL study. Thin film of PEDOT:PSS–TiO{sub 2} (100 nm) has shown maximum quenching in PL spectra, along with fairly good visible-light absorption. For further studies, 5 wt% TiO{sub 2} (100 nm) nanoparticles dispersion in PEDOT:PSS has been utilized for the fabrication of ITO/PEDOT:PSS–TiO{sub 2}/PFO-DBT:MEH-PPV:PC{sub 71}BM/Al photodiode. The PEDOT:PSS–TiO{sub 2} suspension has been spun coated onto the ITO substrates primarily and annealed to densify the film by vaporizing water contents in the film. A ternary blend of PFO-DBT:MEH-PPV:PC{sub 71}BM in optimized volumetric ratio has been sequentially spun-cast to serve as a photoactive film. Significantly improved values of the sensing parameters such as responsivity (4 mA/W) and photo-to-dark current ratio (∼6.4 × 10{sup 4}) have also been found. Response/recovery times of the fabricated sensor remain almost the same (<1 s) as previously reported for PFO-DBT:MEH-PPV:PC{sub 71}BM ternary blend.

  16. Vegetable Oil-Based Hyperbranched Thermosetting Polyurethane/Clay Nanocomposites

    Directory of Open Access Journals (Sweden)

    Deka Harekrishna

    2009-01-01

    Full Text Available Abstract The highly branched polyurethanes and vegetable oil-based polymer nanocomposites have been showing fruitful advantages across a spectrum of potential field of applications.Mesua ferreaL. seed oil-based hyperbranched polyurethane (HBPU/clay nanocomposites were prepared at different dose levels by in situ polymerization technique. The performances of epoxy-cured thermosetting nanocomposites are reported for the first time. The partially exfoliated structure of clay layers was confirmed by XRD and TEM. FTIR spectra indicate the presence of H bonding between nanoclay and the polymer matrix. The present investigation outlines the significant improvement of tensile strength, scratch hardness, thermostability, water vapor permeability, and adhesive strength without much influencing impact resistance, bending, and elongation at break of the nanocomposites compared to pristine HBPU thermoset. An increment of two times the tensile strength, 6 °C of melting point, and 111 °C of thermo-stability were achieved by the formation of nanocomposites. An excellent shape recovery of about 96–99% was observed for the nanocomposites. Thus, the formation of partially exfoliated clay/vegetable oil-based hyperbranched polyurethane nanocomposites significantly improved the performance.

  17. Vegetable Oil-Based Hyperbranched Thermosetting Polyurethane/Clay Nanocomposites.

    Science.gov (United States)

    Deka, Harekrishna; Karak, Niranjan

    2009-04-25

    The highly branched polyurethanes and vegetable oil-based polymer nanocomposites have been showing fruitful advantages across a spectrum of potential field of applications. Mesua ferrea L. seed oil-based hyperbranched polyurethane (HBPU)/clay nanocomposites were prepared at different dose levels by in situ polymerization technique. The performances of epoxy-cured thermosetting nanocomposites are reported for the first time. The partially exfoliated structure of clay layers was confirmed by XRD and TEM. FTIR spectra indicate the presence of H bonding between nanoclay and the polymer matrix. The present investigation outlines the significant improvement of tensile strength, scratch hardness, thermostability, water vapor permeability, and adhesive strength without much influencing impact resistance, bending, and elongation at break of the nanocomposites compared to pristine HBPU thermoset. An increment of two times the tensile strength, 6 degrees C of melting point, and 111 degrees C of thermo-stability were achieved by the formation of nanocomposites. An excellent shape recovery of about 96-99% was observed for the nanocomposites. Thus, the formation of partially exfoliated clay/vegetable oil-based hyperbranched polyurethane nanocomposites significantly improved the performance.

  18. Rheological and electrical properties of hybrid nanocomposites of epoxy resins filled with graphite nanoplatelets and carbon black.

    Science.gov (United States)

    Truong, Quang-Trung; Lee, Seon-Suk; Lee, Dai-Soo

    2011-02-01

    Graphite nanoplatelets (GNP) were prepared by microwave irradiation of natural graphites intercalated with ferric chloride in nitromethane (GIC). Intercalated structure of GIC was confirmed by X-ray diffraction patterns. SEM images of GIC after microwave irradiation showed the exfoliation of GIC, the formation of GNPs. Hybrid nanocomposites of bisphenol-A type epoxy resins filled with GNP and a conductive carbon black (CB) were prepared and rheological and electrical properties of the nanocomposites were investigated. Viscosity and electrical surface resistivity of the nanocomposites showed minima at certain mixtures of GNP and CB in the epoxy resins.

  19. Biomimetic synthesis of hybrid nanocomposite scaffolds by freeze

    Indian Academy of Sciences (India)

    The aim of this study is to biomimetically synthesize hydroxyapatite–hydrophilic polymer scaffolds for biomedical applications. This organic–inorganic hybrid has been structurally characterized and reveals a good microstructural control as seen by the SEM analysis and the nanosize of the particulates is confirmed by AFM ...

  20. Hybrid finite elements nanocomposite characterization by stochastic microstructuring

    Science.gov (United States)

    Esteva, Milton

    In this thesis the impact of entangled and non-straight fibers in the determination of the effective elastic and thermal properties of polymer nanocomposite (PNC) is addressed. Most of the models in recent studies assume nanotubes to be well dispersed straight fibers with fixed size. Nonetheless experiments reveal that nanotube formation become wavy during the manufacturing process, due to their high aspect ratio and low bending stiffness. Furthermore, experiments also show that nanotubes come in a variety of diameters and lengths. In the thesis an attempt to model the behavior of entangled fibers is made in which the distributions regarding the nanotube length and diameter are incorporated. First, an approach to generate random microstructures is developed. Then, using the finite element (FE) method with embedded fibers, the effective properties are computed for each of the random microstructures. This approach requires only a regular grid for the FE mesh, circumventing the requisite computationally costly and human labor intensive mesh refinement of ordinary FE in order to capture the local morphology of the composite material. Finally, a Monte Carlo simulation approach is used to obtain statistics of the computed effective physical properties. The numerical results are found in good agreement with experimental data reported in the open literature.

  1. Crystallization behaviour of nanostructured hybrid SiO2-TiO2 gel glasses to nanocomposites.

    Science.gov (United States)

    Tsvetelina, Gerganova; Yordanka, Ivanova; Yuliya, Vueva; Miranda, Salvado Isabel M; Helena, Fernandes Maria

    2010-04-01

    The crystallization behaviour of hybrid SiO2-TiO2 nanocomposites derived from titanosiloxanes by sol-gel method has been investigated depending on the type of siloxane precursor and the pirolysis temperature. The resulting hybrid titanosiloxanes, crosslinked with trimethylsilil isocyanate (nitrogen-modified) or methyltrietoxisilane (carbon-modified), were pirolyzed in an inert atmosphere in the temperature range between 600 to 1100 degrees C in order to form C-(N)-Si-O-TiO2 nanocomposites. By means of XRD, FTIR, 29Si NMR, SEM, TEM and AFM investigations have been established that the transformation of the nanostructured SiO2-TiO2 hybrid materials into nanocomposites as well as the crystalline size depend on the titanium content and the type of cross-linking agents used in the synthesizes.

  2. Conducting polymer nanocomposite-based supercapacitors

    OpenAIRE

    Liew, Soon Yee; Walsh, Darren A.; Chen, George Z.

    2016-01-01

    The use of nanocomposites of electronically-conducting polymers for supercapacitors has increased significantly over the past years, due to their high capacitances and abilities to withstand many charge-discharge cycles. We have recently been investigating the use of nanocomposites of electronically-conducting polymers containing conducting and non-conducting nanomaterials such as carbon nanotubes and cellulose nanocrystals, for use in supercapacitors. In this contribution, we provide a summa...

  3. Metal–carbon nanocomposites based on pyrolysed polyacrylonitrile

    Directory of Open Access Journals (Sweden)

    Irina A. Zaporotskova

    2015-06-01

    Full Text Available The electronic structure and geometry of metal−carbon nanocomposites based on pyrolyzed polyacrylonitrile (PPAN with Cu, Si, Fe, Co and Ni atoms using the DFT method have been theoretically studied. The effect of nitrogen on the stability of PPAN and its conductivity has been determined. The electrophysical properties and structure of metal nanocomposites have been studied using the XFA method. The composites have been produced by IR heating. We suggest that metal−carbon nanocomposites form due to the special processing of the (PAN−MeR samples. Metal nanoparticles are regularly dispersed in the nanocrystalline matrix of PPAN. The conductivity of these metal−carbon nanocomposites has an activation character and varies from 10−1 to 103 Om/cm depending on synthesis temperature (T=600–900 °С. The results of theoretical and experimental research are in a good agreement.

  4. Structural, morphological and Raman studies on hybridized PVDF/BaTiO3 nanocomposites

    Science.gov (United States)

    Rajamanickam, N.; Jayakumar, K.; Ramachandran, K.

    2017-05-01

    Hybridized nanocomposites of polyvinylidene fluoride (PVDF) and nano - barium titanate (BaTiO3) were prepared using the solution casting method for different concentrations of nano-BaTiO3 and were characterized by X-ray diffraction and scanning electron microscopy. The flower like structure for morphology was observed in SEM. Raman analysis showed that the modified BaTiO3 particles, due to higher specific surfaces, induce, predominantly, the crystallization of the electrically active β-phase of PVDF, while the initial micron size particles induce the formation of the most common but non-polar α-crystal form.

  5. Nanoscratching of nylon 66-based ternary nanocomposites

    International Nuclear Information System (INIS)

    Dasari, Aravind; Yu Zhongzhen; Mai Yiuwing

    2007-01-01

    The nanoscratch behavior of nylon 66/SEBS-g-MA/clay ternary nanocomposites produced by different blending protocols with contrasting microstructures is studied by using atomic force and transmission electron microscopy. A standard diamond Berkovich indenter is used for scratching and a low load of 1 mN, along with a low sliding velocity of 1 μm s -1 , are employed for this purpose. It is shown that in order to resist penetration it is more important to have exfoliated clay in the continuous nylon matrix during nanoscratching than to have the clay in the dispersed soft rubber domains. The results obtained also explain the preferred usage of ternary nanocomposites compared to binary nanocomposites, particularly nylon 66/exfoliated clay nanocomposites. This research extends current basic knowledge and provides new insights on the nature of nanoscale processes that occur during nanoscratching of polymer nanocomposites. Critical questions are raised on the relationships between the penetration depth and material deformation and damage left behind the moving indenter

  6. Thermal conductivity and viscosity of hybrid nanfluids prepared with magnetic nanodiamond-cobalt oxide (ND-Co3O4 nanocomposite

    Directory of Open Access Journals (Sweden)

    L. Syam Sundar

    2016-03-01

    Full Text Available Synthesis of magnetic nanodiamond-cobalt oxide (ND-Co3O4 nanocomposite material; preparation of nanofluids and estimation of thermal properties such as thermal conductivity and viscosity has been explained experimentally in this paper. The nanocomposite material has been synthesized by using in-situ growth technique and chemical coprecipitation between cobalt chloride and sodium borohydrate. The various techniques such as XRD, TEM, XPS and VSM have been used to confirm the ND and Co3O4 phase of synthesized nanocomposite. The hybrid nanofluids have been prepared by dispersing synthesized ND-Co3O4 nanocomposite in water, ethylene glycol/water mixtures. The thermal properties such as thermal conductivity and viscosity have been measured experimentally at different weight concentrations and temperatures. The results reveal that the thermal conductivity enhancements are about 16%, 9%, 14%, 11% and 10% for water, EG, 20:80%, 40:60%, and 60:40% EG/W based nanofluids at 0.15 wt% concentrations and at 60 °C respectively. Similarly the viscosity enhancements are about 1.45-times, 1.46-times, 1.15-times, 1.19-times, and 1.51-times for water, EG, 20:80%, 40:60%, and 60:40% EG/W based nanofluids at 0.15 wt% concentrations and at 60 °C respectively. Based on the experimental data new correlations for thermal conductivity and viscosity have been developed.

  7. Nanocomposites Based on Luminescent Colloidal Nanocrystals and Polymeric Ionic Liquids towards Optoelectronic Applications

    Directory of Open Access Journals (Sweden)

    Annamaria Panniello

    2014-01-01

    Full Text Available Polymeric ionic liquids (PILs are an interesting class of polyelectrolytes, merging peculiar physical-chemical features of ionic liquids with the flexibility, mechanical stability and processability typical of polymers. The combination of PILs with colloidal semiconducting nanocrystals leads to novel nanocomposite materials with high potential for batteries and solar cells. We report the synthesis and properties of a hybrid nanocomposite made of colloidal luminescent CdSe nanocrystals incorporated in a novel ex situ synthesized imidazolium-based PIL, namely, either a poly(N-vinyl-3-butylimidazolium hexafluorophosphate or a homologous PIL functionalized with a thiol end-group exhibiting a chemical affinity with the nanocrystal surface. A capping exchange procedure has been implemented for replacing the pristine organic capping molecules of the colloidal CdSe nanocrystals with inorganic chalcogenide ions, aiming to disperse the nano-objects in the PILs, by using a common polar solvent. The as-prepared nanocomposites have been studied by TEM investigation, UV-Vis, steady-state and time resolved photoluminescence spectroscopy for elucidating the effects of the PIL functionalization on the morphological and optical properties of the nanocomposites.

  8. Synthesis and Mechanical Properties Investigation of Nano TiO2/Glass/Epoxy Hybrid Nanocomposite

    Directory of Open Access Journals (Sweden)

    Hamid Reza Salehi

    2015-10-01

    Full Text Available Mechanical properties of epoxy and glass/epoxy filled with 0.25, 0.5 and 1 vol% of TiO2 nanoparticles have been studied using tensile and three-point bending tests. For the TiO2/epoxy nanocomposites, the results showed that the strength and stiffness were improved, though the strain at ultimate strength point and breaking strain decreased. Moreover, the hybrid nanocomposites composed of 4 layers of woven E-glass fabric and TiO2/epoxy matrix were fabricated and cut onaxis and 45° off-axis by water jet. The results of tensile and three-point bending tests indicated a remarkable improvement in the strength and stiffness that could not be related to the mechanical improvement of the matrix. The samples containing 1 vol% nano TiO2 were improved relative to samples without the nanoparticles. The tensile strength of the on-axis and off-axis samples containing 1 vol% TiO2 increased by about 25.9% and 17.9%, in the order given, compared to that of the glass/epoxy specimens. In three-point bending test, the strength of the on-axis and off-axis specimens was improved 26% and 23.2%, respectively. In addition, the tensile stiffness of the onaxis and off-axis samples containing 1 vol% TiO2 increased, respectively, by about 14.4% and 17.5% compared to that of the glass/epoxy specimens. Also for the same on-axis and off-axis samples the three-point bending stiffness increased about 19.8% and 14.6%, respectively. The whole investigation on the microstructure of the hybrid nanocomposites illustrated that stronger interfaces between the fiber and TiO2/epoxy matrix were formed and improvement was noticed on mechanical properties of ternary composite compared to those of the fiber/epoxy composites. The analysis of damage zones of hybrid nanocomposites showed that the surface area of the damaged zone declined considerably due to the brittle behavior of TiO2-filled specimens but the area below the stress-strain curve, showing energy absorption during the test

  9. Increasing the operation temperature of polymer electrolyte membranes for fuel cells: From nanocomposites to hybrids

    Science.gov (United States)

    Licoccia, Silvia; Traversa, Enrico

    Among the possible systems investigated for energy production with low environmental impact, polymeric electrolyte membrane fuel cells (PEMFCs) are very promising as electrochemical power sources for application in portable technology and electric vehicles. For practical applications, operating FCs at temperatures above 100 °C is desired, both for hydrogen and methanol fuelled cells. When hydrogen is used as fuel, an increase of the cell temperature produces enhanced CO tolerance, faster reaction kinetics, easier water management and reduced heat exchanger requirement. The use of methanol instead of hydrogen as a fuel for vehicles has several practical benefits such as easy transport and storage, but the slow oxidation kinetics of methanol needs operating direct methanol fuel cells (DMFCs) at intermediate temperatures. For this reason, new membranes are required. Our strategy to achieve the goal of operating at temperatures above 120 °C is to develop organic/inorganic hybrid membranes. The first approach was the use of nanocomposite class I hybrids where nanocrystalline ceramic oxides were added to Nafion. Nanocomposite membranes showed enhanced characteristics, hence allowing their operation up to 130 °C when the cell was fuelled with hydrogen and up to 145 °C in DMFCs, reaching power densities of 350 mW cm -2. The second approach was to prepare Class II hybrids via the formation of covalent bonds between totally aromatic polymers and inorganic clusters. The properties of such covalent hybrids can be modulated by modifying the ratio between organic and inorganic groups and the nature of the chemical components allowing to reach high and stable conductivity values up to 6.4 × 10 -2 S cm -1 at 120 °C.

  10. Synthesis, characterization and optical properties of hybridized CdS-PVA nanocomposites

    International Nuclear Information System (INIS)

    Wang Hongmei; Chen Zhe; Fang Pengfei; Wang Shaojie

    2007-01-01

    Hybrid nanocomposites of CdS nanoparticles embedded in poly(vinyl alcohol)(PVA) matrixes had been prepared and characterized. The -OH groups acted as the coordination sites for cadmium ion aggregations and nanosized CdS particles were successfully grown in situ at these sites with the release of S 2- ions from thioacetamide. The density and size of the nanoparticles were found to be a function of molar quantity of cadmium ion used. X-ray diffraction results showed that the obtained CdS nanoparticles were hexagonal phase. Ionic clustering within the PVA matrix occurred and had provided a confined medium for particles growth in uniform size. The optical properties of the prepared CdS-PVA hybrid nanocomposites were characterized by absorption and emission spectroscopies. The absorption spectra showed a blue shift as compared to bulk CdS band-gap. The photoluminescence studies indicated the emission peak observed in samples could be assigned to the optical transition of the first excitonic state of the CdS nanoparticles

  11. Hybrid chemical vapour and nanoceramic aerosol assisted deposition for multifunctional nanocomposite thin films

    Energy Technology Data Exchange (ETDEWEB)

    Warwick, Michael E.A.; Dunnill, Charles W.; Goodall, Josie; Darr, Jawwad A.; Binions, Russell, E-mail: uccarbi@ucl.ac.uk

    2011-07-01

    Hybrid atmospheric pressure chemical vapour and aerosol assisted deposition via the reaction of vanadium acetylacetonate and a suspension of preformed titanium dioxide or cerium dioxide nanoparticles, led to the production of vanadium dioxide nanocomposite thin films on glass substrates. The preformed nanoparticle oxides used for the aerosol were synthesised using a continuous hydrothermal flow synthesis route involving the rapid reaction of a metal salt solution with a flow of supercritical water in a flow reactor. Multifunctional nanocomposite thin films from the hybrid deposition process were characterised using scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The functional properties of the films were evaluated using variable temperature optical measurements to assess thermochromic behaviour and methylene blue photodecolourisation experiments to assess photocatalytic activity. The tests show that the films are multifunctional in that they are thermochromic (having a large change in infra-red reflectivity upon exceeding the thermochromic transition temperature) and have significant photocatalytic activity under irradiation with 254 nm light.

  12. PBAT based nanocomposites for medical and industrial applications

    International Nuclear Information System (INIS)

    Fukushima, Kikku; Wu, Meng-Hsiu; Bocchini, Sergio; Rasyida, Amaliya; Yang, Ming-Chien

    2012-01-01

    Poly(butylene adipate-co-terephthalate) (PBAT) based nanocomposites were prepared by melt blending PBAT with 5 and 10 wt.% of clay nanoparticles (unmodified and modified montmorillonites, unmodified and modified fluoro-hectorites, and unmodified sepiolites). All nanocomposites showed a good level of clay distribution and dispersion into PBAT, especially nanocomposites with high clay chemical affinity with the polymer matrix. DSC results showed that addition of layered silicates slightly hindered kinetics and extent of crystallization of PBAT; however, sepiolite particles were able to promote polymer crystallization kinetics and the transformation of the PBAT crystal structure to a more ordered form. Similar increases in the thermal stability of PBAT in nitrogen and air were obtained upon addition of all clays, due to a barrier effect of the clays toward polymer decomposition product ablation. Preliminary biocompatibility tests indicated that PBAT based materials with 10% clay content have good biological safety and display almost no cytotoxicity. The addition of all nanofillers increased the hardness of PBAT matrix. The DMA analysis showed that all nanocomposites presented higher E′ values than neat PBAT, indicating that addition of clays improved the mechanical properties of PBAT. For layered silicate nanocomposites, the main influencing factors on the thermo-mechanical properties appeared to be the aspect ratio and dispersion of clay nanoplatelets, rather than polymer/clay chemical affinity. The highest E′ values of sepiolite based nanocomposites make this nanoparticle the most attractive material for tissue engineering and environmental industrial applications. Highlights: ► PBAT nanocomposites with high thermo-mechanical properties were obtained. ► The effects of clay presence on PBAT crystalline structure were elucidated. ► The presence of the clays used in PBAT showed good biological safety. ► Sepiolites brought the higher improvements in PBAT

  13. PBAT based nanocomposites for medical and industrial applications

    Energy Technology Data Exchange (ETDEWEB)

    Fukushima, Kikku, E-mail: kikku81@gmail.com [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei 10607, Taiwan (China); Wu, Meng-Hsiu [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei 10607, Taiwan (China); Bocchini, Sergio [Dipartimento di Scienze dei Materiali ed Ingegneria Chimica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Torino (Italy); Rasyida, Amaliya; Yang, Ming-Chien [Department of Materials Science and Engineering, National Taiwan University of Science and Technology, 43, Sec. 4, Keelung Rd., Taipei 10607, Taiwan (China)

    2012-08-01

    Poly(butylene adipate-co-terephthalate) (PBAT) based nanocomposites were prepared by melt blending PBAT with 5 and 10 wt.% of clay nanoparticles (unmodified and modified montmorillonites, unmodified and modified fluoro-hectorites, and unmodified sepiolites). All nanocomposites showed a good level of clay distribution and dispersion into PBAT, especially nanocomposites with high clay chemical affinity with the polymer matrix. DSC results showed that addition of layered silicates slightly hindered kinetics and extent of crystallization of PBAT; however, sepiolite particles were able to promote polymer crystallization kinetics and the transformation of the PBAT crystal structure to a more ordered form. Similar increases in the thermal stability of PBAT in nitrogen and air were obtained upon addition of all clays, due to a barrier effect of the clays toward polymer decomposition product ablation. Preliminary biocompatibility tests indicated that PBAT based materials with 10% clay content have good biological safety and display almost no cytotoxicity. The addition of all nanofillers increased the hardness of PBAT matrix. The DMA analysis showed that all nanocomposites presented higher E Prime values than neat PBAT, indicating that addition of clays improved the mechanical properties of PBAT. For layered silicate nanocomposites, the main influencing factors on the thermo-mechanical properties appeared to be the aspect ratio and dispersion of clay nanoplatelets, rather than polymer/clay chemical affinity. The highest E Prime values of sepiolite based nanocomposites make this nanoparticle the most attractive material for tissue engineering and environmental industrial applications. Highlights: Black-Right-Pointing-Pointer PBAT nanocomposites with high thermo-mechanical properties were obtained. Black-Right-Pointing-Pointer The effects of clay presence on PBAT crystalline structure were elucidated. Black-Right-Pointing-Pointer The presence of the clays used in PBAT showed

  14. On the key role of SiO2@POSS hybrid filler in tailoring networking and interfaces in rubber nanocomposites

    Czech Academy of Sciences Publication Activity Database

    Redaelli, M.; D´Arienzo, M.; Brus, Jiří; Di Credico, B.; Geppi, M.; Giannini, L.; Matějka, Libor; Martini, F.; Panattoni, F.; Špírková, Milena; Šlouf, Miroslav; Scotti, R.; Morazzoni, F.

    2018-01-01

    Roč. 65, February (2018), s. 429-439 ISSN 0142-9418 Grant - others:European Commission(XE) COST Action MP1202 HINT Institutional support: RVO:61389013 Keywords : rubber nanocomposites * hybrid materials * POSS Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 2.464, year: 2016

  15. Environmental implications and applications of engineered nanoscale magnetite and its hybrid nanocomposites: A review of recent literature

    Science.gov (United States)

    This review focus on environmental implications and applications of engineered magnetite (Fe3O4) nanoparticles (MNPs) as a single phase or a component of a hybrid nanocomposite that take advantages of their superparamagnetism and high surface area. MNPs are synthesized via co-pre...

  16. Development of nanocomposites based on potato starch

    International Nuclear Information System (INIS)

    Brito, Luciana Macedo; Tavares, Maria Ines Bruno

    2013-01-01

    Nanocomposites of potato starch were prepared by the solution intercalation method with the addition of organically modified montmorillonite clay (Viscogel B and unmodified sodic clay (NT25) as well as modified and unmodified silica (R972 and A200, respectively), using water as the solvent. The nanocomposites were characterized by conventional techniques of X-ray diffraction and thermogravimetric analysis. They were also characterized using the non-conventional low-field nuclear magnetic resonance, which is an effective alternative technique for characterizing nanocomposites. This technique allows one to investigate dispersion of nanofillers by the degree of intercalation and/or exfoliation, in addition to determine the distribution of nanoparticles in the polymer matrix and modifications of the molecular mobility of these fillers. The nanostructured materials obtained with the clays presented good dispersion and formation of mixed nanomaterials, with different degrees of intercalation and exfoliation. The mobility of the material decreased upon adding silica in the starch matrix, which applied to both types of silica. From the TGA technique, a slight increase in thermal stability of the nanocomposite was noted in relation to the starch matrix. (author)

  17. Fabrication and Spectral Properties of Wood-Based Luminescent Nanocomposites

    Directory of Open Access Journals (Sweden)

    Xianjun Li

    2014-01-01

    Full Text Available Pressure impregnation pretreatment is a conventional method to fabricate wood-based nanocomposites. In this paper, the wood-based luminescent nanocomposites were fabricated with the method and its spectral properties were investigated. The results show that it is feasible to fabricate wood-based luminescent nanocomposites using microwave modified wood and nanophosphor powders. The luminescent strength is in positive correlation with the amount of phosphor powders dispersed in urea-formaldehyde resin. Phosphors absorb UV and blue light efficiently in the range of 400–470 nm and show a broad band of bluish-green emission centered at 500 nm, which makes them good candidates for potential blue-green luminescent materials.

  18. Friction-stir processing of an AA8026-TiB{sub 2}-Al{sub 2}O{sub 3} hybrid nanocomposite: Microstructural developments and mechanical properties

    Energy Technology Data Exchange (ETDEWEB)

    Eskandari, H.; Taheri, R. [Department of Mechanical Engineering, Persian Gulf University, Bushehr 75168 (Iran, Islamic Republic of); Khodabakhshi, F., E-mail: farzadkhodabakhshi83@gmail.com [Department of Materials Science and Engineering, School of Engineering, Shiraz University, Zand Boulevard, Shiraz (Iran, Islamic Republic of)

    2016-04-13

    In this study, micro- and nano-sized TiB{sub 2} and Al{sub 2}O{sub 3} particles were incorporated separately and simultaneously through the AA8026 aluminum base alloy during multi-pass friction stir processing (FSP) with 100% overlapping to fabricate metal matrix mono and hybrid nanocomposites. Various FSP conditions including different rotational speeds (w), traverse velocities (v), and processing pass numbers were assessed to attain a homogenous distribution of reinforcing particles through the Al-metal matrix. Moreover, the impacts of size (micro or nano) and type of reinforcement particles (TiB{sub 2} and Al{sub 2}O{sub 3}) on the process-ability of single and hybrid nanocomposite systems were examined. Microstructures of different zones and distributions of reinforcing ceramic particles through the Al-matrix under various processing conditions were studied and characterized by using optical (OM), scanning (SEM), and transmission electron microscopy (TEM) techniques, respectively. The main mechanical characteristics of the prepared nanocomposites, such as, indentation Vickers hardness, tensile properties, and wear resistance were measured and compared for all of the various processing conditions. By optimization of the FSP parameters, as a rotational speed of 1600 rpm and a traverse velocity of 40 mm/min after 4 passes, a uniform AA8026-TiB{sub 2}-Al{sub 2}O{sub 3} hybrid nanocomposite was attained with significant improvements (~70–100%) in the different mechanical properties. As a result, the tensile yield strength of ~270 MPa, elongation of ~4.5%, and indentation Vickers hardness of ~141 HV were obtained. Also, the average wear rate was reduced from the 21×10{sup −3} mg/m value for the AA8026 base alloy down to 2.6×10{sup −3} mg/m for the best processed nanocomposite. A direct relationship between the wear rate and the indentation hardness resistance was demonstrated. Finally, effects of FSP processing conditions and reinforcement particles (type and

  19. Properties and applications of polymer nanocomposites clay and carbon based polymer nanocomposites

    CERN Document Server

    Prasad Sahoo, Bibhu

    2017-01-01

    The aim of the present edited book is to furnish scientific information about manufacturing, properties, and application of clay and carbon based polymer nanocomposites. It can be used as handbook for undergraduate and post graduate courses (for example material science and engineering, polymer science and engineering, rubber technology, manufacturing engineering, etc.) as well as as reference book for research fellows and professionals. Polymer nanocomposites have received outstanding importance in the present decade because of their broad range of high-performance applications in various areas of engineering and technology due to their special material properties. A great interest is dedicated to nanofiller based polymeric materials, which exhibit excellent enhancement in macroscopic material properties (mechanical, thermal, dynamic mechanical, electrical and many more) at very low filler contents and can therefore be used for the development of next-generation composite materials.

  20. Application of nonlinear rheology to assess the effect of secondary nanofiller on network structure of hybrid polymer nanocomposites

    Science.gov (United States)

    Kamkar, Milad; Aliabadian, Ehsan; Shayesteh Zeraati, Ali; Sundararaj, Uttandaraman

    2018-02-01

    Carbon nanotube (CNT)/polymer nanocomposites exhibit excellent electrical properties by forming a percolated network. Adding a secondary filler can significantly affect the CNTs' network, resulting in changing the electrical properties. In this work, we investigated the effect of adding manganese dioxide nanowires (MnO2NWs) as a secondary nanofiller on the CNTs' network structure inside a poly(vinylidene fluoride) (PVDF) matrix. Incorporating MnO2NWs to PVDF/CNT samples produced a better state of dispersion of CNTs, as corroborated by light microscopy and transmission electron microscopy. The steady shear and oscillatory shear flows were employed to obtain a better insight into the nanofiller structure and viscoelastic behavior of the nanocomposites. The transient response under steady shear flow revealed that the stress overshoot of hybrid nanocomposites (two-fillers), PVDF/CNT/MnO2NWs, increased dramatically in comparison to binary nanocomposites (single-filler), PVDF/CNT and PVDF/MnO2NWs. This can be attributed to microstructural changes. Large amplitude oscillatory shear characterization was also performed to further investigate the effect of the secondary nanofiller on the nonlinear viscoelastic behavior of the samples. The nonlinear rheological observations were explained using quantitative nonlinear parameters [strain-stiffening ratio (S) and shear-thickening ratio (T)] and Lissajous-Bowditch plots. Results indicated that a more rigid nanofiller network was formed for the hybrid nanocomposites due to the better dispersion state of CNTs and this led to a more nonlinear viscoelastic behavior.

  1. Graphene-polyethylenedioxythiophene conducting polymer nanocomposite based supercapacitor

    International Nuclear Information System (INIS)

    Alvi, Farah; Ram, Manoj K.; Basnayaka, Punya A.; Stefanakos, Elias; Goswami, Yogi; Kumar, Ashok

    2011-01-01

    Graphical abstract: Schematic diagrams of an electrochemical double layer type capacitor showing the charged (left) and discharged (right) states. Highlights: → The Graphene-PEDOT nanocomposite based smart coating has shown the excellent redox properties in acidic, organic electrolytes, which is promising for suprecapcitor application. → The electrochemical impedance studies have also been estimated which clearly indicates the high conductivity and less charge transfer resistance in the synthesized material. → The specific capacitance of 380F/g have been calculated for G-Pedot material, also it shows the columbic efficiency of 95% for 800 cycles, which tells the remarkable stability of synthesized material. - Abstract: We present here the synthesis, characterization and application of graphene (G)-polyethylenedioxythiophene (PEDOT) nanocomposites as electrode material for supercapacitor applications. The G-PEDOT nanocomposite was synthesized using a chemical oxidative polymerization technique, and characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, FTIR spectroscopy, X-ray-diffraction, electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) techniques. The electrochemical charge/discharge characteristics of G-PEDOT nanocomposites were investigated in different electrolytic media, and the specific discharge capacitance was estimated to be 374 Farad/gram (F/gm). This manuscript presents the capacitance studies on supercapacitor G-PEDOT electrode with respect to stability of material, specific capacitance, electrical conductivity and specific charge/discharge properties of the supercapacitor electrodes. Our study has revealed that the G-PEDOT nanocomposite could be a transformable and viable electrode material for supercapacitor applications.

  2. Asphaltenes-based polymer nano-composites

    Science.gov (United States)

    Bowen, III, Daniel E

    2013-12-17

    Inventive composite materials are provided. The composite is preferably a nano-composite, and comprises an asphaltene, or a mixture of asphaltenes, blended with a polymer. The polymer can be any polymer in need of altered properties, including those selected from the group consisting of epoxies, acrylics, urethanes, silicones, cyanoacrylates, vulcanized rubber, phenol-formaldehyde, melamine-formaldehyde, urea-formaldehyde, imides, esters, cyanate esters, allyl resins.

  3. Structure and Optical Properties of Titania-PDMS Hybrid Nanocomposites Prepared by In Situ Non-Aqueous Synthesis

    Directory of Open Access Journals (Sweden)

    Antoine R. M. Dalod

    2017-12-01

    Full Text Available Organic-inorganic hybrid materials are attractive due to the combination of properties from the two distinct types of materials. In this work, transparent titania-polydimethylsiloxane hybrid materials with up to 15.5 vol. % TiO2 content were prepared by an in situ non-aqueous method using titanium (IV isopropoxide and hydroxy-terminated polydimethylsiloxane as precursors. Spectroscopy (Fourier transform infrared, Raman, Ultraviolet-visible, ellipsometry and small-angle X-ray scattering analysis allowed to describe in detail the structure and the optical properties of the nanocomposites. Titanium alkoxide was successfully used as a cross-linker and titania-like nanodomains with an average size of approximately 4 nm were shown to form during the process. The resulting hybrid nanocomposites exhibit high transparency and tunable refractive index from 1.42 up to 1.56, depending on the titania content.

  4. Hybrid MoS2/h-BN Nanofillers As Synergic Heat Dissipation and Reinforcement Additives in Epoxy Nanocomposites.

    Science.gov (United States)

    Ribeiro, Hélio; Trigueiro, João Paulo C; Silva, Wellington M; Woellner, Cristiano F; Owuor, Peter S; Cristian Chipara, Alin; Lopes, Magnovaldo C; Tiwary, Chandra S; Pedrotti, Jairo J; Villegas Salvatierra, Rodrigo; Tour, James M; Chopra, Nitin; Odeh, Ihab N; Silva, Glaura G; Ajayan, Pulickel M

    2017-09-26

    Two-dimensional (2D) nanomaterials as molybdenum disulfide (MoS 2 ), hexagonal boron nitride (h-BN), and their hybrid (MoS 2 /h-BN) were employed as fillers to improve the physical properties of epoxy composites. Nanocomposites were produced in different concentrations and studied in their microstructure, mechanical and thermal properties. The hybrid 2D mixture imparted efficient reinforcement to the epoxy leading to increases of up to 95% in tensile strength, 60% in ultimate strain, and 58% in Young's modulus. Moreover, an enhancement of 203% in thermal conductivity was achieved for the hybrid composite as compared to the pure polymer. The incorporation of MoS 2 /h-BN mixture nanofillers in epoxy resulted in nanocomposites with multifunctional characteristics for applications that require high mechanical and thermal performance.

  5. Highly Controlled Diffusion Drug Release from Ureasil-Poly(ethylene oxide)-Na+-Montmorillonite Hybrid Hydrogel Nanocomposites.

    Science.gov (United States)

    Jesus, Celso R N; Molina, Eduardo F; Pulcinelli, Sandra H; Santilli, Celso V

    2018-06-06

    In this work, we report the effects of incorporation of variable amounts (1-20 wt %) of sodium montmorillonite (MMT) into a siloxane-poly(ethylene oxide) hybrid hydrogel prepared by the sol-gel route. The aim was to control the nanostructural features of the nanocomposite, improve the release profile of the sodium diclofenac (SDCF) drug, and optimize the swelling behavior of the hydrophilic matrix. The nanoscopic characteristics of the siloxane-cross-linked poly(ethylene oxide) network, the semicrystallinity of the hybrid, and the intercalated or exfoliated structure of the clay were investigated by X-ray diffraction, small-angle X-ray scattering, and differential scanning calorimetry. The correlation between the nanoscopic features of nanocomposites containing different amounts of MMT and the swelling behavior revealed the key role of exfoliated silicate in controlling the water uptake by means of a flow barrier effect. The release of the drug from the nanocomposite displayed a stepped pattern kinetically controlled by the diffusion of SDCF molecules through the mass transport barrier created by the exfoliated silicate. The sustained SDCF release provided by the hybrid hydrogel nanocomposite could be useful for the prolonged treatment of painful conditions, such as arthritis, sprains and strains, gout, migraine, and pain after surgical procedures.

  6. Chitosan based metallic nanocomposite scaffolds as antimicrobial wound dressings.

    Science.gov (United States)

    Mohandas, Annapoorna; Deepthi, S; Biswas, Raja; Jayakumar, R

    2018-09-01

    Chitosan based nanocomposite scaffolds have attracted wider applications in medicine, in the area of drug delivery, tissue engineering and wound healing. Chitosan matrix incorporated with nanometallic components has immense potential in the area of wound dressings due to its antimicrobial properties. This review focuses on the different combinations of Chitosan metal nanocomposites such as Chitosan/nAg, Chitosan/nAu, Chitosan/nCu, Chitosan/nZnO and Chitosan/nTiO 2 towards enhancement of healing or infection control with special reference to the antimicrobial mechanism of action and toxicity.

  7. Biocompatible nanocomposite for PET/MRI hybrid imaging

    Directory of Open Access Journals (Sweden)

    Locatelli E

    2012-12-01

    Full Text Available Erica Locatelli,1 Larraitz Gil,2 Liron Limor Israel,3 Lorena Passoni,4,5 Maria Naddaka,1 Andrea Pucci,1 Torsten Reese,6 Vanessa Gomez-Vallejo,2 Paolo Milani,5,7 Michela Matteoli,4,8 Jordi Llop,2 Jean Paul Lellouche,3 Mauro Comes Franchini11Department of Industrial Chemistry “Toso Montanari”. University of Bologna, Italy; 2Radiochemistry Department, Molecular Imaging Unit, CIC biomaGUNE, San Sebastián, Guipúzcoa, Spain; 3Department of Chemistry, Nanomaterials Research Centre, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, Israel; 4Department of Medical Biotechnology and Translational Medicine, University of Milano, Italy; 5Fondazione Filarete, Milano, Italy; 6Imaging Department, Molecular Imaging Unit, CIC biomaGUNE, San Sebastián, Guipúzcoa, Spain; 7CIMAINA and Department of Physics, University of Milano, Italy; 8Humanitas Clinical and Research Center, Rozzano, ItalyAbstract: A novel nanocarrier system was designed and developed with key components uniquely structured at the nanoscale for early cancer diagnosis and treatment. In order to perform magnetic resonance imaging, hydrophilic superparamagnetic maghemite nanoparticles (NPs were synthesized and coated with a lipophilic organic ligand. Next, they were entrapped into polymeric NPs made of biodegradable poly(lactic-co-glycolic acid linked to polyethylene glycol. In addition, resulting NPs have been conjugated on their surface with a 2,2'-(7-(4-((2-aminoethylamino-1-carboxy-4-oxobutyl-1,4,7-triazonane-1,4-diyldiacetic acid ligand for subsequent 68Ga incorporation. A cell-based cytotoxicity assay has been employed to verify the in vitro cell viability of human pancreatic cancer cells exposed to this nanosystem. Finally, in vivo positron emission tomography-computerized tomography biodistribution studies in healthy animals were performed.Keywords: maghemite nanoparticles, organic coating, polymeric nanoparticles, magnetic resonance imaging

  8. Largely enhanced thermal and mechanical properties of polymer nanocomposites via incorporating C60@graphene nanocarbon hybrid

    International Nuclear Information System (INIS)

    Song, Ping’an; Liu, Lina; Yu, Youming; Huang, Guobo; Guo, Qipeng

    2013-01-01

    Although considerable progress has been achieved to create advanced polymer nanocomposites using nanocarbons including fullerene (C 60 ) and graphene, it remains a major challenge to effectively disperse them in a polymer matrix and to fully exert their extraordinary properties. Here we report a novel approach to fabricate the C 60 @graphene nanocarbon hybrid (C 60 : ∼47.9 wt%, graphene: ∼35.1%) via three-step reactions. The presence of C 60 on a graphene sheet surface can effectively prevent the aggregation of the latter which in turn helps the dispersion of the former in a polymer matrix during melt-processing. C 60 @graphene is found to be uniformly dispersed in a polypropylene (PP) matrix. Compared with pristine C 60 or graphene, C 60 @graphene further improves the thermal stability and mechanical properties of PP. The incorporation of 2.0 wt% C 60 @graphene (relative to PP) can remarkably increase the initial degradation temperature by around 59 ° C and simultaneously enhance the tensile strength and Young’s modulus by 67% and 76%, respectively, all of which are higher than those of corresponding PP/C 60 (graphene) nanocomposites. These significant performance improvements are mainly due to the free-radical-trapping effect of C 60 , and the thermal barrier and reinforcing effects of graphene nanosheets as well as the effective stress load transfer. This work provides a new methodology to design multifunctional nanohybrids for creating advanced materials. (paper)

  9. Prussian blue-nitrogen-doped graphene nanocomposite as hybrid electrode for energy storage applications

    International Nuclear Information System (INIS)

    Sookhakian, M.; Basirun, W.J.; Teridi, Mohd Asri Mat; Mahmoudian, M.R.; Azarang, Majid; Zalnezhad, Erfan; Yoon, G.H.; Alias, Y.

    2017-01-01

    Highlights: • Novel and inexpensive Prussian blue-N-graphene composite for hybrid battery- supercapacitor. • Prussian blue leads to a significant increase of the capacity. • Prussian blue leads to enhancement of cycling stability of N-graphene. - Abstract: Water-soluble Prussian blue nanoparticles (PB NPs) supported on nitrogen-doped graphene (N-graphene) with high dispersion was fabricated for high performance energy storage hybrid electrodes. An efficient loading of the PB NPs and nitrogen doping of graphene were achieved. The structure and morphology of the composite was determined by X-ray diffraction, transmission electron microscopy, Raman spectrometry and X-ray photoelectron spectrometry. The energy storage performance was assessed by cyclic voltammetry and galvanostatic charge/discharge techniques. The nanocomposite was fabricated as a hybrid battery-supercapacitor electrode and exhibited excellent performance with the highest capacity of 660 C g −1 at 1 A g −1 , which was higher than pure PB NPs and N-graphene electrodes. Moreover, the synergistic effect of N-graphene and the PB NPs prevented the N-graphene from shrinking and swelling and increased the cycle stability to 84.7% retention after 1500 cycles at 6 A g −1 , compared to the pure N-graphene.

  10. Well-ordered organic–inorganic hybrid layered manganese oxide nanocomposites with excellent decolorization performance

    International Nuclear Information System (INIS)

    Zhou, Junli; Yu, Lin; Sun, Ming; Ye, Fei; Lan, Bang; Diao, Guiqiang; He, Jun

    2013-01-01

    Well-ordered organic–inorganic hybrid layered manganese oxide nanocomposites (CTAB-Al-MO) with excellent decolorization performance were prepared through a two-step process. Specifically, the MnO 2 nanosheets were self-assembled in the presence of CTAB, and subsequently pillared with Keggin ions. The obtained CTAB-Al-MO with the basal spacing of 1.59 nm could be stable at 300 °C for 2 h and also possesses high total pore volumes (0.41 cm³ g −1 ) and high specific BET surface area (161 m 2 g −1 ), which is nine times larger than that of the pristine (19 m 2 g −1 ). Possible formation process for the highly thermal stable CTAB-Al-MO is proposed here. The decolorization experiments of methyl orange showed that the obtained CTAB-Al-MO exhibit excellent performance in wastewater treatment and the decolorization rate could reach 95% within 5 min. - Graphical Abstract: Well-ordered organic–inorganic hybrid LMO nanocomposites (CTAB-Al-MO) with excellent decolorization performance were prepared through a two-step process. Specifically, the MnO 2 nanosheets were self-assembled by CTAB, and subsequently pillared with Keggin ions. Highlights: ► A two-step synthesis method was used to prepare the CTAB-Al-MO. ► The CTAB-Al-MO has the large basal spacing and high specific BET surface area. ► The thermal stability of the well-ordered CTAB-Al-MO could obviously improve. ► The CTAB-Al-MO exhibits excellent oxidation and absorption ability to remove organic pollutants.

  11. Ordered mesoporous silica-based inorganic nanocomposites

    International Nuclear Information System (INIS)

    Wang Qingqing; Shantz, Daniel F.

    2008-01-01

    This article reviews the synthesis and characterization of nanoparticles and nanowires grown in ordered mesoporous silicas (OMS). Summarizing work performed over the last 4 years, this article highlights the material properties of the final nanocomposite in the context of the synthesis methodology employed. While certain metal-OMS systems (e.g. gold in MCM-41) have been extensively studied this article highlights that there is a rich set of chemistries that have yet to be explored. The article concludes with some thoughts on future developments and challenges in this area. - Graphical abstract: HAADF TEM image of gold nanoparticles in amine-functionalized MCM-41 (from Ref. [22])

  12. Physical and mechanical properties of hybrid montmorillonite/zinc oxide reinforced carboxymethyl cellulose nanocomposites.

    Science.gov (United States)

    Zahedi, Younes; Fathi-Achachlouei, Bahram; Yousefi, Ali Reza

    2018-03-01

    In this research, a novel carboxymethyl cellulose (CMC)-based nanocomposite films containing sodium montmorillonite (MMT) (5%wt) and zinc oxide (ZnO) (1, 2, 3 and 4%wt) nanoparticles (NPs) were fabricated via casting method. The results revealed that addition of NPs decreased water vapor permeability of the films by about 53%, while moisture content, density and glass transition temperature increased. The nanomaterials enhanced resistance of the nanocomposites against tensile stress at the expense of elongation at break. Nano-ZnO was very effective than nanoclay in UV-light blocking (99% vs. 60%) associated with sacrificing the films transparency. Formation of hydrogen bonds between the hydroxyl groups of CMC and MMT was evidenced by FTIR spectroscopy. According to the XRD analysis, clay nanolayers formed an exfoliated structure in the nanocomposites, whereas ZnO NPs raised crystallinity. SEM micrographs showed well-dispersed MMT and ZnO NPs through the films surface. Antibacterial test showed that vulnerability of Gram-positive S. aureus toward ZnO NPs was more than that of Gram-negative E. Coli. In conclusion, simultaneous incorporation of MMT and ZnO NPs improved the functional characteristics of CMC film and extended the potential for food packaging applications. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. nanoparticles-decorated activated carbon nanocomposite based ...

    Indian Academy of Sciences (India)

    T K APARNA

    2018-02-07

    Feb 7, 2018 ... oxide nanohexagon-reduced graphene oxide nanocom- posite39 was reported ..... istic vibrations of the chemical bonds were inferred. The electrochemical .... hybrid decorated with molybdenum disulfide flowers. Microchim.

  14. Development of polymer nanocomposites based on layered double hydroxides

    Directory of Open Access Journals (Sweden)

    Sipusic, J.

    2009-05-01

    Full Text Available Polymeric nanocomposites are commonly considered as systems composed of a polymeric matrix and - usually inorganic - filler. The types of nanofillers are indicated in Fig. 1. Beside wellknown layered silicate fillers, recent attention is attracted to layered double hydroxide fillers (LDH, mainly of synthetic origin. The structure of LDH is based on brucite, or magnesium hydroxide, Mg(OH2 and is illustrated in Fig. 2. The modification of LDHs is commonly done by organic anions, to increase the original interlayer distance and to improve the organophilicity of the filler, keeping in mind their final application as fillers for, usually hydrophobic, polymer matrices. We have used the modified rehydration procedure for preparing organically modified LDH. The stoichiometric quantities of Ca33Al2O6, CaO and benzoic (B (or undecenoic (U acid were mixed with water and some acetone. After long and vigorous shaking, the precipitated fillers were washed, dried and characterized. X-ray diffraction method (XRD has shown the increase of the original interlayer distance for unmodified LDH (OH–-saturated of 0.76 nm to the 1.6 nm in LDH-B or LDH-U fillers (Fig. 3. Infrared spectroscopy method (FTIR has confirmed the incorporation of benzoic anion within the filler layers (Fig. 4. For the preparation of LDH-B and LDH-U composites with polystyrene (PS, poly(methyl methacrylate (PMMA and copolymer (SMMA matrices, a two-step in situ bulk radical polymerization was selected (Table 1 for recipes, azobisisobutyronitrile as initiator, using conventional stirred tank reactor in the first step, and heated mold with the movable wall (Fig. 6 in the second step of polymerization. All the prepared composites with LDH-U fillers were macroscopically phase-separated, as was the PMMA/LDH-B composite.PS/LDH-B and SMMA/LDH-B samples were found to be transparent and were further examined for deduction of their structure (Fig. 5 and thermal properties. FTIR measurements showed that

  15. Moessbauer investigation of maghemite-based glycolic acid nanocomposite

    International Nuclear Information System (INIS)

    Santos, J. G.; Silveira, L. B.; Oliveira, A. C.; Garg, V. K.; Lacava, B. M.; Tedesco, A. C.; Morais, P. C.

    2007-01-01

    Transmission electron microscopy, X-ray diffraction and Moessbauer spectroscopy were used in the characterization of a nanocomposite containing magnetic nanoparticles dispersed in a glycolic acid-based template. Maghemite nanoparticles were identified as the iron oxide phase dispersed in the polymeric template. From the low-temperature Moessbauer data the amount of the iron-based, non-magnetic material at the nanoparticle surface was estimated as roughly one monolayer in thickness.

  16. In Situ Synthesis of Poly(methyl methacrylate/SiO2 Hybrid Nanocomposites via “Grafting Onto” Strategy Based on UV Irradiation in the Presence of Iron Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Hong Zhang

    2012-01-01

    Full Text Available Poly(methyl methacrylate/SiO2 (PMMA/SiO2 hybrid composites were prepared via “grafting onto” strategy based on UV irradiation in the presence of iron aqueous solution. Two steps were used to graft polymethyl methacrylate (PMMA onto the surface of nanosilica, anchoring 3-(methacryloxy propyl trimethoxysilane (MPTS onto the surface of nanosilica to modify it with double bonds, and then grafting PMMA onto the surface of nanosilica with FeCl3 as photoinitiator. The products were characterized by FT-IR, TGA, TEM, DLS, and XPS. The results showed that it is easy to graft PMMA onto the surface of nanosilica under UV irradiation, and the hybrid particles are monodisperse and have core-shell structure with nanosilica as the core and PMMA layers as the shell. Furthermore, the products initiated by FeCl3 have higher monomer conversion, percent grafting, and better monodispersion compared with the products initiated by traditional photoinitiator such as 2-hydroxy-4-(2-hydroxyethoxy-2-methyl-propiophenone (Irgacure 2959.

  17. Comparative Study of the Photocatalytic Activity of Semiconductor Nanostructures and Their Hybrid Metal Nanocomposites on the Photodegradation of Malathion

    Directory of Open Access Journals (Sweden)

    Dina Mamdouh Fouad

    2012-01-01

    Full Text Available This work is devoted to synthesize different semiconductor nanoparticles and their metal-hybrid nanocomposites such as TiO2, Au/TiO2, ZnO, and Au/ZnO. The morphology and crystal structure of the prepared nanomaterials are characterized by the TEM and XRD, respectively. These materials are used as catalysts for the photodegradation of Malathion which is one of the most commonly used pesticides in the developing countries. The degradation of 10 ppm Malathion under ultraviolet (UV and visible light in the presence of the different synthesized nanocomposites was analyzed with high-performance liquid chromatography (HPLC and UV-Visible Spectra. A comprehensive study is carried out for the catalytic efficiency of the prepared nanoparticles. Different factors influencing the catalytic photodegradation are investigated, as different light source, surface coverage, and nature of the organic contaminants. The results indicate that hybrid nanocomposite of the semiconductor-metal hybrid serves as a better catalytic system compared with semiconductor nanoparticles themselves.

  18. Influence of miscibility phenomenon on crystalline polymorph transition in poly(vinylidene fluoride)/acrylic rubber/clay nanocomposite hybrid.

    Science.gov (United States)

    Abolhasani, Mohammad Mahdi; Naebe, Minoo; Jalali-Arani, Azam; Guo, Qipeng

    2014-01-01

    In this paper, intercalation of nanoclay in the miscible polymer blend of poly(vinylidene fluoride) (PVDF) and acrylic rubber(ACM) was studied. X-ray diffraction was used to investigate the formation of nanoscale polymer blend/clay hybrid. Infrared spectroscopy and X-ray analysis revealed the coexistence of β and γ crystalline forms in PVDF/Clay nanocomposite while α crystalline form was found to be dominant in PVDF/ACM/Clay miscible hybrids. Flory-Huggins interaction parameter (B) was used to further explain the miscibility phenomenon observed. The B parameter was determined by combining the melting point depression and the binary interaction model. The estimated B values for the ternary PVDF/ACM/Clay and PVDF/ACM pairs were all negative, showing both proper intercalation of the polymer melt into the nanoclay galleries and the good miscibility of PVDF and ACM blend. The B value for the PVDF/ACM blend was almost the same as that measured for the PVDF/ACM/Clay hybrid, suggesting that PVDF chains in nanocomposite hybrids interact with ACM chains and that nanoclay in hybrid systems is wrapped by ACM molecules.

  19. Influence of miscibility phenomenon on crystalline polymorph transition in poly(vinylidene fluoride/acrylic rubber/clay nanocomposite hybrid.

    Directory of Open Access Journals (Sweden)

    Mohammad Mahdi Abolhasani

    Full Text Available In this paper, intercalation of nanoclay in the miscible polymer blend of poly(vinylidene fluoride (PVDF and acrylic rubber(ACM was studied. X-ray diffraction was used to investigate the formation of nanoscale polymer blend/clay hybrid. Infrared spectroscopy and X-ray analysis revealed the coexistence of β and γ crystalline forms in PVDF/Clay nanocomposite while α crystalline form was found to be dominant in PVDF/ACM/Clay miscible hybrids. Flory-Huggins interaction parameter (B was used to further explain the miscibility phenomenon observed. The B parameter was determined by combining the melting point depression and the binary interaction model. The estimated B values for the ternary PVDF/ACM/Clay and PVDF/ACM pairs were all negative, showing both proper intercalation of the polymer melt into the nanoclay galleries and the good miscibility of PVDF and ACM blend. The B value for the PVDF/ACM blend was almost the same as that measured for the PVDF/ACM/Clay hybrid, suggesting that PVDF chains in nanocomposite hybrids interact with ACM chains and that nanoclay in hybrid systems is wrapped by ACM molecules.

  20. Influence of Miscibility Phenomenon on Crystalline Polymorph Transition in Poly(Vinylidene Fluoride)/Acrylic Rubber/Clay Nanocomposite Hybrid

    Science.gov (United States)

    Abolhasani, Mohammad Mahdi; Naebe, Minoo; Jalali-Arani, Azam; Guo, Qipeng

    2014-01-01

    In this paper, intercalation of nanoclay in the miscible polymer blend of poly(vinylidene fluoride) (PVDF) and acrylic rubber(ACM) was studied. X-ray diffraction was used to investigate the formation of nanoscale polymer blend/clay hybrid. Infrared spectroscopy and X-ray analysis revealed the coexistence of β and γ crystalline forms in PVDF/Clay nanocomposite while α crystalline form was found to be dominant in PVDF/ACM/Clay miscible hybrids. Flory-Huggins interaction parameter (B) was used to further explain the miscibility phenomenon observed. The B parameter was determined by combining the melting point depression and the binary interaction model. The estimated B values for the ternary PVDF/ACM/Clay and PVDF/ACM pairs were all negative, showing both proper intercalation of the polymer melt into the nanoclay galleries and the good miscibility of PVDF and ACM blend. The B value for the PVDF/ACM blend was almost the same as that measured for the PVDF/ACM/Clay hybrid, suggesting that PVDF chains in nanocomposite hybrids interact with ACM chains and that nanoclay in hybrid systems is wrapped by ACM molecules. PMID:24551141

  1. Morphological and Wear behaviour of new Al-SiCmicro-SiCnano hybrid nanocomposites fabricated through powder metallurgy

    Science.gov (United States)

    Arif, Sajjad; Tanwir Alam, Md; Aziz, Tariq; Ansari, Akhter H.

    2018-04-01

    In the present work, aluminium matrix composites reinforced with 10 wt% SiC micro particles along with x% SiC nano particles (x = 0, 1, 3, 5 and 7 wt%) were fabricated through powder metallurgy. The fabricated hybrid composites were characterized by x-ray diffractometer (XRD), scanning electron microscope (SEM), energy dispersive spectrum (EDS) and elemental mapping. The relative density, hardness and wear behaviour of all hybrid nanocomposites were studied. The influence of various control factors like SiC reinforcement, sliding distance (300, 600, 900 and 1200 m) and applied load (20, 30 and 40 N) were explored using pin-on-disc wear apparatus. The uniform distribution of micro and nano SiC particles in aluminium matrix is confirmed by elemental maps. The hardness and wear test results showed that properties of the hybrid composite containing 5 wt% nano SiC was better than other hybrid composites. Additionally, the wear loss of all hybrid nanocomposites increases with increasing sliding distance and applied load. The identification of wear phenomenon were studied through the SEM images of worn surface.

  2. Structural analysis of nanocomposites based on HDPE/EPDM blends.

    Science.gov (United States)

    Zitzumbo, Roberto; Alonso, Sergio; Avalos, Felipe; Ortiz, José C; López-Manchado, Miguel A; Arroyo, Miguel

    2006-02-01

    Intercalated and exfoliated nanocomposites based on HDPE and EPDM blends with an organoclay have been obtained through the addition of EPDM-g-MA as a compatibilizer. The combined effect of clay and EPDM-g-MA on the rheological behaviour is very noticeable with a sensible increase in viscosity which suggests the formation of a structural net of percolation induced by the presence of intercalated and exfoliated silicate layer. As deduced from rheological studies, a morphology based on nanostructured micro-domains dispersed in HDPE continuous phase is proposed for EPDM/HDPE blend nanocomposites. XRD and SEM analysis suggest that two different transport phenomena take simultaneously place during the intercalation process in the melt. One due to diffusion of HDPE chains into the tactoid and the other to diffusion of EPDM-g-MA into the silicate galleries.

  3. Polyaniline/partially exfoliated multi-walled carbon nanotubes based nanocomposites for supercapacitors

    International Nuclear Information System (INIS)

    Potphode, Darshna D.; Sivaraman, P.; Mishra, Sarada P.; Patri, Manoranjan

    2015-01-01

    In the present study, polyaniline (PANI)/partially exfoliated multi-walled carbon nanotubes (Px-MWCNT) nanocomposites were investigated for supercapacitor application. Nanocomposites with varying weight/weight ratio of PANI and Px-MWCNT were prepared by in-situ polymerization of aniline over Px-MWCNT. Transmission and scanning electron microscopic analysis showed that the MWCNT was partial unzipped along the length of tubes. The morphology of PANI/Px-MWCNT nanocomposites exhibited wrapping of PANI over Px-MWCNT. Symmetric supercapacitors containing PANI/Px-MWCNT nanocomposites as the electrode material were fabricated. The electrochemical characterization of the nanocomposites was carried by two electrode method (unit cell configuration). Cyclic voltammetric analysis showed a synergistic increase in specific capacitance of the nanocomposites. Charge-discharge cycle study indicated that nanocomposites have greater charge-discharge rate capability than pure PANI. The observed result is attributed to the shorter diffusion length of ions in the nanocomposites as compared to that of pure PANI. The electrochemical impedance spectra of supercapacitors were resolved into real and losscapacitances. The loss capacitance indicated that the time constant of the nanocomposites decreases with increase in the Px-MWCNT content. The supercapacitors showed enhanced stability during continuous charge-discharge cycling as the PX-MWCNT content in the nanocomposites increased. PANI-50 and PANI-25 nanocomposites based supercapacitors exhibited 91% and 93% capacitive retention after 2000 charge-discharge cycle while pure PANI showed only 67% capacitance retention for the same number of cycles

  4. Rare Earth-Activated Silica-Based Nanocomposites

    Directory of Open Access Journals (Sweden)

    C. Armellini

    2007-01-01

    Full Text Available Two different kinds of rare earth-activated glass-based nanocomposite photonic materials, which allow to tailor the spectroscopic properties of rare-earth ions: (i Er3+-activated SiO2-HfO2 waveguide glass ceramic, and (ii core-shell-like structures of Er3+-activated silica spheres obtained by a seed growth method, are presented.

  5. Vegetable oil based liquid nanocomposite dielectric

    Directory of Open Access Journals (Sweden)

    Leon Chetty

    2013-01-01

    Full Text Available Physically smaller dielectric materials would improve the optimisation of space for power systems. Development of nanotechnology provides an effective way to improve the performances of insulating oils used in power system applications. In this research study, we focused on the development of nanomodified vegetable oils to be used in power transformers. Higher conduction currents were observed in virgin linseed oil than in virgin castor oil. However, for both virgin linseed and virgin castor oil, the DC conduction current increased approximately linearly with the applied DC voltage. In nanomodified linseed oil, the characteristic curve showed two distinct regions: a linear region (at lower applied voltage and a saturation region (at slightly higher voltage. Conversely, in nanomodified castor oil, the characteristic curve showed three distinct regions: a linear region (at lower applied voltage, a saturation region (at intermediate applied voltage and an exponential growth region (at higher applied voltage. The nanomodified linseed oil exhibited a better dielectric performance than the nanomodified castor oil. Overall, the addition of nanodielectrics to vegetable oils decreased the dielectric performance of the vegetable oils. The results of this study contribute to the understanding of the pre-breakdown phenomenon in liquid nanocomposite dielectrics.

  6. Titania based nanocomposites as a photocatalyst: A review

    Directory of Open Access Journals (Sweden)

    Farha Modi

    2016-08-01

    Full Text Available Titanium dioxide or Titania is a semiconductor compound having remarkable dielectric, electronic and physico-chemical surface properties. It has excellent photocatalytic efficiency in presence of UV light. The curious grey matter of scientists has forced them to focus their attention to make Titania capable of utilizing the whole visible spectrum of light also. The hurdle that they faced was larger band gap of 3 eV and more, for this, efforts were directed towards adding other materials to Titania. The present article reviews the recent advances in the synthesis of different Titanium-based nanocomposite materials and their photocatalytic efficiency so as to apply them for several applications such as removal of dyes, other water pollutants, microbes and metals. A brief explanation of the photocatalytic process and the structural properties of TiO2 are also touched upon. Various past and recent approaches made in these directions of utilizing Titania based nanocomposites for photocatalytic activities are reviewed. It is suggested that there is a need to establish the kinetics of photo-corrosion and thermodynamic part of the photo-corrosion of various composites developed by different group across the globe, so that Titania based nanocomposites could be commercially utilized.

  7. Research Progress on Visible-light Responding ZnO-based Nanocomposite Photocatalyst

    Directory of Open Access Journals (Sweden)

    ZHAO Yan-ru

    2017-06-01

    Full Text Available In this review, different types and properties, photocatalysis and functional mechanism of ZnO-based nanocomposite were summarized. Besides, the research advances were discussed in applications of visible-light responding ZnO-based nanocomposite in fields of degradation of organic pollutants,photocatalytic hydrogen production and antibacterial agents, and the way of thinking and suggestions for further research on ZnO-based nanocomposite photocatalyst were put forward. With the developing of basic research and application, ZnO-based nanocomposite photocatalyst will be widely used in the fields of high efficiency catalyst, environmental purification, solar energy conversion and so on.

  8. Amperometric urea biosensors based on sulfonated graphene/polyaniline nanocomposite

    Directory of Open Access Journals (Sweden)

    Das G

    2015-08-01

    Full Text Available Gautam Das, Hyon Hee Yoon Department of Chemical and Biological Engineering, Gachon University, Seongnam, Gyeonggi-do, South Korea Abstract: An electrochemical biosensor based on sulfonated graphene/polyaniline nanocomposite was developed for urea analysis. Oxidative polymerization of aniline in the presence of sulfonated graphene oxide was carried out by electrochemical methods in an aqueous environment. The structural properties of the nanocomposite were characterized by Fourier-transform infrared, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy techniques. The urease enzyme-immobilized sulfonated graphene/polyaniline nanocomposite film showed impressive performance in the electroanalytical detection of urea with a detection limit of 0.050 mM and a sensitivity of 0.85 µA·cm-2·mM-1. The biosensor achieved a broad linear range of detection (0.12–12.3 mM with a notable response time of approximately 5 seconds. Moreover, the fabricated biosensor retained 81% of its initial activity (based on sensitivity after 15 days of storage at 4°C. The ease of fabrication coupled with the low cost and good electrochemical performance of this system holds potential for the development of solid-state biosensors for urea detection. Keywords: electrochemical deposition, sulfonated graphene oxide, urease

  9. Influence of expanded graphite (EG) and graphene oxide (GO) on physical properties of PET based nanocomposites

    OpenAIRE

    Paszkiewicz Sandra; Nachman Małgorzata; Szymczyk Anna; Špitalský Zdeno; Mosnáček Jaroslav; Rosłaniec Zbigniew

    2014-01-01

    This work is the continuation and refinement of already published communications based on PET/EG nanocomposites prepared by in situ polymerization1, 2. In this study, nanocomposites based on poly(ethylene terephthalate) with expanded graphite were compared to those with functionalized graphite sheets (GO). The results suggest that the degree of dispersion of nanoparticles in the PET matrix has important effect on the structure and physical properties of the nanocomposites. The existence of gr...

  10. Preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage

    International Nuclear Information System (INIS)

    Konuklu, Yeliz; Ersoy, Orkun

    2016-01-01

    Highlights: • Sepiolite-based phase change material nanocomposites were prepared. • An easy direct impregnation process was used. • This paper is one of the first study about sepiolite-based phase change material nanocomposites. • Influence of PCM type on thermal properties of nanocomposites was reported. - Abstract: This paper is one of the first study about the preparation and characterization of sepiolite-based phase change material nanocomposites for thermal energy storage applications. Sepiolite is an important natural fibrous raw material. Nanoscale fibrous tubular structure of sepiolite becomes important in nanocomposite preparation. In this study, sepiolite/paraffin and sepiolite/decanoic acid nanocomposites were manufactured by the direct impregnation method. By the preparation of nanocomposites, PCM move in tubular channels of sepiolite, phase changing occurs in these tubes and surface area increases like as in microencapsulation. The structure and properties of nanocomposites PCMs (CPCM) have been characterized via scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). The SEM results prove the successful preparation of phase change material/sepiolite nanocomposites and point out that the fibers of sepiolite is modified with phase change materials in the nanocomposite. The phase change enthalpies of melting and freezing were about 62.08 J/g and −62.05 J/g for sepiolite/paraffin nanocomposites and 35.69 J/g and −34.55 J/g for sepiolite/decanoic acid nanocomposites, respectively. The results show that PCM/sepiolite nanocomposites were prepared successfully and their properties are very suitable for thermal energy storage applications.

  11. Effect of stacking sequence and surface treatment on the thermal conductivity of multilayered hybrid nano-composites

    Science.gov (United States)

    Papanicolaou, G. C.; Pappa, E. J.; Portan, D. V.; Kotrotsos, A.; Kollia, E.

    2018-02-01

    The aim of the present investigation was to study the effect of both the stacking sequence and surface treatment on the thermal conductivity of multilayered hybrid nano-composites. Four types of multilayered hybrid nanocomposites were manufactured and tested: Nitinol- CNTs (carbon nanotubes)- Acrylic resin; Nitinol- Acrylic resin- CNTs; Surface treated Nitinol- CNTs- Acrylic resin and Surface treated Nitinol- Acrylic resin- CNTs. Surface treatment of Nitinol plies was realized by means of the electrochemical anodization. Surface topography of the anodized nitinol sheets was investigated through Scanning Electron Microscopy (SEM). It was found that the overall thermal response of the manufactured multilayered nano-composites was greatly influenced by both the anodization and the stacking sequence. A theoretical model for the prediction of the overall thermal conductivity has been developed considering the nature of the different layers, their stacking sequence as well as the interfacial thermal resistance. Thermal conductivity and Differential Scanning Calorimetry (DSC) measurements were conducted, to verify the predicted by the model overall thermal conductivities. In all cases, a good agreement between theoretical predictions and experimental results was found.

  12. The modification of nanocomposite hybrid polymer surfaces by exposure to oxygen containing plasmas

    Science.gov (United States)

    Figueiredo, Ashley; Zimmermann, Katherine; Augustine, Brian; Hughes, Chris; Chusuei, Charles

    2006-11-01

    The wetting properties of the surfaces of the nanocomposite hybrid polymer poly[(propylmethacryl-heptaisobutyl- polyhedral oligomeric silsequioxane)-co-(methylmethacrylate)] (POSS-PMMA)has been studied before and after exposure to plasmas containing oxygen. The contact angle of water droplets on the surface showed a substantial decrease after plasma exposure indicating an increase in the hydrophilicity of the surface. A model was developed in which the plasma preferentially removed organic material including both the PMMA backbone and isobutyl groups from the corners of the POSS cages leaving behind a surface characterized by the silicon oxide-like POSS material. Measurements of surface concentrations of oxygen, silicon, and carbon by x-ray photoelectron spectroscopy (XPS) showed an increase in the amount of oxygen and silicon compared to carbon and the appropriate chemical shifts were observed in the XPS data to support the model of Si-O enrichment on the surface. Variable angle spectroscopic ellipsometry (VASE) and atomic force microscopy (AFM) measurements also supported the model and these results will be presented.

  13. Microstructural, mechanical, and thermal characteristics of recycled cellulose fiber-halloysite-epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.

    2012-02-26

    Epoxy hybrid-nanocomposites reinforced with recycled cellulose fibers (RCF) and halloysite nanotubes (HNTs) have been fabricated and investigated. The dispersion of HNTs was studied by synchrotron radiation diffraction (SRD) and transmission electron microscopy (TEM). The influences of RCF/HNTs dispersion on the mechanical properties and thermal properties of these composites have been characterized in terms of flexural strength, flexural modulus, fracture toughness, impact toughness, impact strength, and thermogravimetric analysis. The fracture surface morphology and toughness mechanisms were investigated by SEM. Results indicated that mechanical properties increased because of the addition of HNTs into the epoxy matrix. Flexural strength, flexural modulus, fracture toughness, and impact toughness increased by 20.8, 72.8, 56.5, and 25.0%, respectively, at 1 wt% HNTs load. The presence of RCF dramatically enhanced flexural strength, fracture toughness, impact strength, and impact toughness of the composites by 160%, 350%, 444%, and 263%, respectively. However, adding HNTs to RCF/epoxy showed only slight enhancements in flexural strength and fracture toughness. The inclusion of 5 wt% HNTs into RCF/epoxy ecocomposites increased the impact toughness by 27.6%. The presence of either HNTs or RCF accelerated the thermal degradation of neat epoxy. However, at high temperature, samples reinforced with RCF and HNTs displayed better thermal stability with increased char residue than neat resin. © 2012 Society of Plastics Engineers.

  14. Novel amperometric glucose biosensor based on MXene nanocomposite

    KAUST Repository

    Rakhi, R. B.

    2016-11-10

    A biosensor platform based on Au/MXene nanocomposite for sensitive enzymatic glucose detection is reported. The biosensor leverages the unique electrocatalytic properties and synergistic effects between Au nanoparticles and MXene sheets. An amperometric glucose biosensor is fabricated by the immobilization of glucose oxidase (GOx) enzyme on Nafion solubilized Au/ MXene nanocomposite over glassy carbon electrode (GCE). The biomediated Au nanoparticles play a significant role in facilitating the electron exchange between the electroactive center of GOx and the electrode. The GOx/Au/MXene/Nafion/GCE biosensor electrode displayed a linear amperometric response in the glucose concentration range from 0.1 to 18 mM with a relatively high sensitivity of 4.2 μAmM−1 cm−2 and a detection limit of 5.9 μM (S/N = 3). Furthermore, the biosensor exhibited excellent stability, reproducibility and repeatability. Therefore, the Au/MXene nanocomposite reported in this work is a potential candidate as an electrochemical transducer in electrochemical biosensors.

  15. Novel amperometric glucose biosensor based on MXene nanocomposite

    KAUST Repository

    Baby, Rakhi Raghavan; Nayuk, Pranati; Xia, Chuan; Alshareef, Husam N.

    2016-01-01

    A biosensor platform based on Au/MXene nanocomposite for sensitive enzymatic glucose detection is reported. The biosensor leverages the unique electrocatalytic properties and synergistic effects between Au nanoparticles and MXene sheets. An amperometric glucose biosensor is fabricated by the immobilization of glucose oxidase (GOx) enzyme on Nafion solubilized Au/ MXene nanocomposite over glassy carbon electrode (GCE). The biomediated Au nanoparticles play a significant role in facilitating the electron exchange between the electroactive center of GOx and the electrode. The GOx/Au/MXene/Nafion/GCE biosensor electrode displayed a linear amperometric response in the glucose concentration range from 0.1 to 18 mM with a relatively high sensitivity of 4.2 μAmM−1 cm−2 and a detection limit of 5.9 μM (S/N = 3). Furthermore, the biosensor exhibited excellent stability, reproducibility and repeatability. Therefore, the Au/MXene nanocomposite reported in this work is a potential candidate as an electrochemical transducer in electrochemical biosensors.

  16. Nanocomposite/Hybrid Materials of Electroactive Polymers With Inorganic Oxides for Biosensor Applications

    National Research Council Canada - National Science Library

    Wei, Yen

    2001-01-01

    As proposed, we have successfully synthesized new electroactive and electronically conductive polyaniline polymethacrylate-silica nanocomposites and fabricated biosensor devices, aimed for detecting...

  17. Synthesis and biological evaluation of PMMA/MMT nanocomposite as denture base material.

    Science.gov (United States)

    Zheng, Junping; Su, Qiang; Wang, Chen; Cheng, Gang; Zhu, Ran; Shi, Jin; Yao, Kangde

    2011-04-01

    Inorganic-polymer nanocomposites are of significant interest for emerging materials due to their improved properties and unique combination of properties. Poly (methylmethacrylate) (PMMA)/montmorillonite (MMT) nanocomposites were prepared by in situ suspension polymerization with dodecylamine used as MMT-modifier. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to characterize the structures of the nanocomposites. Cytotoxicity test, hemolysis test, acute systemic toxicity test, oral mucous membrane irritation test, guinea-pig maximization test and mouse bone-marrow micronucleus test were used to evaluate the biocompatibility of PMMA/MMT nanocomposites. The results indicated that an exfoliated nanocomposite was achieved, and the resulting nanocomposites exhibited excellent biocompatibility as denture base material and had potential application in dental materials.

  18. Epoxy based nanocomposites with fully exfoliated unmodified clay: mechanical and thermal properties.

    Science.gov (United States)

    Li, Binghai; Zhang, Xiaohong; Gao, Jianming; Song, Zhihai; Qi, Guicun; Liu, Yiqun; Qiao, Jinliang

    2010-09-01

    The unmodified clay has been fully exfoliated in epoxy resin with the aid of a novel ultrafine full-vulcanized powdered rubber. Epoxy/rubber/clay nanocomposites with exfoliated morphology have been successfully prepared. The microstructures of the nanocomposites were characterized by means of X-ray diffraction and transmission electron microscopy. It was found that the unmodified clay was fully exfoliated and uniformly dispersed in the resulting nanocomposite. Characterizations of mechanical properties revealed that the impact strength of this special epoxy/rubber/clay nanocomposite increased up 107% over the neat epoxy resin. Thermal analyses showed that thermal stability of the nanocomposite was much better than that of epoxy nanocomposite based on organically modified clay.

  19. Fe{sub 2}O{sub 3}-Poly-pyrrole hybrid nano-composite materials for super-capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Mallouki, M.; Tran-Van, F.; Sarrazin, C.; Chevrot, C. [Cergy-Pontoise Univ., Lab. de Physicochimie des Polymeres et des Interfaces (LPPI), EA 2528 95 (France); Fauvarque, J.F. [CNAM, Lab. d' Electrochimie Industrielle, 75 - Paris (France); Simon, P. [Universite Paul Sabatier, CIRIMAT-LCMIE, UMR 5085, 31 - Toulouse (France); De, A. [Saha Institute of Nuclear Physics, Calcutta (India)

    2004-07-01

    Fe{sub 2}O{sub 3}-Poly-pyrrole hybrid nano-composite materials chemically synthesized from colloid particles of iron oxide in aqueous solution have been processed to realize electrode materials for super-capacitor applications. The performances have been evaluated by cyclic voltammetry and galvano-static techniques in a three-electrode cell. The capacitance of Fe{sub 2}O{sub 3}-PPy hybrid nano-composite doped with para-toluene-sulfonate reaches 47 mAh/g in PC/NEt{sub 4}BF{sub 4} with a good stability during cycling (loss of 3% after 1000 cycles). Transmission Electronic Microscopy indicates a porous nano-structure with spherical particles in a range of 400-500 nm which ensures a good accessibility of the electrolyte in the bulk of the electro-active hybrid material. Preliminary studies with room temperature ionic liquid show promising results since the specific capacitance reaches 427 F/g in 1- ethyl-3-methyl-imidazolium bis((tri-fluoro-methyl)sulfonyl)amide (EMITFSI). (authors)

  20. Inorganic/organic hybrid nanocomposite coating applications: Formulation, characterization, and evaluation

    Science.gov (United States)

    Eyassu, Tsehaye

    Nanotechnology applications in coatings have shown significant growth in recent years. Systematic incorporation of nano-sized inorganic materials into polymer coating enhances optical, electrical, thermal and mechanical properties significantly. The present dissertation will focus on formulation, characterization and evaluation of inorganic/organic hybrid nanocomposite coatings for heat dissipation, corrosion inhibition and ultraviolet (UV) and near infrared (NIR) cut applications. In addition, the dissertation will cover synthesis, characterization and dispersion of functional inorganic fillers. In the first project, we investigated factors that can affect the "Molecular Fan" cooling performance and efficiency. The investigated factors and conditions include types of nanomaterials, size, loading amount, coating thickness, heat sink substrate, substrate surface modification, and power input. Using the optimal factors, MF coating was formulated and applied on commercial HDUs, and cooling efficiencies up to 22% and 23% were achieved using multi-walled carbon nanotube and graphene fillers. The result suggests that molecular fan action can reduce the size and mass of heat-sink module and thus offer a low cost of LED light unit. In the second project, we report the use of thin organic/inorganic hybrid coating as a protection for corrosion and as a thermal management to dissipate heat from galvanized steel. Here, we employed the in-situ phosphatization method for corrosion inhibition and "Molecular fan" technique to dissipate heat from galvanized steel panels and sheets. Salt fog tests reveal successful completion of 72 hours corrosion protection time frame for samples coated with as low as ~0.7microm thickness. Heat dissipation measurement shows 9% and 13% temperature cooling for GI and GL panels with the same coating thickness of ~0.7microm respectively. The effect of different factors, in-situ phosphatization reagent (ISPR), cross-linkers and nanomaterial on corrosion

  1. A hybrid molecularly imprinted polymer coated quantum dot nanocomposite optosensor for highly sensitive and selective determination of salbutamol in animal feeds and meat samples.

    Science.gov (United States)

    Raksawong, Phannika; Chullasat, Kochaporn; Nurerk, Piyaluk; Kanatharana, Proespichaya; Davis, Frank; Bunkoed, Opas

    2017-08-01

    A hybrid molecularly imprinted polymer (MIP)-coated quantum dot (QD) nanocomposite was synthesized and applied as a fluorescence probe for the highly sensitive and selective determination of salbutamol. The hybrid MIP-coated QD nanocomposite was synthesized via a copolymerization process in the presence of thioglycolic acid capped CdTe QDs with salbutamol as a template, 3-aminopropyltriethoxysilane as the functional monomer, and tetraethyl orthosilicate as a cross-linker. The optimum molar ratio of template, monomer, and cross-linker was 1:6:20. The fluorescence intensity of the hybrid MIP-coated QDs was efficiently quenched after salbutamol rebound to the recognition sites, as a result of charge transfer from QDs to salbutamol. The synthesized hybrid MIP-coated QD nanocomposite showed high sensitivity and good selectivity toward salbutamol. Under the optimal recognition conditions, the fluorescence intensity was quenched linearly with increasing concentration of salbutamol in the range from 0.10 to 25.0 μg L -1 , with a detection limit of 0.034 μg L -1 . The hybrid optosensor developed was successfully applied in the determination of salbutamol in animal feeds and meat samples. Satisfactory recoveries were obtained in the range from 85% to 98%, with a standard deviation of less than 8%. Furthermore, the accuracy of the hybrid MIP-coated QD nanocomposite was investigated by comparison with a conventional high-performance liquid chromatography method, with the results obtained with two methods agreeing well with each other. The advantages of this sensing method are simplicity, rapidity, cost-effectiveness, high sensitivity, and good selectivity. Graphical Abstract The synthesis of hybrid MIP-coated QDs nanocomposite.

  2. Self-cleaning performance of superhydrophobic hybrid nanocomposite coatings on Al with excellent corrosion resistance

    International Nuclear Information System (INIS)

    Raj, V.; Mohan Raj, R.

    2016-01-01

    Highlights: • Ceramic-poly(Ani-co-oPD) coatings were formed on Al by anodization and electro-polymerisation techniques. • The superhydrophobic coating was fabricated on copolymer by electrodeposition of zinc stearate. • The superhydrophobicity mechanism relies on morphologies and chemical components on surface is the key factor. • Ceramic-poly(Ani-co-oPD)-zinc stearate coated Al has excellent corrosion resistance and good self-cleaning performance. - Abstract: Protective ceramic-PANI, ceramic-poly(Ani-co-oPD) and ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coatings were formed on Al surface by the processes involving anodization, electropolymerisation and electrodeposition under optimum conditions. The prepared nanocomposite coatings were evaluated by ATR-IR and XRD studies. SEM studies performed on nanocomposite coatings reveal that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating shows a cauliflower-like cluster with crack-free morphology compared to ceramic-PANI and ceramic-poly(Ani-co-oPD) nanocomposite coatings. The mechanical properties of different nanocomposite coatings were measured using Vicker microhardness tester and Taber Abrasion tester. The ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite has higher mechanical stability. The corrosion resistance of the coatings measured by Tafel polarization and electrochemical impedance spectroscopy, shows that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coated aluminum has higher corrosion resistance than other coatings and bare Al. Wettability studies prove that superhydrophobic nature of ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating with contact angle of 155.8° is responsible for good self-cleaning property and excellent corrosion resistance of aluminum.

  3. Self-cleaning performance of superhydrophobic hybrid nanocomposite coatings on Al with excellent corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Raj, V., E-mail: alaguraj2@rediffmail.com; Mohan Raj, R., E-mail: chem_mohan@rediffmail.com

    2016-12-15

    Highlights: • Ceramic-poly(Ani-co-oPD) coatings were formed on Al by anodization and electro-polymerisation techniques. • The superhydrophobic coating was fabricated on copolymer by electrodeposition of zinc stearate. • The superhydrophobicity mechanism relies on morphologies and chemical components on surface is the key factor. • Ceramic-poly(Ani-co-oPD)-zinc stearate coated Al has excellent corrosion resistance and good self-cleaning performance. - Abstract: Protective ceramic-PANI, ceramic-poly(Ani-co-oPD) and ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coatings were formed on Al surface by the processes involving anodization, electropolymerisation and electrodeposition under optimum conditions. The prepared nanocomposite coatings were evaluated by ATR-IR and XRD studies. SEM studies performed on nanocomposite coatings reveal that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating shows a cauliflower-like cluster with crack-free morphology compared to ceramic-PANI and ceramic-poly(Ani-co-oPD) nanocomposite coatings. The mechanical properties of different nanocomposite coatings were measured using Vicker microhardness tester and Taber Abrasion tester. The ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite has higher mechanical stability. The corrosion resistance of the coatings measured by Tafel polarization and electrochemical impedance spectroscopy, shows that ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coated aluminum has higher corrosion resistance than other coatings and bare Al. Wettability studies prove that superhydrophobic nature of ceramic-poly(Ani-co-oPD)-zinc stearate nanocomposite coating with contact angle of 155.8° is responsible for good self-cleaning property and excellent corrosion resistance of aluminum.

  4. PVDF-PZT nanocomposite film based self-charging power cell.

    Science.gov (United States)

    Zhang, Yan; Zhang, Yujing; Xue, Xinyu; Cui, Chunxiao; He, Bin; Nie, Yuxin; Deng, Ping; Lin Wang, Zhong

    2014-03-14

    A novel PVDF-PZT nanocomposite film has been proposed and used as a piezoseparator in self-charging power cells (SCPCs). The structure, composed of poly(vinylidene fluoride) (PVDF) and lead zirconate titanate (PZT), provides a high piezoelectric output, because PZT in this nanocomposite film can improve the piezopotential compared to the pure PVDF film. The SCPC based on this nanocomposite film can be efficiently charged up by the mechanical deformation in the absence of an external power source. The charge capacity of the PVDF-PZT nanocomposite film based SCPC in 240 s is ∼0.010 μA h, higher than that of a pure PVDF film based SCPC (∼0.004 μA h). This is the first demonstration of using PVDF-PZT nanocomposite film as a piezoseparator for SCPC, and is an important step for the practical applications of SCPC for harvesting and storing mechanical energy.

  5. Hybrid Nanocomposites of 2D Black Phosphorous Nanosheets Encapsulated in PMMA Polymer Material: New Platforms for Advanced Device Fabrication.

    Science.gov (United States)

    Telesio, Francesca; Passaglia, Elisa; Cicogna, Francesca; Costantino, Federica; Serrano-Ruiz, Manuel; Peruzzini, Maurizio; Heun, Stefan

    2018-04-12

    Hybrid materials, containing a 2D filler embedded in a polymeric matrix, are an interesting platform for several applications, because of the variety of properties that the filler can impart to the polymer matrix when dispersed at the nanoscale. Moreover, novel properties could arise from the interaction between the two. Mostly the bulk properties of these materials have been studied so far, especially focusing on how the filler changes the polymeric matrix properties. Here we propose a complete change of perspective by using the hybrid nanocomposite material as a platform suitable to engineer the properties of the filler and to exploit its potential in the fabrication of devices. As a proof of concept of the versatility and potentiality of the new method, we applied this approach to prepare black phosphorus nanocomposites through its dispersion in poly (methyl methacrylate). Black phosphorus is a very interesting 2D material, whose application have so far been limited by its very high reactivity to oxygen and water. In this respect, we show that electronic-grade black phosphorus flakes, already embedded in a protecting matrix since their exfoliation from the bulk material, are endowed with significant increased stability, and can be further processed into devices without degrading their properties. Creative Commons Attribution license.

  6. EFFECT OF IMMERSION TEMPERATURE ON THE WATER UPTAKE OF POLYPROPYLENE/WOOD FLOUR/ORGANOCLAY HYBRID NANOCOMPOSITE

    Directory of Open Access Journals (Sweden)

    Behzad Kord

    2011-02-01

    Full Text Available Polypropylene/wood flour/organoclay hybrid nanocomposites were melt-compounded in an internal mixer at 190 oC and 60 rpm rotor speed. Then samples were fabricated by injection molding. Effects of immersion temperature on the water uptake of hybrid nanocomposite were investigated. To meet this objective, water absorption of samples was determined after 24 h immersion in distilled water at different temperatures (25, 50, 75, and 100 °C. Results indicated that immersion temperature had a significant influence on the water absorption of composites. By increasing the temperature, water absorption increases as well. The maximum water absorption of composite is decreased by increasing the nanoclay and compatibilizer content. The morphology of nanoclay was determined by X-ray diffraction (XRD and transmission electron microscopy. The effect of morphology on water absorption was also evaluated. Due to inadequate compatibilizer, exfoliated morphology of nanoclay was not obtained, but there was evidence of intercalation. The order of intercalation for samples containing 3 phc was higher than that of 6 phc at the same PP-g-MA content due to some agglomerations of organoclay.

  7. Investigation of a Mesoporous Silicon Based Ferromagnetic Nanocomposite

    Directory of Open Access Journals (Sweden)

    Roca AG

    2009-01-01

    Full Text Available Abstract A semiconductor/metal nanocomposite is composed of a porosified silicon wafer and embedded ferromagnetic nanostructures. The obtained hybrid system possesses the electronic properties of silicon together with the magnetic properties of the incorporated ferromagnetic metal. On the one hand, a transition metal is electrochemically deposited from a metal salt solution into the nanostructured silicon skeleton, on the other hand magnetic particles of a few nanometres in size, fabricated in solution, are incorporated by immersion. The electrochemically deposited nanostructures can be tuned in size, shape and their spatial distribution by the process parameters, and thus specimens with desired ferromagnetic properties can be fabricated. Using magnetite nanoparticles for infiltration into porous silicon is of interest not only because of the magnetic properties of the composite material due to the possible modification of the ferromagnetic/superparamagnetic transition but also because of the biocompatibility of the system caused by the low toxicity of both materials. Thus, it is a promising candidate for biomedical applications as drug delivery or biomedical targeting.

  8. Preparation, characterization and X-ray attenuation property of Gd2O3-based nanocomposites

    Science.gov (United States)

    Jayakumar, Sangeetha; Saravanan, T.; Philip, John

    2017-11-01

    In an attempt to develop an alternate to lead-based X-ray shielding material, we describe the X-ray attenuation property of nanocomposites containing Gd2O3 as nanofiller and silicone resin as matrix, prepared by a simple solution-casting technique. Gd2O3 nanoparticles of size 30 and 56 nm are used at concentrations of 25 and 2.5 wt%. The nanoparticles and the nanocomposites are characterized using X-ray diffraction (XRD) studies, small angle X-ray spectroscopy (SAXS), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and atomic force microscopy (AFM). The X-ray attenuation property of nanocomposites, studied using an industrial X-ray unit, shows that nanocomposites containing nanoparticles of size 56 nm (G2) exhibit better attenuation than nanocomposites containing nanoparticles of size 30 nm (G1), which is attributed to the greater interfacial interaction between the G2 nanofillers and silicone matrix. In the case of nanocomposites containing G1 nanoparticles, the interfacial interaction between the nanofiller and the matrix is so weak that it results in pulling out of nanofillers, causing voids in the matrix, which act as X-ray transparent region, thereby reducing the overall X-ray attenuation property of G1 nanocomposites. This is further corroborated from the AFM images of the nanocomposites. The weight loss and heat flow curves of pure silicone matrix and the nanocomposites containing Gd2O3 nanoparticles of size 30 and 56 nm show the degradation of silicone resin, due to chain scission, between 403 and 622 °C. The same onset temperature (403 °C) of degradation of matrix with and without nanoparticles shows that the addition of nanofillers to the matrix does not deteriorate the thermal stability of the matrix. This confirms the thermal stability of nanocomposites. Therefore, our study shows that nanocomposites containing G2 nanoparticles are potential candidates for the development of X-ray opaque fabric material.

  9. Biocompatible epoxy modified bio-based polyurethane nanocomposites: mechanical property, cytotoxicity and biodegradation.

    Science.gov (United States)

    Dutta, Suvangshu; Karak, Niranjan; Saikia, Jyoti Prasad; Konwar, Bolin Kumar

    2009-12-01

    Epoxy modified Mesua ferrea L. seed oil (MFLSO) based polyurethane nanocomposites with different weight % of clay loadings (1%, 2.5% and 5%) have been evaluated as biocompatible materials. The nanocomposites were prepared by ex situ solution technique under high mechanical shearing and ultrasonication at room temperature. The partially exfoliated nanocomposites were characterized by Fourier transform infra-red (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The mechanical properties such as tensile strength and scratch hardness were improved 2 and 5 times, respectively by nanocomposites formation. Even the impact resistance improved a little. The thermostability of the nanocomposites was enhanced by about 40 degrees C. Biodegradation study confirmed 5-10 fold increase in biodegradation rate for the nanocomposites compared to the pristine polymers. All the nanocomposites showed non-cytotoxicity as evident from RBC hemolysis inhibition observed in anti-hemolytic assay carried over the sterilized films. The study reveals that the epoxy modified MFLSO based polyurethane nanocomposites deserve the potential to be applicable as biomaterials.

  10. Ternary hybrid polymeric nanocomposites through grafting of polystyrene on graphene oxide-TiO{sub 2} by surface initiated atom transfer radical polymerization (SI-ATRP)

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Arvind; Bansal, Ankushi; Behera, Babita; Jain, Suman L.; Ray, Siddharth S., E-mail: ssray@iip.res.in

    2016-04-01

    A ternary hybrid of graphene oxide-titania-polystyrene (GO-TiO{sub 2}-PS) nanocomposite is developed where polystyrene composition is regulated by controlling growth of polymer chains and nanoarchitectonics is discussed. Graphene Oxide-TiO{sub 2} (GO-TiO{sub 2}) nanocomposite is prepared by in-situ hydrothermal method and the surface is anchored with α-bromoisobutyryl bromide to activate GO-TiO{sub 2} as initiator for polymerization. In-situ grafting of polystyrene through surface initiated atom transfer radical polymerization (SI- ATRP) on this Br-functionalized nano-composite initiator yields GO-TiO{sub 2}-PS ternary hybrid. Varying the monomer amount and keeping the concentration of initiator constant, polystyrene chain growth is regulated with narrow poly-dispersivity to achieve desired composition. This composite is well characterized by various analytical techniques like FTIR, XRD, DSC, SEM, TEM, and TGA. - Highlights: • Nanocomposite of ternary hybrid of GO-TiO{sub 2} with polystyrene. • PS is surface grafted on GO-TiO{sub 2}. • Polymer chain lengths are well regulated by SI-ATRP living polymerization. • Thermal stability of this hybrid is relatively high.

  11. Ternary hybrid polymeric nanocomposites through grafting of polystyrene on graphene oxide-TiO_2 by surface initiated atom transfer radical polymerization (SI-ATRP)

    International Nuclear Information System (INIS)

    Kumar, Arvind; Bansal, Ankushi; Behera, Babita; Jain, Suman L.; Ray, Siddharth S.

    2016-01-01

    A ternary hybrid of graphene oxide-titania-polystyrene (GO-TiO_2-PS) nanocomposite is developed where polystyrene composition is regulated by controlling growth of polymer chains and nanoarchitectonics is discussed. Graphene Oxide-TiO_2 (GO-TiO_2) nanocomposite is prepared by in-situ hydrothermal method and the surface is anchored with α-bromoisobutyryl bromide to activate GO-TiO_2 as initiator for polymerization. In-situ grafting of polystyrene through surface initiated atom transfer radical polymerization (SI- ATRP) on this Br-functionalized nano-composite initiator yields GO-TiO_2-PS ternary hybrid. Varying the monomer amount and keeping the concentration of initiator constant, polystyrene chain growth is regulated with narrow poly-dispersivity to achieve desired composition. This composite is well characterized by various analytical techniques like FTIR, XRD, DSC, SEM, TEM, and TGA. - Highlights: • Nanocomposite of ternary hybrid of GO-TiO_2 with polystyrene. • PS is surface grafted on GO-TiO_2. • Polymer chain lengths are well regulated by SI-ATRP living polymerization. • Thermal stability of this hybrid is relatively high.

  12. Preparation, Characterization, and Electrochromic Properties of Nanocellulose-Based Polyaniline Nanocomposite Films.

    Science.gov (United States)

    Zhang, Sihang; Sun, Gang; He, Yongfeng; Fu, Runfang; Gu, Yingchun; Chen, Sheng

    2017-05-17

    On the basis of nanocellulose obtained by acidic swelling and ultrasonication, rodlike nanocellulose/polyaniline nanocomposites with a core-shell structure have been prepared via in situ polymerization. Compared to pure polyaniline, the nanocomposites show superior film-forming properties, and the prepared nanocomposite films demonstrate excellent electrochemical and electrochromic properties in electrolyte solution. Nanocomposite films, especially the one prepared with 40% polyaniline coated nanocomposite, exhibited faster response time (1.5 s for bleaching and 1.0 s for coloring), higher optical contrast (62.9%), higher coloration efficiency (206.2 cm 2 /C), and more remarkable switching stability (over 500 cycles). These novel nanocellulose-based nanorod network films are promising novel electrochromic materials with excellent properties.

  13. Biobased Epoxy Nanocomposites Derived from Lignin-Based Monomers.

    Science.gov (United States)

    Zhao, Shou; Abu-Omar, Mahdi M

    2015-07-13

    Biobased epoxy nanocomposites were synthesized based on 2-methoxy-4-propylphenol (dihydroeugenol, DHE), a molecule that has been obtained from the lignin component of biomass. To increase the content of hydroxyl groups, DHE was o-demethylated using aqueous HBr to yield propylcatechol (DHEO), which was subsequently glycidylated to epoxy monomer. Optimal conditions in terms of yield and epoxy equivalent weight were found to be 60 °C with equal NaOH/phenolic hydroxyl molar ratio. The structural evolution from DHE to cured epoxy was followed by (1)H NMR and Fourier transform infrared spectroscopy. The nano-montmorillonite modified DHEO epoxy exhibited improved storage modulus and thermal stability as determined from dynamic mechanical analysis and thermogravimetric analysis. This study widens the synthesis routes of biobased epoxy thermosets from lignin-based molecules.

  14. Modeling and Optimization of NLDH/PVDF Ultrafiltration Nanocomposite Membrane Using Artificial Neural Network-Genetic Algorithm Hybrid.

    Science.gov (United States)

    Arefi-Oskoui, Samira; Khataee, Alireza; Vatanpour, Vahid

    2017-07-10

    In this research, MgAl-CO 3 2- nanolayered double hydroxide (NLDH) was synthesized through a facile coprecipitation method, followed by a hydrothermal treatment. The prepared NLDHs were used as a hydrophilic nanofiller for improving the performance of the PVDF-based ultrafiltration membranes. The main objective of this research was to obtain the optimized formula of NLDH/PVDF nanocomposite membrane presenting the best performance using computational techniques as a cost-effective method. For this aim, an artificial neural network (ANN) model was developed for modeling and expressing the relationship between the performance of the nanocomposite membrane (pure water flux, protein flux and flux recovery ratio) and the affecting parameters including the NLDH, PVP 29000 and polymer concentrations. The effects of the mentioned parameters and the interaction between the parameters were investigated using the contour plot predicted with the developed model. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and water contact angle techniques were applied to characterize the nanocomposite membranes and to interpret the predictions of the ANN model. The developed ANN model was introduced to genetic algorithm (GA) as a bioinspired optimizer to determine the optimum values of input parameters leading to high pure water flux, protein flux, and flux recovery ratio. The optimum values for NLDH, PVP 29000 and the PVDF concentration were determined to be 0.54, 1, and 18 wt %, respectively. The performance of the nanocomposite membrane prepared using the optimum values proposed by GA was investigated experimentally, in which the results were in good agreement with the values predicted by ANN model with error lower than 6%. This good agreement confirmed that the nanocomposite membranes prformance could be successfully modeled and optimized by ANN-GA system.

  15. Synthesis and characterization of nanocomposites based on poly(3 ...

    Indian Academy of Sciences (India)

    The structure and morphologies of LNMO/P3HT- g -CNTs nanocomposites have also been performed by SEM, XRD and TEM. The electrochemical performance of LNMO/P3HT- g -CNTs nanocomposites as cathode materials of lithium-ion batteries were investigated by cyclic voltammetry and electrochemical impedance ...

  16. Synthesis and characterization of nanocomposites based on PANI and carbon nanostructures prepared by electropolymerization

    Energy Technology Data Exchange (ETDEWEB)

    Petrovski, Aleksandar; Paunović, Perica [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of); Avolio, Roberto; Errico, Maria E.; Cocca, Mariacristina; Gentile, Gennaro [Institute for Polymers, Composites and Biomaterials, National Research Council, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli (Italy); Grozdanov, Anita, E-mail: anita.grozdanov@yahoo.com [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of); Avella, Maurizio [Institute for Polymers, Composites and Biomaterials, National Research Council, Via Campi Flegrei 34, 80078, Pozzuoli, Napoli (Italy); Barton, John [Tyndall National Institute, University College Cork, Dyke Parade, T12 R5CP, Cork (Ireland); Dimitrov, Aleksandar [Faculty of Technology and Metallurgy, SS Cyril and Methodius University, Rudjer Bošković, 16, 1000, Skopje (Macedonia, The Former Yugoslav Republic of)

    2017-01-01

    Nanocomposites based on polyaniline (PANI) and carbon nanostructures (CNSs) (graphene (G) and multiwall carbon nanotubes (MWCNTs)) were prepared by in situ electrochemical polymerization. CNSs were inserted into the PANI matrix by dispersing them into the electrolyte before the electropolymerization. Electrochemical characterization by means of cyclic voltammetry and steady state polarization were performed in order to determine conditions for electro-polymerization. Electro-polymerization of the PANI based nanocomposites was carried out at 0.75 V vs. saturated calomel electrode (SCE) for 40 and 60 min. The morphology and structural characteristics of the obtained nanocomposites were studied by scanning electron microscopy (SEM) and Raman spectroscopy, while thermal stability was determined using thermal gravimetric analysis (TGA). According to the morphological and structural study, fibrous and porous structure of PANI based nanocomposites was detected well embedding both G and MWCNTs. Also, strong interaction between quinoidal structure of PANI with carbon nanostructures via π–π stacking was detected by Raman spectroscopy. TGA showed the increased thermal stability of composites reinforced with CNSs, especially those reinforced with graphene. - Highlights: • Nanocomposites of PANI with carbon nanostructures were prepared for sensing application. • By cyclic voltammetry, conductive form of PANI (green colored emeraldine phase) is obtained 0.75 V • Using 4 Probe method, nanocomposite PANI/CNS tablet was tested for sensing application. • Micro-structural properties of nanocomposites were studied by SEM, TGA and Raman analysis.

  17. Preparation, characterization, and nonlinear optical properties of hybridized graphene @ gold nanorods nanocomposites

    Science.gov (United States)

    Guo, Jia; Ning, Tingyin; Han, Yanshun; Sheng, Yingqiang; Li, Chonghui; Zhao, Xiaofei; Lu, Zhengyi; Man, Baoyuan; Jiao, Yang; Jiang, Shouzhen

    2018-03-01

    The methods of chemical vapor deposition (CVD) and seed-mediated growth were used to obtain graphene and gold nanorods (GNRs), respectively. We fabricate graphene @ gold nanorods (G@GNRs) nanocomposites by successively using dropping and transferring methods Through SEM, Raman spectra and TEM analysis, the number of graphene layers is 6-7. The diameter of gold nanorods (GNRs) is about 10 nm and the average aspect ratio is 6.5. In addition, we systematically investigate their nonlinear optical responses by using open-aperture Z-scan technique. In contrast with graphene and GNRs, the G@GNRs nanocomposites exhibit excellent nonlinear optical response with a modulation depth of about 51% and a saturable intensity of about 6.23 GW/cm2. The results suggest that the G@GNRs nanocomposites could potentially be used as an optical modulator in pulsed laser generation.

  18. PET based nanocomposite films for microwave packaging applications

    International Nuclear Information System (INIS)

    Galdi, M. R.; Olivieri, R.; Liguori, L.; Albanese, D.; Di Matteo, M.; Di Maio, L.

    2015-01-01

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET

  19. PET based nanocomposite films for microwave packaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Galdi, M. R., E-mail: mrgaldi@unisa.it; Olivieri, R.; Liguori, L.; Albanese, D., E-mail: dalbanese@unisa.it; Di Matteo, M.; Di Maio, L., E-mail: ldimaio@unisa.it [Industrial Engineering Department, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (Italy)

    2015-12-17

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET.

  20. PET based nanocomposite films for microwave packaging applications

    Science.gov (United States)

    Galdi, M. R.; Olivieri, R.; Liguori, L.; Albanese, D.; Di Matteo, M.; Di Maio, L.

    2015-12-01

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET.

  1. An ultrasensitive electrochemical DNA biosensor based on a copper oxide nanowires/single-walled carbon nanotubes nanocomposite

    International Nuclear Information System (INIS)

    Chen, Mei; Hou, Changjun; Huo, Danqun; Yang, Mei; Fa, Huanbao

    2016-01-01

    Graphical abstract: A novel and sensitive electrochemical biosensor based on hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH) was first developed for the detection of the specific-sequence target DNA. This schematic represents the fabrication procedure of our DNA biosensor. - Highlights: • An ultrasensitive DNA electrochemical biosensor was developed. • CuO NWs entangled with the SWCNTs formed a mesh structure with good conductivity. • It is the first time use of CuONWs-SWCNTs hybrid nanocomposite for DNA detection. • The biosensor is simple, selective, stable, and sensitive. • The biosensor has great potential for use in analysis of real samples. - Abstract: Here, we developed a novel and sensitive electrochemical biosensor to detect specific-sequence target DNA. The biosensor was based on a hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH). The resulting CuO NWs/SWCNTs layers exhibited a good differential pulse voltammetry (DPV) current response for the target DNA sequences, which we attributed to the properties of CuO NWs and SWCNTs. CuO NWs and SWCNTs hybrid composites with highly conductive and biocompatible nanostructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). Immobilization of the probe DNA on the electrode surface was largely improved due to the unique synergetic effect of CuO NWs and SWCNTs. DPV was applied to monitor the DNA hybridization event, using adriamycin as an electrochemical indicator. Under optimal conditions, the peak currents of adriamycin were linear with the logarithm of target DNA concentrations (ranging from 1.0 × 10"−"1"4 to 1.0 × 10"−"8 M), with a detection limit of 3.5 × 10"−"1"5 M (signal/noise ratio of 3). The biosensor also showed high selectivity to

  2. An ultrasensitive electrochemical DNA biosensor based on a copper oxide nanowires/single-walled carbon nanotubes nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mei [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Hou, Changjun, E-mail: houcj@cqu.edu.cn [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology, Chongqing University, Chongqing 400044 (China); Huo, Danqun [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); National Key Laboratory of Fundamental Science of Micro/Nano-Device and System Technology, Chongqing University, Chongqing 400044 (China); Yang, Mei [Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Chongqing 400044 (China); Fa, Huanbao [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044 (China)

    2016-02-28

    Graphical abstract: A novel and sensitive electrochemical biosensor based on hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH) was first developed for the detection of the specific-sequence target DNA. This schematic represents the fabrication procedure of our DNA biosensor. - Highlights: • An ultrasensitive DNA electrochemical biosensor was developed. • CuO NWs entangled with the SWCNTs formed a mesh structure with good conductivity. • It is the first time use of CuONWs-SWCNTs hybrid nanocomposite for DNA detection. • The biosensor is simple, selective, stable, and sensitive. • The biosensor has great potential for use in analysis of real samples. - Abstract: Here, we developed a novel and sensitive electrochemical biosensor to detect specific-sequence target DNA. The biosensor was based on a hybrid nanocomposite consisting of copper oxide nanowires (CuO NWs) and carboxyl-functionalized single-walled carbon nanotubes (SWCNTs-COOH). The resulting CuO NWs/SWCNTs layers exhibited a good differential pulse voltammetry (DPV) current response for the target DNA sequences, which we attributed to the properties of CuO NWs and SWCNTs. CuO NWs and SWCNTs hybrid composites with highly conductive and biocompatible nanostructure were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and cyclic voltammetry (CV). Immobilization of the probe DNA on the electrode surface was largely improved due to the unique synergetic effect of CuO NWs and SWCNTs. DPV was applied to monitor the DNA hybridization event, using adriamycin as an electrochemical indicator. Under optimal conditions, the peak currents of adriamycin were linear with the logarithm of target DNA concentrations (ranging from 1.0 × 10{sup −14} to 1.0 × 10{sup −8} M), with a detection limit of 3.5 × 10{sup −15} M (signal/noise ratio of 3). The biosensor also showed high

  3. Biphenyl liquid crystalline epoxy resin as a low-shrinkage resin-based dental restorative nanocomposite.

    Science.gov (United States)

    Hsu, Sheng-Hao; Chen, Rung-Shu; Chang, Yuan-Ling; Chen, Min-Huey; Cheng, Kuo-Chung; Su, Wei-Fang

    2012-11-01

    Low-shrinkage resin-based photocurable liquid crystalline epoxy nanocomposite has been investigated with regard to its application as a dental restoration material. The nanocomposite consists of an organic matrix and an inorganic reinforcing filler. The organic matrix is made of liquid crystalline biphenyl epoxy resin (BP), an epoxy resin consisting of cyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (ECH), the photoinitiator 4-octylphenyl phenyliodonium hexafluoroantimonate and the photosensitizer champhorquinone. The inorganic filler is silica nanoparticles (∼70-100 nm). The nanoparticles were modified by an epoxy silane of γ-glycidoxypropyltrimethoxysilane to be compatible with the organic matrix and to chemically bond with the organic matrix after photo curing. By incorporating the BP liquid crystalline (LC) epoxy resin into conventional ECH epoxy resin, the nanocomposite has improved hardness, flexural modulus, water absorption and coefficient of thermal expansion. Although the incorporation of silica filler may dilute the reinforcing effect of crystalline BP, a high silica filler content (∼42 vol.%) was found to increase the physical and chemical properties of the nanocomposite due to the formation of unique microstructures. The microstructure of nanoparticle embedded layers was observed in the nanocomposite using scanning and transmission electron microscopy. This unique microstructure indicates that the crystalline BP and nanoparticles support each other and result in outstanding mechanical properties. The crystalline BP in the LC epoxy resin-based nanocomposite was partially melted during exothermic photopolymerization, and the resin expanded via an order-to-disorder transition. Thus, the post-gelation shrinkage of the LC epoxy resin-based nanocomposite is greatly reduced, ∼50.6% less than in commercialized methacrylate resin-based composites. This LC epoxy nanocomposite demonstrates good physical and chemical properties and good biocompatibility

  4. Performance enhancement of quantum dot-sensitized solar cells based on polymer nano-composite catalyst

    International Nuclear Information System (INIS)

    Seo, Hyunwoong; Gopi, Chandu V.V.M.; Kim, Hee-Je; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu

    2017-01-01

    Highlights: •We studied polymer nano-composite containing TiO 2 nano-particles as a catalyst. •Polymer nano-composite was applied for quantum dot-sensitized solar cells. •Polymer nano-composite catalyst was considerably improved with TiO 2 nano-particles. •Polymer nano-composite showed higher photovoltaic performance than conventional Au. -- Abstract: Polymer nano-composite composed of poly(3,4-ethylenedioxythiophene):poly (styrenesulfonate) and TiO 2 nano-particles was deposited on fluorine-doped tin oxide substrate and applied as an alternative to Au counter electrode of quantum dot-sensitized solar cell (QDSC). It became surface-richer with the increase in nano-particle amount so that catalytic reaction was increased by widened catalytic interface. Electrochemical impedance spectroscopy and cyclic voltammetry clearly demonstrated the enhancement of polymer nano-composite counter electrode. A QDSC based on polymer nano-composite counter electrode showed 0.56 V of V OC , 12.24 mA cm −2 of J SC , 0.57 of FF, and 3.87% of efficiency and this photovoltaic performance was higher than that of QDSC based on Au counter electrode (3.75%).

  5. Hybrid density functional study on the mechanism for the enhanced photocatalytic properties of the ultrathin hybrid layered nanocomposite g-C3N4/BiOCl

    Science.gov (United States)

    Yao, Wenzhi; Zhang, Jihua; Wang, Yuanxu; Ren, Fengzhu

    2018-03-01

    To investigate the origin of the high photocatalytic performance of experimentally synthesized g-C3N4/ BiOCl, we studied its geometry structure, electronic structure, and photocatalytic properties by means of hybrid density-functional theory (DFT). The calculated band alignment of g-C3N4 and few-layer BiOCl sheets clearly shows that g-C3N4/ BiOCl is a standard type-II nanocomposite. The density of states, Bader charge, partial charge density, charge density difference, and the effective masses show that electron-hole pair can be effectively separated in the g-C3N4/BiOCl interface. The calculated absorption coefficients indicate an obvious redshift of the absorption edge. The band gap of g-C3N4/BiOCl can be modulated by external electric field, and a semiconductor-semimetal transition is observed. The type-II vdW heterostructure is still maintained during the changes of external electric field. Especially, when the electric field reaches to +0.7 V/Å, the impurity states have been eliminated with the band gap of 2.3 eV. An analysis of optical properties shows that the absorption coefficient in the visible-light region is enhanced considerably as the electric-field strength increases. Our calculation results suggest that the ultrathin hybrid layered g-C3N4/BiOCl nanocomposite may have significant advantages for visible-light photocatalysis.

  6. Polylactide-based polyurethane shape memory nanocomposites (Fe3O4/PLAUs) with fast magnetic responsiveness

    International Nuclear Information System (INIS)

    Gu, Shu-Ying; Jin, Sheng-Peng; Gao, Xie-Feng; Mu, Jian

    2016-01-01

    Polylactide-based polyurethane shape memory nanocomposites (Fe 3 O 4 /PLAUs) with fast magnetic responsiveness are presented. For the purpose of fast response and homogeneous dispersion of magnetic nanoparticles, oleic acid was used to improve the dispersibility of Fe 3 O 4 nanoparticles in a polymer matrix. A homogeneous distribution of Fe 3 O 4 nanoparticles in the polymer matrix was obtained for nanocomposites with low Fe 3 O 4 loading content. A small agglomeration was observed for nanocomposites with 6 wt% and 9 wt% loading content, leading to a small decline in the mechanical properties. PLAU and its nanocomposites have glass transition around 52 °C, which can be used as the triggering temperature. PLAU and its nanocomposites have shape fixity ratios above 99%, shape recovery ratios above 82% for the first cycle and shape recovery ratios above 91% for the second cycle. PLAU and its nanocomposites also exhibit a fast water bath or magnetic responsiveness. The magnetic recovery time decreases with an increase in the loading content of Fe 3 O 4 nanoparticles due to an improvement in heating performance for increased weight percentage of fillers. The nanocomposites have fast responses in an alternating magnetic field and have potential application in biomedical areas such as intravascular stent. (paper)

  7. Environmental implications and applications of engineered nanoscale magnetite and its hybrid nanocomposites: A review of recent literature

    Energy Technology Data Exchange (ETDEWEB)

    Su, Chunming, E-mail: su.chunming@epa.gov

    2017-01-15

    Highlights: • Environmental impact of engineered MNPs. • MNPs and their hybrids explored for use in energy, analytical chemistry, and catalysis. • Surface modification to MNPs allow biocompatible applications. • Adsorptive and separative removal of a wide range of contaminants from aquatic environments. • Active remediation and natural attenuation of contaminants in soil and groundwater using MNPs. - Abstract: This review focuses on environmental implications and applications of engineered magnetite (Fe{sub 3}O{sub 4}) nanoparticles (MNPs) as a single phase or a component of a hybrid nanocomposite that exhibits superparamagnetism and high surface area. MNPs are synthesized via co-precipitation, thermal decomposition and combustion, hydrothermal process, emulsion, microbial process, and green approaches. Aggregation/sedimentation and transport of MNPs depend on surface charge of MNPs and geochemical parameters such as pH, ionic strength, and organic matter. MNPs generally have low toxicity to humans and ecosystem. MNPs are used for constructing chemical/biosensors and for catalyzing a variety of chemical reactions. MNPs are used for air cleanup and carbon sequestration. MNP nanocomposites are designed as antimicrobial agents for water disinfection and flocculants for water treatment. Conjugated MNPs are widely used for adsorptive/separative removal of organics, dyes, oil, arsenic, phosphate, molybdate, fluoride, selenium, Cr(VI), heavy metal cations, radionuclides, and rare earth elements. MNPs can degrade organic/inorganic contaminants via chemical reduction or catalyze chemical oxidation in water, sediment, and soil. Future studies should further explore mechanisms of MNP interactions with other nanomaterials and contaminants, economic and green approaches of MNP synthesis, and field scale demonstration of MNP utilization.

  8. Environmental implications and applications of engineered nanoscale magnetite and its hybrid nanocomposites: A review of recent literature

    International Nuclear Information System (INIS)

    Su, Chunming

    2017-01-01

    Highlights: • Environmental impact of engineered MNPs. • MNPs and their hybrids explored for use in energy, analytical chemistry, and catalysis. • Surface modification to MNPs allow biocompatible applications. • Adsorptive and separative removal of a wide range of contaminants from aquatic environments. • Active remediation and natural attenuation of contaminants in soil and groundwater using MNPs. - Abstract: This review focuses on environmental implications and applications of engineered magnetite (Fe_3O_4) nanoparticles (MNPs) as a single phase or a component of a hybrid nanocomposite that exhibits superparamagnetism and high surface area. MNPs are synthesized via co-precipitation, thermal decomposition and combustion, hydrothermal process, emulsion, microbial process, and green approaches. Aggregation/sedimentation and transport of MNPs depend on surface charge of MNPs and geochemical parameters such as pH, ionic strength, and organic matter. MNPs generally have low toxicity to humans and ecosystem. MNPs are used for constructing chemical/biosensors and for catalyzing a variety of chemical reactions. MNPs are used for air cleanup and carbon sequestration. MNP nanocomposites are designed as antimicrobial agents for water disinfection and flocculants for water treatment. Conjugated MNPs are widely used for adsorptive/separative removal of organics, dyes, oil, arsenic, phosphate, molybdate, fluoride, selenium, Cr(VI), heavy metal cations, radionuclides, and rare earth elements. MNPs can degrade organic/inorganic contaminants via chemical reduction or catalyze chemical oxidation in water, sediment, and soil. Future studies should further explore mechanisms of MNP interactions with other nanomaterials and contaminants, economic and green approaches of MNP synthesis, and field scale demonstration of MNP utilization.

  9. Influence of expanded graphite (EG and graphene oxide (GO on physical properties of PET based nanocomposites

    Directory of Open Access Journals (Sweden)

    Paszkiewicz Sandra

    2014-12-01

    Full Text Available This work is the continuation and refinement of already published communications based on PET/EG nanocomposites prepared by in situ polymerization1, 2. In this study, nanocomposites based on poly(ethylene terephthalate with expanded graphite were compared to those with functionalized graphite sheets (GO. The results suggest that the degree of dispersion of nanoparticles in the PET matrix has important effect on the structure and physical properties of the nanocomposites. The existence of graphene sheets nanoparticles enhances the crystallization rate of PET. It has been confirmed that in situ polymerization is the effective method for preparation nanocomposites which can avoid the agglomeration of nanoparticles in polymer matrices and improve the interfacial interaction between nanofiller and polymer matrix. The obtained results have shown also that due to the presence of functional groups on GO surface the interactions with PET matrix can be stronger than in the case of exfoliated graphene (EG and matrix.

  10. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    International Nuclear Information System (INIS)

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik; Hundley, Angel; Vig, Komal; Singh, Shree Ram; Pillai, Shreekumar

    2010-01-01

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of ∼ 80 μm size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 μg demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 ± 6.72 mm, 19.4 ± 3.64 mm, 21.9 ± 4.33 mm, and 24.1 ± 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 ± 2.13 mm, 28.6 ± 4.27 mm, 22.6 ± 1.27 mm, and 27.0 ± 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 μg were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial strains tested. Further, the

  11. Synthesis of Ag/CNT hybrid nanoparticles and fabrication of their Nylon-6 polymer nanocomposite fibers for antimicrobial applications

    Energy Technology Data Exchange (ETDEWEB)

    Rangari, Vijaya K; Mohammad, Ghouse M; Jeelani, Shaik [Materials Science and Engineering, Center for Advanced Materials, Tuskegee University, Tuskegee, AL 36088 (United States); Hundley, Angel; Vig, Komal; Singh, Shree Ram; Pillai, Shreekumar, E-mail: rangariv@tuskegee.edu [Center for NanoBiotechnology Research, Alabama State University, Montgomery, AL 36104 (United States)

    2010-03-05

    Ag-coated CNTs hybrid nanoparticles (Ag/CNTs) were prepared by ultrasonic irradiation of dimethylformamide (DMF) and silver (I) acetate precursors in the presence of CNTs. The morphology of Ag/CNTs was characterized using x-ray diffraction and transmission electron microscopy (TEM) techniques. The Nylon-6 powder and 1 wt% Ag/CNTs mixture was dispersed uniformly using a noncontact spinning technique. The dried mixture was melted in a single screw extrusion machine and then extruded through an orifice. Extruded filaments were later stretched and stabilized by sequentially passing them through a set of tension adjusters and a secondary heater. The Nylon-6/Ag/CNT hybrid polymer nanocomposite (HPNC) fibers, which were of {approx} 80 {mu}m size, were tested for their tensile properties. The failure stress and modulus of the extruded HPNC fibers (doped with 1% Ag/CNTs) was about 72.19 % and 342.62% higher than the neat extruded Nylon-6 fiber, respectively. DSC results indicated an increase in the thermal stability and crystallization for HPNC fibers. The antibacterial activity of the Ag-coated CNTs, commercial Ag, neat Nylon-6 and plain CNTs were evaluated. Ag-coated CNTs at 25 {mu}g demonstrated good antimicrobial activity against four common bacterial pathogens as tested by the Kirby-Bauer assay. The mean diameters of the zones of inhibition were 27.9 {+-} 6.72 mm, 19.4 {+-} 3.64 mm, 21.9 {+-} 4.33 mm, and 24.1 {+-} 4.14 mm, respectively, for Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Salmonella enterica serovar Typhimurium. By comparison, those obtained using the broad spectrum antibiotic amoxicillin-clavulanic acid were 37.7 {+-} 2.13 mm, 28.6 {+-} 4.27 mm, 22.6 {+-} 1.27 mm, and 27.0 {+-} 1.41 mm, respectively, for the same strains. The zones of inhibition obtained for Nylon-6 Ag-coated CNT powder at 25 {mu}g were also high, ranging from 15.2 to 25.3 mm in contrast to commercial silver or neat Nylon-6, which did not inhibit the bacterial

  12. Elastomeric Nanocomposite Based on Exfoliated Graphene Oxide and Its Characteristics without Vulcanization

    OpenAIRE

    Nasser Abdullah Habib; Buong Woei Chieng; Norkhairunnisa Mazlan; Umer Rashid; Robiah Yunus; Suraya Abdul Rashid

    2017-01-01

    Rubber nanocomposites have emerged as one of the advanced materials in recent years. The aim of this work was to homogeneously disperse graphene oxide (GO) sheets into Nitrile Butadiene Rubber (NBR) and investigate the characteristics of GO/NBR nanocomposite without vulcanization. A suitable solvent was found to dissolve dry NBR while GO was exfoliated completely in an aqueous base solution using sonication. GO was dispersed into NBR at different loadings by solution mixing to produce unvulca...

  13. Polymer-filler interactions in polyether based thermoplastic polyureathane/silica nanocomposites

    OpenAIRE

    Heinz, Özge; Heinz, Ozge

    2013-01-01

    Thermoplastic polyurethaneureas (TPU) are a unique class of materials that are used in a broad range of applications due to their tailorable chemistry and morphology that allow engineering materials with targeted properties. The central theme of this dissertation is to develop an understanding on polymer-filler interfacial interactions and related reinforcing mechanism of silica nanoparticles in polyether based TPU/silica nanocomposites. Prior to our investigation on nanocomposite materials, ...

  14. 3D printing of CNT- and graphene-based conductive polymer nanocomposites by fused deposition modeling

    OpenAIRE

    Gnanasekaran, K.; Heijmans, T.; van Bennekom, S.; Woldhuis, H.; Wijnia, S.; de With, G.; Friedrich, H.

    2017-01-01

    Fused deposition modeling (FDM) is limited by the availability of application specific functional materials. Here we illustrate printing of non-conventional polymer nanocomposites (CNT- and graphene-based polybutylene terephthalate (PBT)) on a commercially available desktop 3D printer leading toward printing of electrically conductive structures. The printability, electrical conductivity and mechanical stability of the polymer nanocomposites before and after 3D printing was evaluated. The res...

  15. Bioinspired Graphene-Based Nanocomposites and Their Application in Flexible Energy Devices.

    Science.gov (United States)

    Wan, Sijie; Peng, Jingsong; Jiang, Lei; Cheng, Qunfeng

    2016-09-01

    Graphene is the strongest and stiffest material ever identified and the best electrical conductor known to date, making it an ideal candidate for constructing nanocomposites used in flexible energy devices. However, it remains a great challenge to assemble graphene nanosheets into macro-sized high-performance nanocomposites in practical applications of flexible energy devices using traditional approaches. Nacre, the gold standard for biomimicry, provides an excellent example and guideline for assembling two-dimensional nanosheets into high-performance nanocomposites. This review summarizes recent research on the bioinspired graphene-based nanocomposites (BGBNs), and discusses different bioinspired assembly strategies for constructing integrated high-strength and -toughness graphene-based nanocomposites through various synergistic effects. Fundamental properties of graphene-based nanocomposites, such as strength, toughness, and electrical conductivities, are highlighted. Applications of the BGBNs in flexible energy devices, as well as potential challenges, are addressed. Inspired from the past work done by the community a roadmap for the future of the BGBNs in flexible energy device applications is depicted. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Physicochemical and antifungal properties of bio-nanocomposite film based on gelatin-chitin nanoparticles.

    Science.gov (United States)

    Sahraee, Samar; Milani, Jafar M; Ghanbarzadeh, Babak; Hamishehkar, Hamed

    2017-04-01

    The gelatin-based nanocomposite films containing chitin nanoparticles (N-chitin) with concentrations of 0, 3, 5 and 10% were prepared and their physical, thermal and anti-microbial properties were investigated. Scanning electron microscopy (SEM) micrographs showed that N-chitin size distribution was around 60-70nm which dispersed appropriately at low concentration in gelatin matrix. The results showed that incorporation of N-chitin significantly influenced apparent color and transparency of the gelatin films. The reduced water vapor permeability (WVP) and solubility and higher surface hydrophobicity of the nanocomposite films were obtained by enhancing N-chitin concentration in film formulation. The use of N-chitin up to 5% concentration in the gelatin based nanocomposite film led to improved mechanical properties. Also, the results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed improved stability of nanocomposite films against melting and degradation at high temperatures in comparison to neat gelatin film. The well compatibility of chitin nanoparticles with gelatin polymer was concluded from Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) plots. Finally, the gelatin based nanocomposite films had anti-fungal properties against Aspergillus niger in the contact surface zone. Increasing the concentration of N-chitin up to 5% enlarged inhibition zone diameter, but the nanocomposite film containing 10% N-chitin showed smaller inhibition zone. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Carbon nanotubes and carbon onions for modification of styrene-acrylate copolymer based nanocomposites

    International Nuclear Information System (INIS)

    Merijs-Meri, Remo; Zicans, Janis; Ivanova, Tatjana; Bitenieks, Juris; Kuzhir, Polina; Maksimenko, Sergey; Kuznetsov, Vladimir; Moseenkov, Sergey

    2014-01-01

    Styrene acrylate polymer (SAC) nanocomposites with various carbon nanofillers (multiwalled carbon nanotubes MWCNTs and onion like carbon OLC) are manufactured by means of latex based routes. Concentration of the carbon nanofillers is changed in a broad interval starting from 0.01 up to 10 wt. %. Elastic, dielectric and electromagnetic properties of SAC nanocomposites are investigated. Elastic modulus, electrical conductivity and electromagnetic radiation absorption of the investigated SAC nanocomposites increase along with rising nanofiller content. The effect of the addition of anisometric MWCNTs on the elastic properties of the composite is higher than in the case of the addition of OLC. Higher electrical conductivity of the OLC containing nanocomposites is explained with the fact that reasonable agglomeration of the nanofiller can promote the development of electrically conductive network. Efficiency of the absorption of electromagnetic radiation depends on the development of conductive network within the SAC matrix

  18. Carbon nanotubes and carbon onions for modification of styrene-acrylate copolymer based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Merijs-Meri, Remo; Zicans, Janis; Ivanova, Tatjana; Bitenieks, Juris [Institute of Polymer Materials, Riga Technical University, Azenes street 14/24, LV-1048, Riga (Latvia); Kuzhir, Polina; Maksimenko, Sergey [Institute of Nuclear Problems, Belarus State University, Bobruiskaya str. 11, 220030, Minsk (Belarus); Kuznetsov, Vladimir; Moseenkov, Sergey [Boreskov Institute of Catalyst Siberian branch of RAS, pr. Lavrentieva 5, 630090, Novosibirsk (Russian Federation)

    2014-05-15

    Styrene acrylate polymer (SAC) nanocomposites with various carbon nanofillers (multiwalled carbon nanotubes MWCNTs and onion like carbon OLC) are manufactured by means of latex based routes. Concentration of the carbon nanofillers is changed in a broad interval starting from 0.01 up to 10 wt. %. Elastic, dielectric and electromagnetic properties of SAC nanocomposites are investigated. Elastic modulus, electrical conductivity and electromagnetic radiation absorption of the investigated SAC nanocomposites increase along with rising nanofiller content. The effect of the addition of anisometric MWCNTs on the elastic properties of the composite is higher than in the case of the addition of OLC. Higher electrical conductivity of the OLC containing nanocomposites is explained with the fact that reasonable agglomeration of the nanofiller can promote the development of electrically conductive network. Efficiency of the absorption of electromagnetic radiation depends on the development of conductive network within the SAC matrix.

  19. One-step route to a hybrid TiO2/TixW1−xN nanocomposite by in situ selective carbothermal nitridation

    Directory of Open Access Journals (Sweden)

    Zoë Schnepp, Martin J Hollamby, Masahiko Tanaka, Yoshitaka Matsushita, Yoshio Katsuya and Yoshio Sakka

    2012-01-01

    Full Text Available Metal oxide/nitride nanocomposites have many existing and potential applications, e.g. in energy conversion or ammonia synthesis. Here, a hybrid oxide/nitride nanocomposite (anatase/TixW1−xN was synthesized by an ammonia-free sol–gel route. Synchrotron x-ray diffraction, complemented with electron microscopy and thermogravimetric analysis, was used to study the structure, composition and mechanism of formation of the nanocomposite. The nanocomposite contained nanoparticles (<5 nm diameter of two highly intermixed phases. This was found to arise from controlled nucleation and growth of a single oxide intermediate from the gel precursor, followed by phase separation and in situ selective carbothermal nitridation. Depending on the preparation conditions, the composition varied from anatase/TixW1−xN at low W content to an isostructural mixture of Ti-rich and W-rich TixW1−xN at high W content. In situ selective carbothermal nitridation offers a facile route to the synthesis of nitride-oxide nanocomposites. This conceptually new approach is a significant advance from previous methods, which generally require ammonolysis of a pre-synthesized oxide.

  20. Studying the Properties of Polyvinyl Alcohol/Cellulose Nanofiber/Hydroxyapatite Hybrid Nanocomposite

    Directory of Open Access Journals (Sweden)

    Mostafa Yahyavi

    2015-06-01

    Full Text Available Nanocomposite materials have recently attracted much attention because of their desirable and unique physical and mechanical properties. Today, many studies have focused on the preparation of high performance new nanocomposites made of biobased and biodegradable materials as both the matrix and reinforcement phases. Because of biocompatibility, biofunctionality, and biological safety in the body, hydroxyapatite-polyvinyl alcohol composites are vastly used in medical applications, specially in the bone tissue regeneration. The properties of a new generation of nanocomposites consisting of hydroxyapatite nanoparticles and cellulose nanofibers, dispersed in polyvinyl alcohol matrix, were investigated. The percentage by weight of each component in the final formulation and the time of ultrasonication were studied as factors affecting the physical and mechanical properties. Tensile strength, elastic modulus and resistance to water dissolution were evaluated. The results showed that by increasing the percentage by weight of PVA and cellulose nanofibers and ultrasonication time, the tensile strength and elastic modulus increased and the resistance to water dissolution and weight loss decreased. On the other hand, with increasing the amount of hydroxyapatite nanoparticles in the final formulation, the elastic modulus and resistance to water solubility increased, while the tensile strength decreased significantly. Scanning electron microscopy (SEM micrographs were used to find exact correlations between the observed physical and mechanical properties and the structural morphology.

  1. Hybrid Organic/Inorganic Perovskite–Polymer Nanocomposites: Toward the Enhancement of Structural and Electrical Properties

    KAUST Repository

    Privitera, Alberto

    2017-11-30

    Hybrid organic/inorganic perovskite nanoparticles (NPs) have garnered remarkable research attention because of their promising photophysical properties. New and interesting properties emerge after combining perovskite NPs with semiconducting materials. Here, we report the synthesis and investigation of a composite material obtained by mixing CH3NH3PbBr3 nanocrystals with the semiconducting polymer poly(3-hexylthiophene) (P3HT). By the combination of structural techniques and optical and magnetic spectroscopies we observed multiple effects of the perovskite NPs on the P3HT: (i) an enlargement of P3HT crystalline domains, (ii) a strong p-doping of the P3HT, and (iii) an enhancement of interchain order typical of H-aggregates. These observations open a new avenue toward innovative perovskite NP-based applications.

  2. Hybrid Organic/Inorganic Perovskite–Polymer Nanocomposites: Toward the Enhancement of Structural and Electrical Properties

    KAUST Repository

    Privitera, Alberto; Righetto, Marcello; de Bastiani, Michele; Carraro, Francesco; Rancan, Marzio; Armelao, Lidia; Granozzi, Gaetano; Bozio, Renato; Franco, Lorenzo

    2017-01-01

    Hybrid organic/inorganic perovskite nanoparticles (NPs) have garnered remarkable research attention because of their promising photophysical properties. New and interesting properties emerge after combining perovskite NPs with semiconducting materials. Here, we report the synthesis and investigation of a composite material obtained by mixing CH3NH3PbBr3 nanocrystals with the semiconducting polymer poly(3-hexylthiophene) (P3HT). By the combination of structural techniques and optical and magnetic spectroscopies we observed multiple effects of the perovskite NPs on the P3HT: (i) an enlargement of P3HT crystalline domains, (ii) a strong p-doping of the P3HT, and (iii) an enhancement of interchain order typical of H-aggregates. These observations open a new avenue toward innovative perovskite NP-based applications.

  3. EPR and rheological study of hybrid interfaces in gold-clay-epoxy nanocomposites.

    Science.gov (United States)

    Angelov, Verislav; Velichkova, Hristiana; Ivanov, Evgeni; Kotsilkova, Rumiana; Delville, Marie-Hélène; Cangiotti, Michela; Fattori, Alberto; Ottaviani, Maria Francesca

    2014-11-11

    With the aim to obtain new materials with special properties to be used in various industrial and biomedical applications, ternary "gold-clay-epoxy" nanocomposites and their nanodispersions were prepared using clay decorated with gold nanoparticles (AuNPs), at different gold contents. Nanocomposites structure was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Rheology and electron paramagnetic resonance (EPR) techniques were used in order to evaluate the molecular dynamics in the nanodispersions, as well as dynamics at interfaces in the nanocomposites. The percolation threshold (i.e., the filler content related to the formation of long-range connectivity of particles in the dispersed media) of the gold nanoparticles was determined to be ϕp = 0.6 wt % at a fixed clay content of 3 wt %. The flow activation energy and the relaxation time spectrum illustrated the presence of interfacial interactions in the ternary nanodispersions around and above the percolation threshold of AuNPs; these interfacial interactions suppressed the global molecular dynamics. It was found that below ϕp the free epoxy polymer chains ratio dominated over the chains attracted on the gold surfaces; thus, the rheological behavior was not significantly changed by the presence of AuNPs. While, around and above ϕp, the amount of the bonded epoxy polymer chains on the gold surface was much higher than that of the free chains; thus, a substantial increase in the flow activation energy and shift in the spectra to higher relaxation times appeared. The EPR signals of the nanocomposites depended on the gold nanoparticle contents and the preparation procedure thus providing a fingerprint of the different nanostructures. The EPR results from spin probes indicated that the main effect of the gold nanoparticles above ϕp, was to form a more homogeneous, viscous and polar clay-epoxy mixture at the nanoparticle surface. The knowledge

  4. Synthesis, characterization and optical properties of polymer-based ZnS nanocomposites.

    Science.gov (United States)

    Tiwari, A; Khan, S A; Kher, R S; Dhoble, S J; Chandel, A L S

    2016-03-01

    Nanostructured polymer-semiconductor hybrid materials such as ZnS-poly(vinyl alcohol) (ZnS-PVA), ZnS-starch and ZnS-hydroxypropylmethyl cellulose (Zns-HPMC) are synthesized by a facile aqueous route. The obtained nanocomposites are characterized using various techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), UV/vis spectroscopy and photoluminescence (PL). XRD studies confirm the zinc blende phase of the nanocomposites and indicate the high purity of the samples. SEM studies indicate small nanoparticles clinging to the surface of a bigger particle. The Energy Dispersive Analysis by X-rays (EDAX) spectrum reveals that the elemental composition of the nanocomposites consists primarily of Zn:S. FTIR studies indicate that the polymer matrix is closely associated with ZnS nanoparticles. The large number of hydroxyl groups in the polymer matrix facilitates the complexation of metal ions. The absorption spectra of the specimens show a blue shift in the absorption edge. The spectrum reveals an absorption edge at 320, 310 and 325 nm, respectively. PL of nanocomposites shows broad peaks in the violet-blue region (420-450 nm). The emission intensity changes with the nature of capping agent. The PL intensity of ZnS-HPMC nanocomposites is found to be highest among the studied nanocomposites. The results clearly indicate that hydroxyl-functionalized HPMC is much more effective at nucleating and stabilizing colloidal ZnS nanoparticles in aqueous suspensions compared with PVA and starch. Copyright © 2015 John Wiley & Sons, Ltd.

  5. Fabrication of a Biomass-Based Hydrous Zirconium Oxide Nanocomposite for Preferable Phosphate Removal and Recovery.

    Science.gov (United States)

    Qiu, Hui; Liang, Chen; Zhang, Xiaolin; Chen, Mindong; Zhao, Yunxia; Tao, Tao; Xu, Zhengwen; Liu, Gang

    2015-09-23

    Advanced removal of phosphate by low-cost adsorbents from municipal wastewater or industrial effluents is an effective and economic way to prevent the occurrence of eutrophication. Here, we proposed a novel method to immobilize hydrous zirconium oxide nanoparticle within quaternary-aminated wheat straw, and obtained an inexpensive, eco-friendly nanocomposite Ws-N-Zr. The biomass-based Ws-N-Zr exhibited higher preference toward phosphate than commercial anion exchanger IRA-900 when competing sulfate ions coexisted at relatively high levels. Such excellent performance of Ws-N-Zr resulted from its specific hybrid structure, the quaternary ammonium groups bonded on the host favor the preconcentration of phosphate ions inside the wheat straw based on Donnan effect, and the encapsulated HZO nanoparticle exhibits preferable sequestration of phosphate ions through specific interaction, as further demonstrated by FTIR and X-ray photoelectron spectroscopy. Cycle adsorption and regeneration experiments demonstrated that Ws-N-Zr could be employed for repeated use without significant capacity loss, when the binary NaOH-NaCl solution was employed as the regenerant. The influence of solution pH and contact time was also examined. The results suggested that Ws-N-Zr has a great potential in efficient removal of phosphate in contaminated waters.

  6. Tough nanocomposite ionogel-based actuator exhibits robust performance.

    Science.gov (United States)

    Liu, Xinhua; He, Bin; Wang, Zhipeng; Tang, Haifeng; Su, Teng; Wang, Qigang

    2014-10-20

    Ionogel electrolytes can be fabricated for electrochemical actuators with many desirable advantages, including direct low-voltage control in air, high electrochemical and thermal stability, and complete silence during actuation. However, the demands for active actuators with above features and load-driving ability remain a challenge; much work is necessary to enhance the mechanical strength of electrolyte materials. Herein, we describe a cross-linked supramolecular approach to prepare tough nanocomposite gel electrolytes from HEMA, BMIMBF4, and TiO2 via self-initiated UV polymerization. The tough and stable ionogels are emerging to fabricate electric double-layer capacitor-like soft actuators, which can be driven by electrically induced ion migration. The ionogel-based actuator shows a displacement response of 5.6 mm to the driving voltage of 3.5 V. After adding the additional mass weight of the same as the actuator, it still shows a large displacement response of 3.9 mm. Furthermore, the actuator can not only work in harsh temperature environments (100°C and -10°C) but also realize the goal of grabbing an object by adjusting the applied voltage.

  7. Fracture behavior of α-zirconium phosphate-based epoxy nanocomposites

    International Nuclear Information System (INIS)

    Sue, H.-J.; Gam, K.T.; Bestaoui, N.; Clearfield, A.; Miyamoto, M.; Miyatake, N.

    2004-01-01

    The fracture behaviors of α-zirconium phosphate (α-ZrP) based epoxy nanocomposites, with and without core-shell rubber (CSR) toughening, were investigated. The state of exfoliation and dispersion of α-ZrP nanofiller in epoxy were characterized using X-ray scattering and various microscopy tools. The level of enhancement in storage moduli of epoxy nanocomposite against neat epoxy is found to depend on the state of exfoliation of α-ZrP as well as the damping characteristics of the epoxy matrix. The fracture process in epoxy nanocomposite is dominated by preferred crack propagation along the weak intercalated α-ZrP interfaces, and the presence of α-ZrP does not alter the fracture toughness of the epoxy matrix. However, the toughening using CSR can significantly improve the fracture toughness of the nanocomposite. The fracture mechanisms responsible for such a toughening effect in CSR-toughened epoxy nanocomposite are rubber particle cavitation, followed by shear banding of epoxy matrix. The ductility and toughenability of epoxy do not appear to be affected by the incorporation of α-ZrP. Approaches for producing toughened high performance polymer nanocomposites are discussed

  8. Elastomeric Nanocomposite Based on Exfoliated Graphene Oxide and Its Characteristics without Vulcanization

    Directory of Open Access Journals (Sweden)

    Nasser Abdullah Habib

    2017-01-01

    Full Text Available Rubber nanocomposites have emerged as one of the advanced materials in recent years. The aim of this work was to homogeneously disperse graphene oxide (GO sheets into Nitrile Butadiene Rubber (NBR and investigate the characteristics of GO/NBR nanocomposite without vulcanization. A suitable solvent was found to dissolve dry NBR while GO was exfoliated completely in an aqueous base solution using sonication. GO was dispersed into NBR at different loadings by solution mixing to produce unvulcanized GO/NBR nanocomposites. Scanning Electron Microscopy (SEM, Fourier-Transform Infrared Spectroscopy (FTIR, and X-Ray Diffraction (XRD were used to characterize the samples. Furthermore, mechanical and electrical properties of unvulcanized GO/NBR nanocomposites were carried out to determine the influence of GO on the NBR properties. The results showed that the modulus of GO/NBR nanocomposite at 1 wt% of GO was enhanced by about 238% compared with unfilled NBR. These results provide insight into the properties of unvulcanized GO/NBR nanocomposite for application as coatings or adhesives.

  9. Synthesis and photocatalytic activity of graphene based doped TiO2 nanocomposites

    International Nuclear Information System (INIS)

    Gu, Yongji; Xing, Mingyang; Zhang, Jinlong

    2014-01-01

    Graphical abstract: - Highlights: • Graphene based doped TiO 2 nanocomposites were prepared. • The intimate contact between doped TiO 2 and graphene is achieved simultaneously. • These nanocomposites showed higher photocatalytic activity than TiO 2 and doped TiO 2 . • Photocatalytic mechanism was explained thoroughly. - Abstract: The nanocomposites of reduced graphene oxide based nitrogen doped TiO 2 (N–TiO 2 –RGO) and reduced graphene oxide based nitrogen and vanadium co-doped TiO 2 (N, V–TiO 2 –RGO) were prepared via a facile hydrothermal reaction of graphene oxide and TiO 2 in a water solvent. In this hydrothermal treatment, the reduction of graphene oxide and the intimate contact between nitrogen doped TiO 2 (N–TiO 2 ) or nitrogen and vanadium co-doped TiO 2 (N,V–TiO 2 ) and the RGO sheet is achieved simultaneously. Both N–TiO 2 –RGO and N,V–TiO 2 –RGO nanocomposites exhibit much higher visible light photocatalytic activity than N–TiO 2 and N,V–TiO 2 , and the order of visible light photocatalytic activity is N,V–TiO 2 –RGO > N–TiO 2 –RGO > N,V–TiO 2 > N–TiO 2 > TiO 2 . According to the characterization, the enhanced photocatalytic activity of the nanocomposites is attributed to reasons, such as enhancement of adsorption of pollutants, light absorption intensity, minimizing the recombination of photoinduced electrons and holes and more excited states of these nanocomposites under visible light irradiation. Overall, this work provides a more marked contrast of graphene based semiconductor nanocomposites and a more comprehensive explanation of the mechanism

  10. Hazy Al2O3-FTO Nanocomposites: A Comparative Study with FTO-Based Nanocomposites Integrating ZnO and S:TiO2 Nanostructures

    Directory of Open Access Journals (Sweden)

    Shan-Ting Zhang

    2018-06-01

    Full Text Available In this study, we report the use of Al2O3 nanoparticles in combination with fluorine doped tin oxide (F:SnO2, aka FTO thin films to form hazy Al2O3-FTO nanocomposites. In comparison to previously reported FTO-based nanocomposites integrating ZnO and sulfur doped TiO2 (S:TiO2 nanoparticles (i.e., ZnO-FTO and S:TiO2-FTO nanocomposites, the newly developed Al2O3-FTO nanocomposites show medium haze factor HT of about 30%, while they exhibit the least loss in total transmittance Ttot. In addition, Al2O3-FTO nanocomposites present a low fraction of large-sized nanoparticle agglomerates with equivalent radius req > 1 μm; effectively 90% of the nanoparticle agglomerates show req < 750 nm. The smaller feature size in Al2O3-FTO nanocomposites, as compared to ZnO-FTO and S:TiO2-FTO nanocomposites, makes them more suitable for applications that are sensitive to roughness and large-sized features. With the help of a simple optical model developed in this work, we have simulated the optical scattering by a single nanoparticle agglomerate characterized by bottom radius r0, top radius r1, and height h. It is found that r0 is the main factor affecting the HT(λ, which indicates that the haze factor of Al2O3-FTO and related FTO nanocomposites is mainly determined by the total surface coverage of all the nanoparticle agglomerates present.

  11. HYDROXYETHYL METHACRYLATE BASED NANOCOMPOSITE HYDROGELS WITH TUNABLE PORE ARCHITECTURE

    Directory of Open Access Journals (Sweden)

    Erhan Bat

    2016-10-01

    Full Text Available Hydroxyethyl methacrylate (HEMA based hydrogels have found increasing number of applications in areas such as chromatographic separations, controlled drug release, biosensing, and membrane separations. In all these applications, the pore size and pore interconnectivity are crucial for successful application of these materials as they determine the rate of diffusion through the matrix. 2-Hydroxyethyl methacrylate is a water soluble monomer but its polymer, polyHEMA, is not soluble in water. Therefore, during polymerization of HEMA in aqueous media, a porous structure is obtained as a result of phase separation. Pore size and interconnectivity in these hydrogels is a function of several variables such as monomer concentration, cross-linker concentration, temperature etc. In this study, we investigated the effect of monomer concentration, graphene oxide addition or clay addition on hydrogel pore size, pore interconnectivity, water uptake, and thermal properties. PolyHEMA hydrogels have been prepared by redox initiated free radical polymerization of the monomer using ethylene glycol dimethacrylate as a cross-linker. As a nanofiller, a synthetic hectorite Laponite® XLG and graphene oxide were used. Graphene oxide was prepared by the Tour Method. Pore morphology of the pristine HEMA based hydrogels and nanocomposite hydrogels were studied by scanning electron microscopy. The formed hydrogels were found to be highly elastic and flexible. A dramatic change in the pore structure and size was observed in the range between 22 to 24 wt/vol monomer at 0.5 % of cross-linker. In this range, the hydrogel morphology changes from typical cauliflower architecture to continuous hydrogel with dispersed water droplets forming the pores where the pores are submicron in size and show an interconnected structure. Such controlled pore structure is highly important when these hydrogels are used for solute diffusion or when there’s flow through monolithic hydrogels

  12. Effect of Nanodiamonds on Structure and Durability of Polyethylene Oxide-Based Nanocomposites

    Directory of Open Access Journals (Sweden)

    Rossella Arrigo

    2016-01-01

    Full Text Available Polymer-based nanocomposites containing nanodiamonds (NDs are attractive multifunctional materials with a growing range of applications. In this work, in the frame of developing completely biocompatible systems, nanocomposites based on polyethylene oxide (PEO and different amount of NDs have been formulated through melt mixing and fully characterized. In particular, the reinforcement effect of NDs in PEO has been probed through tensile tests, and the rheological response of PEO-based nanocomposites as a function of the nanoparticles amount has been investigated and discussed. The obtained results show that the presence of well-distributed NDs strengthens the mechanical performance of the nanocomposites and brings about an increase of the PEO crystallinity, suggesting a strong adhesion between NDs and polymer matrix. Furthermore, as a result of NDs adding, alterations of the rheological behaviour of neat PEO can be noticed, as NDs are able to significantly influence the long-range dynamics of PEO chains. Besides, accelerated aging tests demonstrate that NDs show a remarkable protective ability against PEO photodegradation, due to their ability to attenuate efficiently UV radiation. The latter opens up new avenues for the use of NDs as multifunctional nanofillers for polymer-based nanocomposites with enhanced photooxidative resistance.

  13. Synthesis of Polyimides in Molecular-Scale Confinement for Low-Density Hybrid Nanocomposites.

    Science.gov (United States)

    Isaacson, Scott G; Fostvedt, Jade I; Koerner, Hilmar; Baur, Jeffery W; Lionti, Krystelle; Volksen, Willi; Dubois, Geraud; Dauskardt, Reinhold H

    2017-11-08

    In this work, we exploit a confinement-induced molecular synthesis and a resulting bridging mechanism to create confined polyimide thermoset nanocomposites that couple molecular confinement-enhanced toughening with an unprecedented combination of high-temperature properties at low density. We describe a synthesis strategy that involves the infiltration of individual polymer chains through a nanoscale porous network while simultaneous imidization reactions increase the molecular backbone stiffness. In the extreme limit where the confinement length scale is much smaller than the polymer's molecular size, confinement-induced molecular mechanisms give rise to exceptional mechanical properties. We find that polyimide oligomers can undergo cross-linking reactions even in such molecular-scale confinement, increasing the molecular weight of the organic phase and toughening the nanocomposite through a confinement-induced energy dissipation mechanism. This work demonstrates that the confinement-induced molecular bridging mechanism can be extended to thermoset polymers with multifunctional properties, such as excellent thermo-oxidative stability and high service temperatures (>350 °C).

  14. Influence of metal nanoparticle decorated CNTs on polyurethane based electro active shape memory nanocomposite actuators

    International Nuclear Information System (INIS)

    Raja, Mohan; Shanmugharaj, A.M.; Ryu, Sung Hun; Subha, J.

    2011-01-01

    Highlights: → Polyurethane based on pristine and metal (Ag and Cu) nanoparticle decorated CNTs nanocomposites are prepared through melt blending process. → The electrical, mechanical, dynamic mechanical, thermal conductivity and electro active shape memory properties of the PU nanocomposites were investigated. → The influence of metal nanoparticle decorated CNTs showed significant improvement in their all properties to compare to pristine CNTs. → Electro active shape memory studies of the PU/M-CNTs nanocomposites reveal extraordinary recoverability of its shape at lower applied dc voltages. - Abstract: Polymer nanocomposites based on thermoplastic polyurethane (PU) elastomer and metal nanoparticle (Ag and Cu) decorated multiwall carbon nanotubes (M-CNTs) were prepared through melt mixing process and investigated for its mechanical, dynamic mechanical and electro active shape memory properties. Structural characterization and morphological characterization of the PU nanocomposites were done using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Morphological characterization revealed better dispersion of M-CNTs in the polyurethane, which is attributed to the improved interaction between the M-CNTs and polyurethane. Loading of the metal nanoparticle coated carbon nanotubes resulted in the significant improvement on the mechanical properties such as tensile strength of the PU composites in comparison to the pristine carbon nanotubes (P-CNTs). Dynamic mechanical analysis showed that the glass transition temperature (Tg) of the polyurethane increases slightly with increasing loading of both pristine and metal nanoparticle functionalized carbon nanotubes. The metal nanoparticles decorated carbon nanotubes also showed significant improvement in the thermal and electrical conductivity of the PU/M-CNTs nanocomposites. Shape memory studies of the PU/M-CNTs nanocomposites exhibit remarkable recoverability of its shape at lower applied dc voltages.

  15. CAPACITANCE OF SUPERCAPACITORS WITH ELECTRODES BASED ON CARBON NANOCOMPOSITE MATERIAL

    OpenAIRE

    S.L Revo; B.I Rachiy; S Hamamda; T.G Avramenko; K.O Ivanenko

    2012-01-01

    This work presents the results of our research of the structure and practically important characteristics of a nanocomposite material on the basis of nanoporous carbon and thermally exfoliated graphite. This work shows that the use of the abovementioned composition in electrodes for supercapacitors allows to attain the level of their specific electrical capacitance at (155...160) F/g.

  16. Lead-free LiNbO3 nanowire-based nanocomposite for piezoelectric power generation

    Science.gov (United States)

    2014-01-01

    In a flexible nanocomposite-based nanogenerator, in which piezoelectric nanostructures are mixed with polymers, important parameters to increase the output power include using long nanowires with high piezoelectricity and decreasing the dielectric constant of the nanocomposite. Here, we report on piezoelectric power generation from a lead-free LiNbO3 nanowire-based nanocomposite. Through ion exchange of ultra-long Na2Nb2O6-H2O nanowires, we synthesized long (approximately 50 μm in length) single-crystalline LiNbO3 nanowires having a high piezoelectric coefficient (d33 approximately 25 pmV-1). By blending LiNbO3 nanowires with poly(dimethylsiloxane) (PDMS) polymer (volume ratio 1:100), we fabricated a flexible nanocomposite nanogenerator having a low dielectric constant (approximately 2.7). The nanogenerator generated stable electric power, even under excessive strain conditions (approximately 105 cycles). The different piezoelectric coefficients of d33 and d31 for LiNbO3 may have resulted in generated voltage and current for the e33 geometry that were 20 and 100 times larger than those for the e31 geometry, respectively. This study suggests the importance of the blending ratio and strain geometry for higher output-power generation in a piezoelectric nanocomposite-based nanogenerator. PACS 77.65.-j; 77.84.-s; 73.21.Hb PMID:24386884

  17. Advanced Bio-Based Nanocomposites and Manufacturing Processes

    Science.gov (United States)

    Spinella, Stephen Matthew

    The aim of the PhD thesis concerns with the modification of cellulose nanocrystals (CNCs) via esterification or a radical grafting "from" approach to achieve polymeric nanocomposites of exceptional properties (Chapters 1 to 4). In addition to CNCs modification, other green routes have been introduced in this thesis in order to environmentally friendly polyester-based materials, i.e. Chapters five and six. The second chapter focuses on expanding on a one-pot cellulose acid hydrolysis/Fischer esterification to produce highly compatible CNCs without any organic solvent. It consists of modifying CNCs with acetic- and lactic- acid and exploring how such surface chemistry has an effect of dispersion in the case of polylactide (PLA)-based nanocomposites. The degree of substitution for AA-CNCs and LA-CNCs, determined by FTIR, are 0.12 and 0.13, respectively. PLA-based materials represent the best bioplastics relating to its high stiffness and biodegradability, but suffer from its poor thermal performances, namely its Heat Deflection Temperature (HDT). To improve the HDT of PLA, nanocomposites have been therefore prepared with modified cellulose nanocrystals (CNCs) by melt blending. After blending at 5 wt-% loading of CNCs, LA-CNCs gives superior reinforcement below and above the glass temperature of PLA. An increase in PLA's heat deflection temperature by 10°C and 20°C is achieved by melt-blending PLA with 5 and 20 wt-% LA-CNCs, respectively. Chapter three concerns with expanding this process to a series of hydrophilic and hydrophobic acids yielding functional CNCs for electronic and biomedical applications. Hydrophilic acids include citric-, malonic- and malic acid. Modification with the abovementioned organic acids allows for the introduction of free acids onto the surface of CNCs. Modification with citric-, malonic- and malic- acid is verified by Fourier Transform Infrared Spectroscopy and 13C solid state magic-angle spinning (MAS) NMR experiments. The degree of

  18. Graphene-based hybrid plasmonic modulator

    International Nuclear Information System (INIS)

    Shin, Jin-Soo; Kim, Jin-Soo; Tae Kim, Jin

    2015-01-01

    A graphene-based hybrid plasmonic modulator is designed based on an asymmetric double-electrode plasmonic waveguide structure. The photonic device consists of a monolayer graphene, a thin metal strip, and a thin dielectric layer that is inserted between the grapheme and the metal strip. By electrically tuning the graphene’s refractive index, the propagation loss of the hybrid long-range surface plasmon polariton strip mode in the proposed graphene-based hybrid plasmonic waveguide is switchable, and hence the intensity of the guided modes is modulated. The highest modulation depth is observed at the graphene’s epsilon-near-zero region. The device characteristics are characterized over the entire C-band (1.530–1.565 μm). (paper)

  19. Preparation and characterization of transparent PMMA-cellulose-based nanocomposites.

    Science.gov (United States)

    Kiziltas, Esra Erbas; Kiziltas, Alper; Bollin, Shannon C; Gardner, Douglas J

    2015-01-01

    Nanocomposites of polymethylmethacrylate (PMMA) and cellulose were made by a solution casting method using acetone as the solvent. The nanofiber networks were prepared using three different types of cellulose nanofibers: (i) nanofibrillated cellulose (NFC), (ii) cellulose nanocrystals (CNC) and (iii) bacterial cellulose from nata de coca (NDC). The loading of cellulose nanofibrils in the PMMA varied between 0.25 and 0.5 wt%. The mechanical properties of the composites were evaluated using a dynamic mechanical thermal analyzer (DMTA). The flexural modulus of the nanocomposites reinforced with NDC at the 0.5 wt% loading level increased 23% compared to that of pure PMMA. The NFC composite also exhibited a slightly increased flexural strength around 60 MPa while PMMA had a flexural strength of 57 MPa. The addition of NDC increased the storage modulus (11%) compared to neat PMMA at room temperature while the storage modulus of PPMA/CNC nanocomposite containing 0.25 and 0.5 wt% cellulose increased about 46% and 260% to that of the pure PMMA at the glass transition temperature, respectively. Thermogravimetric analysis (TGA) indicated that there was no significant change in thermal stability of the composites. The UV-vis transmittance of the CNF nanocomposites decreased by 9% and 27% with the addition of 0.25 wt% CNC and NDC, respectively. This work is intended to spur research and development activity for application of CNF reinforced PMMA nanocomposites in applications such as: packaging, flexible screens, optically transparent films and light-weight transparent materials for ballistic protection. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Processing-structure-properties relationships in PLA nanocomposite films

    Science.gov (United States)

    Di Maio, L.; Scarfato, P.; Garofalo, E.; Galdi, M. R.; D'Arienzo, L.; Incarnato, L.

    2014-05-01

    This work deals on the possibility to improve performances of PLA-based nanocomposite films, for packaging applications, through conveniently tuning materials and processing conditions in melt compounding technology. In particular, two types of polylactic acid and different types of filler selected from montmorillonites and bentonites families were used to prepare the hybrid systems by using a twin-screw extruder. The effect of biaxial drawing on morphology and properties of the nanocomposites, produced by film blowing, was investigated.

  1. Development of bone-like zirconium oxide nanoceramic modified chitosan based porous nanocomposites for biomedical application.

    Science.gov (United States)

    Bhowmick, Arundhati; Pramanik, Nilkamal; Jana, Piyali; Mitra, Tapas; Gnanamani, Arumugam; Das, Manas; Kundu, Patit Paban

    2017-02-01

    Here, zirconium oxide nanoparticles (ZrO 2 NPs) were incorporated for the first time in organic-inorganic hybrid composites containing chitosan, poly(ethylene glycol) and nano-hydroxypatite (CS-PEG-HA) to develop bone-like nanocomposites for bone tissue engineering application. These nanocomposites were characterized by FT-IR, XRD, TEM combined with SAED. SEM images and porosity measurements revealed highly porous structure having pore size of less than 1μm to 10μm. Enhanced water absorption capacity and mechanical strengths were obtained compared to previously reported CS-PEG-HA composite after addition of 0.1-0.3wt% of ZrO 2 NPs into these nanocomposites. The mechanical strengths and porosities were similar to that of human spongy bone. Strong antimicrobial effects against gram-negative and gram-positive bacterial strains were also observed. Along with getting low alkalinity pH (7.4) values, similar to the pH of human plasma, hemocompatibility and cytocompatibility with osteoblastic MG-63 cells were also established for these nanocomposites. Addition of 15wt% HA-ZrO 2 (having 0.3wt% ZrO 2 NPs) into CS-PEG (55:30wt%) composite resulted in greatest mechanical strength, porosity, antimicrobial property and cytocompatibility along with suitable water absorption capacity and compatibility with human pH and blood. Thus, this nanocomposite could serve as a potential candidate to be used for bone tissue engineering. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Comparison of the mechanical properties between carbon nanotube and nanocrystalline cellulose polypropylene based nano-composites

    International Nuclear Information System (INIS)

    Huang, Jun; Rodrigue, Denis

    2015-01-01

    Highlights: • SWCNT and NCC can effectively improve the mechanical properties of nano-composites. • SWCNT is more effective than NCC to increase modulus and strength. • Longer NCC is more effective to improve the mechanical properties of nano-composites. • It is more economic to use NCC than SWCNT to improve mechanical properties. - Abstract: Using beam and tetrahedron elements to simulate nanocrystalline cellulose (NCC), single wall carbon nanotube (SWCNT) and polypropylene (PP), finite element method (FEM) is used to predict the mechanical properties of nano-composites. The bending, shear and torsion behaviors of nano-composites are especially investigated due to the limited amount of information in the present literature. First, mixed method (MM) and FEM are used to compare the bending stiffness of NCC/PP and SWCNT/PP composites. Second, based on mechanics of materials, the shear moduli of both types of nano-composites are obtained. Finally, fixing the number of fibers and for different volume contents, four NCC lengths are used to determine the mechanical properties of the composites. The bending and shearing performances are also compared between NCC and SWCNT based composites. In all cases, the elastic–plastic analyses are carried out and the stress or strain distributions for specific regions are also investigated. From all the results obtained, an economic analysis shows that NCC is more interesting than SWCNT to reinforce PP

  3. Multiscale modeling of graphene- and nanotube-based reinforced polymer nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Montazeri, A. [Computational Physical Sciences Research Laboratory, School of Nano-Science, Institute for Research in Fundamental Sciences (IPM), Tehran (Iran, Islamic Republic of); Rafii-Tabar, H., E-mail: rafii-tabar@nano.ipm.ac.ir [Computational Physical Sciences Research Laboratory, School of Nano-Science, Institute for Research in Fundamental Sciences (IPM), Tehran (Iran, Islamic Republic of); Department of Medical Physics and Biomedical Engineering, and Research Centre for Medical Nanotechnology and Tissue Engineering, Shahid Beheshti University of Medical Sciences, Evin, Tehran (Iran, Islamic Republic of)

    2011-10-31

    A combination of molecular dynamics, molecular structural mechanics, and finite element method is employed to compute the elastic constants of a polymeric nanocomposite embedded with graphene sheets, and carbon nanotubes. The model is first applied to study the effect of inclusion of graphene sheets on the Young modulus of the composite. To explore the significance of the nanofiller geometry, the elastic constants of nanotube-based and graphene-based polymer composites are computed under identical conditions. The reinforcement role of these nanofillers is also investigated in transverse directions. Moreover, the dependence of the nanocomposite's axial Young modulus on the presence of ripples on the surface of the embedded graphene sheets, due to thermal fluctuations, is examined via MD simulations. Finally, we have also studied the effect of sliding motion of graphene layers on the elastic constants of the nanocomposite. -- Highlights: → A hierarchical MD/FEM multiscale model of nanocomposites is developed. → At low nanofiller content, graphene layers perform significantly better than CNTs. → Ripples in the graphene layers reduce the Young modulus of nanocomposites. → The elastic moduli is considerably affected by the shear of graphene layers.

  4. Multiscale modeling of graphene- and nanotube-based reinforced polymer nanocomposites

    International Nuclear Information System (INIS)

    Montazeri, A.; Rafii-Tabar, H.

    2011-01-01

    A combination of molecular dynamics, molecular structural mechanics, and finite element method is employed to compute the elastic constants of a polymeric nanocomposite embedded with graphene sheets, and carbon nanotubes. The model is first applied to study the effect of inclusion of graphene sheets on the Young modulus of the composite. To explore the significance of the nanofiller geometry, the elastic constants of nanotube-based and graphene-based polymer composites are computed under identical conditions. The reinforcement role of these nanofillers is also investigated in transverse directions. Moreover, the dependence of the nanocomposite's axial Young modulus on the presence of ripples on the surface of the embedded graphene sheets, due to thermal fluctuations, is examined via MD simulations. Finally, we have also studied the effect of sliding motion of graphene layers on the elastic constants of the nanocomposite. -- Highlights: → A hierarchical MD/FEM multiscale model of nanocomposites is developed. → At low nanofiller content, graphene layers perform significantly better than CNTs. → Ripples in the graphene layers reduce the Young modulus of nanocomposites. → The elastic moduli is considerably affected by the shear of graphene layers.

  5. Comparison of sodium borohydride hydrolysis kinetics on Co-based nanocomposite catalysts

    International Nuclear Information System (INIS)

    Hristov, Georgi; Chorbadzhiyska, Elitsa; Mitov, Mario; Rashkov, Rashko; Hubenova, Yolina

    2011-01-01

    In this study, we compared the results, obtained with several Co-based nanocomposites (CoMnB, CoNiMnB and CoNiMoW) produced by electrodeposition on Ni-foam, as catalysts for the sodium borohydride hydrolysis reaction. Based on the comparative analyses, we propose CoNiMnB electrodeposits as most suitable catalysts for development of Hydrogen-on-Demand (HOD) system, while CoNiMoW ones as potential anodes for Direct Borohydride Fuel Cells (DBFCs). Keywords: Hydrogen-on-Demand (HOD), Nanocomposites, Hydrolysis, Catalyst, Kinetic

  6. Optimizing Properties of Aluminum-Based Nanocomposites by Genetic Algorithm Method

    Directory of Open Access Journals (Sweden)

    M.R. Dashtbayazi

    2015-07-01

    Full Text Available Based on molecular dynamics simulation results, a model was developed for determining elastic properties of aluminum nanocomposites reinforced with silicon carbide particles. Also, two models for prediction of density and price of nanocomposites were suggested. Then, optimal volume fraction of reinforcement was obtained by genetic algorithm method for the least density and price, and the highest elastic properties. Based on optimization results, the optimum volume fraction of reinforcement was obtained equal to 0.44. For this optimum volume fraction, optimum Young’s modulus, shear modulus, the price and the density of the nanocomposite were obtained 165.89 GPa, 111.37 GPa, 8.75 $/lb and 2.92 gr/cm3, respectively.

  7. Micromechanical analysis of nanocomposites using 3D voxel based material model

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon

    2012-01-01

    A computational study on the effect of nanocomposite structures on the elastic properties is carried out with the use of the 3D voxel based model of materials and the combined Voigt–Reuss method. A hierarchical voxel based model of a material reinforced by an array of exfoliated and intercalated...... nanoclay platelets surrounded by interphase layers is developed. With this model, the elastic properties of the interphase layer are estimated using the inverse analysis. The effects of aspect ratio, intercalation and orientation of nanoparticles on the elastic properties of the nanocomposites are analyzed....... For modeling the damage in nanocomposites with intercalated structures, “four phase” model is suggested, in which the strength of “intrastack interphase” is lower than that of “outer” interphase around the nanoplatelets. Analyzing the effect of nanoreinforcement in the matrix on the failure probability...

  8. Advanced clay nanocomposites based on in situ photopolymerization utilizing novel polymerizable organoclays

    Science.gov (United States)

    Kim, Soon Ki

    Polymer nanocomposite technology has had significant impact on material design. With the environmental advantages of photopolymerization, a research has recently focused on producing nanocomposites utilizing inexpensive clay particles based on in situ photopolymerization. In this research, novel polymerizable organoclays and thiol-ene photopolymerization have been utilized to develop advanced photopolymer clay nanocomposites and to overcome several limitations in conventional free radical photopolymers. To this end, factors important in nanocomposite processes such as monomer composition, clay dispersion, and photopolymerization behavior in combination with the evolution of ultimate nanocomposite properties have been investigated. For monomer-organoclay compositions, higher chemical compatibility of components induces enhanced clay exfoliation, resulting in photopolymerization rate increases due to an amplified clay template effect. Additionally, by affecting the stoichiometric ratio between thiol and acrylate double bond in the clay gallery, thiolated organoclays enhance thiol-ene copolymerization with increased final thiol conversion while acrylated organoclays encourage acrylate homopolymerization. In accordance with the reaction behavior, incorporation of thiolated organoclays makes polymer chains more flexible with decreased glass transition temperature due to higher formation of thio-ether linkages while adding acrylated organoclays significantly increases the modulus. Photopolymer nanocomposites also help overcome two major drawbacks in conventional free radical photopolymerization, namely severe polymerization shrinkage and oxygen inhibition during polymerization. With addition of a low level of thiol monomers, the oxygen inhibition in various acrylate systems can be overcome by addition of only 5wt% thiolated organoclay. The same amount of polymerizable organoclay also induces up to 90% decreases in the shrinkage stress for acrylate or thiol

  9. Cr(OH)3-NPs-CNC hybrid nanocomposite: a sorbent for adsorptive removal of methylene blue and malachite green from solutions.

    Science.gov (United States)

    Nekouei, Farzin; Nekouei, Shahram; Keshtpour, Farzaneh; Noorizadeh, Hossein; Wang, Shaobin

    2017-11-01

    In this article, Cr(OH) 3 nanoparticle-modified cellulose nanocrystal (CNC) as a novel hybrid nanocomposite (Cr(OH) 3 -NPs-CNC) was prepared by a simple procedure and used as a sorbent for adsorptive removal of methylene blue (MB) and malachite green (MG) from aqueous solution. Different kinetic models were tested, and the pseudo-second-order kinetic model was found more suitable for the MB and MG adsorption processes. The BET and Langmuir models were more suitable for the adsorption processes of MB and MG. Thermodynamic studies suggested that the adsorption of MB and MG onto Cr(OH) 3 -NPs-CNC nanocomposite was a spontaneous and endothermic process. The maximum adsorption capacities for MB and MG were reached 106 and 104 mg/g, respectively, which were almost two times higher than unmodified CNC. The chemical stability and leaching tests of the Cr(OH) 3 -NPs-CNC hybrid nanocomposite showed that only small amounts of chromium were leached into the solution.

  10. Determination of grafting conversion degree in PS/PS-graft-POSS/POSS hybrid nanocomposites obtained through reactive processing

    International Nuclear Information System (INIS)

    Bianchi, Otavio; Repenning, Gustavo B.; Mauler, Raquel S.; Oliveira, Ricardo V.B.; Canto, Leonardo B.

    2011-01-01

    Hybrid nanocomposites of polystyrene (PS) and polyhedral oligomeric silsesquioxanes (POSS) - PS/PS-graft-POSS/POSS - with different grafting degrees were prepared by reactive melt processing using dicumyl peroxide (DCP) as initiator in the presence or absence of styrene monomer as radical transfer agent. Gel permeation chromatography (GPC) using triple-detector and proton nuclear magnetic resonance (NMR 1 H) analyses were used together to determine the conversion degree of PS-graft-POSS as a function of the reactive processing conditions adopted. GPC was employed to evaluate the effects of grafting (PS-graft-POSS) and PS chains degradation (β scission) that occur simultaneously during processing on the variation of average molecular masses and distributions for each PS/POSS sample. PS/POSS systems processed with styrene showed higher weight average molecular weights (M w ) and lower polydispersity indexes (M w /M n ), as a result of higher grafting (PS-graft-POSS) conversion (28-40%) and lower PS chain degradation level, as compared to PS/POSS systems processed without styrene in which the degree of grafting conversion was around 25-28%. (author)

  11. Enhancing the Heat Transfer Efficiency in Graphene-Epoxy Nanocomposites Using a Magnesium Oxide-Graphene Hybrid Structure.

    Science.gov (United States)

    Du, Fei-Peng; Yang, Wen; Zhang, Fang; Tang, Chak-Yin; Liu, Sheng-Peng; Yin, Le; Law, Wing-Cheung

    2015-07-08

    Composite materials, such as organic matrices doped with inorganic fillers, can generate new properties that exhibit multiple functionalities. In this paper, an epoxy-based nanocomposite that has a high thermal conductivity and a low electrical conductivity, which are required for the use of a material as electronic packaging and insulation, was prepared. The performance of the epoxy was improved by incorporating a magnesium oxide-coated graphene (MgO@GR) nanomaterial into the epoxy matrix. We found that the addition of a MgO coating not only improved the dispersion of the graphene in the matrix and the interfacial bonding between the graphene and epoxy but also enhanced the thermal conductivity of the epoxy while preserving the electrical insulation. By adding 7 wt % MgO@GR, the thermal conductivity of the epoxy nanocomposites was enhanced by 76% compared with that of the neat epoxy, and the electrical resistivity was maintained at 8.66 × 10(14) Ω m.

  12. Isothermal curing of polymer layered silicate nanocomposites based upon epoxy resin by means of anionic homopolymerisation

    International Nuclear Information System (INIS)

    Román, Frida; Calventus, Yolanda; Colomer, Pere; Hutchinson, John M.

    2013-01-01

    Highlights: • The nanocomposite with low content of clay displayed improved thermal properties. • The vitrification was observed in the isothermal curing. • Dielectric relaxations outside and inside of the clay galleries were detected. - Abstract: The use of an initiator, 4-(dimethylamino) pyridine (DMAP), to promote an anionic homopolymerisation reaction for the isothermal cure of polymer layered silicate (PLS) nanocomposites based on an epoxy resin, as well as the effect of the nanoclay content, have been studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), dielectric relaxation spectroscopy (DRS) and transmission electron microscopy (TEM). The vitrification phenomenon was observed during the isothermal cure process, and it was found that the nanocomposite with a low clay content (2 wt%), denoted EDM2, shows improved thermal properties with respect to the unreinforced resin (denoted ED), while the nanocomposite with a higher clay content (5 wt%), denoted EDM5, displayed inferior properties. The cure kinetics were analysed by different methods, and it was observed that the activation energy and kinetic parameters of EDM2 were lower compared to the other two systems. Examination of the nanostructure of the cured EDM2 nanocomposite showed partial exfoliation, while the EDM5 system retains an intercalated nanostructure. In the DRS studies of the curing process of the EDM2 system, two dielectric relaxations were detected, which are associated with the molecular mobility in the curing reaction which takes place both outside and inside the clay galleries

  13. Long-term aging of a CeO2 based nanocomposite used for wood protection

    International Nuclear Information System (INIS)

    Auffan, Melanie; Masion, Armand; Labille, Jerome; Diot, Marie-Ange; Liu, Wei; Olivi, Luca; Proux, Olivier; Ziarelli, Fabio; Chaurand, Perrine; Geantet, Christophe; Bottero, Jean-Yves; Rose, Jerome

    2014-01-01

    A multi-scale methodology was used to characterize the long-term behavior and chemical stability of a CeO 2 -based nanocomposite used as UV filter in wood stains. ATR-FTIR and 13 C NMR demonstrated that the citrate coated chelates with Ce(IV) through its central carboxyl- and its α-hydroxyl- groups at the surface of the unaged nanocomposite. After 42 days under artificial daylight, the citrate completely disappeared and small amount of degradation products remained attached to the surface even after 112 days. Moreover, the release/desorption of the citrate layer led to a surface reorganization of the nano-sized CeO 2 core observed by XANES (Ce L 3 -edge). Such a surface and structural transformation of the commercialized nanocomposite could have implications in term of fate, transport, and potential impacts towards the environment. - Highlights: • Organic coating of the nano-composite is degradated after 1.5 month. • Structural reorganization of the nano-sized CeO 2 core over aging. • Potential implications in term of exposure and impact towards biological organisms. - The long-term aging of a CeO 2 nanocomposite lead to surface chemistry and structural changes in aquatic environments

  14. Dielectric properties of ligand-modified gold nanoparticle/SU-8 photopolymer based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Toor, Anju, E-mail: atoor@berkeley.edu [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); So, Hongyun, E-mail: hyso@berkeley.edu [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Pisano, Albert P. [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Department of Mechanical and Aerospace Engineering, University of California, San Diego, CA 92093 (United States)

    2017-08-31

    Highlights: • Ligand-modified gold NP/SU-8 nanocomposites were synthesized and demonstrated. • Particle agglomeration and dispersion were characterized with different NPs concentration. • Nanocomposites showed higher average dielectric permittivity compared to SU-8 only. • Relatively lower dielectric loss (average 0.09 at 1 kHz) was achieved with 10 % w/w NPs. - Abstract: This article reports the enhanced dielectric properties of a photodefinable polymer nanocomposite material containing sub–10 nm coated metal nanoparticles (NPs). The surface morphology of the synthesized dodecanethiol-functionalized gold NPs was characterized using the transmission electron microscopy (TEM). We investigated the particle agglomeration and dispersion during the various stages of the nanocomposite synthesis using TEM. Physical properties such as dielectric permittivity and dielectric loss were measured experimentally. The dependence of the dielectric permittivity and loss tangent on the particle concentration, and frequency was studied. Nanocomposite films showed an approximately three times enhancement in average dielectric constant over the polymer base value and an average dielectric loss of 0.09 at 1 kHz, at a filler loading of 10% w/w.

  15. Electrochromic nanocomposite films

    Science.gov (United States)

    Milliron, Delia; Llordes, Anna; Buonsanti, Raffaella; Garcia, Guillermo

    2018-04-10

    The present invention provides an electrochromic nanocomposite film. In an exemplary embodiment, the electrochromic nanocomposite film, includes (1) a solid matrix of oxide based material and (2) transparent conducting oxide (TCO) nanostructures embedded in the matrix. In a further embodiment, the electrochromic nanocomposite film farther includes a substrate upon which the matrix is deposited. The present invention also provides a method of preparing an electrochromic nanocomposite film.

  16. Nanocomposites based on titanium dioxide and polythiophene: structure and properties

    Czech Academy of Sciences Publication Activity Database

    Vu, Q. T.; Pavlík, Martin; Hebestreit, N.; Rammelt, U.; Plieth, W.; Pfleger, Jiří

    2005-01-01

    Roč. 65, 1-2 (2005), s. 69-77 ISSN 1381-5148. [International Conference on Polymers and Organic Chemistry /11./. Prague, 18.06.2004-23.06.2004] R&D Projects: GA AV ČR IAA4050406 Grant - others:European Graduate School: Advanced Polymeric Materials(XE) IGK720 Institutional research plan: CEZ:AV0Z40500505 Keywords : polythiophene * titanium dioxide * nanocomposites Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.565, year: 2005

  17. Polymer waveguide couplers based on metal nanoparticle–polymer nanocomposites

    International Nuclear Information System (INIS)

    Signoretto, M; Suárez, I; Chirvony, V S; Martínez-Pastor, J; Abargues, R; Rodríguez-Cantó, P J

    2015-01-01

    In this work Au nanoparticles (AuNPs) are incorporated into poly(methyl methacrylate) (PMMA) waveguides to develop optical couplers that are compatible with planar organic polymer photonics. A method for growing AuNPs (of 10 to 100 nm in size) inside the commercially available Novolak resist is proposed with the intention of tuning the plasmon resonance and the absorption/scattering efficiencies inside the patterned structures. The refractive index of the MNP–Novolak nanocomposite (MNPs: noble metal nanoparticles) is carefully analysed both experimentally and numerically in order to find the appropriate fabrication conditions (filling factor and growth time) to optimize the scattering cross section at a desired wavelength. Then the nanocomposite is patterned inside a PMMA waveguide to exploit its scattering properties to couple and guide a normal incident laser light beam along the polymer. In this way, light coupling is experimentally demonstrated in a broad wavelength range (404–780 nm). Due to the elliptical shape of the MNPs the nanocomposite demonstrates a birefringence, which enhances the coupling to the TE mode up to efficiencies of around 1%. (paper)

  18. Flexible Transparent Supercapacitors Based on Hierarchical Nanocomposite Films.

    Science.gov (United States)

    Chen, Fanhong; Wan, Pengbo; Xu, Haijun; Sun, Xiaoming

    2017-05-31

    Flexible transparent electronic devices have recently gained immense popularity in smart wearable electronics and touch screen devices, which accelerates the development of the portable power sources with reliable flexibility, robust transparency and integration to couple these electronic devices. For potentially coupled as energy storage modules in various flexible, transparent and portable electronics, the flexible transparent supercapacitors are developed and assembled from hierarchical nanocomposite films of reduced graphene oxide (rGO) and aligned polyaniline (PANI) nanoarrays upon their synergistic advantages. The nanocomposite films are fabricated from in situ PANI nanoarrays preparation in a blended solution of aniline monomers and rGO onto the flexible, transparent, and stably conducting film (FTCF) substrate, which is obtained by coating silver nanowires (Ag NWs) layer with Meyer rod and then coating of rGO layer on polyethylene terephthalate (PET) substrate. Optimization of the transparency, the specific capacitance, and the flexibility resulted in the obtained all-solid state nanocomposite supercapacitors exhibiting enhanced capacitance performance, good cycling stability, excellent flexibility, and superior transparency. It provides promising application prospects for exploiting flexible, low-cost, transparent, and high-performance energy storage devices to be coupled into various flexible, transparent, and wearable electronic devices.

  19. Dielectric properties of ligand-modified gold nanoparticles/SU-8 photopolymer based nanocomposites

    KAUST Repository

    Toor, Anju; So, Hongyun; Pisano, Albert P.

    2017-01-01

    This article reports the enhanced dielectric properties of a photodefinable nanocomposite material containing sub–10 nm coated metal nanoparticles (NPs). The surface morphology of the synthesized dodecanethiol-functionalized gold NPs was characterized using the transmission electron microscopy (TEM). We investigated the particle agglomeration and dispersion during the various stages of the nanocomposite synthesis using TEM. Physical properties such as dielectric permittivity and dielectric loss were measured experimentally. The dependence of dielectric permittivity and loss tangent on particle concentration and frequency was studied. Nanocomposite films showed an approximately three times enhancement in average dielectric constant over the polymer base value and an average dielectric loss of 0.09 at 1 kHz, at a filler loading of 10% w/w.

  20. Cytotoxicity and mechanical behavior of chitin-bentonite clay based polyurethane bio-nanocomposites.

    Science.gov (United States)

    Zia, Khalid Mahmood; Zuber, Mohammad; Barikani, Mehdi; Hussain, Rizwan; Jamil, Tahir; Anjum, Sohail

    2011-12-01

    Chitin based polyurethane bio-nanocomposites (PUBNC) were prepared using chitin, Delite HPS bentonite nanoclay enriched in montmorillonite (MMT), 4,4'-diphenylmethane diisocyanate (MDI) and polycaprolactone polyol CAPA 231 (3000 g/mol(-1)). The prepolymers having different concentration of Delite HPS bentonite nanoclay were extended with 2 moles of chitin. The structures of the resulted polymers were determined by FT-IR technique. The effect of nanoclay contents on mechanical properties and in vitro biocompatibility was investigated. The mechanical properties of the synthesized materials were improved with increase in the Delite HPS bentonite nanoclay contents. Optimum mechanical properties were obtained from the PU bio-nanocomposite samples having 4% Delite HPS bentonite nanoclay. The results revealed that the final PU bio-nanocomposite having 2% Delite HPS bentonite nanoclay contents is ideal contenders for surgical threads with on going investigations into their in vitro biocompatibility, non-toxicity, and mechanical properties. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Dielectric properties of ligand-modified gold nanoparticles/SU-8 photopolymer based nanocomposites

    KAUST Repository

    Toor, Anju

    2017-04-15

    This article reports the enhanced dielectric properties of a photodefinable nanocomposite material containing sub–10 nm coated metal nanoparticles (NPs). The surface morphology of the synthesized dodecanethiol-functionalized gold NPs was characterized using the transmission electron microscopy (TEM). We investigated the particle agglomeration and dispersion during the various stages of the nanocomposite synthesis using TEM. Physical properties such as dielectric permittivity and dielectric loss were measured experimentally. The dependence of dielectric permittivity and loss tangent on particle concentration and frequency was studied. Nanocomposite films showed an approximately three times enhancement in average dielectric constant over the polymer base value and an average dielectric loss of 0.09 at 1 kHz, at a filler loading of 10% w/w.

  2. Poly(lactic acid) (PLA) based nanocomposites-a novel way of drug-releasing

    International Nuclear Information System (INIS)

    Chen Chen; Lv Gang; Pan Chao; Song Min; Wu Chunhui; Guo Dadong; Wang Xuemei; Chen Baoan; Gu Zhongze

    2007-01-01

    In this communication, poly(lactic acid) nanofibers have been fabricated by electrospinning and then poly(lactic acid) (PLA) based nanocomposites have been prepared by accumulating anticancer drug daunorubicin on PLA nanofibers combined with TiO 2 nanoparticles. Our atomic force microscopy (AFM) and laser-scanning confocal microscope (LSCM) studies demonstrate that the respective drug molecules could be readily self-assembled on the surface of the blends of nano-TiO 2 with PLA polymer nanocomposites, which could further efficiently facilitate the drug permeation and accumulation on the target leukemia K562 cells. Besides, the respective new nanocomposites have good biocompatibility, ease of surface chemistry modification and very high surface area, which may afford the possibility for their promising application in pharmacology and biomedical engineering areas. (communication)

  3. Analysis of polariton dispersion in metal nanocomposite based novel superlattice system

    Science.gov (United States)

    DoniPon, V.; Joseph Wilson, K. S.; Malarkodi, A.

    2018-06-01

    The influence of metal nanoparticles in tuning the polaritonic gap in a novel piezoelectric superlattice is studied. Dielectric function of the metal nanoparticles is analyzed using Kawabata-Kubo effect and Drude's theory. The effective dielectric function of the nanocomposite system is studied using Maxwell Garnett approximation. Nanocomposite based LiTaO3 novel superlattice is formed by arranging the nanocomposite systems in such a way that their orientations are in the opposite direction. Hence there are two additional modes of propagation. The top most modes reflect the metal behavior of the nanoparticles. It is found that these modes of propagation vary with the filling factor. These additional modes of propagations can be exploited in the field of communication.

  4. Process modeling of conductivity in nanocomposites based on reticulated polymers and carbon nanotubes

    International Nuclear Information System (INIS)

    Dolgoshej, V.B.; Korskanov, V.V.; Karpova, I.L.; Bardash, L.V.

    2012-01-01

    The dependences of electric conductivities of thermosetting polymer nanocomposites based on epoxy polymer and polycyanurate filled by carbon nanotubes were investigated. Low values of percolation threshold at volume fraction of carbon nanotubes from 0.001 to 0.002 were observed for all samples.Absolute values of the percolation threshold are in good agreement with the results of mathematical modeling. It is established that electrical properties of thermosetting polymer nanocomposites can be characterized in the frame of the same theoretical model despite difference in polymers properties

  5. Bio-based hyperbranched thermosetting polyurethane/triethanolamine functionalized multi-walled carbon nanotube nanocomposites as shape memory materials.

    Science.gov (United States)

    Kalita, Hemjyoti; Karak, Niranjan

    2014-07-01

    Here, bio-based shape memory polymers have generated immense interest in recent times. Here, Bio-based hyperbranched polyurethane/triethanolamine functionalized multi-walled carbon nanotube (TEA-f-MWCNT) nanocomposites were prepared by in-situ pre-polymerization technique. The Fourier transform infrared spectroscopy and the transmission electron microscopic studies showed the strong interfacial adhesion and the homogeneous distribution of TEA-f-MWCNT in the polyurethane matrix. The prepared epoxy cured thermosetting nanocomposites exhibited enhanced tensile strength (6.5-34.5 MPa), scratch hardness (3.0-7.5 kg) and thermal stability (241-288 degrees C). The nanocomposites showed excellent shape fixity and shape recovery. The shape recovery time decreases (24-10 s) with the increase of TEA-f-MWCNT content in the nanocomposites. Thus the studied nanocomposites have potential to be used as advanced shape memory materials.

  6. In vitro study of a new biodegradable nanocomposite based on poly propylene fumarate as bone glue

    Energy Technology Data Exchange (ETDEWEB)

    Shahbazi, S.; Moztarzadeh, F. [Department of Medical Engineering, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Sadeghi, G. Mir Mohamad [Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Jafari, Y., E-mail: y.j.arisman@gmail.com [Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan (Iran, Islamic Republic of)

    2016-12-01

    A novel poly propylene fumarate (PPF)-based glue which is reinforced by nanobioactive glass (NBG) particles and promoted by hydroxyethyl methacrylate (HEMA) as crosslinker agent, was developed and investigated for bone-to-bone bonding applications. In-vitro bioactivity, biodegradability, biocompatibility, and bone adhesion were tested and the results have verified that it can be used as bone glue. In an in-vitro condition, the prepared nanocomposite (PPF/HEMA/NBG) showed improved adhesion to wet bone surfaces. The combined tension and shear resistance between two wet bone surfaces was measured, and its maximum value was 9 ± 59 MPa. To investigate the bioactivity and biodegradability of the nanocomposite, it has been immersed in simulated body fluid (SBF). After 14 days exposure to SBF, a hydroxyapatite (HA) layer formed on the surface of the composite confirms the bioactivity of this material. In the XRD pattern of the nanocomposite surface, the HA characteristic diffraction peak at θ = 26 and 31.8 were observed. Also, by monitoring the weight change after 8 weeks immersion in SBF, the mass loss was about 16.46 wt%. It has been confirmed that this nanocomposite is a biodegradable material. Also, bioactivity and biodegradability of nanocomposite have been proved by SEM images. It has been showed that by using NBG particles and HEMA precursor, mechanical properties increased significantly. The ultimate tensile strength (UTS) of nanocomposite which contains 20% NBG and the ratio of 70/30 wt% PPF/HEMA (PHB.732) was approximately 62 MPa, while the UTS in the pure PPF/HEMA was about 32 MPa. High cell viability in this nanocomposite (MTT assays, 85–95%) can be attributed to the NBG nature which contains calcium phosphate and is similar to physiological environment. Furthermore, it possesses biomineralization and biodegradation which significantly affected by impregnation of hydrophilic HEMA in the PPF-based polymeric matrix. The results indicated that the new

  7. Sensitive methanol sensor based on PMMA-G-CNTs nanocomposites deposited onto glassy carbon electrodes.

    Science.gov (United States)

    Rahman, Mohammed M; Hussein, Mahmoud A; Alamry, Khalid A; Al Shehry, Faten M; Asiri, Abdullah M

    2016-04-01

    A new series of polymethyl methacrylate-graphene-carbon nanotubes crossbred nanocomposites in the form of PMMA-G-CNTs has been synthesized using simple dissolution procedure in organic media. The desired nanocomposites have been prepared using different loading (2 ∼ 30%) from consequently mixed GNPs/CNTs ratio and confirmed by various characterization techniques utilized to corroborate the assembly of these new hybrid series including X-ray diffraction analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. The PMMA-G-CNTs nanocomposites were deposited on flat glassy carbon electrodes (GCE) to result in a sensor that has a fast response toward methanol in the phosphate buffer phase. Features including high sensitivity, low-sample volume, reliability, reproducibility, ease of integration, long-term stability, and enhanced electrochemical responses are investigated. The calibration plot is linear (r(2)=0.9895) over the 1.0 nmol L(-1) to 10.0 mmol L(-1) methanol concentration ranges. The sensitivity and detection limit is 13.491 µA cm(-2) mmol L(-2) and 0.39 ± 0.1 nmol L(-1) (at a signal-to-noise-ratio, SNR of 3), respectively. With such excellent features of analytical parameters, the developed sensor provides a new strategy for determination of methanol in biomedical and environmental analytes with satisfactory results. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. 3D printing of CNT- and graphene-based conductive polymer nanocomposites by fused deposition modeling

    NARCIS (Netherlands)

    Gnanasekaran, K.; Heijmans, T.; van Bennekom, S.; Woldhuis, H.; Wijnia, S.; de With, G.; Friedrich, H.

    2017-01-01

    Fused deposition modeling (FDM) is limited by the availability of application specific functional materials. Here we illustrate printing of non-conventional polymer nanocomposites (CNT- and graphene-based polybutylene terephthalate (PBT)) on a commercially available desktop 3D printer leading toward

  9. Understanding the antimicrobial mechanism of TiO2-based nanocomposite films in a pathogenic bacterium

    NARCIS (Netherlands)

    Kubacka, A.; Suarez Diez, M.; Rojo, D.; Bargiela, R.; Ciordia, S.; Zapico, I.; Albar, J.P.; Barbas, C.; Martins Dos Santos, V.A.P.; Fernández-García, M.; Ferrer, M.

    2014-01-01

    Titania (TiO2)-based nanocomposites subjected to light excitation are remarkably effective in eliciting microbial death. However, the mechanism by which these materials induce microbial death and the effects that they have on microbes are poorly understood. Here, we assess the low dose

  10. Microstructural characterization of Mg-based bulk metallic glass and nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Babilas, Rafał, E-mail: rafal.babilas@polsl.pl [Institute of Engineering Materials and Biomaterials, Silesian University of Technology, Konarskiego 18a St., 44-100 Gliwice (Poland); Nowosielski, Ryszard; Pawlyta, Mirosława [Institute of Engineering Materials and Biomaterials, Silesian University of Technology, Konarskiego 18a St., 44-100 Gliwice (Poland); Fitch, Andy [European Synchrotron Radiation Facility, CS40220, 38043 Grenoble (France); Burian, Andrzej [A. Chelkowski Institute of Physics, University of Silesia, Uniwersytecka 4 St., 40-007 Katowice (Poland)

    2015-04-15

    New magnesium-based bulk metallic glasses Mg{sub 60}Cu{sub 30}Y{sub 10} have been prepared by pressure casting. Glassy alloys were successfully annealed to become nanocomposite containing 200 nm crystallites in an amorphous matrix. The microstructure of bulk glassy alloy and nanocomposite obtained during heat treatment was examined by X-ray diffraction and scanning and high-resolution electron microscopy. Metallic glass has been also studied to explain the structural characteristics by the reverse Monte Carlo (RMC) modeling based on the diffraction data. The HRTEM images allow to indicate some medium-range order (MRO) regions about 2–3 nm in size and formation of local atomic clusters. The RMC modeling results confirmed some kinds of short range order (SRO) structures. It was found that the structure of bulk metallic glass formed by the pressure casting is homogeneous. The composite material contained very small particles in the amorphous matrix. Homogeneous glassy alloy had better corrosion resistance than a composite containing nanocrystalline particles in a glassy matrix. - Highlights: • RMC modeling demonstrates some kinds of SRO structures in Mg-based BMGs. • HRTEM indicated MRO regions about 2–3 nm and SRO regions about 0.5 nm in size. • Mg-based glassy alloys were successfully annealed to become nanocomposite material. • Crystalline particles have spherical morphology with an average diameter of 200 nm. • Glassy alloy had higher corrosion resistance than a nanocomposite sample.

  11. Morphology and properties of nanocomposites based on polymer blend and organoclay

    CSIR Research Space (South Africa)

    Gcwabaza, T

    2008-10-01

    Full Text Available improved properties.1-4 such a compatibilizer may be a homopolymer, a block, graft or star copolymer. However, there are few reports on clay containing nanocomposites based on polymer blends, whether miscible or immiscible. Such composite materials offer...

  12. Polylactide based nanocomposites: Processing, structure and performance relationship

    Science.gov (United States)

    Karami, Shahir

    The application of biodegradable polymers has been offered to the packing industry wishing to overcome the environmental consequence of employing the petroleum-based polymers. Furthermore, the unstable oil market urged the industry to look for the substitution of the renewable resources. Polylactide is known as the most popular biodegradable polymer developed on a large scale. Nevertheless, the growing contribution of polylactide to packing industry is somewhat restricted owing to its inherent brittleness and weak barrier properties. Therefore, the main objective of this thesis was defined to build a fundamental relationship between processing parameters and solid-state microstructure to improve the performance of polylactide. Polylactide nanocomposites were prepared through a multi-step melt compounding process. Dispersion of organically modified layered nanoparticles was detected by the WAXS and TEM characterizations, demonstrating the formation of intercalated nanocomposites. Relaxation spectrum exhibited the restricted dynamics of fraction of amorphous phase confined in polymer-particle interphase through dynamic rheological measurements. The fraction of rigid amorphous chains was estimated using TMDSC and DMA. This increased with nanoparticle content, levelling off upon the aggregation of nanoparticles. The annealing-induced molecular ordering was detected by FR-IR, increasing the rigid amorphous fraction. Cold crystallization was investigated during non-isothermal process using TMDSC. Crystallization kinetic was studied through the evaluation of Avrami parameters in isothermal process at the temperature range of Tg+30°C to Tg+70°C. The crystallization rate depressed with the nanoparticle content due to the enhanced fraction of rigid amorphous chains, as well as, the topological constraints derived from the formation of network structure. Nevertheless, the nanoparticles acted as heterogeneous nucleating sites upon devitrification of the rigid amorphous

  13. High performances unsaturated polyester based nanocomposites: Effect of vinyl modified nanosilica on mechanical properties

    Directory of Open Access Journals (Sweden)

    J. D. Rusmirovic

    2016-02-01

    Full Text Available Influences of the vinyl modified nanosilica Aerosil® 380, i.e./i>, vinyl and methacryloyl silane coupling agent and linseed oil fatty acids (BD reactive residues, on the mechanical properties of the unsaturated polyester resins (UPes based nanocomposites, was studied. The polycondensation of maleic anhydride and products of poly(ethylene terephthalate (PET depolymerization with propylene glycol, with and without separation of ethylene glycol, yields UPe1 and UPe2 resin, respectively. The hydroxyl terminated PET depolymerization products (glycolyzates and UPes were characterized by acid and hydroxyl values, Fourier Transform Infrared (FTIR and nuclear magneti resonance (NMR spectroscopies. Transmission electron microscopy (TEM confirmed that silica nanoparticles formed domains of aggregates in the polymer matrix. An increase from 195 to 247% of stress at break (σb, and from 109 to 131% of impact strength (σi of UPes based nanocomposites was obtained for 1 wt% addition of vinyl modified silica. Flexural strength (σf increase from 106 to 156% for both UPes based nanocomposites with 1 wt% addition of BD modified silica. Cross-linking density (ν, storage modulus (G', tanδ and Tg of the nanocomposite were determined from the dynamic mechanical testing and discussed in relation to the structure of silica modification.

  14. Hierarchical hybrid of Ni{sub 3}N/N-doped reduced graphene oxide nanocomposite as a noble metal free catalyst for oxygen reduction reaction

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Qi; Li, Yingjun; Li, Yetong [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Huang, Keke [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012 (China); Wang, Qin, E-mail: qinwang@imu.edu.cn [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Inner Mongolia Key Lab. of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021 (China); Zhang, Jun, E-mail: cejzhang@imu.edu.cn [College of Chemistry and Chemical Engineering, Inner Mongolia University, Hohhot 010021 (China); Inner Mongolia Key Lab. of Nanoscience and Nanotechnology, Inner Mongolia University, Hohhot 010021 (China)

    2017-04-01

    Highlights: • Hybrid of Ni{sub 3}N/N-RGO catalysts are synthesized by using a two-step method. • The catalysts manifest superior catalytic activity towards the ORR. • High activities are attributed to enhanced electron density and synergistic effects. - Abstract: Novel nickel nitride (Ni{sub 3}N) nanoparticles supported on nitrogen-doped reduced graphene oxide nanosheets (N-RGOs) are synthesized via a facile strategy including hydrothermal and subsequent calcination methods, in which the reduced graphene oxide nanosheets (RGOs) are simultaneously doped with nitrogen species. By varying the content of the RGOs, a series of Ni{sub 3}N/N-RGO nanocomposites are obtained. The Ni{sub 3}N/N-RGO-30% hybrid nanocomposite exhibits superior catalytic activity towards oxygen reduction reaction (ORR) under alkaline condition (0.1 M KOH). Furthermore, this hybrid catalyst also demonstrates high tolerance to methanol poisoning. The RGO containing rich N confers the nanocomposite with large specific surface area and high electronic conduction ability, which can enhance the catalytic efficiency of Ni{sub 3}N nanoparticles. The enhanced catalytic activity can be attributed to the synergistic effect between Ni{sub 3}N and nitrogen doped reduced graphene oxide. In addition, the sufficient contact between Ni{sub 3}N nanoparticles and the N-RGO nanosheets simultaneously promotes good nanoparticle dispersion and provides a consecutive activity sites to accelerate electron transport continuously, which further enhance the ORR performance. The Ni{sub 3}N/N-RGO may be further an ideal candidate as efficient and inexpensive noble metal-free ORR electrocatalyst in fuel cells.

  15. Enhanced extraction and purification of plasmid DNA from escherichia coli by applying a hybrid magnetic nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Silva, R.J. da; Chavez-Guajardo, A.E.; Medina-llamas, J.C.; Alcaraz-Espinoza, J.J.; Melo, C.P. de [Universidade Federal de Pernambuco (UFPE), PE (Brazil)

    2016-07-01

    Full text: Plasmid DNA (pDNA), a special kind of nucleic acid usually found in bacteria, is a small molecule physically distinct from chromosomal DNA that can replicate independently. This genetic material has been used in a wide set of biotechnological methodologies, such as genetic engineering, production of recombinant drugs and gene therapy, among others. In all these applications, the extraction and purification of pDNA appears as a crucial step. In this work, we describe the synthesis of a polyaniline and maghemite (PANI/?-Fe2O3) magnetic nanocomposite (MNC) and its use in a new Escherichia coli (E. coli) pDNA extraction and purification protocol. We have used transmission electron microscopy (TEM), UV-Vis spectroscopy, infrared spectroscopy (FTIR), X-ray diffraction (XRD), dynamic light scattering (DLS) and magnetic measurements to characterize the MNC, which was synthesized through an emulsion polymerization method. The yield, purity and quality of the pDNA extracted by using our proposed MNC protocol were evaluated through UV-Vis, agarose gel electrophoreses and PCR techniques, respectively. After comparing our results to those obtained by use of a commercial kit (Promega Wizard Plus SV Minipreps), we suggest that the novel protocol here proposed appears as a competitive alternative methodology. Not only the purification step can be completed within only 10 min, but the high adsorption capacity of the MNC results in pDNA yields that are almost twice the best values obtained by using the commercial kit. Hence, this new MNC methodology can be of general interest and find widespread use in different types of biomedical applications. (author)

  16. Functional energy nanocomposites surfaces based on mesoscopic microspheres, polymers and graphene flakes

    Science.gov (United States)

    Alekseev, S. A.; Dmitriev, A. S.; Dmitriev, A. A.; Makarov, P. G.; Mikhailova, I. A.

    2017-11-01

    In recent years, there has been a great interest in the development and creation of new functional energy materials, including for improving the energy efficiency of power equipment and for effectively removing heat from energy devices, microelectronics and optoelectronics (power micro electronics, supercapacitors, cooling of processors, servers and Data centers). In this paper, the technology of obtaining a new nanocomposite based on mesoscopic microspheres, polymers and graphene flakes is considered. The methods of sequential production of functional materials from graphite flakes of different volumetric concentration using polymers based on epoxy resins and polyimide, as well as the addition of a mesoscopic medium in the form of monodisperse microspheres are described. The data of optical and electron microscopy of such nanocomposites are presented, the main problems in the appearance of defects in such materials are described, the possibilities of their elimination by the selection of different concentrations and sizes of the components. Data are given on the measurement of the hysteresis of the contact angle and the evaporation of droplets on similar substrates. The results of studying the mechanical, electrophysical and thermal properties of such nanocomposites are presented. Particular attention is paid to the investigation of the thermal conductivity of these nanocomposites with respect to the creation of thermal interface materials for cooling devices of electronics, optoelectronics and power engineering.

  17. Thermoelectric properties of graphene nanosheets-modified polyaniline hybrid nanocomposites by an in situ chemical polymerization

    International Nuclear Information System (INIS)

    Lu, Yan; Song, Ying; Wang, Fuping

    2013-01-01

    A hybrid material of polyaniline protonated with hydrochloric acid and conductive graphene nanosheets (PANi/GNs) has been prepared by an in situ chemical polymerization method. The interactions between PANi and GNs in the hybrid composites are investigated by utilizing XRD, FT-IR, UV–vis and Raman. It is found that the PANi are adsorbed on the surface of the GNs, and the morphology of PANi transforms from twist structure to extended structure after the GNs are introduced. The thermoelectric (TE) properties of PANi/GNs composites have been investigated in the range from 323 K to 453 K. The electrical conductivity and the Seebeck coefficient of PANi/GNs composites are obviously higher than those of the PANi, while the thermal conductivity of the composites still keeps relatively low values even with high GNs content, resulting in the increase in dimensionless figure of merit (ZT). A highest ZT value of 1.95 × 10 −3 has been obtained for the composite containing 30 wt % GNs at 453 K, which is about 70 times higher than that obtained from the PANi. - Highlights: ► PANi adsorbed on the surface of the GNs possesses more extended structure. ► Electrical conductivity and Seebeck coefficient of PANi/GNs composites are superior to those of PANi. ► Thermal conductivity of the composites still keeps relatively low values

  18. Facile synthesis of graphene oxide @ mesoporous carbon hybrid nanocomposites for lithium sulfur battery

    International Nuclear Information System (INIS)

    Bao, Weizhai; Zhang, Zhian; Chen, Wei; Zhou, Chengkun; Lai, Yanqing; Li, Jie

    2014-01-01

    Graphical abstract: - Highlights: • A novel design and synthesis of GO@Meso-C using GO@MOF-5 as precursor. • GO@Meso-C hybrid material as a host material was applied for sulfur cathode. • Electrochemical performances were improved in sulfur cathode using Go@Meso-C. - Abstract: We present a design and synthesis of a hierarchical architecture of graphene oxide @ mesoporous carbon (GO@Meso-C) using graphene oxide @ metal-organic framework hybrid materials (GO@MOF-5) as both the template and precursor. Active sulfur is encapsulated into the GO@Meso-C matrix prepared via carbonize GO@MOF-5 polyhedrons for high performance lithium sulfur battery. The initial and 100th cycle discharge capacity of GO@Meso-C/S sulfur cathode are as high as 1122 mAh g −1 and 820 mAh g −1 at a current rate of 0.2 C. The remarkably high special capacity and capacity retention rate indicate that the GO@Meso-C is a promising host material for the sulfur cathode in the lithium sulfur battery applications

  19. Polydimethyl siloxane based nanocomposites with antibiofilm properties for biomedical applications.

    Science.gov (United States)

    Sankar, G Gomathi; Murthy, P Sriyutha; Das, Arindam; Sathya, S; Nankar, Rakesh; Venugopalan, V P; Doble, Mukesh

    2017-07-01

    Polydimethyl siloxane (PDMS) is an excellent implant material for biomedical applications, but often fails as it is prone to microbial colonization which forms biofilms. In the present study CuO, CTAB capped CuO, and ZnO nanoparticles were tested as nanofillers to enhance the antibiofilm property of PDMS against Staphylococcus aureus and Escherichia coli. In general S. aurues (Gram positive and more hydrophobic) favor PDMS surface than glass while E. coli (Gram negative and more hydrophilic) behaves in a reverse way. Incorporation of nanofillers renders the PDMS surface antibacterial and reduces the attachment of both bacteria. These surfaces are also not cytotoxic nor show any cell damage. Contact angle of the material and the cell surface hydrophobicity influenced the extent of bacterial attachment. Cell viability in biofilms was dependent on the antimicrobial property of the nanoparticles incorporated in the PDMS matrix. Simple regression relationships were able to predict the bacterial attachment and number of dead cells on these nanocomposites. Among the nanocomposites tested, PDMS incorporated with CTAB (cetyl trimethylammonium bromide)-capped CuO appears to be the best antibacterial material with good cyto-compatibility. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1075-1082, 2017. © 2016 Wiley Periodicals, Inc.

  20. A Novel Ultraviolet Irradiation Technique for Fabrication of Polyacrylamide-metal (M = Au, Pd) Nanocomposites at Room Temperature

    International Nuclear Information System (INIS)

    Zhou, Y.; Hao, L.Y.; Zhu, Y.R.; Hu, Y.; Chen, Z.Y.

    2001-01-01

    Polyacrylamide (PAM)-metal (M = gold, palladium) nanocomposites with metal nanoparticles homogeneously dispersed in the polymer matrix have been prepared via a novel ultraviolet irradiation technique at room temperature, which is based on the simultaneous occurrence of photo-reduction formation of the colloidal metal particles and photo-polymerization of the acrylamide (AM) monomer. The UV-vis absorption spectra and TEM were employed to characterize the M-PAM nanocomposites by different irradiation times. The average sizes of the colloidal gold and palladium particles dispersed in the nanocomposites were calculated by XRD patterns and TEM images. The present method may be extended to prepare other metal-polymer hybrid nanocomposite materials

  1. Enhancement of the mechanical properties of an aluminum metal matrix nanocomposite by the hybridization technique

    Directory of Open Access Journals (Sweden)

    Kalidindi Sita Rama Raju

    2016-07-01

    Full Text Available A uniform distribution of nanoparticles in the matrix plays a prominent role in improving the composite strength. In the present investigation, two types of launching vehicles, such as aluminum powder (primary and CNTs (secondary, are considered to uniformly carry and launch ultra-fine nanoparticles (13 nm into molten metal. The use of a secondary launching vehicle is identified to promote strengthening compared to a regular primary vehicle, as indicated by the good distribution observed from electron micrographs. CNTs are responsible for hybridizing the composite and also assist strengthening by anchoring to the matrix through the destroyed outer-walls and their axial orientation with the matrix. These results help us in attaining a strength of 197 MPa and a hardness of 93 BHN, with a minimal loss in ductility for the H-3 sample.

  2. Effect of reduced graphene oxide-carbon nanotubes hybrid nanofillers in mechanical properties of polymer nanocomposites

    Science.gov (United States)

    Sa, Kadambinee; Mahakul, Prakash C.; Subramanyam, B. V. R. S.; Raiguru, Jagatpati; Das, Sonali; Alam, Injamul; Mahanandia, Pitamber

    2018-03-01

    Graphene and carbon nanotubes (CNTs) have tremendous interest as reinforcing fillers due to their excellent physical properties. However, their reinforcing effect in polymer matrix is limited due to agglomeration of graphene and CNTs within the polymer matrix. Mechanical properties by the admixture of reduced graphene oxide (rGO) and CNTs in Poly (methyl methacrylate) (PMMA) prepared by solution mixing method has been investigated. The prepared samples are characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM) and Raman spectroscopy. The hybrid composite shows improvement in the mechanical properties compared to rGO/PMMA and MWCNTs/PMMA composites due to better interaction between rGO-MWCNTs and polymer matrix.

  3. Development of multifunctional fluoroelastomers based on nanocomposites; Desenvolvimento de elastomeros fluorados multifuncionais baseados em nanocompositos

    Energy Technology Data Exchange (ETDEWEB)

    Zen, Heloisa Augusto

    2015-07-01

    The fluoropolymers are known for their great mechanical properties, high thermal stability and resistance to aggressive chemical environment, and because of those properties they are widely used in industries, such as automobile, petroleum, chemistry, manufacturing, among others. To improve the thermal properties and gases barrier of the polymeric matrix, the incorporation of nanoparticle is used, this process permits the polymer to maintain their own characteristics and acquire new properties of nanoparticle. Because of those properties, the structural and morphological modification of fluoropolymers are very hard to be obtained through traditional techniques, in order to surmount this difficulty, the ionizing radiation is a well-known and effective method to modify fluoropolymers structures. In this thesis a nanocomposite polymeric based on fluoroelastomer (FKM) was developed and incorporated with four different configurations of nanoparticles: clay Cloisite 15A, POSS 1159, POSS 1160 and POSS 1163. After the nanocomposites films were obtained, a radiation induced grafting process was carried out, followed by sulfonation in order to obtain a ionic exchanged membrane. The effect of nanoparticle incorporation and the ionizing radiation onto films were characterized by X-ray diffraction, thermal and mechanical analysis, scanning electron microscopy and swelling; and the membranes were evaluated by degree of grafting, ionic exchange capacity and swelling. After the films were characterized, the crosslinking effect was observed to be predominant for the nanocomposites irradiated before the vulcanization, whereas the degradation was the predominant effect in the nanocomposites irradiated after vulcanization. (author)

  4. Carboxymethyl chitosan based nanocomposites containing chemically bonded quantum dots and magnetic nanoparticles

    Science.gov (United States)

    Ding, Yongling; Yin, Hong; Chen, Rui; Bai, Ru; Chen, Chunying; Hao, Xiaojuan; Shen, Shirley; Sun, Kangning; Liu, Futian

    2018-03-01

    A biocompatible nanocomposite consisting of fluorescent quantum dots (QDs) and magnetic nanoparticles (MNPs) has been constructed via carboxymethyl chitosan (CMCS), resulting in magnetic-fluorescent nanoparticles (MFNPs). In these MFNPs, QDs and MNPs are successfully conjugated via covalent bonds onto the surface of CMCS. The composite retains favorable magnetic and fluorescent properties and shows a good colloidal stability in physiological environments. Folate (FA) as a specific targeting ligand was further incorporated into the nanocomposites to form a delivery vehicle with a targeting function. The therapeutic activity was achieved by loading chemotherapeutic drug doxorubicin (DOX) through electrostatic and hydrophobic interactions. The cumulative DOX release profile shows pH-sensitive. Both flow cytometry analysis and confocal laser scanning microscopic observation suggested that these nanocomposites were uptaken by cancer cells via FA receptor-mediated endocytosis pathway. In summary, the CMCS based nanocomposites developed in this work have a great potential for effective cancer-targeting and drug delivery, as well as in situ cellular imaging.

  5. A new nanocomposite polymer electrolyte based on poly(vinyl alcohol) incorporating hypergrafted nano-silica

    KAUST Repository

    Hu, Xian-Lei

    2012-01-01

    Solid-state nanocomposite polymer electrolytes based on poly(vinyl alcohol)(PVA) incorporating hyperbranched poly(amine-ester) (HBPAE) grafted nano-silica (denoted as SiO2-g-HBPAE) have been prepared and investigated. Through surface pretreatment of nanoparticles, followed by Michael-addition and a self-condensation process, hyperbranched poly(amine-ester) was directly polymerized from the surface of nano-silica. Then the hypergrafted nanoparticles were added to PVA matrix, and blended with lithium perchlorate via mold casting method to fabricate nanocomposite polymer electrolytes. By introducing hypergrafted nanoparticles, ionic conductivity of solid composite is improved significantly at the testing temperature. Hypergrafted nano-silica may act as solid plasticizer, promoting lithium salt dissociation in the matrix as well as improving segmental motion of matrix. In addition, tensile testing shows that such materials are soft and tough even at room temperature. From the dielectric spectra of nanocomposite polymer electrolyte as the function of temperature, it can be deduced that Arrhenius behavior appears depending on the content of hypergrafted nano-silica and concentration of lithium perchlorate. At a loading of 15 wt% hypergrafted nano-silica and 54 wt% lithium perchlorate, promising ionic conductivities of PVA nanocomposite polymer electrolyte are achieved, about 1.51 × 10 -4 S cm-1 at 25 °C and 1.36 × 10-3 S cm-1 at 100 °C. © The Royal Society of Chemistry.

  6. MEMS sensor material based on polypyrrole carbon nanotube nanocomposite: film deposition and characterization

    Science.gov (United States)

    Teh, Kwok-Siong; Lin, Liwei

    2005-11-01

    Conductive polymer-based nanocomposite has been utilized as a MEMS sensing material via a one-step, selective on-chip deposition process at room temperature. A doped polypyrrole (PPy) variant synthesized by incorporating multi-walled carbon nanotube (MWCNT) into electropolymerized PPy has been shown to improve the sensing performance utilizing a two-terminal, micro-gap chemiresistor architecture. The dodecylbenzenesulfonate (DBS)-doped PPy-MWCNT nanocomposites are found to be responsive to oxidants, such as hydrogen peroxide (H2O2), and this effect can be extended to glucose detection using H2O2 as a proxy material. The oxidant sensing effect is demonstrated by subjecting a glucose oxidase (GOx)-laden PPy-MWCNT nanocomposite film to various concentrations of glucose solution. Such PPy-MWCNT nanocomposite, when applied in a chemiresistor configuration, obviates the need for reference electrode and electron mediators, by measuring the direct and reversible, oxidation-reduction induced conductivity change. Experimentally, GOx-laden, doped PPy-MWCNT is tested to be sensitive to glucose concentration up to 20 mM, which covers the physiologically important range for diabetics of 0-20 mM.

  7. An Insilico Design of Nanoclay Based Nanocomposites and Scaffolds in Bone Tissue Engineering

    Science.gov (United States)

    Sharma, Anurag

    A multiscale in silico approach to design polymer nanocomposites and scaffolds for bone tissue engineering applications is described in this study. This study focuses on the role of biomaterials design and selection, structural integrity and mechanical properties evolution during degradation and tissue regeneration in the successful design of polymer nanocomposite scaffolds. Polymer nanocomposite scaffolds are synthesized using aminoacid modified montmorillonite nanoclay with biomineralized hydroxyapatite and polycaprolactone (PCL/in situ HAPclay). Representative molecular models of polymer nanocomposite system are systematically developed using molecular dynamics (MD) technique and successfully validated using material characterization techniques. The constant force steered molecular dynamics (fSMD) simulation results indicate a two-phase nanomechanical behavior of the polymer nanocomposite. The MD and fSMD simulations results provide quantitative contributions of molecular interactions between different constituents of representative models and their effect on nanomechanical responses of nanoclay based polymer nanocomposite system. A finite element (FE) model of PCL/in situ HAPclay scaffold is built using micro-computed tomography images and bridging the nanomechanical properties obtained from fSMD simulations into the FE model. A new reduction factor, K is introduced into modeling results to consider the effect of wall porosity of the polymer scaffold. The effect of accelerated degradation under alkaline conditions and human osteoblast cells culture on the evolution of mechanical properties of scaffolds are studied and the damage mechanics based analytical models are developed. Finally, the novel multiscale models are developed that incorporate the complex molecular and microstructural properties, mechanical properties at nanoscale and structural levels and mechanical properties evolution during degradation and tissue formation in the polymer nanocomposite

  8. Ultrasensitive and simultaneous detection of heavy metal ions based on three-dimensional graphene-carbon nanotubes hybrid electrode materials

    International Nuclear Information System (INIS)

    Huang, Hui; Chen, Ting; Liu, Xiuyu; Ma, Houyi

    2014-01-01

    Highlights: • Three-dimensional graphene-MWCNTs nanocomposites were prepared. • Graphene-MWCNTs based electrochemical sensor was used to detect heavy metal ions for the first time. • The proposed sensor was certified capable for real sample with satisfactory results. - Abstract: A green and facile method was developed to prepare a novel hybrid nanocomposite that consisted of one-dimensional multi-walled carbon nanotubes (MWCNTs) and two-dimensional graphene oxide (GO) sheets. The as-prepared three-dimensional GO–MWCNTs hybrid nanocomposites exhibit excellent water-solubility owing to the high hydrophilicity of GO components; meanwhile, a certain amount of MWCNTs loaded on the surface of GO sheets through π–π interaction seem to be “dissolved” in water. Moreover, the graphene(G)-MWCNTs nanocomposites with excellent conductivity were obtained conveniently by the direct electrochemical reduction of GO–MWCNTs nanocomposites. Seeing that there is a good synergistic effect between MWCNTs and graphene components in enhancing preconcentration efficiency of metal ions and accelerating electron transfer rate at G-MWCNTs/electrolyte interface, the G-MWCNTs nanocomposites possess fast, simultaneous and sensitive detection performance for trace amounts of heavy metal ions. The electrochemical results demonstrate that the G-MWCNTs nanocomposites can act as a kind of practical sensing material to simultaneously determine Pb 2+ and Cd 2+ ions in terms of anodic stripping voltammetry (ASV). The linear calibration plots for Pb 2+ and Cd 2+ ranged from 0.5 μg L −1 to 30 μg L −1 . The detection limits were determined to be 0.2 μg L −1 (S/N = 3) for Pb 2+ and 0.1 μg L −1 (S/N = 3) for Cd 2+ in the case of a deposition time of 180 s. It is worth mentioning that the G-MWCNTs modified electrodes were successfully applied to the simultaneous detection of Cd 2+ and Pb 2+ ions in real electroplating effluent samples containing lots of surface active impurities

  9. Ultrasensitive and simultaneous detection of heavy metal ions based on three-dimensional graphene-carbon nanotubes hybrid electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Hui; Chen, Ting [Key Laboratory for Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China); Liu, Xiuyu [Shandong Academy of Sciences, Jinan 250114 (China); Ma, Houyi, E-mail: hyma@sdu.edu.cn [Key Laboratory for Colloid and Interface Chemistry of State Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100 (China)

    2014-12-10

    Highlights: • Three-dimensional graphene-MWCNTs nanocomposites were prepared. • Graphene-MWCNTs based electrochemical sensor was used to detect heavy metal ions for the first time. • The proposed sensor was certified capable for real sample with satisfactory results. - Abstract: A green and facile method was developed to prepare a novel hybrid nanocomposite that consisted of one-dimensional multi-walled carbon nanotubes (MWCNTs) and two-dimensional graphene oxide (GO) sheets. The as-prepared three-dimensional GO–MWCNTs hybrid nanocomposites exhibit excellent water-solubility owing to the high hydrophilicity of GO components; meanwhile, a certain amount of MWCNTs loaded on the surface of GO sheets through π–π interaction seem to be “dissolved” in water. Moreover, the graphene(G)-MWCNTs nanocomposites with excellent conductivity were obtained conveniently by the direct electrochemical reduction of GO–MWCNTs nanocomposites. Seeing that there is a good synergistic effect between MWCNTs and graphene components in enhancing preconcentration efficiency of metal ions and accelerating electron transfer rate at G-MWCNTs/electrolyte interface, the G-MWCNTs nanocomposites possess fast, simultaneous and sensitive detection performance for trace amounts of heavy metal ions. The electrochemical results demonstrate that the G-MWCNTs nanocomposites can act as a kind of practical sensing material to simultaneously determine Pb{sup 2+} and Cd{sup 2+} ions in terms of anodic stripping voltammetry (ASV). The linear calibration plots for Pb{sup 2+} and Cd{sup 2+} ranged from 0.5 μg L{sup −1} to 30 μg L{sup −1}. The detection limits were determined to be 0.2 μg L{sup −1} (S/N = 3) for Pb{sup 2+} and 0.1 μg L{sup −1} (S/N = 3) for Cd{sup 2+} in the case of a deposition time of 180 s. It is worth mentioning that the G-MWCNTs modified electrodes were successfully applied to the simultaneous detection of Cd{sup 2+} and Pb{sup 2+} ions in real electroplating

  10. Graphene oxide-silica nanohybrids as fillers for PA6 based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Maio, A. [Department of Civil, Environmental, Aerospace, Materials Engineering, University of Palermo, Viale delle Scienze, Ed. 6, 90128, Palermo, Italy and STEBICEF, Section of Biology and Chemistry, University of Palermo, Viale delle Scienze, Parco d' Orleans (Italy); Fucarino, R.; Khatibi, R. [Dipartimento di Ingegneria Chimica, Gestionale, Informatica, Meccanica, University of Palermo, Viale delle Scienze, Ed. 6, 90128, Palermo (Italy); Botta, L.; Scaffaro, R. [Department of Civil, Environmental, Aerospace, Materials Engineering, University of Palermo, Viale delle Scienze, Ed. 6, 90128, Palermo (Italy); Rosselli, S.; Bruno, M. [STEBICEF, Section of Biology and Chemistry, University of Palermo, Viale delle Scienze, Parco d' Orleans II, 90128 Palermo (Italy)

    2014-05-15

    Graphene oxide (GO) was prepared by oxidation of graphite flakes by a mixture of H{sub 2}SO{sub 4}/H{sub 3}PO{sub 4} and KMnO{sub 4} based on Marcano's method. Two different masterbatches containing GO (33.3%) and polyamide-6 (PA6) (66.7%) were prepared both via solvent casting in formic acid and by melt mixing in a mini-extruder (Haake). The two masterbatches were then used to prepare PA6-based nanocomposites with a content of 2% in GO. For comparison, a nanocomposite by direct mixing of PA6 and GO (2%) and PA6/graphite nanocomposites were prepared, too. The oxidation of graphite into GO was assessed by X-ray diffraction (XRD), Micro-Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) analyses. All these techniques demonstrated the effectiveness of the graphite modification, since the results put into evidence that, after the acid treatment, interlayer distance, oxygen content and defects increased. SEM micrographs carried out on the nanocomposites, showed GO layers totally surrounded by polyamide-6, this feature is likely due to the strong interaction between the hydrophilic moieties located both on GO and on PA6. On the contrary, no interactions were observed when graphite was used as filler. Mechanical characterization, carried out by tensile and dynamic-mechanical tests, marked an improvement of the mechanical properties observed. Photoluminescence and EPR measurements were carried out onto nanoparticles and nanocomposites to study the nature of the interactions and to assess the possibility to use this class of materials as semiconductors or optical sensors.

  11. Graphene oxide-silica nanohybrids as fillers for PA6 based nanocomposites

    International Nuclear Information System (INIS)

    Maio, A.; Fucarino, R.; Khatibi, R.; Botta, L.; Scaffaro, R.; Rosselli, S.; Bruno, M.

    2014-01-01

    Graphene oxide (GO) was prepared by oxidation of graphite flakes by a mixture of H 2 SO 4 /H 3 PO 4 and KMnO 4 based on Marcano's method. Two different masterbatches containing GO (33.3%) and polyamide-6 (PA6) (66.7%) were prepared both via solvent casting in formic acid and by melt mixing in a mini-extruder (Haake). The two masterbatches were then used to prepare PA6-based nanocomposites with a content of 2% in GO. For comparison, a nanocomposite by direct mixing of PA6 and GO (2%) and PA6/graphite nanocomposites were prepared, too. The oxidation of graphite into GO was assessed by X-ray diffraction (XRD), Micro-Raman spectroscopy, scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) analyses. All these techniques demonstrated the effectiveness of the graphite modification, since the results put into evidence that, after the acid treatment, interlayer distance, oxygen content and defects increased. SEM micrographs carried out on the nanocomposites, showed GO layers totally surrounded by polyamide-6, this feature is likely due to the strong interaction between the hydrophilic moieties located both on GO and on PA6. On the contrary, no interactions were observed when graphite was used as filler. Mechanical characterization, carried out by tensile and dynamic-mechanical tests, marked an improvement of the mechanical properties observed. Photoluminescence and EPR measurements were carried out onto nanoparticles and nanocomposites to study the nature of the interactions and to assess the possibility to use this class of materials as semiconductors or optical sensors

  12. Multilevel structures of Li3V2(PO4)3/phosphorus-doped carbon nanocomposites derived from hybrid V-MOFs for long-life and cheap lithium ion battery cathodes

    Science.gov (United States)

    Wang, Zhaoyang; He, Wen; Zhang, Xudong; Yue, Yuanzheng; Liu, Jinhua; Zhang, Chuanjiang; Fang, Leyong

    2017-10-01

    The Li3V2(PO4)3/phosphorus-doped carbon (LVP/P-C) nanocomposites with multilevel structures (such as spheroidal, foam, prism and flower-like structures) are synthesized via one-pot in-situ synthesis using hybrid vanadium metal-organic frameworks (V-MOFs) as precursor. The structure and morphology of the LVP/P-C nanocomposites were characterized by scanning electron microscopy, transmission electron microscopy, Raman, X-ray diffraction and element mapping. The results show that the multilevel structures are generated from the assemblies of the hybrid surfactant templates in the glass fiber drawing wastewater (GFDW) and the hybrid V-MOFs. The structure of LVP/P-C nanocomposite is controlled by V-MOFs. The nanocomposites exhibit a long service life, a discharge capacity of 65 mA h g-1 at 10 C with 90% capacity retention after 1100 cycles. The high cycling stability is attributed to the multilevel structures, which is ideal for making rechargeable lithium ion batteries. More importantly, our results have demonstrated that GFDW can be transformed into treasure of multilevel structure nanocomposites for cheap Li ion batteries.

  13. An insight into the mechanism of charge transfer properties of hybrid organic (MEH-PPV): Inorganic (TiO2) nanocomposites

    International Nuclear Information System (INIS)

    Mittal, Tanu; Tiwari, Sangeeta; Mehta, Aarti; Sharma, Shailesh N.

    2016-01-01

    Now a days, inorganic nanoparticles are gaining importance and are potential candidate in different organic electronic device application like (LEDs, PVs) due to their novel properties and confinement in Nano-dimensions. [1, 2] In the present work, we have compared the properties of titanium di oxide (TiO 2 ) nanoparticles (NPs) synthesized by using two different chemical routes aqueous and ethanol respectively. These synthesized TiO 2 nanoparticles have been characterized by X-ray diffraction spectroscopy (XRD) for phase confirmation. It was observed that synthesized nanoparticles are in anatase phase for both preparation routes. Morphological information was collected by scanning electron microscopy (SEM) which confirms that particles are almost spherical in shape and distributed uniformly which is further ensured by transmission electron microscopy (TEM). Dynamic light scattering (DLS) technique was also used for further confirmation of size distribution of as-synthesized nanoparticles. Optical properties were also investigated by photoluminescence and UV-Vis spectroscopy and calculated bandgap was found to be in the range of 3.3-3.5eV for TiO 2 (aq/eth) nanoparticles. The increase in bandgap values with respect to bulk (3.2 eV) confirms that as- synthesized nanoparticles are confined in nanodimensions. As synthesized nanoparticles were interacted with MEHPPV polymer (donor) matrix to make their respective MEHPPV: TiO 2 nanocomposites and to confirm the charge transfer mechanism from polymer to nanoparticles. It can be observed from photoluminescence (PL) quenching experiments that continuous quenching obtained for respective nanocomposites confirms better charge transfer from polymer to inorganic TiO 2 nanoparticles respectively. Because of, better quenching and simultaneously enhanced charge transfer of respective nanocomposites, ensures that these nanocomposites are greatly applicable for photovoltaics (PVs) especially in Hybrid Solar cells (HSCs).

  14. Preparation of polymer nanocomposites with enhanced mechanical properties using hybrid of graphene and partially wrapped multi-wall carbon nanotube as nanofiller

    Institute of Scientific and Technical Information of China (English)

    Jiao You; Jiang-Yong-Quan Cao; Si-Chong Chen; Yu-Zhong Wang

    2017-01-01

    Triblock copolymer of poly(p-dioxanone) and polyethylene glycol end-capped with pyrene moieties ((Py-PPDO)2-b-PEG) was synthesized and used as modifier for multi-wall carbon nanotubes (MWCNTs).Nano-aggregates ((Py-PPDO)2-b-PEG@NWCNTs) with shish-kebab like partially wrapped morphology and very good stability were obtained by incorporating the copolymer with MWCNTs.The bare MWCNT sections of (Py-PPDO)2-b-PEG@MWCNTs were able to induce π-π interactions with graphene (GE) and resulted in a novel GE/(Py-PPDO)2-b-PEG@MWCNTs hybrid.The dispersity of GE in solution or polymer matrix was therefore greatly improved.The PCL nanocomposite films using GE/(Py-PPDO)2-b-PEG@MWCNTs as hybrid nanofiller exhibited obviously improved mechanical properties especially at very low hybrid nanofiller content.The influence of the nanofiller content and feed ratio of GE/ MWCNTs on the mechanical properties of composites films was evaluated.When the feed ratio of GE to MWCNTs is 2:8 and the total loading of nanofiller is only 0.01 wt%,the tensile strength of the composite film increased by 163% and the elongation at break increased by 17% compared to those of neat PCL These results can be attributed to fine dispersion of the nanofillers in PCL matrix and the hybrid interactions between GE and MWCNTs.Therefore,this work provides a novel method for preparing polymer nanocomposites with high mechanical performance and low nanofiller loading.

  15. Hybrid employment recommendation algorithm based on Spark

    Science.gov (United States)

    Li, Zuoquan; Lin, Yubei; Zhang, Xingming

    2017-08-01

    Aiming at the real-time application of collaborative filtering employment recommendation algorithm (CF), a clustering collaborative filtering recommendation algorithm (CCF) is developed, which applies hierarchical clustering to CF and narrows the query range of neighbour items. In addition, to solve the cold-start problem of content-based recommendation algorithm (CB), a content-based algorithm with users’ information (CBUI) is introduced for job recommendation. Furthermore, a hybrid recommendation algorithm (HRA) which combines CCF and CBUI algorithms is proposed, and implemented on Spark platform. The experimental results show that HRA can overcome the problems of cold start and data sparsity, and achieve good recommendation accuracy and scalability for employment recommendation.

  16. Multifunctional nanocomposite based on graphene oxide for in vitro hepatocarcinoma diagnosis and treatment.

    Science.gov (United States)

    Shen, Ai-Jun; Li, Dong-Liang; Cai, Xiao-Jun; Dong, Chun-Yan; Dong, Hai-Qing; Wen, Hui-Yun; Dai, Gong-Hua; Wang, Pei-Jun; Li, Yong-Yong

    2012-09-01

    Because of its unique chemical and physical properties, graphene oxide (GO) has attracted a large number of researchers to explore its biomedical applications in the past few years. Here, we synthesized a novel multifunctional nanocomposite based on GO and systemically investigated its applications for in vitro hepatocarcinoma diagnosis and treatment. This multifunctional nanocomposite named GO-PEG-FA/Gd/DOX was obtained as the following procedures: gadolinium-diethylenetriamine-pentaacetic acid-poly(diallyl dimethylammonium) chloride (Gd-DTPA-PDDA) as magnetic resonance imaging (MRI) probe was applied to modify GO by simple physical sorption with a loading efficiency of Gd(3+) up to 0.314 mg mg(-1). In order to improve its tumor targeting imaging and treatment efficiency, the obtained intermediate product was further modified with folic acid (FA). Finally, the nanocomposite was allowed to load anticancer drug doxorubicin hydrochloride via π-π stacking and hydrophobic interaction with the loading capacity reaching 1.38 mg mg(-1). MRI test revealed that GO-PEG-FA/Gd/DOX exhibit superior tumor targeting imaging efficiency over free Gd(3+). The in vitro release of DOX from the nanocomposite under tumor relevant condition (pH 5.5) was fast at the initial 10 h and then become relatively slow afterward. Moreover, we experimentally demonstrated that the multifunctional nanocomposite exhibited obviously cytotoxic effect upon cancer cells. Above results are promising for the next in vivo experiment and make it possible to be a potential candidate for malignancy early detection and specific treatment. Copyright © 2012 Wiley Periodicals, Inc.

  17. IPN hydrogel nanocomposites based on agarose and ZnO with antifouling and bactericidal properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jingjing, E-mail: jjwang1@hotmail.com; Hu, Hongkai; Yang, Zhonglin; Wei, Jun; Li, Juan

    2016-04-01

    Nanocomposite hydrogels with interpenetrating polymer network (IPN) structure based on poly(ethylene glycol) methyl ether methacrylate modified ZnO (ZnO-PEGMA) and 4-azidobenzoic agarose (AG-N{sub 3}) were prepared by a one-pot strategy under UV irradiation. The hydrogels exhibited a highly macroporous spongelike structure, and the pore size decreased with the increase of the ZnO-PEGMA content. Due to the entanglement and favorable interactions between the two crosslinked networks, the IPN hydrogels exhibited excellent mechanical strength and light transmittance. The maximum compressive and tensile strengths of the IPN hydrogels reached 24.8 and 1.98 MPa respectively. The transparent IPN hydrogels transmitted more than 85% of visible light at all wavelengths (400–800 nm). The IPN hydrogels exhibited anti-adhesive property towards Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), and the bactericidal activity increased with the ZnO-PEGMA content. The incorporation of ZnO-PEGMA did not reduce the biocompatibility of the IPN hydrogels and all the IPN nanocomposites showed negligible cytotoxicity. The present study not only provided a facile method for preparing hydrogel nanocomposites with IPN structure but also developed a new hydrogel material which might be an excellent candidate for wound dressings. - Highlights: • IPN hydrogel nanocomposites were prepared by a one-pot strategy. • The maximum compressive and tensile strengths reached 24.8 and 1.98 MPa. • IPN hydrogels displayed excellent antibacterial activity and cytocompatibility. • This study provided a facile method for preparing IPN hydrogel nanocomposites.

  18. Modeling the oxygen diffusion of nanocomposite-based food packaging films.

    Science.gov (United States)

    Bhunia, Kanishka; Dhawan, Sumeet; Sablani, Shyam S

    2012-07-01

    Polymer-layered silicate nanocomposites have been shown to improve the gas barrier properties of food packaging polymers. This study developed a computer simulation model using the commercial software, COMSOL Multiphysics to analyze changes in oxygen barrier properties in terms of relative diffusivity, as influenced by configuration and structural parameters that include volume fraction (φ), aspect ratio (α), intercalation width (W), and orientation angle (θ) of nanoparticles. The simulation was performed at different φ (1%, 3%, 5%, and 7%), α (50, 100, 500, and 1000), and W (1, 3, 5, and 7 nm). The θ value was varied from 0° to 85°. Results show that diffusivity decreases with increasing volume fraction, but beyond φ = 5% and α = 500, diffusivity remained almost constant at W values of 1 and 3 nm. Higher relative diffusivity coincided with increasing W and decreasing α value for the same volume fraction of nanoparticles. Diffusivity increased as the rotational angle increased, gradually diminishing the influence of nanoparticles. Diffusivity increased drastically as θ changed from 15° to 30° (relative increment in relative diffusivity was almost 3.5 times). Nanoparticles with exfoliation configuration exhibited better oxygen barrier properties compared to intercalation. The finite element model developed in this study provides insight into oxygen barrier properties for nanocomposite with a wide range of structural parameters. This model can be used to design and manufacture an ideal nanocomposite-based food packaging film with improved gas barrier properties for industrial applications. The model will assist in designing nanocomposite polymeric structures of desired gas barrier properties for food packaging applications. In addition, this study will be helpful in formulating a combination of nanoparticle structural parameters for designing nanocomposite membranes with selective permeability for the industrial applications including membrane

  19. BisGMA-polyvinylpyrrolidone blend based nanocomposites reinforced with chitosan grafted f-multiwalled carbon nanotubes

    Directory of Open Access Journals (Sweden)

    A. Praharaj

    2015-01-01

    Full Text Available In this work, initially a non-destroyable surface grafting of acid functionalized multiwalled carbon nanotubes (f-MWCNTs with biopolymer chitosan (CS was carried out using glutaraldehyde as a cross-linking agent via the controlled covalent deposition method which was characterized by Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM. Then, BisGMA (bisphenol-A glycidyldimethacrylate-polyvinylpyrrolidone (PVP blend was prepared (50:50 wt% by a simple sonication method. The CS grafted f-MWCNTs (CS/f-MWCNTs were finally dispersed in BisGMA-PVP blend (BGP50 system in different compositions i.e. 0, 2, 5 and 7 wt% and pressed into molds for the fabrication of reinforced nanocomposites which were characterized by SEM. Nanocomposites reinforced with 2 wt% raw MWCNTs and acid f-MWCNTs were also fabricated and their properties were studied in detail. The results of comparative study report lower values of the investigated properties in nanocomposites with 2 wt% raw and f-MWCNTs than the one with 2 wt% CS/f-MWCNTs proving it to be a better reinforcing nanofiller. Further, the mechanical behavior of the nanocomposites with various CS/f-MWCNTs content showed a dramatic increase in Young’s Modulus, tensile strength, impact strength and hardness along with improved dynamic mechanical, thermal and electrical properties at 5 wt% content of CS/f-MWCNTs. The addition of CS/f-MWCNTs also resulted in reduced corrosion and swelling properties. Thus, the fabricated nanocomposites with optimum nanofiller content could serve as low cost and light weight structural, thermal and electrical materials compatible in various corrosive and solvent based environments.

  20. Synthesis, Morphology, and Optical Properties of Au/CdS Hybrid Nanocomposites Stabilized by Branched Polymer Matrices

    Directory of Open Access Journals (Sweden)

    V. A. Chumachenko

    2016-01-01

    Full Text Available Metal/semiconductor (Au/CdS nanocomposites were synthesized in the solution of branched D-g-PAA polymer. TEM and DLS of Au/CdS/D-g-PAA nanocomposites revealed complicated nanocomposite structure consisting of the Au nanoparticles (NPs of 6 nm in size surrounded by small CdS NPs with size of 3 nm. These nanocomposites formed the aggregates-clusters with average size of 50–800 nm. Absorption spectra of Au/CdS nanocomposites consist of the bands of excitons in CdS NPs and surface plasmons in Au ones. The surface plasmon band of gold NPs is red shifted and broadened in Au/CdS/D-g-PAA nanocomposites comparing to the one of Au NPs in Au/D-g-PAA proving the fact of close location of CdS and Au NPs in the synthesized Au/CdS/D-g-PAA nanocomposites. The PL spectra of Au/CdS nanocomposites originate from the radiative transitions in excitons in CdS NPs. The 4-fold increase of intensity of free exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA that is due to PL enhancement by local field of surface plasmons of Au NPs. Also, the 12-fold decrease of intensity of localized exciton PL is observed for CdS NPs in Au/CdS/D-g-PAA comparing to CdS ones in CdS/D-g-PAA. Most probably, it is due to passivation of the surface of CdS NPs carried out by the Au ones.

  1. Irradiation induced crossover from 1D to 3D transport behaviors of PEDOT-titanium dioxide hybrid nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Sarmah, Smritimala [Department of Physics, Girijananda Chowdhury Institute of Management and Technology, Guwahati 781017, Assam (India); Kumar, A. [Materials Research Laboratory, Department of Physics, Tezpur University, Tezpur 784028, Assam (India)

    2012-12-15

    Conductive poly(3,4-ethylenedioxythiophene)/TiO{sub 2} nanocomposites were synthesized via a facile oxidative polymerization approach using dodecylbenzene sulfonic acid as a dopant and ammonium peroxydisulfate as an oxidant and irradiated with 90 MeV O{sup 7+} ions at the fluences of 5 x 10{sup 10}, 1 x 10{sup 11}, 5 x 10{sup 11}, and 1 x 10{sup 12} ions cm{sup -2} using 15UD Pelletron accelerator under high vacuum. X-ray diffraction studies show that microstrain and domain crystallite size of the nanocomposites increases with the increase of ion fluence resulting in highly ordered PEDOT-TiO{sub 2} nanocomposites. Thermogravimmetric analysis shows that the thermal stability of the nanocomposites increases with the increase of irradiation fluences which can be attributed to the crosslinking of polymer chains due to high electronic energy deposition. Scanning electron micrographs show that there is grain growth after swift heavy ion (SHI) irradiation resulting highly dense and less porous microstructure of nanocomposite films. DC conductivity of unirradiated nanocomposites exhibits Mott's 1D variable range hopping (VRH) mechanism. However, there is cross over to 3D VRH mechanism at higher irradiation fluence of 5 x 10{sup 11} and 1 x 10{sup 12} ions cm{sup -2}. There is an enhancement in the electrical conductivity of the nanocomposites upon SHI irradiation correlating crosslinking with DC conductivity of the nanocomposites. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Synthesis of polydopamine-functionalized magnetic graphene and carbon nanotubes hybrid nanocomposites as an adsorbent for the fast determination of 16 priority polycyclic aromatic hydrocarbons in aqueous samples.

    Science.gov (United States)

    Chen, Kun; Jin, Rongrong; Luo, Chen; Song, Guoxin; Hu, Yaoming; Cheng, Hefa

    2018-04-01

    A novel adsorbent made of polydopamine-functionalized magnetic graphene and carbon nanotubes hybrid nanocomposite was synthesized and applied to determine 16 priority polycyclic aromatic hydrocarbons by magnetic solid phase extraction in water samples. FTIR spectroscopy, transmission electron microscopy, scanning electron microscopy, and Raman spectroscopy consistently indicate that the synthesized adsorbents are made of core-shell nanoparticles well dispersed on the surface of graphene and carbon nanotubes. The major factors affecting the extraction efficiency, including the pH value of samples, the amount of adsorbent, adsorption time and desorption time, type and volume of desorption solvent, were systematically optimized. Under the optimum extraction conditions, a linear response was obtained for polycyclic aromatic hydrocarbons between concentrations of 10 and 500 ng/L with the correlation coefficients ranging from 0.9958 to 0.9989, and the limits of detection (S/N = 3) were between 0.1 and 3.0 ng/L. Satisfactory results were also obtained when applying these magnetic graphene/carbon nanotubes/polydopamine hybrid nanocomposites to detect polycyclic aromatic hydrocarbons in several environmental aqueous samples. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Recent Progress on Ferroelectric Polymer-Based Nanocomposites for High Energy Density Capacitors: Synthesis, Dielectric Properties, and Future Aspects.

    Science.gov (United States)

    Prateek; Thakur, Vijay Kumar; Gupta, Raju Kumar

    2016-04-13

    Dielectric polymer nanocomposites are rapidly emerging as novel materials for a number of advanced engineering applications. In this Review, we present a comprehensive review of the use of ferroelectric polymers, especially PVDF and PVDF-based copolymers/blends as potential components in dielectric nanocomposite materials for high energy density capacitor applications. Various parameters like dielectric constant, dielectric loss, breakdown strength, energy density, and flexibility of the polymer nanocomposites have been thoroughly investigated. Fillers with different shapes have been found to cause significant variation in the physical and electrical properties. Generally, one-dimensional and two-dimensional nanofillers with large aspect ratios provide enhanced flexibility versus zero-dimensional fillers. Surface modification of nanomaterials as well as polymers adds flavor to the dielectric properties of the resulting nanocomposites. Nowadays, three-phase nanocomposites with either combination of fillers or polymer matrix help in further improving the dielectric properties as compared to two-phase nanocomposites. Recent research has been focused on altering the dielectric properties of different materials while also maintaining their superior flexibility. Flexible polymer nanocomposites are the best candidates for application in various fields. However, certain challenges still present, which can be solved only by extensive research in this field.

  4. Injection Molding and Mechanical Properties of Bio-Based Polymer Nanocomposites

    Directory of Open Access Journals (Sweden)

    Maria Chiara Mistretta

    2018-04-01

    Full Text Available The use of biodegradable/bio-based polymers is of great importance in addressing several issues related to environmental protection, public health, and new, stricter legislation. Yet some applications require improved properties (such as barrier or mechanical properties, suggesting the use of nanosized fillers in order to obtain bio-based polymer nanocomposites. In this work, bionanocomposites based on two different biodegradable polymers (coming from the Bioflex and MaterBi families and two different nanosized fillers (organo-modified clay and hydrophobic-coated precipitated calcium carbonate were prepared and compared with traditional nanocomposites with high-density polyethylene (HDPE as matrix. In particular, the injection molding processability, as well as the mechanical and rheological properties of the so-obtained bionanocomposites were investigated. It was found that the processability of the two biodegradable polymers and the related nanocomposites can be compared to that of the HDPE-based systems and that, in general, the bio-based systems can be taken into account as suitable alternatives.

  5. Hybrid-Based Dense Stereo Matching

    Science.gov (United States)

    Chuang, T. Y.; Ting, H. W.; Jaw, J. J.

    2016-06-01

    Stereo matching generating accurate and dense disparity maps is an indispensable technique for 3D exploitation of imagery in the fields of Computer vision and Photogrammetry. Although numerous solutions and advances have been proposed in the literature, occlusions, disparity discontinuities, sparse texture, image distortion, and illumination changes still lead to problematic issues and await better treatment. In this paper, a hybrid-based method based on semi-global matching is presented to tackle the challenges on dense stereo matching. To ease the sensitiveness of SGM cost aggregation towards penalty parameters, a formal way to provide proper penalty estimates is proposed. To this end, the study manipulates a shape-adaptive cross-based matching with an edge constraint to generate an initial disparity map for penalty estimation. Image edges, indicating the potential locations of occlusions as well as disparity discontinuities, are approved by the edge drawing algorithm to ensure the local support regions not to cover significant disparity changes. Besides, an additional penalty parameter 𝑃𝑒 is imposed onto the energy function of SGM cost aggregation to specifically handle edge pixels. Furthermore, the final disparities of edge pixels are found by weighting both values derived from the SGM cost aggregation and the U-SURF matching, providing more reliable estimates at disparity discontinuity areas. Evaluations on Middlebury stereo benchmarks demonstrate satisfactory performance and reveal the potency of the hybrid-based dense stereo matching method.

  6. Enhanced photocatalytic property of hybrid graphitic C3N4 and graphitic ZnO nanocomposite: the effects of interface and doping

    Science.gov (United States)

    Cui, Jie; Liang, Shuhua; Sun, Shaodong; Zheng, Xing; Zhang, Jianmin

    2018-05-01

    Using first-principles calculations, we present a potential new way to improve the photocatalytic efficiency of the g-C3N4 sheet by coupling with the g-ZnO sheet to form heterojunction nanostructure followed by the addition of N atom at an atomic level. The result indicates the g-C3N4/g-ZnO heterojunction is a staggered band alignment (type II) structure and a polarized field is generated by the electrons transfer across the interface simultaneously, which facilitate the separation of e‑–h+ pairs and promote the photocatalytic activity. Furthermore, a great difference in energy levels between redox potentials and band edges of the C3N4/g-ZnO nanocomposite ensures that the water splitting/CO2 reduction reaction is energetically favored. In addition, through the incorporation of nitrogen dopant, the g-C3N4/N-g-ZnO nanocomposite displays desirable properties. The N-derived doping peak causes a decrease of the band gap width of the g-C3N4/g-ZnO nanocomposite, resulting in the enhanced optical absorption from UV into visible light. This theoretical predictions provide insightful outlooks in understanding the effects of interface and doping on the enhanced photocatalytic property of the g-C3N4/g-ZnO nanocomposites, which will assist in engineering highly efficient g-C3N4-based photocatalysts.

  7. Optimal energy management for a flywheel-based hybrid vehicle

    NARCIS (Netherlands)

    Berkel, van K.; Hofman, T.; Vroemen, B.G.; Steinbuch, M.

    2011-01-01

    This paper presents the modeling and design of an optimal Energy Management Strategy (EMS) for a flywheel-based hybrid vehicle, that does not use any electrical motor/generator, or a battery, for its hybrid functionalities. The hybrid drive train consists of only low-cost components, such as a

  8. Reversible light-controlled conductance switching of azobenzene-based metal/polymer nanocomposites

    International Nuclear Information System (INIS)

    Pakula, Christina; Zaporojtchenko, Vladimir; Strunskus, Thomas; Faupel, Franz; Zargarani, Dordaneh; Herges, Rainer

    2010-01-01

    We present a new concept of light-controlled conductance switching based on metal/polymer nanocomposites with dissolved chromophores that do not have intrinsic current switching ability. Photoswitchable metal/PMMA nanocomposites were prepared by physical vapor deposition of Au and Pt clusters, respectively, onto spin-coated thin poly(methylmethacrylate) films doped with azo-dye molecules. High dye concentrations were achieved by functionalizing the azo groups with tails and branches, thus enhancing solubility. The composites show completely reversible optical switching of the absorption bands upon alternating irradiation with UV and blue light. We also demonstrate reversible light-controlled conductance switching. This is attributed to changes in the metal cluster separation upon isomerization based on model experiments where analogous conductance changes were induced by swelling of the composite films in organic vapors and by tensile stress.

  9. Real time polymer nanocomposites-based physical nanosensors: theory and modeling

    Science.gov (United States)

    Bellucci, Stefano; Shunin, Yuri; Gopeyenko, Victor; Lobanova-Shunina, Tamara; Burlutskaya, Nataly; Zhukovskii, Yuri

    2017-09-01

    Functionalized carbon nanotubes and graphene nanoribbons nanostructures, serving as the basis for the creation of physical pressure and temperature nanosensors, are considered as tools for ecological monitoring and medical applications. Fragments of nanocarbon inclusions with different morphologies, presenting a disordered system, are regarded as models for nanocomposite materials based on carbon nanoсluster suspension in dielectric polymer environments (e.g., epoxy resins). We have formulated the approach of conductivity calculations for carbon-based polymer nanocomposites using the effective media cluster approach, disordered systems theory and conductivity mechanisms analysis, and obtained the calibration dependences. Providing a proper description of electric responses in nanosensoring systems, we demonstrate the implementation of advanced simulation models suitable for real time control nanosystems. We also consider the prospects and prototypes of the proposed physical nanosensor models providing the comparisons with experimental calibration dependences.

  10. GRAPHENE BASED METAL AND METAL OXIDE NANOCOMPOSITES: SYNTHESIS, PROPERTIES AND THEIR APPLICATIONS

    KAUST Repository

    Khan, Mujeeb

    2015-06-11

    Graphene, an atomically thin two-dimensional carbonaceous material, has attracted tremendous attention in the scientific community, due to its exceptional electronic, electrical, and mechanical properties. Indeed, with the recent explosion of methods for a large-scale synthesis of graphene, the number of publications related to graphene and other graphene based materials have increased exponentially. Particularly the easy preparation of graphene like materials, such as, highly reduced graphene oxide (HRG) via reduction of graphite oxide (GO), offers a wide range of possibilities for the preparation of graphene based inorganic nanocomposites by the incorporation of various functional nanomaterials for a variety of applications. In this review, we discuss the current development of graphene based metal and metal oxide nanocomposites, with a detailed account of their synthesis and properties. Specifically, much attention has been given to their wide range of applications in various fields, including, electronics, electrochemical and electrical fields. Overall, by the inclusion of various references, this review covers in detail aspects of the graphene-based inorganic nanocomposites.

  11. GRAPHENE BASED METAL AND METAL OXIDE NANOCOMPOSITES: SYNTHESIS, PROPERTIES AND THEIR APPLICATIONS

    KAUST Repository

    Khan, Mujeeb; Tahir, Muhammad Nawaz; Adil, Syed F; Khan, Hadayat Ullah; Siddiqui, Rafiq H; Al-Warthan, Abdulrahman Abdullah; Tremel, Wolfgang

    2015-01-01

    Graphene, an atomically thin two-dimensional carbonaceous material, has attracted tremendous attention in the scientific community, due to its exceptional electronic, electrical, and mechanical properties. Indeed, with the recent explosion of methods for a large-scale synthesis of graphene, the number of publications related to graphene and other graphene based materials have increased exponentially. Particularly the easy preparation of graphene like materials, such as, highly reduced graphene oxide (HRG) via reduction of graphite oxide (GO), offers a wide range of possibilities for the preparation of graphene based inorganic nanocomposites by the incorporation of various functional nanomaterials for a variety of applications. In this review, we discuss the current development of graphene based metal and metal oxide nanocomposites, with a detailed account of their synthesis and properties. Specifically, much attention has been given to their wide range of applications in various fields, including, electronics, electrochemical and electrical fields. Overall, by the inclusion of various references, this review covers in detail aspects of the graphene-based inorganic nanocomposites.

  12. Silicon based quantum dot hybrid qubits

    Science.gov (United States)

    Kim, Dohun

    2015-03-01

    The charge and spin degrees of freedom of an electron constitute natural bases for constructing quantum two level systems, or qubits, in semiconductor quantum dots. The quantum dot charge qubit offers a simple architecture and high-speed operation, but generally suffers from fast dephasing due to strong coupling of the environment to the electron's charge. On the other hand, quantum dot spin qubits have demonstrated long coherence times, but their manipulation is often slower than desired for important future applications. This talk will present experimental progress of a `hybrid' qubit, formed by three electrons in a Si/SiGe double quantum dot, which combines desirable characteristics (speed and coherence) in the past found separately in qubits based on either charge or spin degrees of freedom. Using resonant microwaves, we first discuss qubit operations near the `sweet spot' for charge qubit operation. Along with fast (>GHz) manipulation rates for any rotation axis on the Bloch sphere, we implement two independent tomographic characterization schemes in the charge qubit regime: traditional quantum process tomography (QPT) and gate set tomography (GST). We also present resonant qubit operations of the hybrid qubit performed on the same device, DC pulsed gate operations of which were recently demonstrated. We demonstrate three-axis control and the implementation of dynamic decoupling pulse sequences. Performing QPT on the hybrid qubit, we show that AC gating yields π rotation process fidelities higher than 93% for X-axis and 96% for Z-axis rotations, which demonstrates efficient quantum control of semiconductor qubits using resonant microwaves. We discuss a path forward for achieving fidelities better than the threshold for quantum error correction using surface codes. This work was supported in part by ARO (W911NF-12-0607), NSF (PHY-1104660), DOE (DE-FG02-03ER46028), and by the Laboratory Directed Research and Development program at Sandia National Laboratories

  13. Multifunctional Electroactive Nanocomposites Based on Piezoelectric Boron Nitride Nanotubes

    Science.gov (United States)

    Kang, Jin Ho; Sauti, Godfrey; Park, Cheol; Yamakov, Vesselin I.; Wise, Kristopher E.; Lowther, Sharon E.; Fay, Catharine C.; Thibeault, Sheila A.; Bryant, Robert G.

    2015-01-01

    Space exploration missions require sensors and devices capable of stable operation in harsh environments such as those that include high thermal fluctuation, atomic oxygen, and high-energy ionizing radiation. However, conventional or state-of-the-art electroactive materials like lead zirconate titanate, poly(vinylidene fluoride), and carbon nanotube (CNT)-doped polyimides have limitations on use in those extreme applications. Theoretical studies have shown that boron nitride nanotubes (BNNTs) have strength-to-weight ratios comparable to those of CNTs, excellent high-temperature stability (to 800 C in air), large electroactive characteristics, and excellent neutron radiation shielding capability. In this study, we demonstrated the experimental electroactive characteristics of BNNTs in novel multifunctional electroactive nanocomposites. Upon application of an external electric field, the 2 wt % BNNT/polyimide composite was found to exhibit electroactive strain composed of a superposition of linear piezoelectric and nonlinear electrostrictive components. When the BNNTs were aligned by stretching the 2 wt % BNNT/polyimide composite, electroactive characteristics increased by about 460% compared to the nonstretched sample. An all-nanotube actuator consisting of a BNNT buckypaper layer between two single-walled carbon nanotube buck-paper electrode layers was found to have much larger electroactive properties. The additional neutron radiation shielding properties and ultraviolet/visible/near-infrared optical properties of the BNNT composites make them excellent candidates for use in the extreme environments of space missions. utilizing the unique characteristics of BNNTs.

  14. Multifunctional polymer nano-composite based superhydrophobic surface

    Science.gov (United States)

    Maitra, Tanmoy; Asthana, Ashish; Buchel, Robert; Tiwari, Manish K.; Poulikakos, Dimos

    2014-11-01

    Superhydrophobic surfaces become desirable in plethora of applications in engineering fields, automobile industry, construction industries to name a few. Typical fabrication of superhydrophobic surface consists of two steps: first is to create rough morphology on the substrate of interest, followed by coating of low energy molecules. However, typical exception of the above fabrication technique would be direct coating of functional polymer nanocomposites on substrate where superhydrophobicity is needed. Also in this case, the use of different nanoparticles in the polymer matrix can be exploited to impart multi-functional properties to the superhydrophobic coatings. Herein, different carbon nanoparticles like graphene nanoplatelets (GNP), carbon nanotubes (CNT) and carbon black (CB) are used in fluropolymer matrix to prepare superhydrophobic coatings. The multi-functional properties of coatings are enhanced by combining two different carbon fillers in the matrix. The aforementioned superhydrophobic coatings have shown high electrical conductivity and excellent droplet meniscus impalement resistance. Simultaneous superhydrophobic and oleophillic character of the above coating is used to separate mineral oil and water through filtration of their mixture. Swiss National Science Foundation (SNF) Grant 200021_135479.

  15. Nanocomposites Based on Thermoplastic Polymers and Functional Nanofiller for Sensor Applications

    Directory of Open Access Journals (Sweden)

    Serena Coiai

    2015-06-01

    Full Text Available Thermoplastic polymers like polyolefins, polyesters, polyamide, and styrene polymers are the most representative commodity plastics thanks to their cost-efficient manufacturing processes, excellent thermomechanical properties and their good environmental compatibility, including easy recycling. In the last few decades much effort has been devoted worldwide to extend the applications of such materials by conferring on them new properties through mixing and blending with different additives. In this latter context, nanocomposites have recently offered new exciting possibilities. This review discusses the successful use of nanostructured dispersed substrates in designing new stimuli-responsive nanocomposites; in particular, it provides an updated description of the synthetic routes to prepare nanostructured systems having the typical properties of thermoplastic polymers (continuous matrix, but showing enhanced optical, conductive, and thermal features dependent on the dispersion topology. The controlled nanodispersion of functional labeled clays, noble metal nanoparticles and carbon nanotubes is here evidenced to play a key role in producing hybrid thermoplastic materials that have been used in the design of devices, such as NLO devices, chemiresistors, temperature and deformation sensors.

  16. Nanocomposites Based on Thermoplastic Polymers and Functional Nanofiller for Sensor Applications

    Science.gov (United States)

    Coiai, Serena; Passaglia, Elisa; Pucci, Andrea; Ruggeri, Giacomo

    2015-01-01

    Thermoplastic polymers like polyolefins, polyesters, polyamide, and styrene polymers are the most representative commodity plastics thanks to their cost-efficient manufacturing processes, excellent thermomechanical properties and their good environmental compatibility, including easy recycling. In the last few decades much effort has been devoted worldwide to extend the applications of such materials by conferring on them new properties through mixing and blending with different additives. In this latter context, nanocomposites have recently offered new exciting possibilities. This review discusses the successful use of nanostructured dispersed substrates in designing new stimuli-responsive nanocomposites; in particular, it provides an updated description of the synthetic routes to prepare nanostructured systems having the typical properties of thermoplastic polymers (continuous matrix), but showing enhanced optical, conductive, and thermal features dependent on the dispersion topology. The controlled nanodispersion of functional labeled clays, noble metal nanoparticles and carbon nanotubes is here evidenced to play a key role in producing hybrid thermoplastic materials that have been used in the design of devices, such as NLO devices, chemiresistors, temperature and deformation sensors.

  17. Nonenzymatic Glucose Sensor Based on In Situ Reduction of Ni/NiO-Graphene Nanocomposite

    Directory of Open Access Journals (Sweden)

    Xiaohui Zhang

    2016-10-01

    Full Text Available Ni/NiO nanoflower modified reduced graphene oxide (rGO nanocomposite (Ni/NiO-rGO was introduced to screen printed electrode (SPE for the construction of a nonenzymatic electrochemical glucose biosensor. The Ni/NiO-rGO nanocomposite was synthesized by an in situ reduction process. Graphene oxide (GO hybrid Nafion sheets first chemical adsorbed Ni ions and assembled on the SPE. Subsequently, GO and Ni ions were reduced by hydrazine hydrate. The electrochemical properties of such a Ni/NiO-rGO modified SPE were carefully investigated. It showed a high activity for electrocatalytic oxidation of glucose in alkaline medium. The proposed nonenzymatic sensor can be utilized for quantification of glucose with a wide linear range from 29.9 μM to 6.44 mM (R = 0.9937 with a low detection limit of 1.8 μM (S/N = 3 and a high sensitivity of 1997 μA/mM∙cm−2. It also exhibited good reproducibility as well as high selectivity.

  18. Properties of poly(lactic acid nanocomposites based on montmorillonite, sepiolite and zirconium phosphonate

    Directory of Open Access Journals (Sweden)

    K. Fukushima

    2012-11-01

    Full Text Available Poly(lactic acid (PLA based nanocomposites based on 5 wt.% of an organically modified montmorillonite (CLO, unmodified sepiolite (SEP and organically modified zirconium phosphonate (ZrP were obtained by melt blending. Wide angle X-ray scattering (WAXS and scanning electron microscopy (SEM analysis showed a different dispersion level depending on the type and functionalisation of nanoparticles. Differenctial scanning calorimetric (DSC analysis showed that PLA was able to crystallize on heating, and that the addition of ZrP could promote extent of PLA crystallization, whereas the presence of CLO and SEP did not significantly affect the crystallization on heating and melting behaviour of PLA matrix. Dynamic Mechanical Thermoanalysis (DMTA results showed that addition of all nanoparticles brought considerable improvements in E' of PLA, resulting in a remarkable increase of elastic properties for PLA nanocomposites. The melt viscosity and dynamic shear moduli (G',G" of PLA nanocomposites were also enhanced significantly by the presence of CLO and SEP, and attributed to the formation of a PLA/nanoparticle interconnected structure within the polymer matrix. The oxygen permeability of PLA did not significantly vary upon addition of SEP and ZrP nanoparticles. Only addition of CLO led to about 30% decrease compared to PLA permeability, due to the good clay dispersion and clay platelet-like morphology. The characteristic high transparency of PLA in the visible region was kept upon addition of the nanoparticles. Based on these achievements, a high potential of these PLA nanocomposites in sustainable packaging applications could be envisaged.

  19. Enhanced electrochemical performance of in situ reduced graphene oxide-polyaniline nanotubes hybrid nanocomposites using redox-additive aqueous electrolyte

    Science.gov (United States)

    Devi, Madhabi; Kumar, A.

    2018-02-01

    Reduced graphene oxide (RGO)-polyaniline nanotubes (PAniNTs) nanocomposites have been synthesized by in situ reduction of GO. The morphology and structure of the nanocomposites are characterized by HRTEM, XRD and micro-Raman spectroscopy. The electrical and electrochemical performances of the nanocomposites are investigated for different RGO concentrations by conductivity measurements, cyclic voltammetry, charge-discharge and electrochemical impedance spectroscopy. Highest gravimetric specific capacitance of 448.71 F g-1 is obtained for 40 wt.% of RGO-PAniNTs nanocomposite as compared to 194.92 F g-1 for pure PAniNTs in 1 M KCl electrolyte. To further improve the electrochemical performance of the nanocomposite electrode, KI is used as redox-additive with 1 M KCl electrolyte. Highest gravimetric specific capacitance of 876.43 F g-1 and an improved cyclic stability of 91% as compared to 79% without KI after 5000 cycles is achieved for an optimized 0.1 M KI concentration. This is attributed to the presence of different ionic species of I- ions that give rise to a number of possible redox reactions improving the pseudocapacitance of the electrode. This improved capacitive performance is compared with that of catechol redox-additive in 1 M KCl electrolyte, and that of KI and catechol redox-additives added to 1 M H2SO4 electrolyte.

  20. Interactive effects between carbon allotrope fillers on the mechanical reinforcement of polyisoprene based nanocomposites

    Directory of Open Access Journals (Sweden)

    M. Galimberti

    2014-06-01

    Full Text Available Interactive effects of carbon allotropes on the mechanical reinforcement of polymer nanocomposites were investigated. Carbon nanotubes (CNT and nano-graphite with high shape anisotropy (nanoG were melt blended with poly(1,4-cis-isoprene, as the only fillers or in combination with carbon black (CB, measuring the shear modulus at low strain amplitudes for peroxide crosslinked composites. The nanofiller was found to increase the low amplitude storage modulus of the matrix, with or without CB, by a factor depending on nanofiller type and content. This factor, fingerprint of the nanofiller, was higher for CNT than for nanoG. The filler-polymer interfacial area was able to correlate modulus data of composites with CNT, CB and with the hybrid filler system, leading to the construction of a common master curve.

  1. Preparation and characterization of polymer nanocomposites based on chitosan and clay minerals

    International Nuclear Information System (INIS)

    Fiori, Ana Paula Santos de Melo; Gabiraba, Victor Parizio; Praxedes, Ana Paula Perdigao; Nunes, Marcelo Ramon da Silva; Balliano, Tatiane L.; Silva, Rosanny Christhinny da; Tonholo, Josealdo; Ribeiro, Adriana Santos

    2014-01-01

    In this work nanocomposites based on chitosan and different clays were prepared using polyethyleneglycol (PEG) as plasticizer. The samples obtained were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), thermogravimetric analysis (TGA/DTG) and by mechanical characterization (tensile test) with the aim of investigating the interactions between chitosan and clay. The nanocomposite films prepared using sodium bentonite (Ben) showed an increase of 81.2% in the maximum tensile stress values and a decrease of 16.0% in the Young’s modulus when compared to the chitosan with PEG (QuiPEG) films, evidencing that the introduction of the clay into the polymer matrix provided a more flexible and resistant film, whose elongation at break was 93.6% higher than for the QuiPEG film. (author)

  2. New nanocomposite surfaces and thermal interface materials based on mesoscopic microspheres, polymers and graphene flakes

    Science.gov (United States)

    Dmitriev, Alex A.; Dmitriev, Alex S.; Makarov, Petr; Mikhailova, Inna

    2018-04-01

    In recent years, there has been a great interest in the development and creation of new functional energy mate-rials, including for improving the energy efficiency of power equipment and for effectively removing heat from energy devices, microelectronics and optoelectronics (power micro electronics, supercapacitors, cooling of processors, servers and data centers). In this paper, the technology of obtaining new nanocomposites based on mesoscopic microspheres, polymers and graphene flakes is considered. The methods of sequential production of functional materials from graphene flakes of different volumetric concentration using epoxy polymers, as well as the addition of monodisperse microspheres are described. Data are given on the measurement of the contact angle and thermal conductivity of these nanocomposites with respect to the creation of thermal interface materials for cooling devices of electronics, optoelectronics and power engineering.

  3. Rapid magnetic hardening by rapid thermal annealing in NdFeB-based nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Chu, K.-T.; Jin, Z Q; Chakka, Vamsi M; Liu, J P [Department of Physics, University of Texas at Arlington, Arlington, TX 76019 (United States)

    2005-11-21

    A systematic study of heat treatments and magnetic hardening of NdFeB-based melt-spun nanocomposite ribbons have been carried out. Comparison was made between samples treated by rapid thermal annealing and by conventional furnace annealing. Heating rates up to 200 K s{sup -1} were adopted in the rapid thermal processing. It was observed that magnetic hardening can be realized in an annealing time as short as 1 s. Coercivity of 10.2 kOe in the nanocomposites has been obtained by rapid thermal annealing for 1 s, and prolonged annealing did not give any increase in coercivity. Detailed results on the effects of annealing time, temperature and heating rate have been obtained. The dependence of magnetic properties on the annealing parameters has been investigated. Structural characterization revealed that there is a close correlation between magnetic hardening and nanostructured morphology. The coercivity mechanism was also studied by analysing the magnetization minor loops.

  4. Preparation of nanocomposites based on poly(Butylene Succinate) and montmorillonite organoclay via in situ polymerization

    International Nuclear Information System (INIS)

    Ferreira, Leticia P.; Moreira, Andrei N.; Souza Junior, Fernando G. de; Pinto, Jose Carlos Costa da Silva

    2014-01-01

    Nanocomposites based on poly(butylene succinate) (PBS) and organophilic montmorillonite were synthesized via in situ polymerization using three different clay compositions (4, 6 and 8 wt%). The products were characterized by several different techniques. X-ray diffraction was useful to confirm the increase of the interlayer spacing of the clay due to the presence of the polymer chains among layers. Thermal analysis indicated that the polymerization method chosen led to materials with lower thermal stability compared to the pure PBS, due to the difficulty of chain growth in the presence of the clay. Low-field NMR technique was used to assess clay dispersion in the polymer, with exfoliated structures predominating in the nanocomposites. (author)

  5. Nanocomposites based on thermoplastic elastomers with functional basis of nano titanium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Yulovskaya, V. D.; Kuz’micheva, G. M., E-mail: galina-kuzmicheva@list.ru [Federal State Budget Educational Institution of Higher Education “Moscow Technological University” (Russian Federation); Klechkovskaya, V. V. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Orekhov, A. S.; Zubavichus, Ya. V. [National Research Centre “Kurchatov Institute” (Russian Federation); Domoroshchina, E. N.; Shegay, A. V. [Federal State Budget Educational Institution of Higher Education “Moscow Technological University” (Russian Federation)

    2016-03-15

    Nanocomposites based on a thermoplastic elastomer (TPE) (low-density polyethylene (LDPE) and 1,2-polybutadiene in a ratio of 60/40) with functional titanium dioxide nanoparticles of different nature, TiO{sub 2}/TPE, have been prepared and investigated by a complex of methods (X-ray diffraction analysis using X-ray and synchrotron radiation beams, scanning electron microscopy, transmission electron microscopy, and X-ray energy-dispersive spectroscopy). The morphology of the composites is found to be somewhat different, depending on the TiO{sub 2} characteristics. It is revealed that nanocomposites with cellular or porous structures containing nano-TiO{sub 2} aggregates with a large specific surface and large sizes of crystallites and nanoparticles exhibit the best deformation‒strength and fatigue properties and stability to the effect of active media under conditions of ozone and vapor‒air aging.

  6. Shape-memory effect of nanocomposites based on liquid-crystalline elastomers

    Science.gov (United States)

    Marotta, A.; Lama, G. C.; Gentile, G.; Cerruti, P.; Carfagna, C.; Ambrogi, V.

    2016-05-01

    In this work, nanocomposites based on liquid crystalline (LC) elastomers were prepared and characterized in their shape memory properties. For the synthesis of materials, p-bis(2,3-epoxypropoxy)-α-methylstilbene (DOMS) was used as mesogenic epoxy monomer, sebacic acid (SA) as curing agent and multi-walled carbon nanotubes (MWCNT) and graphene oxide (GO) as fillers. First, an effective compatibilization methodology was set up to improve the interfacial adhesion between the matrix and the carbonaceous nanofillers, thus obtaining homogeneous distribution and dispersion of the nanofillers within the polymer phase. Then, the obtained nanocomposite films were characterized in their morphological and thermal properties. In particular, the effect of the addition of the nanofillers on liquid crystalline behavior, as well as on shape-memory properties of the realized materials was investigated. It was found that both fillers were able to enhance the thermomechanical response of the LC elastomers, making them good candidates as shape memory materials.

  7. Characterization of Electret Based on Inorganic-organic Nanocomposite Using Fluoropolymer and Silica Nanoparticles

    International Nuclear Information System (INIS)

    Suzuki, M; Shimokizaki, M; Takahashi, T; Aoyagi, S; Yoshikawa, Y

    2015-01-01

    An A novel electret based on inorganic-organic nano composite using fluoropolymer and silica nanoparticles was developed in this study. CYTOP® is used to fabricate the nanocomposite electret, which is one of fluoropolymer. Three kinds of silica nanoparticles dispersed in methyl ethyl ketone were employed. Each type of nanoparticles was mixed in the CYTOP or stuck between three layers of CYTOP. Then, negative charge was implanted by corona discharge method. The initial surface potential of the nanocomposite electret was higher than that of a control electret made of pure CYTOP. Additionally, time stability of those was also better than that of control electret. However, above mentioned properties of the mix-typed electret was worse than that of stuck-typed electret, because of discharging through aggregates composed of the nanoparticles. (paper)

  8. Fabrication and Characterization of Magnetoresponsive Electrospun Nanocomposite Membranes Based on Methacrylic Random Copolymers and Magnetite Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ioanna Savva

    2012-01-01

    Full Text Available Magnetoresponsive polymer-based fibrous nanocomposites belonging to the broad category of stimuli-responsive materials, is a relatively new class of “soft” composite materials, consisting of magnetic nanoparticles embedded within a polymeric fibrous matrix. The presence of an externally applied magnetic field influences the properties of these materials rendering them useful in numerous technological and biomedical applications including sensing, magnetic separation, catalysis and magnetic drug delivery. This study deals with the fabrication and characterization of magnetoresponsive nanocomposite fibrous membranes consisting of methacrylic random copolymers based on methyl methacrylate (MMA and 2-(acetoacetoxyethyl methacrylate (AEMA (MMA-co-AEMA and oleic acid-coated magnetite (OA·Fe3O4 nanoparticles. The AEMA moieties containing β-ketoester side-chain functionalities were introduced for the first time in this type of materials, because of their inherent ability to bind effectively onto inorganic surfaces providing an improved stabilization. For membrane fabrication the electrospinning technique was employed and a series of nanocomposite membranes was prepared in which the polymer content was kept constant and only the inorganic (OA·Fe3O4 content varied. Further to the characterization of these materials in regards to their morphology, composition and thermal properties, assessment of their magnetic characteristics disclosed tunable superparamagnetic behaviour at ambient temperature.

  9. Temperature Effect on Electrical Treeing and Partial Discharge Characteristics of Silicone Rubber-Based Nanocomposites

    Directory of Open Access Journals (Sweden)

    Mohd Hafizi Ahmad

    2015-01-01

    Full Text Available This study investigated electrical treeing and its associated phase-resolved partial discharge (PD activities in room-temperature, vulcanized silicone rubber/organomontmorillonite nanocomposite sample materials over a range of temperatures in order to assess the effect of temperature on different filler concentrations under AC voltage. The samples were prepared with three levels of nanofiller content: 0% by weight (wt, 1% by wt, and 3% by wt. The electrical treeing and PD activities of these samples were investigated at temperatures of 20°C, 40°C, and 60°C. The results show that the characteristics of the electrical tree changed with increasing temperature. The tree inception times decreased at 20°C due to space charge dynamics, and the tree growth time increased at 40°C due to the increase in the number of cross-link network structures caused by the vulcanization process. At 60°C, more enhanced and reinforced properties of the silicone rubber-based nanocomposite samples occurred. This led to an increase in electrical tree inception time and electrical tree growth time. However, the PD characteristics, particularly the mean phase angle of occurrence of the positive and negative discharge distributions, were insensitive to variations in temperature. This reflects an enhanced stability in the nanocomposite electrical properties compared with the base polymer.

  10. Novel high-performance nanocomposite proton exchange membranes based on poly (ether sulfone)

    Energy Technology Data Exchange (ETDEWEB)

    Hasani-Sadrabadi, Mohammad Mahdi [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Biomedical Engineering Department, Amirkabir University of Technology, Tehran (Iran); Dashtimoghadam, Erfan; Ghaffarian, Seyed Reza [Polymer Engineering Department, Amirkabir University of Technology, Tehran (Iran); Hasani Sadrabadi, Mohammad Hossein [Faculty of Social and Economics Science, Alzahra University, Tehran (Iran); Heidari, Mahdi [Graduate School of Management and Economics, Sharif University of Technology, Tehran (Iran); Moaddel, Homayoun [Department of Materials Science and Engineering, University of California, Los Angeles, CA (United States)

    2010-01-15

    In the present research, proton exchange membranes based on partially sulfonated poly (ether sulfone) (S-PES) with various degrees of sulfonation were synthesized. It was found that the increasing of sulfonation degree up to 40% results in the enhancement of water uptake, ion exchange capacity and proton conductivity properties of the prepared membranes to 28.1%, 1.59 meq g{sup -1}, and 0.145 S cm{sup -1}, respectively. Afterwards, nanocomposite membranes based on S-PES (at the predetermined optimum sulfonation degree) containing various loading weights of organically treated montmorillonite (OMMT) were prepared via the solution intercalation technique. X-ray diffraction patterns revealed the exfoliated structure of OMMT in the macromolecular matrices. The S-PES nanocomposite membrane with 3.0 wt% of OMMT content showed the maximum selectivity parameter of about 520,000 S s cm{sup -3} which is related to the high conductivity of 0.051 S cm{sup -1} and low methanol permeability of 9.8 x 10{sup -8} cm{sup 2} s{sup -1}. Furthermore, single cell DMFC fuel cell performance test with 4 molar methanol concentration showed a high power density (131 mW cm{sup -2}) of the nanocomposite membrane at the optimum composition (40% of sulfonation and 3.0 wt% of OMMT loading) compared to the Nafion {sup registered} 117 membrane (114 mW cm{sup -2}). Manufactured nanocomposite membranes thanks to their high selectivity, ease of preparation and low cost could be suggested as the ideal candidate for the direct methanol fuel cell applications. (author)

  11. Sol-gel silica-based nanocomposites containing a high PEG amount: Chemical characterization and study of biological properties

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, Michelina; Bollino, Flavia [Department of Industrial and Information Engineering, Second University of Naples, Via Roma 29, 81031 Aversa (CE) (Italy); Gloria, Antonio [Institute of Polymers, Composites and Biomaterials - National Research Council of Italy, V.le J. F. Kennedy 54 - Mostra d’Oltremare Pad. 20, 80125 Naples (Italy)

    2016-05-18

    The objective of the present study was to synthesize and to characterize Silica/polyethylene glycol (SiO{sub 2}/PEG) organic-inorganic hybrid materials containing a high polymer amount (60 and 70 wt%) for biomedical applications. Scanning electron microscopy (SEM) showed that the samples are homogeneous on the nanometer scale, confirming that they are nanocomposites. Fourier transform infrared spectroscopy (FT-IR) proved that the materials are class I hybrids because the two phases (SiO{sub 2} and PEG) interact by hydrogen bonds. To evaluate the possibility of using them in the biomedical field, the bioactivity and biocompatibility of the synthesized hybrids have been ascertained. The formation of a hydroxyapatite layer was observed on the hybrid surface by SEM/EDX and FTIR after soaking in simulated body fluid (SBF). Moreover, their biocompatibility was assessed by performing WST-8 cytotoxicity assay in vitro.

  12. Sol-gel silica-based nanocomposites containing a high PEG amount: Chemical characterization and study of biological properties

    Science.gov (United States)

    Catauro, Michelina; Bollino, Flavia; Gloria, Antonio

    2016-05-01

    The objective of the present study was to synthesize and to characterize Silica/polyethylene glycol (SiO2/PEG) organic-inorganic hybrid materials containing a high polymer amount (60 and 70 wt%) for biomedical applications. Scanning electron microscopy (SEM) showed that the samples are homogeneous on the nanometer scale, confirming that they are nanocomposites. Fourier transform infrared spectroscopy (FT-IR) proved that the materials are class I hybrids because the two phases (SiO2 and PEG) interact by hydrogen bonds. To evaluate the possibility of using them in the biomedical field, the bioactivity and biocompatibility of the synthesized hybrids have been ascertained. The formation of a hydroxyapatite layer was observed on the hybrid surface by SEM/EDX and FTIR after soaking in simulated body fluid (SBF). Moreover, their biocompatibility was assessed by performing WST-8 cytotoxicity assay in vitro.

  13. Sol-gel silica-based nanocomposites containing a high PEG amount: Chemical characterization and study of biological properties

    International Nuclear Information System (INIS)

    Catauro, Michelina; Bollino, Flavia; Gloria, Antonio

    2016-01-01

    The objective of the present study was to synthesize and to characterize Silica/polyethylene glycol (SiO 2 /PEG) organic-inorganic hybrid materials containing a high polymer amount (60 and 70 wt%) for biomedical applications. Scanning electron microscopy (SEM) showed that the samples are homogeneous on the nanometer scale, confirming that they are nanocomposites. Fourier transform infrared spectroscopy (FT-IR) proved that the materials are class I hybrids because the two phases (SiO 2 and PEG) interact by hydrogen bonds. To evaluate the possibility of using them in the biomedical field, the bioactivity and biocompatibility of the synthesized hybrids have been ascertained. The formation of a hydroxyapatite layer was observed on the hybrid surface by SEM/EDX and FTIR after soaking in simulated body fluid (SBF). Moreover, their biocompatibility was assessed by performing WST-8 cytotoxicity assay in vitro.

  14. Tough hybrid ceramic-based material with high strength

    International Nuclear Information System (INIS)

    Guo, Shuqi; Kagawa, Yutaka; Nishimura, Toshiyuki

    2012-01-01

    This study describes a tough and strong hybrid ceramic material consisting of platelet-like zirconium compounds and metal. A mixture of boron carbide and excess zirconium powder was heated to 1900 °C using a liquid-phase reaction sintering technique to produce a platelet-like ZrB 2 -based hybrid ceramic bonded by a thin zirconium layer. The platelet-like ZrB 2 grains were randomly present in the as-sintered hybrid ceramic. Relative to non-hybrid ceramics, the fracture toughness and flexural strength of the hybrid ceramic increased by approximately 2-fold.

  15. SU-8 photoresist and SU-8 based nanocomposites for broadband acoustical matching at 1 GHz

    Energy Technology Data Exchange (ETDEWEB)

    Ndieguene, A; Campistron, P; Carlier, J; Wang, S; Callens-Debavelaere, D; Nongaillard, B, E-mail: Assane.Ndieguene@meletu.univ-valenciennes.f [Univ Lille Nord de France, F-59000 Lille (France)

    2009-11-01

    So as to integrate acoustic functions in BioMEMS using 1 GHz ZnO transducers deposited on silicon substrates, acoustic waves propagation through the silicon substrate and its transmission in water needs to be maximized (the insertion losses at the Si / water interface are about 6dB). In the context of integration, it is interesting for mechanical impedance matching to use photosensitive materials such as SU-8 so that patterns may be obtained. Nanocomposite materials based on SU-8 mixed with nanoparticles having adequate impedances were fabricated. These new materials are characterized in terms of their acoustic velocity, impedance and attenuation. For this, the nanocomposite layers are deposited on the substrate by spin coating to obtain a thickness of about 10 {mu}m, in order to separate acoustic echoes from the material (even if {lambda}/4 layer thickness is lower than 1 {mu}m). The insertion losses of the device immersed in water can be simulated as a function of frequency for a given reflection coefficient between the silicon substrate and the photoresist. The characteristics of some nanocomposites made with SU-8 and various concentrations of nanoparticles like Ti0{sub 2}, SrTiO{sub 3} or W have been determined.

  16. Dielectric properties of polyhedral oligomeric silsesquioxane (POSS)-based nanocomposites at 77k

    International Nuclear Information System (INIS)

    Pan, Ming-Jen; Gorzkowski, Edward; McAllister, Kelly

    2011-01-01

    The goal of this study is to develop dielectric nanocomposites for high energy density applications at liquid nitrogen temperature by utilizing a unique nano-material polyhedral oligomeric silsesquioxanes (POSS). A POSS molecule is consisted of a silica cage core with 8 silicon and 12 oxygen atoms and organic functional groups attached to the corners of the cage. In this study, we utilize POSS for the fabrication of nanocomposites both as a silica nanoparticle filler to enhance the breakdown strength and as a surfactant for effective dispersion of high permittivity ceramic nanoparticles in a polymer matrix. The matrix materials selected for the study are polyvinylidene fluoride (PVDF) and poly(methyl methacrylate) (PMMA). The ceramic nanoparticles are barium strontium titanate (BST 50/50) and strontium titanate. The dielectric properties of the solution-cast nanocomposites films were correlated to the composition and processing conditions. We determined that the addition of POSS did not provide enhanced dielectric performance in PVDF- and PMMA-based materials at either room temperature or 77K. In addition, we found that the dielectric breakdown strength of PMMA is lower at 77K than at room temperature, contradicting literature data.

  17. The difference nanocomposite hardness level using LED photoactivation based on curing period variations

    Directory of Open Access Journals (Sweden)

    Hasiana Tatian

    2011-03-01

    Full Text Available Polimerizatian is the critical stage to determine the quality of composites resin, this involves isolated monomer carbon double bonds being converted to an extended network of single bonds. Physical and mechanical properties of composites are influenced by the level of conversion attained during polymerization. An adequate light intensity and light curing time are important to obtain the degree of polymerization. The objective of this study is to evaluate the difference of the hardness nanocomposites which activated by LED LCU based on the variation of curing times. This study is a true experimental research. The samples were made from nanocomposites material with cylinder form of 4 mm in depth, 6 mm in diameter. This samples divided into 3 groups of curing times. Group, I was cured for 20's curing time as a control due to manufactory recommended; Group II was cured for 30's, and Group III was cured for 40's and the hardness (Rebound hardness tester was determined using Rebound scale (RS and converted by Mohs scale (MS. There was a very significant level of hardness rate from each group using ANOVA test. The result of the study concludes that there were the differences on the nanocomposites hardness level cured under different curing times 20, 30 and 40 sec. The longer of curing times, the higher level of hardness.

  18. Preparation and characterization of polymer nanocomposites based on PVDF/PVC doped with graphene nanoparticles

    Directory of Open Access Journals (Sweden)

    I.S. Elashmawi

    Full Text Available Novel nanocomposites based on PVDF/PVC blend containing graphene oxide nanoparticles (GO were prepare using sonicator. IR analysis revealed that the addition of GO prompts a crystal transformation of α-phase of PVDF. The change of the structural before and after adding GO to PVDF/PVC were studied by X-ray diffraction. A decrease in activation energy gap from UV data was observed with increasing GO content, implying a variation of reactivity as a result of reaction extent. The variation of ε′ with frequency is nearly the same as that of ε″. At higher frequencies, the decrease of both ε′ and ε″ becomes nearly constant. The dispersion at lower frequencies ε′ of ε′ polarization is of Maxwell–Wagner interfacial polarization but at higher frequencies, it levels off. The behavior of conductivity (σAC tends to acquire constant values approaching it DC values. The values of σAC was increased after doped GO with exponential increase after the critical value of frequency. All nanocomposites behaved the same fashion revealing that a higher number of polarons were getting added to conducting pool in composites as graphene content was increased. Conduction mechanism appeared to be getting expedited with increasing frequency due to fact that increase in frequency enhances polaron hopping frequency. Keywords: Nanocomposites, Graphene oxide, FT-IR, X-ray, AC conductivity

  19. Plasma deposition of nanocomposite thin films : process concept and realisation

    NARCIS (Netherlands)

    Alcott, G.R.

    2004-01-01

    Recent developments in materials technology, fuelled by the growing hype surrounding nanotechnology, have given rise to a new breed of materials known as nanocomposites. Nanocomposite materials (a subgroup of hybrid materials) are formed from standard polymers impregnated with nanometre sized

  20. Rule-based energy management strategies for hybrid vehicles

    NARCIS (Netherlands)

    Hofman, T.; Druten, van R.M.; Serrarens, A.F.A.; Steinbuch, M.

    2007-01-01

    Int. J. of Electric and Hybrid Vehicles (IJEHV), The highest control layer of a (hybrid) vehicular drive train is termed the Energy Management Strategy (EMS). In this paper an overview of different control methods is given and a new rule-based EMS is introduced based on the combination of Rule-Based

  1. Metal (Ag/Ti)-Containing Hydrogenated Amorphous Carbon Nanocomposite Films with Enhanced Nanoscratch Resistance: Hybrid PECVD/PVD System and Microstructural Characteristics.

    Science.gov (United States)

    Constantinou, Marios; Nikolaou, Petros; Koutsokeras, Loukas; Avgeropoulos, Apostolos; Moschovas, Dimitrios; Varotsis, Constantinos; Patsalas, Panos; Kelires, Pantelis; Constantinides, Georgios

    2018-03-30

    This study aimed to develop hydrogenated amorphous carbon thin films with embedded metallic nanoparticles (a-C:H:Me) of controlled size and concentration. Towards this end, a novel hybrid deposition system is presented that uses a combination of Plasma Enhanced Chemical Vapor Deposition (PECVD) and Physical Vapor Deposition (PVD) technologies. The a-C:H matrix was deposited through the acceleration of carbon ions generated through a radio-frequency (RF) plasma source by cracking methane, whereas metallic nanoparticles were generated and deposited using terminated gas condensation (TGC) technology. The resulting material was a hydrogenated amorphous carbon film with controlled physical properties and evenly dispersed metallic nanoparticles (here Ag or Ti). The physical, chemical, morphological and mechanical characteristics of the films were investigated through X-ray reflectivity (XRR), Raman spectroscopy, Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Transmission Electron Microscopy (TEM) and nanoscratch testing. The resulting amorphous carbon metal nanocomposite films (a-C:H:Ag and a-C:H:Ti) exhibited enhanced nanoscratch resistance (up to +50%) and low values of friction coefficient (<0.05), properties desirable for protective coatings and/or solid lubricant applications. The ability to form nanocomposite structures with tunable coating performance by potentially controlling the carbon bonding, hydrogen content, and the type/size/percent of metallic nanoparticles opens new avenues for a broad range of applications in which mechanical, physical, biological and/or combinatorial properties are required.

  2. Metal (Ag/Ti-Containing Hydrogenated Amorphous Carbon Nanocomposite Films with Enhanced Nanoscratch Resistance: Hybrid PECVD/PVD System and Microstructural Characteristics

    Directory of Open Access Journals (Sweden)

    Marios Constantinou

    2018-03-01

    Full Text Available This study aimed to develop hydrogenated amorphous carbon thin films with embedded metallic nanoparticles (a–C:H:Me of controlled size and concentration. Towards this end, a novel hybrid deposition system is presented that uses a combination of Plasma Enhanced Chemical Vapor Deposition (PECVD and Physical Vapor Deposition (PVD technologies. The a–C:H matrix was deposited through the acceleration of carbon ions generated through a radio-frequency (RF plasma source by cracking methane, whereas metallic nanoparticles were generated and deposited using terminated gas condensation (TGC technology. The resulting material was a hydrogenated amorphous carbon film with controlled physical properties and evenly dispersed metallic nanoparticles (here Ag or Ti. The physical, chemical, morphological and mechanical characteristics of the films were investigated through X-ray reflectivity (XRR, Raman spectroscopy, Scanning Electron Microscopy (SEM, Atomic Force Microscopy (AFM, Transmission Electron Microscopy (TEM and nanoscratch testing. The resulting amorphous carbon metal nanocomposite films (a–C:H:Ag and a–C:H:Ti exhibited enhanced nanoscratch resistance (up to +50% and low values of friction coefficient (<0.05, properties desirable for protective coatings and/or solid lubricant applications. The ability to form nanocomposite structures with tunable coating performance by potentially controlling the carbon bonding, hydrogen content, and the type/size/percent of metallic nanoparticles opens new avenues for a broad range of applications in which mechanical, physical, biological and/or combinatorial properties are required.

  3. Enhanced Plasmonic Biosensors of Hybrid Gold Nanoparticle-Graphene Oxide-Based Label-Free Immunoassay

    Science.gov (United States)

    Chiu, Nan-Fu; Chen, Chi-Chu; Yang, Cheng-Du; Kao, Yu-Sheng; Wu, Wei-Ren

    2018-05-01

    In this study, we propose a modified gold nanoparticle-graphene oxide sheet (AuNP-GO) nanocomposite to detect two different interactions between proteins and hybrid nanocomposites for use in biomedical applications. GO sheets have high bioaffinity, which facilitates the attachment of biomolecules to carboxyl groups and has led to its use in the development of sensing mechanisms. When GO sheets are decorated with AuNPs, they introduce localized surface plasmon resonance (LSPR) in the resonance energy transfer of spectral changes. Our results suggest a promising future for AuNP-GO-based label-free immunoassays to detect disease biomarkers and rapidly diagnose infectious diseases. The results showed the detection of antiBSA in 10 ng/ml of hCG non-specific interfering protein with dynamic responses ranging from 1.45 nM to 145 fM, and a LOD of 145 fM. Considering the wide range of potential applications of GO sheets as a host material for a variety of nanoparticles, the approach developed here may be beneficial for the future integration of nanoparticles with GO nanosheets for blood sensing. The excellent anti-interference characteristics allow for the use of the biosensor in clinical analysis and point-of-care testing (POCT) diagnostics of rapid immunoassay products, and it may also be a potential tool for the measurement of biomarkers in human serum.

  4. Iron-antimony-based hybrid oxides as high-performance anodes for lithium-ion storage

    Science.gov (United States)

    Nguyen, Tuan Loi; Kim, Doo Soo; Hur, Jaehyun; Park, Min Sang; Yoon, Sukeun; Kim, Il Tae

    2018-06-01

    We report a facile approach to synthesize Fe-Sb-based hybrid oxides nanocomposites consisting of Sb, Sb2O3, and Fe3O4 for use as new anode materials for lithium-ion batteries. The composites are synthesized via galvanic replacement between Fe3+ and Sb at high temperature in triethylene glycol medium. The phase, morphology, and composition changes of the composites involved in the various stages of the replacement reaction are characterized using X-ray diffractometry, high-resolution transmission electron microscopy, and energy dispersive X-ray spectroscopy. The as-prepared composites have different compositions with very small particle sizes (interfacial contact area between the nanocomposite and electrolyte, stable structure of the composites owing to a mixture of inactive phases generated by the conversion reaction between Li+ and oxide metal-whose structure serves as an electron conductor, inhibits agglomeration of Sb particles, and acts as an effective buffer against volume change of Sb during cycling-and high Li+ diffusion ability.

  5. Yield performance and stability of CMS-based triticale hybrids.

    Science.gov (United States)

    Mühleisen, Jonathan; Piepho, Hans-Peter; Maurer, Hans Peter; Reif, Jochen Christoph

    2015-02-01

    CMS-based triticale hybrids showed only marginal midparent heterosis for grain yield and lower dynamic yield stability compared to inbred lines. Hybrids of triticale (×Triticosecale Wittmack) are expected to possess outstanding yield performance and increased dynamic yield stability. The objectives of the present study were to (1) examine the optimum choice of the biometrical model to compare yield stability of hybrids versus lines, (2) investigate whether hybrids exhibit a more pronounced grain yield performance and yield stability, and (3) study optimal strategies to predict yield stability of hybrids. Thirteen female and seven male parental lines and their 91 factorial hybrids as well as 30 commercial lines were evaluated for grain yield in up to 20 environments. Hybrids were produced using a cytoplasmic male sterility (CMS)-inducing cytoplasm that originated from Triticumtimopheevii Zhuk. We found that the choice of the biometrical model can cause contrasting results and concluded that a group-by-environment interaction term should be added to the model when estimating stability variance of hybrids and lines. midparent heterosis for grain yield was on average 3 % with a range from -15.0 to 11.5 %. No hybrid outperformed the best inbred line. Hybrids had, on average, lower dynamic yield stability compared to the inbred lines. Grain yield performance of hybrids could be predicted based on midparent values and general combining ability (GCA)-predicted values. In contrast, stability variance of hybrids could be predicted only based on GCA-predicted values. We speculated that negative effects of the used CMS cytoplasm might be the reason for the low performance and yield stability of the hybrids. For this purpose a detailed study on the reasons for the drawback of the currently existing CMS system in triticale is urgently required comprising also the search of potentially alternative hybridization systems.

  6. Influence of amine-grafted multi-walled carbon nanotubes on physical and rheological properties of PMMA-based nanocomposites

    International Nuclear Information System (INIS)

    Kim, Ki-Seok; Park, Soo-Jin

    2011-01-01

    In this work, poly(methyl methacrylate) (PMMA) was grafted onto amine treated multi-walled carbon nanotubes (NH-MWNTs) and the physical and rheological properties of the NH-MWNTs-g-PMMA nanocomposites were investigated. The graft reaction of NH-MWNTs and the PMMA matrix was confirmed from the change of the N 1S peaks, including those of amine oxygen and amide oxygen, by X-ray photoelectron spectroscopy (XPS). The thermal and mechanical properties of the NH-MWNT-g-PMMA nanocomposites were enhanced by the graft reaction between NH-MWNTs and PMMA matrix. In addition, the viscosity of the nanocomposites was increased with the addition of NH-MWNTs. Storage (G') and loss modulus (G'') were significantly increased by increase in the NH-MWNT content compared to acid-treated MWNTs/PMMA nanocomposites. This increase was attributed to the strong interaction by the grafting reaction between NH-MWNTs and the PMMA matrix. - Graphical abstract: This describes the increase of mechanical properties in NH-MWNTs-g-PMMA hybrid composites with different NH-MWNT contents. Highlights: → Aminized carbon nanotubes are used as reinforcement for poly(methylmethacrylate). → Poly(methylmethacrylate) is grafted on aminized carbon nanotubes by thermal reaction. → Grafting of carbon nanotubes and polymer provide enhanced physical properties. → It was due to the strong interaction between carbon nanotubes and polymer matrix.

  7. Magnetic nanocomposite sensor

    KAUST Repository

    Alfadhel, Ahmed

    2016-05-06

    A magnetic nanocomposite device is described herein for a wide range of sensing applications. The device utilizes the permanent magnetic behavior of the nanowires to allow operation without the application of an additional magnetic field to magnetize the nanowires, which simplifies miniaturization and integration into microsystems. In5 addition, the nanocomposite benefits from the high elasticity and easy patterning of the polymer-based material, leading to a corrosion-resistant, flexible material that can be used to realize extreme sensitivity. In combination with magnetic sensor elements patterned underneath the nanocomposite, the nanocomposite device realizes highly sensitive and power efficient flexible artificial cilia sensors for flow measurement or tactile sensing.

  8. Hybrid Drug Delivery Patches Based on Spherical Cellulose Nanocrystals and Colloid Titania—Synthesis and Antibacterial Properties

    Directory of Open Access Journals (Sweden)

    Olga L. Evdokimova

    2018-04-01

    Full Text Available Spherical cellulose nanocrystal-based hybrids grafted with titania nanoparticles were successfully produced for topical drug delivery. The conventional analytical filter paper was used as a precursor material for cellulose nanocrystals (CNC production. Cellulose nanocrystals were extracted via a simple and quick two-step process based on first the complexation with Cu(II solution in aqueous ammonia followed by acid hydrolysis with diluted H2SO4. Triclosan was selected as a model drug for complexation with titania and further introduction into the nanocellulose based composite. Obtained materials were characterized by a broad variety of microscopic, spectroscopic, and thermal analysis methods. The drug release studies showed long-term release profiles of triclosan from the titania based nanocomposite that agreed with Higuchi model. The bacterial susceptibility tests demonstrated that released triclosan retained its antibacterial activity against Escherichia coli and Staphylococcus aureus. It was found that a small amount of titania significantly improved the antibacterial activity of obtained nanocomposites, even without immobilization of model drug. Thus, the developed hybrid patches are highly promising candidates for potential application as antibacterial agents.

  9. Fabrication and in vitro degradation of porous fumarate-based polymer/alumoxane nanocomposite scaffolds for bone tissue engineering.

    Science.gov (United States)

    Mistry, Amit S; Cheng, Stacy H; Yeh, Tiffany; Christenson, Elizabeth; Jansen, John A; Mikos, Antonios G

    2009-04-01

    In this work, the fabrication and in vitro degradation of porous fumarate-based/alumoxane nanocomposites were evaluated for their potential as bone tissue engineering scaffolds. The biodegradable polymer poly (propylene fumarate)/propylene fumarate-diacrylate (PPF/PF-DA), a macrocomposite composed of PPF/PF-DA and boehmite microparticles, and a nanocomposite composed of PPF/PF-DA and surface-modified alumoxane nanoparticles were used to fabricate porous scaffolds by photo-crosslinking and salt-leaching. Scaffolds then underwent 12 weeks of in vitro degradation in phosphate buffered saline at 37 degrees C. The presence of boehmite microparticles and alumoxane nanoparticles in the polymer inhibited scaffold shrinkage during crosslinking. Furthermore, the incorporation of alumoxane nanoparticles into the polymer limited salt-leaching, perhaps due to tighter crosslinking within the nanocomposite. Analysis of crosslinking revealed that the acrylate and overall double bond conversions in the nanocomposite were higher than in the PPF/PF-DA polymer alone, though these differences were not significant. During 12 weeks of in vitro degradation, the nanocomposite lost 5.3% +/- 2.4% of its mass but maintained its compressive mechanical properties and porous architecture. The addition of alumoxane nanoparticles into the fumarate-based polymer did not significantly affect the degradation of the nanocomposite compared with the other materials in terms of mass loss, compressive properties, and porous structure. These results demonstrate the feasibility of fabricating degradable nanocomposite scaffolds for bone tissue engineering by photo-crosslinking and salt-leaching mixtures of fumarate-based polymers, alumoxane nanoparticles, and salt microparticles. Copyright 2008 Wiley Periodicals, Inc.

  10. A prototype Ultraviolet Light Sensor based on ZnO Nanoparticles/Graphene Oxide Nanocomposite Using Low Temperature Hydrothermal Method

    International Nuclear Information System (INIS)

    Al-Fandi, M; Oweis, R; Khwailah, H; Al-Hattami, S; Al-Shawwa, E; Albiss, B A; Al-Akhras, M-Ali; Qutaish, H; AlZoubi, T

    2015-01-01

    A new prototype UV nanosensor using ZnO nanoparticles (NPs)/graphene oxide (GO) nanocomposite (ZnO-NP/GO) on silicon substrate is reported in this paper. The hybrid nanocomposite structure has been developed by an optimized hydrothermal process at low growth temperature (∼50 °C). In this hybrid nanosensor, the ZnO nanoparticles act as UV- absorbing and charge carrier generating material, while graphene with its superior electrical conductivity has been used as a charge transporting material. Various nanostructure characterization techniques were intensively utilized including SEM, EDX, XRD, FTIR and UV-VIS. Also, the I-V measurement was employed to evaluate the prototype sensor. The morphological SEM analysis showed that the ZnO-NPs (average diameter of 20 nm) were dispersed evenly on the GO sheets. As well, the EDX spectra confirmed the exact chemical composition of the intended structure. The room temperature UV-VIS measurement revealed an enhanced optical absorption of UV-light at an absorption band centered on 375 nm. The improved optical and electrical properties were observed at an optimum relative concentration of 1:10. Under UV light illumination, the measured I-V characteristic of the prototype detector exhibited a considerable photocurrent increase of the ZnO-NP/GO nanocomposite compared to pristine ZnO nanostructure. These results can be promising for future enhanced UV- sensing applications. (paper)

  11. Development of bio-hybrid material based on Salmonella ...

    African Journals Online (AJOL)

    The immobilization of a whole microbial cell is an important process used in nanotechnology of biosensors and other related fields, especially the development of bio-hybrid materials based on live organisms and inorganic compounds. Here, we described an essay to develop a bio-hybrid material based on Salmonella ...

  12. Synthesis and utilization of poly (methylmethacrylate) nanocomposites based on modified montmorillonite

    OpenAIRE

    Youssef, Ahmed M.; Malhat, F.M.; Abdel Hakim, A.A.; Dekany, Imre

    2015-01-01

    Poly (methylmethacrylate) nanocomposite was prepared via in-situ emulsion polymerization (PMMA/Mt-CTA). The modified montmorillonite (Mt-CTA) is used as hosts for the preparation of poly (methylmethacrylate) nanocomposites with basal distance 1.95 nm. Moreover, exfoliated nanocomposite was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC). The fashioned nanocomposites exhibited bett...

  13. Preferable removal of phosphate from water using hydrous zirconium oxide-based nanocomposite of high stability

    International Nuclear Information System (INIS)

    Chen, Liang; Zhao, Xin; Pan, Bingcai; Zhang, Weixian; Hua, Ming; Lv, Lu; Zhang, Weiming

    2015-01-01

    Highlights: • The nanocomposite HZO-201 was stable under varying solution chemistry. • HZO-201 exhibited preferable phosphate removal over other ubiquitous anions. • Selective sorption mechanism was probed and discussed. • HZO-201 could be regenerated for cyclic use with constant efficiency. - Abstract: In this study, we employed a new nanocomposite adsorbent HZO-201, which featured high stability under varying solution chemistry, for preferable removal of phosphate from synthetic solution and a real effluent. An anion exchange resin (D-201) was employed as the host of HZO-201, where nano-hydrous zirconium oxide (HZO) was encapsulated as the active species. D-201 binds phosphate through nonspecific electrostatic affinity, whereas the loaded HZO nanoparticles capture phosphate through formation of the inner-sphere complexes. Quantitative contribution of both species to phosphate adsorption was predicted based on the double-Langmuir model. Preferable removal of phosphate by HZO-201 was observed in the presence of the competing anions at higher levels (Cl − , NO 3 − , SO 4 2− , HCO 3 − ). Fixed-bed adsorption indicated that the effective volume capacity of a synthetic water (2.0 mg P-PO 4 3− /L) by using HZO-201 was ∼1600 BV in the first run (<0.5 mg P-PO 4 3− /L), comparable to Fe(III)-based nanocomposite HFO-201 (∼1500 BV) and much larger than D-201 (<250 BV). The exhausted HZO-201 can be in situ regenerated by using a binary NaOH–NaCl solution for cyclic runs, whether fed with the synthetic solution or real effluent. In general, HZO-201 is a promising alternative to Fe(III)-based adsorbents for trace phosphate removal from effluent particularly at acidic pH

  14. Effect of water absorption on the mechanical properties of nanoclay filled recycled cellulose fibre reinforced epoxy hybrid nanocomposites

    KAUST Repository

    Alamri, H.

    2013-01-01

    Recycled cellulose fibre (RCF) reinforced epoxy/clay nanocomposites were successfully synthesized with different weight percentages (0%, 1%, 3% and 5%) of organoclay platelets (30B). The objective of this study was to investigate the effect of water absorption on the physical and mechanical properties of the RCF reinforced epoxy/clay nanocomposites. TEM images indicated a well-intercalated structure of nanoclay/epoxy matrix with some exfoliated regions. Water absorption was found to decrease as the clay content increased. The flexural strength, flexural modulus and fracture toughness significantly decreased as a result of water absorption. However, the properties of impact strength and impact toughness were found to increase after exposing to water. The addition of nanoclay slightly minimized the effect of moisture on the mechanical properties. SEM images showed that water absorption severely damaged the cellulose fibres and the bonding at fibres-matrix interfaces in wet composites. © 2012 Elsevier Ltd. All rights reserved.

  15. Sliding Wear and Fretting Wear of DLC-Based, Functionally Graded Nanocomposite Coatings

    Science.gov (United States)

    Miyoshi, K.; Pohlchuck, B.; Street, Kenneth W.; Zabinski, J. S.; Sanders, J. H.; Voevodin, A. a.; Wu, R. L. C.

    1999-01-01

    Improving the tribological functionality of diamondlike carbon (DLC) films--developing, good wear resistance, low friction, and high load-carrying capacity-was the aim of this investigation. Nanocomposite coatings consisting of an amorphous DLC (a-DLC) top layer and a functionally graded titanium-titanium carbon-diamondlike carbon (Ti-Ti(sub x) C(sub y)-DLC) underlayer were produced on AISI 440C stainless steel substrates by the hybrid technique of magnetron sputtering and pulsed-laser deposition. The resultant DLC films were characterized by Raman spectroscopy, scanning electron microscopy, and surface profilometry. Two types of wear experiment were conducted in this investioation: sliding friction experiments and fretting wear experiments. Unidirectional ball-on-disk sliding friction experiments were conducted to examine the wear behavior of an a-DLC/Ti-Ti(sub x) C(sub y)-DLC-coated AISI 440C stainless steel disk in sliding contact with a 6-mm-diameter AISI 440C stainless steel ball in ultrahigh vacuum, dry nitrogen, and humid air. Although the wear rates for both the coating and ball were low in all three environments, the humid air and dry nitrogen caused mild wear with burnishing, in the a-DLC top layer, and the ultrahigh vacuum caused relatively severe wear with brittle fracture in both the a-DLC top layer and the Ti-Ti(sub x) C(sub y)-DLC underlayer. For reference, amorphous hydrogenated carbon (H-DLC) films produced on a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coatings by using an ion beam were also examined in the same manner. The H-DLC films markedly reduced friction even in ultrahigh vacuum without sacrificing wear resistance. The H-DLC films behaved much like the a-DLC/Ti-Ti(sub x) C(sub y)-DLC nanocomposite coating in dry nitrogen and humid air, presenting low friction and low wear. Fretting wear experiments were conducted in humid air (approximately 50% relative humidity) at a frequency of 80 Hz and an amplitude of 75 micron on an a

  16. Microemulsion based hybrid biofuels using glycerol monooleate

    International Nuclear Information System (INIS)

    Bora, Plaban; Konwar, Lakhya Jyoti; Deka, Dhanapati

    2016-01-01

    Highlights: • Fuel quality of GMO based MHBFs. • Effect of externally added monoglyceride surfactant (GMO) on fuel characteristics of MHBF. • Structural and dynamic behaviors of GMO based MHBFs. • Can offer strong candidature for future biofuel industry. - Abstract: The present investigation aims to highlighten the effect of monoglyceride surfactant (GMO) on structure and dynamic behavior and other fuel characteristics of microemulsion based hybrid biofuels (MHBFs). Fuel quality of MHBFs formulated using purified GMO (>90%), which was prepared by esterification of glycerol, was investigated in the study. Phase behaviors, droplet size distribution, number of droplets present in the system, average droplet size and average length of surface active agents were studied as a part of structural investigations of the GMO based MHBFs. Diffusion coefficient, energy barrier to droplet coalescence and rate of coalescence of droplets were also investigated for the formulated MHBFs. The number of droplets, length of surface active agent and the diffusion co-efficient were in the ranges of 1.87 × 10"2"1–5.66 × 10"2"1/m"3, 0.92–1.07 nm and 1.00 × 10"−"1"1–1.79 × 10"−"1"1 m"2/s, respectively. The rate of droplet coalescence was obtained in the range 2.77 × 10"−"4–8.78 × 10"−"4 times the collision factor. MHBFs incorporating the glycerol derived bio-based nonionic surfactant GMO exhibited viscosity of 4.12 mm"2/s (at 40 °C), gross calorific value (GCV) of 39.17 MJ/kg and pour point of −7 °C.

  17. Fabrication and characterization of mesoporous TiO2/polypyrrole-based nanocomposite for electrorheological fluid

    International Nuclear Information System (INIS)

    Wei Chuan; Zhu Yihua; Jin Yi; Yang Xiaoling; Li Chunzhong

    2008-01-01

    Mesoporous TiO 2 /polypyrrole (PPy)-based nanocomposite for electrorheological fluid was synthesized through one-pot method. By exploiting the combination conductivity of PPy and high dielectric constant of TiO 2 , the ER fluid exhibited an enhanced effect. The shear stress was 3.3 times as high as that of mesoporous TiO 2 . Powder X-ray diffraction (XRD), TEM and Fourier transform infrared (FT-IR) spectroscopy were employed to characterize the as-made samples. Using a modified rotational viscometer, the electrorheological effect was measured. Dielectric spectra were also given to explain the mechanism

  18. Electrochemical behavior of amorphous metal-silicon-carbon nanocomposites based on titanium or tungsten nanophase

    International Nuclear Information System (INIS)

    Pleskov, Yu.V.; Krotova, M.D.; Shupegin, M.L.; Bozhko, A.D.

    2009-01-01

    Electrode behavior of nanocomposite films containing titanium- or tungsten-based conducting nanophase embedded in dielectric silicon-carbon matrix, deposited onto glassceramics substrate, is studied by cyclic voltammetry and electrochemical impedance spectroscopy. As the films' resistivity decreases, their electrochemical behavior gradually changes from that of 'poor conductor' to the nearly metal-like behavior. In particular, the differential capacitance increases, the charge transfer in a model redox system [Fe(CN) 6 ] 3-/4- accelerates, which may be explained by the increasing number of metal-containing clusters at the film/electrolyte solution interface

  19. Synthesis and Characterization of Novel Polycarbonate Based Polyurethane/Polymer Wrapped Hydroxyapatite Nanocomposites: Mechanical Properties, Osteoconductivity and Biocompatibility.

    Science.gov (United States)

    Selvakumar, M; Jaganathan, Saravana Kumar; Nando, Golok B; Chattopadhyay, Santanu

    2015-02-01

    The present investigation reports the preparation of two types of 2D rod-like nano-hydroxyapatite (nHA) (unmodified and Polypropylene glycol (PPG) wrapped) of varying high-aspect ratios, by modified co-precipitation methods, without any templates. These nHA were successfully introduced into novel synthesized Thermoplastic Polyurethane (TPU) matrices based on polycarbonate soft segments, by both in-situ and ex-situ techniques. Physico-mechanical properties of the in-situ prepared TPU/nHA nanocomposites were found to be superior compared to the ex-situ counterparts, and pristine nHA reinforced TPU. Improved biocompatibility of the prepared nanocomposites was confirmed by MTT assays using osteoblast-like MG63 cells. Cell proliferation was evident over an extended period. Osteoconductivity of the nanocomposites was observed by successful formation of an apatite layer on the surface of the samples, after immersion into simulated body fluid (SBF). Prothrombin time (PT) and activated partial thromboplastin time (APTT), as calculated from coagulation assays, displayed an increase in the clotting time, particularly for the PPG-wrapped nHA nanocomposites, prepared through the in-situ technique. Only 0.3% of hemolysis was observed for the in-situ prepared nanocomposites, which establishes the antithrombotic property of the material. The key parameters for enhancing the technical properties and biocompatibility of the nanocomposites are: the interfacial adhesion parameter (B(σy)), the polymer-filler affinity, the aspect ratio of filler and non-covalent modifications, and the state of dispersion. Thus, the novel TPU/polymer wrapped nHA nanocomposites have great potential for biomedical applications, in particular for vascular prostheses, cardiovascular implants, scaffolds, and soft and hard tissues implants.

  20. Synthesis of Collagen-Based Hydrogel Nanocomposites Using Montmorillonite and Study of Adsorption Behavior of Cd from Aqueous Solutions

    Directory of Open Access Journals (Sweden)

    Gholam Bagheri Marandi

    2013-04-01

    Full Text Available Novel collagen-based hydrogel nanocomposites were synthesized by graft copolymerization of acrylamide and maleic anhydrid in the presence of different amounts of montmorillonite, using methylenebisacrylamide (MBAand ammonium persulfate (APS as crosslinker and initiator, respectively. The optimum amount of clay on the swelling properties of the samples was studied. It was found that the hydrogel nanocomposites exhibited improved swelling capacity compared with the clay-free hydrogel. Gel content was also studied and the resultsindicated that the inclusion of montmorillonite causes an increase in gel content. The sorption behavior of heavy metal ion from aqueous solutions was investigated by its relationship with pH, contact time, initial concentration of metal ion and also, montmorillonite content of the nanocomposites. The experimental data showed thatCd2+ ion adsorption increases with increasing initial concentration of Cd2+ ion in solution and the clay content. Also, the results indicated that more than 88% of the maximum adsorption capacities toward Cd2+ ion were achieved within the initial 10 minute. Functional groups of the prepared hydrogels have shown complexation abilitywith metal ions and improving hydrogels' adsorption properties. It was concluded that the nanocomposites could be used as fast-responsive, and high capacity sorbent materials in Cd2+ ion removing processes. The prepared hydrogel nanocomposites were characerized by means of XRD patterns, TGA thermal methods and FTIRspectroscopy. The XRD patterns of nanocomposites showed that the interlayer distance of montmorillonite was changed and the clay sheets were exfoliated. Furthermore, the results showed that by increasing the montmorillonite content, thermal stability of the nanocomposites was clearly improved.

  1. Surface plasmon resonance-based fiber-optic hydrogen gas sensor utilizing palladium supported zinc oxide multilayers and their nanocomposite.

    Science.gov (United States)

    Tabassum, Rana; Gupta, Banshi D

    2015-02-10

    We analyze surface plasmon resonance-based fiber-optic sensor for sensing of small concentrations of hydrogen gas in the visible region of the electromagnetic spectrum. One of the two probes considered has multilayers of zinc oxide (ZnO) and palladium (Pd) while the other has layer of their composite over a silver coated unclad core of the fiber. The analysis is carried out for different volume fractions of palladium nanoparticles dispersed in zinc oxide host material in the nanocomposite layer. For the analysis, a Maxwell-Garnett model is adopted for calculating the dielectric function of a ZnO:Pd nanocomposite having nanoparticles of dimensions smaller than the wavelength of radiation used. The effects of the volume fraction of the nanoparticles in the nanocomposite and the thickness of the nanocomposite layer on the figure of merit of the sensor have been studied. The film thickness of the layer and the volume fraction of nanoparticles in the ZnO:Pd nanocomposite layer have been optimized to achieve the maximum value of the figure of merit of the sensor. It has been found that the figure of merit of the sensing probe coated with ZnO:Pd nanocomposite is more than twofold of the sensing probe coated with multilayers of Pd and ZnO over a silver coated unclad core of the fiber; hence, the sensor with a nanocomposite layer works better than that with multilayers of zinc oxide and palladium. The sensor can be used for online monitoring and remote sensing of hydrogen gas.

  2. A potential bioactive wound dressing based on carboxymethyl cellulose/ZnO impregnated MCM-41 nanocomposite hydrogel

    Energy Technology Data Exchange (ETDEWEB)

    Rakhshaei, Rasul [Research Laboratory of Dendrimers and Nanopolymers, Faculty of Chemistry, University of Tabriz, P.O. Box 51666, Tabriz (Iran, Islamic Republic of); Namazi, Hassan, E-mail: namazi@tabrizu.ac.ir [Research Laboratory of Dendrimers and Nanopolymers, Faculty of Chemistry, University of Tabriz, P.O. Box 51666, Tabriz (Iran, Islamic Republic of); Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Science, Tabriz (Iran, Islamic Republic of)

    2017-04-01

    Lack of antibacterial activity, deficient water vapor and oxygen permeability, and insufficient mechanical properties are disadvantages of existing wound dressings. Hydrogels could absorb wound exudates due to their strong swelling ratio and give a cooling sensation and a wet environment. To overcome these shortcomings, flexible nanocomposite hydrogel films was prepared through combination of zinc oxide impregnated mesoporous silica (ZnO-MCM-41) as a nano drug carrier with carboxymethyl cellulose (CMC) hydrogel. Citric acid was used as cross linker to avoid the cytotoxicity of conventional cross linkers. The prepared nanocomposite hydrogel was characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Zeta potential and UV–vis spectroscopy. Results of swelling and erosion tests showed CMC/ZnO nanocomposite hydrogel disintegrated during the first hours of the test. Using MCM-41 as a substrate for ZnO nanoparticles solved this problem and the CMC/ZnO-MCM-41 showed a great improvement in tensile strength (12%), swelling (100%), erosion (53%) and gas permeability (500%) properties. Drug delivery and antibacterial properties of the nanocomposite hydrogel films studied using tetracycline (TC) as a broad spectrum antibiotic and showed a sustained TC release. This could efficiently decrease bandage exchange. Cytocompatibility of the nanocomposite hydrogel films has been analyzed in adipose tissue-derived stem cells (ADSCs) and results showed cytocompatibility of CMC/ZnO-MCM-41. Based on these results the prepared CMC nanocomposite hydrogel containing ZnO impregnated MCM-41, could serve as a kind of promising wound dressing with sustained drug delivery properties. - Highlights: • CMC nanocomposite hydrogel incorporated with TC loaded ZnO-MCM-41 nanoparticles have been prepared as active wound dressing. • Citric acid was used as cross linker to avoid conventional toxic crosslinkers. • CMC/ZnO-MCM-41

  3. Preparation and Properties of Polyester-Based Nanocomposite Gel Coat System

    Directory of Open Access Journals (Sweden)

    P. Jawahar

    2006-01-01

    Full Text Available Nanocomposite gel coat system is prepared using unsaturated polyester resin with aerosil powder, CaCO3, and organoclay. The influence of organoclay addition on mechanical and water barrier properties of gel coat system is studied for different amount (1, 2, and 3 wt % of organoclay. The nanolevel incorporation of organoclay improves the mechanical and water barrier properties of nanocomposite gel coat system. The nanocomposite gel coat system exhibits 55% improvement in tensile modulus and 25% improvement in flexural modulus. There is a 30% improvement in impact property of nanocomposite gel coat system. The dynamic mechanical analysis shows a slight increase in glass transition temperature for nanocomposite gel coat system.

  4. New MPPT algorithm based on hybrid dynamical theory

    KAUST Repository

    Elmetennani, Shahrazed

    2014-11-01

    This paper presents a new maximum power point tracking algorithm based on the hybrid dynamical theory. A multiceli converter has been considered as an adaptation stage for the photovoltaic chain. The proposed algorithm is a hybrid automata switching between eight different operating modes, which has been validated by simulation tests under different working conditions. © 2014 IEEE.

  5. New MPPT algorithm based on hybrid dynamical theory

    KAUST Repository

    Elmetennani, Shahrazed; Laleg-Kirati, Taous-Meriem; Benmansour, K.; Boucherit, M. S.; Tadjine, M.

    2014-01-01

    This paper presents a new maximum power point tracking algorithm based on the hybrid dynamical theory. A multiceli converter has been considered as an adaptation stage for the photovoltaic chain. The proposed algorithm is a hybrid automata switching between eight different operating modes, which has been validated by simulation tests under different working conditions. © 2014 IEEE.

  6. Design, analysis and modeling of a novel hybrid powertrain system based on hybridized automated manual transmission

    Science.gov (United States)

    Wu, Guang; Dong, Zuomin

    2017-09-01

    Hybrid electric vehicles are widely accepted as a promising short to mid-term technical solution due to noticeably improved efficiency and lower emissions at competitive costs. In recent years, various hybrid powertrain systems were proposed and implemented based on different types of conventional transmission. Power-split system, including Toyota Hybrid System and Ford Hybrid System, are well-known examples. However, their relatively low torque capacity, and the drive of alternative and more advanced designs encouraged other innovative hybrid system designs. In this work, a new type of hybrid powertrain system based hybridized automated manual transmission (HAMT) is proposed. By using the concept of torque gap filler (TGF), this new hybrid powertrain type has the potential to overcome issue of torque gap during gearshift. The HAMT design (patent pending) is described in details, from gear layout and design of gear ratios (EV mode and HEV mode) to torque paths at different gears. As an analytical tool, mutli-body model of vehicle equipped with this HAMT was built to analyze powertrain dynamics at various steady and transient modes. A gearshift was decomposed and analyzed based basic modes. Furthermore, a Simulink-SimDriveline hybrid vehicle model was built for the new transmission, driveline and vehicle modular. Control strategy has also been built to harmonically coordinate different powertrain components to realize TGF function. A vehicle launch simulation test has been completed under 30% of accelerator pedal position to reveal details during gearshift. Simulation results showed that this HAMT can eliminate most torque gap that has been persistent issue of traditional AMT, improving both drivability and performance. This work demonstrated a new type of transmission that features high torque capacity, high efficiency and improved drivability.

  7. Fabrication of robust and thermally stable superhydrophobic nanocomposite coatings based on thermoplastic polyurethane and silica nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Seyfi, Javad [School of Chemical Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Jafari, Seyed Hassan, E-mail: shjafari@ut.ac.ir [School of Chemical Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Khonakdar, Hossein Ali [Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, D-01069 Dresden (Germany); Sadeghi, Gity Mir Mohamad [Department of Polymer Engineering & Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Zohuri, Gholamhossein [Polymer Group, Faculty of Sciences, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Hejazi, Iman [Department of Polymer Engineering & Color Technology, Amirkabir University of Technology, Tehran (Iran, Islamic Republic of); Simon, Frank [Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, D-01069 Dresden (Germany)

    2015-08-30

    Highlights: • Superhydrophobic coatings were prepared from an intrinsically hydrophilic polymer. • The superhydrophobicity remained intact at elevated temperatures. • Polyurethane plays a key role in improving the mechanical robustness of the coatings. • A complete surface coverage of nanosilica is necessary for superhydrophobicity. - Abstract: In this paper, superhydrophobic nanocomposite coatings based on thermoplastic polyurethane (TPU) and modified nanosilica were fabricated using a simple solution-based method. The main challenge was to impart superhydrophobicity to an intrinsically hydrophilic polymer substrate. The prepared nanocomposite coatings were characterized by means of scanning electron microscopy, confocal microscopy and X-ray photoelectron spectroscopy. Based on the obtained results, it was proved that in order to achieve superhydrophobicity, no TPU macromolecule should be present on the coating's top layer, thus a complete coverage of coating's top layer by nanosilica particles was necessary for achieving ultra water repellent coatings. Mechanical and thermal resistance of the coatings, which are the main challenges in commercializing superhydrophobic surfaces, were also studied by drop impact and thermal annealing tests, respectively. It was proved that using TPU as a sublayer results in improving mechanical resistance of the coatings as compared with the pure silica nanocoating. Moreover, the samples showed an excellent resistance against elevated temperatures (150 °C) and remained superhydrophobic; however, further increment of the annealing temperatures to 200 °C caused the TPU macromolecules to migrate onto the top layer of the coatings significantly reducing the water repellency, which was visually proved by SEM.

  8. Fabrication of robust and thermally stable superhydrophobic nanocomposite coatings based on thermoplastic polyurethane and silica nanoparticles

    Science.gov (United States)

    Seyfi, Javad; Jafari, Seyed Hassan; Khonakdar, Hossein Ali; Sadeghi, Gity Mir Mohamad; Zohuri, Gholamhossein; Hejazi, Iman; Simon, Frank

    2015-08-01

    In this paper, superhydrophobic nanocomposite coatings based on thermoplastic polyurethane (TPU) and modified nanosilica were fabricated using a simple solution-based method. The main challenge was to impart superhydrophobicity to an intrinsically hydrophilic polymer substrate. The prepared nanocomposite coatings were characterized by means of scanning electron microscopy, confocal microscopy and X-ray photoelectron spectroscopy. Based on the obtained results, it was proved that in order to achieve superhydrophobicity, no TPU macromolecule should be present on the coating's top layer, thus a complete coverage of coating's top layer by nanosilica particles was necessary for achieving ultra water repellent coatings. Mechanical and thermal resistance of the coatings, which are the main challenges in commercializing superhydrophobic surfaces, were also studied by drop impact and thermal annealing tests, respectively. It was proved that using TPU as a sublayer results in improving mechanical resistance of the coatings as compared with the pure silica nanocoating. Moreover, the samples showed an excellent resistance against elevated temperatures (150 °C) and remained superhydrophobic; however, further increment of the annealing temperatures to 200 °C caused the TPU macromolecules to migrate onto the top layer of the coatings significantly reducing the water repellency, which was visually proved by SEM.

  9. Optical and Electrical Characteristics of Silver Ion Conducting Nanocomposite Solid Polymer Electrolytes Based on Chitosan

    Science.gov (United States)

    Aziz, Shujahadeen B.; Rasheed, Mariwan A.; Abidin, Zul H. Z.

    2017-10-01

    Optical and electrical properties of nanocomposite solid polymer electrolytes based on chitosan have been investigated. Incorporation of alumina nanoparticles into the chitosan:silver triflate (AgTf) system broadened the surface plasmon resonance peaks of the silver nanoparticles and shifted the absorption edge to lower photon energy. A clear decrease of the optical bandgap in nanocomposite samples containing alumina nanoparticles was observed. The variation of the direct-current (DC) conductivity and dielectric constant followed the same trend with alumina concentration. The DC conductivity increased by two orders of magnitude, which can be attributed to hindrance of silver ion reduction. Transmission electron microscopy was used to interpret the space-charge and blocking effects of alumina nanoparticles on the DC conductivity and dielectric constant. The ion conduction mechanism was interpreted based on the dependences of the electrical and dielectric parameters. The dependence of the DC conductivity on the dielectric constant is explained empirically. Relaxation processes associated with conductivity and viscoelasticity were distinguished based on the incomplete semicircular arcs in plots of the real and imaginary parts of the electric modulus.

  10. Structure and properties of carbon nanotubes/sol-gel nanocomposites

    International Nuclear Information System (INIS)

    Pokrass, Mariana

    2013-08-01

    Carbon Nanotubes (CNTs) are promising filler materials owing to their exceptional mechanical, electrical, thermal and optical properties. Since their discovery in 1991, a major effort has been made in developing CNT-polymer nanocomposites, whereas CNT/ceramic based nanocomposites, in particularly, CNT/silica nanocomposites, have been very little studied. This thesis focuses on preparation and characterization of novel CNT/silica nanocomposite glasses synthesized by the Sol-Gel technology. A comprehensive analysis of their morphological, optical, and electrical properties was conducted, and analyzed according to existing theoretical models. The nanocomposites hosting matrix is a hybrid organic/inorganic glass prepared by the Fast-Sol-Gel (FSG) route. Using specific conditions in the FSG procedure, the resultant glasses are nonporous, exhibiting no contraction upon drying. Their analogous Classical-Sol-Gel (CSG) glasses, however, are porous, and do exhibit contraction upon drying. The FSG glasses are relatively new materials, and their physical and optical properties were only meagerly studied. In our present work we have conducted a comprehensive experimental research on some previously ignored characteristics such as: UV-vis-IR optical absorption and transmission, and the organic content effect on the refraction index n, density ρ, thermal expansion coefficient β, and thermo-optic coefficient dn/dT. We found that organic residues within the glass decrease the refractive index, density, and thermo-optic coefficient. The thermal expansion coefficient, however, increases with the organic content. A negative linear dependence of the thermo-optic coefficient on the thermal expansion coefficient was obtained. CNT/FSG nanocomposites were prepared by using a solution mixing method, while CNT/CSG nanocomposites were prepared by means of an in situ polymerization technique. Nanocomposites based on FSG hybrid glasses were characterized for their nonlinear optical and

  11. Degradation and biocompatibility of a poly(propylene fumarate)-based/alumoxane nanocomposite for bone tissue engineering.

    NARCIS (Netherlands)

    Mistry, A.S.; Mikos, A.G.; Jansen, J.A.

    2007-01-01

    In this work, we evaluated the in vitro cytotoxicity and in vivo biocompatibility of a novel poly(propylene fumarate) (PPF)-based/alumoxane nanocomposite for bone tissue engineering applications. The incorporation of functionalized alumoxane nanoparticles into the PPF-based polymer was previously

  12. A novel aluminum based nanocomposite with high strength and good ductility

    Energy Technology Data Exchange (ETDEWEB)

    Ramezanalizadeh, Hossein, E-mail: hralizadeh@ut.ac.ir [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Emamy, Masoud [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Shokouhimehr, Mohammadreza [School of Chemical and Biological Engineering, College of Engineering, Seoul National University, Seoul (Korea, Republic of)

    2015-11-15

    Aluminum based nanocomposite containing nano-sized Al{sub 3}Mg{sub 2} reinforcing was fabricated via mechanical milling followed by hot extrusion techniques. For this, Al and Al{sub 3}Mg{sub 2} powders were mixed mechanically and milled at different times (0, 2, 5, 7, 10, 15 and 20 h) to achieve Al–10 wt.% Al{sub 3}Mg{sub 2} composite powders. Hot extrusion of cold pressed powders was done at 400 °C with extrusion ratio of 6:1. Microstructures of the powders and consolidated materials were studied using transmission electron microscopy, scanning electron microscope and X-ray diffraction. Fracture surfaces were also investigated by scanning electron microscopy equipped with EDS analyzer. The results showed that an increase in milling time caused to reduce the grain size unlike the lattice strain of Al matrix. In addition, the fabricated composites exhibited homogeneous distribution and less agglomerations of the n-Al{sub 3}Mg{sub 2} with increasing milling time. The mechanical behavior of these nanocomposites was investigated by hardness and tensile tests, which revealed it has four times the strength of a conventional Al along with good ductility. It was found that the ultimate tensile strength (UTS) and elongation of the nanocomposites were significantly improved with increases in milling time up to 15 h. This improvement was attributed to the grain refinement strengthening and homogeneous distribution of the n-Al{sub 3}Mg{sub 2}. Fracture surfaces showed that the interfacial bonding between Al and Al{sub 3}Mg{sub 2} could be improved with increasing in milling time. Also HRTEM results from interface showed that a metallurgical clean interface and intimate contact between matrix and second phase. By extending the milling process up to 20 h, there was no significant improvement in mechanical behavior of materials, due to the completion of milling process and dynamic and static recovery of composite at higher milling times. - Highlights: • A novel aluminum-based

  13. Influence of Magnetite Nanoparticles on the Dielectric Properties of Metal Oxide/Polymer Nanocomposites Based on Polypropylene

    Science.gov (United States)

    Maharramov, A. A.; Ramazanov, M. A.; Di Palma, Luca; Shirinova, H. A.; Hajiyeva, F. V.

    2018-01-01

    Structure and dielectric properties of polymer nanocomposites based on isotactic polypropylene and iron oxide (Fe3O4) nanoparticles are studied. Distribution of magnetite nanoparticles in a polymer matrix was studied by scanning electron microscopy (SEM, Carl Zeiss). Dielectric properties of nanocomposites were examined by means of E7-21 impedance spectrometer in the frequency range of 102-106 Hz and temperature interval of 298-433 K. The frequency and temperature dependences of the dielectric permittivity ɛ, as well as the temperature dependence of log (ρ) were constructed. It is shown that introduction of the magnetite (Fe3O4) nanoparticles into a polypropylene matrix increases the dielectric permittivity of nanocomposites. An increase in the dielectric permittivity is explained by the increase in the polarization ability of nanocomposites. It is found that a decrease in the specific resistance with increasing temperature up to 318 K is associated with an increase in the ionic conductivity of nanocomposites. An increase in the resistance at temperatures higher than 358 K is due to the destruction of the crystalline phase of the polymer, as a result of which the distance between the Fe3O4 nanoparticles increases.

  14. Carrageenan-based semi-IPN nanocomposite hydrogels: Swelling kinetic and slow release of sequestrene Fe 138 fertilizer

    Directory of Open Access Journals (Sweden)

    Mohammad Kazem Bahrami

    2016-09-01

    Full Text Available Nanocomposite hydrogels based on kappa-carrageenan were synthesized by incorporating natural sodium montmorillonite (Cloisite nanoclay. Acrylamide (AAm and methylenebisacrylamide (MBA were used as a monomer and a crosslinker, respectively. Effects of reaction variables on the swelling kinetics were studied. The results revealed that the rate of swelling for nanocomposites with high content of MBA was higher than those of nanocomposites consisting of low content of MBA. Similar to the effect of MBA, the rate of swelling enhanced as the carrageenan content was decreased. The influence of clay content on swelling rate was not remarkable. The experimental swelling data were evaluated by pseudo-first-order and pseudo-second-order kinetic models. The swelling data described well by pseudo-second-order kinetic model. Sequestrene Fe 138 (Sq as an agrochemical was loaded into nanocomposites and releasing of this active agent from nanocomposites was studied. The clay-free hydrogel released the whole loaded Sq; whereas the presence of clay restricted the release of Sq.

  15. Synthesis, characterization and antibacterial properties of a novel nanocomposite based on polyaniline/polyvinyl alcohol/Ag

    Directory of Open Access Journals (Sweden)

    Mansour Ghaffari-Moghaddam

    2014-11-01

    Full Text Available In this study, a novel nanocomposite based on polyaniline/polyvinyl alcohol/Ag (PANI/PVA/Ag has been successfully synthesized. The chemical reduction method was used to produce Ag nanoparticle colloidal solution from Ag+ ions. The polymerization of aniline occurred in situ for the preparation of polyaniline (PANI in the presence of ammonium persulfate. With exposure to Ag nanoparticles on the PANI/PVA composite, a new nanocomposite was obtained. The morphology and particle size of the novel nanocomposite was studied by scanning electron microscopy (SEM, X-ray diffraction (XRD, and Fourier transform infrared (FT-IR analyses. According to XRD analysis, the size of nanoparticles was found to be in the range of 10–17 nm. SEM images showed the favored shape of nanoparticles as triangle which is a benign shape for antibacterial analysis. The antibacterial activity of the obtained nanocomposite was also evaluated against Gram positive bacteria Staphylococcus aureus (Staph. aureus and Gram negative Escherichia coli (E. coli using the paper disk diffusion method. The antibacterial study showed that the PANI/PVA composite did not have a very good antibacterial activity but PANI/PVA/Ag nanocomposites were found to be effective against two bacteria.

  16. Tunable green graphene-silk biomaterials: Mechanism of protein-based nanocomposites.

    Science.gov (United States)

    Wang, Fang; Jyothirmayee Aravind, S S; Wu, Hao; Forys, Joseph; Venkataraman, Venkat; Ramanujachary, Kandalam; Hu, Xiao

    2017-10-01

    Green graphene materials prepared by photoreduction of graphite oxide were first time blended with aqueous-based silk fibroin proteins to improve the mechanical and thermal properties of silk biomaterials, and their nanocomposite interaction mechanism was illustrated. Powder X-ray diffraction (XRD) analysis confirmed the complete exfoliation of graphite oxide to graphene in presence of focused pulses of solar radiation. By varying the concentration of graphene (0.1wt% to 10wt%), a series of free standing graphene-silk films were prepared and were systematically characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and nanoindentation measurements. The homogeneity of graphene in silk as well as the thermal stability of the composite films was demonstrated by thermal gravimetric analysis (TGA) and temperature-modulated differential scanning calorimetry (TMDSC). Surprisingly, silk composite film containing only 0.5wt% of graphene gives the highest Young's modulus of 1.65GPa (about 5.8 times higher than the pure silk's modulus), indicating a nano-composite to micro-composite transition of silk-graphene structure occurred around this mixing ratio. This finding provided an easy approach to improve the elastic modulus and other physical properties of silk materials by adding a tiny amount of graphene sheets. Fibroblast cells studies also proved that these graphene-silk materials can significantly improve cell adhesion, growth and proliferation. This protein nanocomposite study provided a useful model to understand how to manipulate the hydrophobic-hydrophobic and polar-polar interactions between high-surface-area inorganic nanomaterials and amphiphilic protein materials, which has many emerging applications in the material science and engineering, such as bio-device fabrication, drug storage and release, and tissue regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Sensitive determination of bisphenol A base on arginine functionalized nanocomposite graphene film

    International Nuclear Information System (INIS)

    Zhang Yan; Wang Letao; Lu Daban; Shi Xuezhao; Wang Chunming; Duan Xiaojuan

    2012-01-01

    Highlights: ► The water-soluble arginine functionalized graphene was produced successfully by an environment-friendly method. ► Electrochemical behaviors and some kinetic parameters of bisphenol A on the Arg-G/GCE were investigated. ► The proposed sensor showed more outstanding sensitivity properties toward the bisphenol A than the reported sensors. ► The proposed method opened a new simply way to detection of bisphenol A in the environmental protection. - Abstract: Arginine (Arg) functionalized graphene (Arg-G) nanocomposite was produced successfully by an environment-friendly method, and the morphology of the nanocomposite was characterized by transmission electron microscopy (TEM), Raman spectra, etc. Based on Arg-G nanocomposite, an electrochemical sensor was fabricated for sensitive detection of bisphenol A (BPA). The electrochemical behaviors of BPA on Arg-G modified glassy carbon electrode (GCE) were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Experimental parameters, such as the accumulation potential and time, scan rate, and the pH value of buffer solution were optimized. Under the optimized conditions, the oxidation peak current was proportional to BPA concentration in the range between 5.0 nmol/L and 40.0 μmol/L with the correlation coefficient of 0.9986 and the limit of detection of 1.1 nmol/L (S/N = 3). Moreover, the fabricated electrode also exhibited good reproducibility and stability. The proposed sensor was successfully employed to determine BPA in real plastic products and the recoveries were satisfactory.

  18. Waste to Want: Polymer nanocomposites using nanoclays extracted from Oil based drilling mud waste

    International Nuclear Information System (INIS)

    Adegbotolu, Urenna V; Njuguna, James; Pollard, Pat; Yates, Kyari

    2014-01-01

    Due to the European Union (EU) waste frame work directive (WFD), legislations have been endorsed in EU member states such as UK for the Recycling of wastes with a vision to prevent and reduce landfilling of waste. Spent oil based drilling mud (drilling fluid) is a waste from the Oil and Gas industry with great potentials for recycling after appropriate clean-up and treatment processes. This research is the novel application of nanoclays extracted from spent oil based drilling mud (drilling fluid) clean-up as nanofiller in the manufacture of nanocomposite materials. Research and initial experiments have been undertaken which investigate the suitability of Polyamide 6 (PA6) as potential polymer of interest. SEM and EDAX were used to ascertain morphological and elemental characteristics of the nanofiller. ICPOES has been used to ascertain the metal concentration of the untreated nanofiller to be treated (by oil and heavy metal extraction) before the production of nanocomposite materials. The challenges faced and future works are also discussed

  19. CRYSTALLIZATION KINETICS OF POLYMERIC NANOCOMPOSITES BASED ON POLYAMIDE 12 MODIFIED BY Cr2O3 NANOPARTICLES

    Directory of Open Access Journals (Sweden)

    E. S. Shapoval

    2014-09-01

    Full Text Available In situ polymerization method is used for obtaining polymeric composites based on polyamide12 matrix (PA 12, filled with Cr2O3 nanoparticles. The carried out researches result in synthesis method development for polymeric nanocomposites based on PA 12 matrix filled with nano-sized Cr2O3magnetic particles providing uniform embedding of the filler into polymeric matrix without formation of nanoparticles agglomerates. Mechanical tests on samples compression are carried out. It is shown that mechanical properties of polymeric composites (Young’s modulus, durability limit are decreased for 20-30 % as compared with not modified PA 12 synthesized by means of the chosen method. The influence of the filler on crystallization morphology and kinetics of polymeric nanocomposites is determined by electron microscopy and differential scanning calorimetry. The values of crystallization degree, crystallization rate constant for different supercooling intervals and parameters of Avrami equation are obtained. The initial nucleation is shown to be going on according to non-thermal mechanism, and nanoparticles are not the germs of crystallization. It is stated that nanoparticles are embedded into polymeric matrix and uniformly allocated in crystallites. Research results can find their application at creation of electric and magnetic fields, micro-sized mechanical devices, and at development of new materials for 3D printers.

  20. A novel tyrosinase biosensor based on hydroxyapatite-chitosan nanocomposite for the detection of phenolic compounds

    International Nuclear Information System (INIS)

    Lu Limin; Zhang Li; Zhang Xiaobing; Huan Shuangyan; Shen Guoli; Yu Ruqin

    2010-01-01

    A novel tyrosinase biosensor based on hydroxyapatite nanoparticles (nano-HA)-chitosan nanocomposite has been developed for the detection of phenolic compounds. The uniform and size controlled nano-HA was synthesized by hydrothermal method, and its morphological characterization was examined by transmission electron microscope (TEM). Tyrosinase was then immobilized on a nano-HA-chitosan nanocomposite-modified gold electrode. Electrochemical impedance spectroscopy and cyclic voltammetry were used to characterize the sensing film. The prepared biosensor was applied to determine phenolic compounds by monitoring the reduction signal of the biocatalytically produced quinone species at -0.2 V (vs. saturated calomel electrode). The effects of the pH, temperature and applied potential on the biosensor performance were investigated, and experimental conditions were optimized. The biosensor exhibited a linear response to catechol over a wide concentration range from 10 nM to 7 μM, with a high sensitivity of 2.11 x 10 3 μA mM -1 cm -2 , and a limit of detection down to 5 nM (based on S/N = 3). The apparent Michaelis-Menten constants of the enzyme electrode were estimated to be 3.16, 1.31 and 3.52 μM for catechol, phenol and m-cresol, respectively. Moreover, the stability and reproducibility of this biosensor were evaluated with satisfactory results.

  1. Synthesis and Examination of Nanocomposites Based on Poly(2-hydroxyethyl methacrylate for Medicinal Use

    Directory of Open Access Journals (Sweden)

    Olena S. Kukolevska

    2017-02-01

    Full Text Available Abstract Preparation of poly(2-hydroxyethyl methacrylate (PHEMA based nanocomposites using different approaches such as synthesis with water as the porogen, filling of polymer matrix by silica and formation of interpenetrating polymer networks with polyurethane was demonstrated. Incorporation of various biologically active compounds (BAC such as metronidazole, decamethoxin, zinc sulphate, silver nitrate or amino acids glycine and tryptophan into nanocomposites was achieved. BAC were introduced into the polymer matrix either (1 directly, or (2 with a solution of colloidal silica, or (3 through immobilization on silica (sol-densil. Morphology of prepared materials was investigated by laser scanning microscopy and low-vacuum scanning electron microscopy. In vacuum freeze-drying, prior imaging was proposed for improving visualization of the porous structure of composites. The interaction between PHEMA matrix and silica filler was investigated by IR spectroscopy. Adsorption of 2-hydroxyethyl methacrylate and BAC from aqueous solution on the silica surface was also examined. Phase composition and thermal stability of composites were studied by the differential thermogravimetry/differential thermal analysis. Release of BAC into water medium from prepared composites were shown to depend on the synthetic method and differed significantly. Obtained PHEMA-base materials which are characterized by controlled release of BAC have a strong potential for application in manufacturing of different surgical devices like implants, catheters and drainages.

  2. Pentacene-Based Thin Film Transistor with Inkjet-Printed Nanocomposite High-K Dielectrics

    Directory of Open Access Journals (Sweden)

    Chao-Te Liu

    2012-01-01

    Full Text Available The nanocomposite gate insulating film of a pentacene-based thin film transistor was deposited by inkjet printing. In this study, utilizing the pearl miller to crumble the agglomerations and the dispersant to well stabilize the dispersion of nano-TiO2 particles in the polymer matrix of the ink increases the dose concentration for pico-jetting, which could be as the gate dielectric film made by inkjet printing without the photography process. Finally, we realized top contact pentacene-TFTs and successfully accomplished the purpose of directly patternability and increase the performance of the device based on the nanocomposite by inkjet printing. These devices exhibited p-channel TFT characteristics with a high field-effect mobility (a saturation mobility of ̃0.58 cm2 V−1 s−1, a large current ratio (>103 and a low operation voltage (<6 V. Furthermore, we accorded the deposited mechanisms which caused the interface difference between of inkjet printing and spin coating. And we used XRD, SEM, Raman spectroscopy to help us analyze the transfer characteristics of pentacene films and the performance of OTFTs.

  3. Preparation and Characterization of Gelatin-Based Mucoadhesive Nanocomposites as Intravesical Gene Delivery Scaffolds

    Directory of Open Access Journals (Sweden)

    Ching-Wen Liu

    2014-01-01

    Full Text Available This study aimed to develop optimal gelatin-based mucoadhesive nanocomposites as scaffolds for intravesical gene delivery to the urothelium. Hydrogels were prepared by chemically crosslinking gelatin A or B with glutaraldehyde. Physicochemical and delivery properties including hydration ratio, viscosity, size, yield, thermosensitivity, and enzymatic degradation were studied, and scanning electron microscopy (SEM was carried out. The optimal hydrogels (H, composed of 15% gelatin A175, displayed an 81.5% yield rate, 87.1% hydration ratio, 42.9 Pa·s viscosity, and 125.8 nm particle size. The crosslinking density of the hydrogels was determined by performing pronase degradation and ninhydrin assays. In vitro lentivirus (LV release studies involving p24 capsid protein analysis in 293T cells revealed that hydrogels containing lentivirus (H-LV had a higher cumulative release than that observed for LV alone (3.7-, 2.3-, and 2.3-fold at days 1, 3, and 5, resp.. Lentivirus from lentivector constructed green fluorescent protein (GFP was then entrapped in hydrogels (H-LV-GFP. H-LV-GFP showed enhanced gene delivery in AY-27 cells in vitro and to rat urothelium by intravesical instillation in vivo. Cystometrogram showed mucoadhesive H-LV reduced peak micturition and threshold pressure and increased bladder compliance. In this study, we successfully developed first optimal gelatin-based mucoadhesive nanocomposites as intravesical gene delivery scaffolds.

  4. Antibacterial properties of nanocomposite materials and compositions on there bases

    International Nuclear Information System (INIS)

    Podol'skaya, V.I.; Vojtenko, O.Yu.; Grishenko, N.I.; Ul'berg, Z.P.; Yakubenko, L.N.

    2012-01-01

    The structured nanobiocomposite materials based on microbial cells and colloidal silver can serve as the new adjuvant systems. These composite materials being filled with active components, in particular the medications allow to prepare the long release preparations with synergetic effect or can just contribute to prolonged drug action

  5. Fullerene and dendrimer based nano-composite gas separation membranes

    NARCIS (Netherlands)

    Sterescu, D.M.

    2007-01-01

    This thesis describes the development of new materials for membrane based gas separation processes. Long-term stable, loosely packed (high free volume) amorphous polymer films were prepared by introduction of super-molecular pendant groups, which possess hardsphere properties to avoid dense

  6. Evaluation of thermal properties of nanocomposites based on Ecobras matrix and vermiculite modified with alkyl phosphonium salt

    International Nuclear Information System (INIS)

    Oliveira, Marcelo F.L. de; Leite, Marcia C.A.M.; Braga, Fernanda C.F.; Oliveira, Marcia G.

    2015-01-01

    The use of biodegradable polymers for producing nanocomposites with mineral fillers fetch the production of new materials with low cost and reduced environmental impact, combined with improvements in the mechanical and thermal properties. Nanocomposites based on Ecobras and vermiculite (VMT) modified with hexadecyl tributyl phosphonium bromide (Ph-VMT) were prepared by melt intercalation. The intercalation of Ph-VMT in Ecobras was characterized by X-ray diffraction (XRD). The thermal properties of Ecobras and their compositions were characterized by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The addition of VMT and Ph- VMT in Ecobras increases the crystallization temperature (Tc) and crystalline melting (Tm), as observed by DSC analysis. The result of the thermogravimetric analysis showed that the addition of Ph-VMT in Ecobras improved thermal stability of the nanocomposite. (author)

  7. Low dielectric and low surface free energy flexible linear aliphatic alkoxy core bridged bisphenol cyanate ester based POSS nanocomposites

    Directory of Open Access Journals (Sweden)

    Muthukaruppan eAlagar

    2013-10-01

    Full Text Available The aim of the present work is to develop a new type of flexible linear aliphatic alkoxy core bridged bisphenol cyanate ester (AECE based POSS nanocomposites for low k applications. The POSS-AECE nanocomposites were developed by incorporating varying weight percentages (0, 5 and 10 wt % of octakis (dimethylsiloxypropylglycidylether silsesquioxane (OG-POSS into cyanate esters. Data from thermal and dielectric studies imply that the POSS reinforced nanocomposite exhibits higher thermal stability and low dielectric value of k=2.4 (10 wt% POSS-AECE4 compared than those of neat AECE. From the contact angle measurement, it is inferred that, the increase in the percentage incorporation of POSS in to AECE, the values of water contact angle was enhanced. Further, the value of surface free energy was lower when compared to that of neat AECE. The molecular level dispersion of POSS into AECE was ascertained from SEM and TEM analyses.

  8. Clay/Polyaniline Hybrid through Diazonium Chemistry: Conductive Nanofiller with Unusual Effects on Interfacial Properties of Epoxy Nanocomposites.

    Science.gov (United States)

    Jlassi, Khouloud; Chandran, Sarath; Poothanari, Mohammed A; Benna-Zayani, Mémia; Thomas, Sabu; Chehimi, Mohamed M

    2016-04-12

    The concept of conductive network structure in thermoset matrix without sacrificing the inherent mechanical properties of thermoset polymer (e.g., epoxy) is investigated here using "hairy" bentonite fillers. The latter were prepared through the in situ polymerization of aniline in the presence of 4-diphenylamine diazonium (DPA)-modified bentonite (B-DPA) resulting in a highly exfoliated bentonite-DPA/polyaniline (B-DPA/PANI). The nanocomposite filler was mixed with diglycidyl ether of bisphenol A (DGEBA), and the curing agent (4,4'-diaminodiphenylsulfone) (DDS) at high temperature in order to obtain nanocomposites through the conventional melt mixing technique. The role of B-DPA in the modification of the interface between epoxy and B-DPA/polyaniline (B-DPA/PANI) is investigated and compared with the filler B/PANI prepared without any diazonium modification of the bentonite. Synergistic improvement in dielectric properties and mechanical properties points to the fact that the DPA aryl groups from the diazonium precursor significantly modify the interface by acting as an efficient stress transfer medium. In DPA-containing nanocomposites, unique fibril formation was observed on the fracture surface. Moreover, dramatic improvement (210-220%) in fracture toughness of epoxy composite was obtained with B-DPA/PANI filler as compared to the weak improvement of 20-30% noted in the case of the B/PANI filler. This work shows that the DPA diazonium salt has an important effect on the improvement of the interfacial properties and adhesion of DGEBA and clay/PANI nanofillers.

  9. Weather forecasting based on hybrid neural model

    Science.gov (United States)

    Saba, Tanzila; Rehman, Amjad; AlGhamdi, Jarallah S.

    2017-11-01

    Making deductions and expectations about climate has been a challenge all through mankind's history. Challenges with exact meteorological directions assist to foresee and handle problems well in time. Different strategies have been investigated using various machine learning techniques in reported forecasting systems. Current research investigates climate as a major challenge for machine information mining and deduction. Accordingly, this paper presents a hybrid neural model (MLP and RBF) to enhance the accuracy of weather forecasting. Proposed hybrid model ensure precise forecasting due to the specialty of climate anticipating frameworks. The study concentrates on the data representing Saudi Arabia weather forecasting. The main input features employed to train individual and hybrid neural networks that include average dew point, minimum temperature, maximum temperature, mean temperature, average relative moistness, precipitation, normal wind speed, high wind speed and average cloudiness. The output layer composed of two neurons to represent rainy and dry weathers. Moreover, trial and error approach is adopted to select an appropriate number of inputs to the hybrid neural network. Correlation coefficient, RMSE and scatter index are the standard yard sticks adopted for forecast accuracy measurement. On individual standing MLP forecasting results are better than RBF, however, the proposed simplified hybrid neural model comes out with better forecasting accuracy as compared to both individual networks. Additionally, results are better than reported in the state of art, using a simple neural structure that reduces training time and complexity.

  10. Microwave-Hydrothermal Synthesis of SnO2-CNTs Hybrid Nanocomposites with Visible Light Photocatalytic Activity.

    Science.gov (United States)

    Wu, Shuisheng; Dai, Weili

    2017-03-03

    SnO2 nanoparticles coated on carbon nanotubes (CNTs) were prepared via a simple microwave-hydrothermal route. The as-obtained SnO2-CNTs composites were characterized using X-ray powder diffraction, Raman spectroscopy, and transmission electron microscopy. The photocatalytic activity of as-prepared SnO2-CNTs for degradation of Rhodamine B under visible light irradiation was investigated. The results show that SnO2-CNTs nanocomposites have a higher photocatalytic activity than pure SnO2 due to the rapid transferring of electrons and the effective separation of holes and electrons on SnO2-CNTs.

  11. Optical band gap tuning and electrical properties of polyaniline and its nanocomposites for hybrid solar cell application

    Science.gov (United States)

    Singh, R.; Choudhary, R. B.; Kandulna, R.

    2018-05-01

    Hcl doped conducting polyaniline-CdS nanocomposite has been prepared via In-situ polymerization in which cadmium nitrate was used as a source for cadmium. The structural morphology was investigated using FESEM and the presence of fibrous polyaniline and CdS nanoparticles. The synthesis of CdS and polyaniline was confirmed using the XRD analysis. I-V characteristic was used to explore the electrical behavior of PANI and its nanocoposites. Optical properties were studied and minimum band gap with highest band absorbance was found for synergistic concentration PANI-CdS (10%) for solar cells application.

  12. Development of nanocomposites based on potato starch; Desenvolvimento de nanocompositos a base de amido de batata

    Energy Technology Data Exchange (ETDEWEB)

    Brito, Luciana Macedo; Tavares, Maria Ines Bruno, E-mail: mibt@ima.ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Instituto de Macromoleculas

    2013-07-01

    Nanocomposites of potato starch were prepared by the solution intercalation method with the addition of organically modified montmorillonite clay (Viscogel B and unmodified sodic clay (NT25) as well as modified and unmodified silica (R972 and A200, respectively), using water as the solvent. The nanocomposites were characterized by conventional techniques of X-ray diffraction and thermogravimetric analysis. They were also characterized using the non-conventional low-field nuclear magnetic resonance, which is an effective alternative technique for characterizing nanocomposites. This technique allows one to investigate dispersion of nanofillers by the degree of intercalation and/or exfoliation, in addition to determine the distribution of nanoparticles in the polymer matrix and modifications of the molecular mobility of these fillers. The nanostructured materials obtained with the clays presented good dispersion and formation of mixed nanomaterials, with different degrees of intercalation and exfoliation. The mobility of the material decreased upon adding silica in the starch matrix, which applied to both types of silica. From the TGA technique, a slight increase in thermal stability of the nanocomposite was noted in relation to the starch matrix. (author)

  13. Hybrid Materials Based on Magnetic Layered Double Hydroxides: A Molecular Perspective.

    Science.gov (United States)

    Abellán, Gonzalo; Martí-Gastaldo, Carlos; Ribera, Antonio; Coronado, Eugenio

    2015-06-16

    dielectric strength, to produce two-dimensional nanosheets with atomic thickness that can be used as macromolecular building blocks in the assembly of nanocomposites. We describe how these advantageous properties turn LDHs into excellent vehicles for the preparation of multifunctional materials with increasing levels of complexity. For clarity, the reader will first find a succinct description of the most relevant aspects controlling the magnetism of LDHs followed by their use in the preparation of magnetic hybrids from a molecular perspective. This includes the intercalation anionic species of increasing nuclearity like paramagnetic mononuclear complexes, stimulus-responsive molecular guests, one- and two-dimensional coordination polymers, or even preassembled 2D networks. This approach allows us to evolve from "dual-function" materials with coexistence, for example, of magnetism and superconductivity, to smart materials in which the magnetic or structural properties of the LDH layers can be tuned by applying an external stimulus like light or temperature. We will conclude with a brief look into the promising features offered by magnetic nanocomposites based on LDHs and our views on the most promising directions to be pursued in this context.

  14. Hybrid Power Management-Based Vehicle Architecture

    Science.gov (United States)

    Eichenberg, Dennis J.

    2011-01-01

    Hybrid Power Management (HPM) is the integration of diverse, state-of-the-art power devices in an optimal configuration for space and terrestrial applications (s ee figure). The appropriate application and control of the various power devices significantly improves overall system performance and efficiency. The basic vehicle architecture consists of a primary power source, and possibly other power sources, that provides all power to a common energy storage system that is used to power the drive motors and vehicle accessory systems. This architecture also provides power as an emergency power system. Each component is independent, permitting it to be optimized for its intended purpose. The key element of HPM is the energy storage system. All generated power is sent to the energy storage system, and all loads derive their power from that system. This can significantly reduce the power requirement of the primary power source, while increasing the vehicle reliability. Ultracapacitors are ideal for an HPM-based energy storage system due to their exceptionally long cycle life, high reliability, high efficiency, high power density, and excellent low-temperature performance. Multiple power sources and multiple loads are easily incorporated into an HPM-based vehicle. A gas turbine is a good primary power source because of its high efficiency, high power density, long life, high reliability, and ability to operate on a wide range of fuels. An HPM controller maintains optimal control over each vehicle component. This flexible operating system can be applied to all vehicles to considerably improve vehicle efficiency, reliability, safety, security, and performance. The HPM-based vehicle architecture has many advantages over conventional vehicle architectures. Ultracapacitors have a much longer cycle life than batteries, which greatly improves system reliability, reduces life-of-system costs, and reduces environmental impact as ultracapacitors will probably never need to be

  15. Very High Output Thermoelectric Devices Based on ITO Nanocomposites

    Science.gov (United States)

    Fralick, Gustave; Gregory, Otto J.

    2009-01-01

    A material having useful thermoelectric properties was synthesized by combining indium-tin-oxide (ITO) with a NiCoCrAlY alloy/alumina cermet. This material had a very large Seebeck coefficient with electromotive-force-versustemperature behavior that is considered to be excellent with respect to utility in thermocouples and other thermoelectric devices. When deposited in thin-film form, ceramic thermocouples offer advantages over precious-metal (based, variously, on platinum or rhodium) thermocouples that are typically used in gas turbines. Ceramic thermocouples exhibit high melting temperatures, chemical stability at high temperatures, and little or no electromigration. Oxide ceramics also resist oxidation better than metal thermocouples, cost substantially less than precious-metal thermocouples, and, unlike precious-metal thermocouples, do not exert catalytic effects.

  16. HYDROGEL-BASED NANOCOMPOSITES OF THERAPEUTIC PROTEINS FOR TISSUE REPAIR.

    Science.gov (United States)

    Zhu, Suwei; Segura, Tatiana

    2014-05-01

    The ability to design artificial extracellular matrices as cell instructive scaffolds has opened the door to technologies capable of studying cell fates in vitro and to guide tissue repair in vivo . One main component of the design of artificial extracellular matrices is the incorporation of protein-based biochemical cues to guide cell phenotypes and multicellular organizations. However, promoting the long-term bioactivity, controlling the bioavailability and understanding how the physical presentations of these proteins impacts cellular fates are among the challenges of the field. Nanotechnolgy has advanced to meet the challenges of protein therapeutics. For example, the approaches to incorporating proteins into tissue repairing scaffolds have ranged from bulk encapsulations to smart nanodepots that protect proteins from degradations and allow opportunities for controlled release.

  17. Sensitive electrochemical immunosensor for α-fetoprotein based on graphene/SnO2/Au nanocomposite.

    Science.gov (United States)

    Liu, Junfeng; Lin, Guanhua; Xiao, Can; Xue, Ying; Yang, Ankang; Ren, Hongxuan; Lu, Wensheng; Zhao, Hong; Li, Xiangjun; Yuan, Zhuobin

    2015-09-15

    A label-free electrochemical immunosensor for sensitive detection of α-fetoprotein (AFP) was developed based on graphene/SnO2/Au nanocomposite. The graphene/SnO2/Au nanocomposite modified glassy carbon electrode was used to immobilize α-fetoprotein antibody (anti-AFP) and to construct the immunosensor. Results demonstrated that the peak currents of [Ru(NH3)6](3+) decreased due to the interaction between antibody and antigen on the modified electrode. Thus, a label-free immunosensor for the detection of AFP was realized by monitoring the peak current change of [Ru(NH3)6](3+). The factors influencing the performance of the immunosensor were investigated in details. Under optimal conditions, the peak currents obtained by DPV decreased linearly with the increasing AFP concentrations in the range from 0.02 to 50 ng mL(-1) with a linear coefficient of 0.9959. This electrochemical immunoassay has a low detection limit of 0.01 ng mL(-1) (S/N=3) and was successfully applied to the determination of AFP in serum samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Fabrication and electrical characterizations of graphene nanocomposite thin film based heterojunction diode

    Science.gov (United States)

    Rahim, Ishrat; Shah, Mutabar; Iqbal, Mahmood; Wahab, Fazal; Khan, Afzal; Khan, Shah Haider

    2017-11-01

    The use of graphene in electronic devices is becoming attractive due to its inherent scalability and is thus well suited for flexible electronic devices. Here we present the electrical characterization of heterojunction diode, based on the nanocomposite of graphene (G) with silver nanoparticles (Ag NPs), at room temperature. The diode was fabricated by depositing nanocomposite on the n-Si substrate. The current - voltage (I - V) characteristic of the fabricated junction shows rectifying behavior similar to a Schottky junction. The junction parameters such as ideality factor (n), series resistance (Rs), and barrier height (ϕb) has been extracted, using various methods, from the experimentally obtained I - V data. The measured values of n, Rs and ϕb are 3.86, 45 Ω and 0.367 eV, respectively, as calculated from the I - V curve. The numerical values of these parameters calculated by different methods are in good agreement with each other showing the consistency of the applied calculating techniques. The conduction mechanism of the fabricated diode seems to have been dominated by the Trap Charge Limited Conduction (TCLC) behavior. The energy distribution of interface states density determined from forward bias I - V characteristic shows an exponential decrease with bias from 27 × 1013 cm-2 eV-1 at (Ec - 0.345) eV to 3 × 1013 cm-2 eV-1at (Ec - 0.398) eV.

  19. Label-free aptamer biosensor for thrombin detection based on functionalized graphene nanocomposites.

    Science.gov (United States)

    Wang, Qingqing; Zhou, Zhixue; Zhai, Yanling; Zhang, Lingling; Hong, Wei; Zhang, Zhiquan; Dong, Shaojun

    2015-08-15

    A label-free and amplified electrochemical impedimetric aptasensor based on functionalized graphene nanocomposites (rGO-AuNPs) was developed for the detection of thrombin, which played a vital role in thrombosis and hemostasis. The thiolated aptamer and dithiothreitol (TBA15-DTT) were firstly immobilized on the gold electrode to capture the thrombin molecules, and then aptamer functionalized graphene nanocomposites (rGO-TBA29) were used to fabricate a sandwich sensing platform for amplifying the impedimetric signals. As numerous negative charges of TBA29 on the electrode repelled to the [Fe(CN)6](4-/3-) anions, resulting in an obvious amplified charge-transfer resistance (Rct) signal. The Rct increase was linearly proportional to the thrombin concentration from 0.3 to 50nM and a detection limit of 0.01nM thrombin was achieved. In addition, graphene could also be labeled with other probes via electrostatic or π-π stacking interactions to produce signals, therefore different detection methods expanding wide application could be used in this model. Copyright © 2015. Published by Elsevier B.V.

  20. 3D printable highly conductive and mechanically strong thermoplastic-based nanocomposites

    Science.gov (United States)

    Tabiai, Ilyass; Therriault, Daniel

    Highly conductive 3D printable inks can be used to design electrical devices with various functionalities and geometries. We use the solvent evaporation assisted 3D-printing method to create high resolution structures made of poly(lactid) acid (PLA) reinforced with multi-walled carbon nanotube (MWCNTs). We characterize fibers with diameters ranging between 100 μm to 330 μm and reinforced with MWCNTs from 0.5 up to 40wt% here. Tensile test, shrinkage ratio, density and electrical conductivity measurements of the printed nanocomposite are presented. The material's electrical conductivity is strongly improved by adding MWCNTs (up to 3000S/m), this value was found to be higher than any 3D-printable carbon based material available in the literature. It is observed that MWCNTs significantly increase the material's strength and stiffness while reducing its ductility. The ink's density was also higher while still being in the range of polymers' densities. The presented nanocomposite is light weight, highly conductive, has good mechanical properties and can be printed in a freeform fashion at the micro scale. A myriad of low power consumption with less resistive heating sensors and devices can potentially be designed using it and integrated into other 3D printable products.

  1. Chitosan-iron oxide nanocomposite based electrochemical aptasensor for determination of malathion

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakar, Nirmal, E-mail: nirmalprabhakar@gmail.com; Thakur, Himkusha; Bharti, Anu; Kaur, Navpreet

    2016-10-05

    An electrochemical aptasensor based on chitosan-iron oxide nanocomposite (CHIT-IO) film deposited on fluorine tin Oxide (FTO) was developed for the detection of malathion. Iron oxide nanoparticles were prepared by co-precipitation method and characterized by Transmission electron microscopy and UV–Visible spectroscopy. The biotinylated DNA aptamer sequence specific to the malathion was immobilized onto the iron oxide doped-chitosan/FTO electrode by using streptavidin as linking molecule. Various characterization studies like Field Emission-Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR), and Electrochemical studies were performed to attest the successful fabrication of bioelectrodes. Experimental parameters like aptamer concentration, response time, stability of electrode and reusability studies were optimized. Aptamer immobilized chitosan-iron oxide nanocomposite (APT/SA/CHIT-IO/FTO) bioelectrodes exhibited LOD of about 0.001 ng/mL within 15 min and spike-in studies revealed about 80–92% recovery of malathion from the lettuce leaves and soil sample. - Highlights: • An electrochemical aptasensor for the detection of Malathion has been developed. • Chitosan-iron oxide NP deposited FTO sheets provides platform for aptamer immobilization. • Aptasensor has efficiency to detect malathion upto 0.001 ng/mL within 15 min.

  2. An acetylcholinesterase biosensor based on graphene-gold nanocomposite and calcined layered double hydroxide.

    Science.gov (United States)

    Zhai, Chen; Guo, Yemin; Sun, Xia; Zheng, Yuhe; Wang, Xiangyou

    2014-05-10

    In this study, a novel acetylcholinesterase-based biosensor was fabricated. Acetylcholinesterase (AChE) was immobilized onto a glassy carbon electrode (GCE) with the aid of Cu-Mg-Al calcined layered double hydroxide (CLDH). CLDH can provide a bigger effective surface area for AChE loading, which could improve the precision and stability of AChE biosensor. However, the poor electroconductibility of CLDHs could lead to the low sensitivity of AChE biosensor. In order to effectively compensate the disadvantages of CLDHs, graphene-gold nanocomposites were used for improving the electron transfer rate. Thus, the graphene-gold nanocomposite (GN-AuNPs) was firstly modified onto the GCE, and then the prepared CLDH-AChE composite was immobilized onto the modified GCE to construct a sensitive AChE biosensor for pesticides detection. Relevant parameters were studied in detail and optimized, including the pH of the acetylthiocholine chloride (ATCl) solution, the amount of AChE immobilized on the biosensor and the inhibition time governing the analytical performance of the biosensor. The biosensor detected chlorpyrifos at concentrations ranging from 0.05 to 150μg/L. The detection limit for chlorpyrifos was 0.05μg/L. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. On the Effect of Nanoparticle Surface Chemistry on the Electrical Characteristics of Epoxy-Based Nanocomposites

    Directory of Open Access Journals (Sweden)

    Celia Yeung

    2016-04-01

    Full Text Available The effect of nanosilica surface chemistry on the electrical behavior of epoxy-based nanocomposites is described. The nanosilica was reacted with different volumes of (3-glycidyloxypropyltrimethoxysilane and the efficacy of the process was demonstrated by infrared spectroscopy and combustion analysis. Nanocomposites containing 2 wt % of nanosilica were prepared and characterized by scanning electron microscopy (SEM, AC ramp electrical breakdown testing, differential scanning calorimetry (DSC and dielectric spectroscopy. SEM examination indicated that, although the nanoparticle dispersion improved somewhat as the degree of surface functionalization increased, all samples nevertheless contained agglomerates. Despite the non-ideal nature of the samples, major improvements in breakdown strength (from 182 ± 5 kV·mm−1 to 268 ± 12 kV·mm−1 were observed in systems formulated from optimally treated nanosilicas. DSC studies of the glass transition revealed no evidence for any modified interphase regions between the nanosilica and the matrix, but interfacial effects were evident in the dielectric spectra. In particular, changes in the magnitude of the real part of the permittivity and variations in the interfacial α′-relaxation suggest that the observed changes in breakdown performance stem from variations in the polar character of the nanosilica surface, which may affect the local density of trapping states and, thereby, charge transport dynamics.

  4. Ternary and quaternary nanocomposites based on polystyrene, SBS, organically modified clay and silicone-polyether

    International Nuclear Information System (INIS)

    Kaneko, Manuela L.Q.A.; Lourenco, Emerson; Paiva, Raphael E.F.; Felisberti, Maria I.; Yoshida, Inez V.P.

    2009-01-01

    This work aims the study of toughened nanocomposites based on polystyrene (PS), poly(styrene-b-butadiene-b-styrene) (SBS), organically modified clay (C20A) and silicone-polyether, PDMS-POE. The intercalation of the copolymer PDMS-POE into the clay galleries increased the interlamellar distance, improving the exfoliation of the clay during the extrusion process of the materials. C20A/PDMS-POE nanocomposite, MC20A, was prepared by mechanical mixture using 1:1 wt% ratio. MC20A was incorporated into PS and PS/SBS blends using an extruder. The materials were characterized by X-ray diffraction and stress-strain mechanical tests. MC20A/PS/SBS, prepared by extrusion, showed an increase in the interlamellar distance, suggesting the intercalation of PS or SBS into the clay galleries. The PDMSPOE acted as a 'plasticizer' for PS and PS/SBS blend. However, this effect was not reverted by the clay addition. On the contrary, the 'plasticizer' effect was intensified by the clay maybe due to the slip characteristics of PDMS-POE associated with the lamella orientation. (author)

  5. Integrated nanophotonic hubs based on ZnO-Tb(OH3/SiO2 nanocomposites

    Directory of Open Access Journals (Sweden)

    Lin Yu

    2011-01-01

    Full Text Available Abstract Optical integration is essential for practical application, but it remains unexplored for nanoscale devices. A newly designed nanocomposite based on ZnO semiconductor nanowires and Tb(OH3/SiO2 core/shell nanospheres has been synthesized and studied. The unique sea urchin-type morphology, bright and sharply visible emission bands of lanthanide, and large aspect ratio of ZnO crystalline nanotips make this novel composite an excellent signal receiver, waveguide, and emitter. The multifunctional composite of ZnO nanotips and Tb(OH3/SiO2 nanoparticles therefore can serve as an integrated nanophotonics hub. Moreover, the composite of ZnO nanotips deposited on a Tb(OH3/SiO2 photonic crystal can act as a directional light fountain, in which the confined radiation from Tb ions inside the photonic crystal can be well guided and escape through the ZnO nanotips. Therefore, the output emission arising from Tb ions is truly directional, and its intensity can be greatly enhanced. With highly enhanced lasing emissions in ZnO-Tb(OH3/SiO2 as well as SnO2-Tb(OH3/SiO2 nanocomposites, we demonstrate that our approach is extremely beneficial for the creation of low threshold and high-power nanolaser.

  6. Carbon nanotube ensembled hybrid nanocomposite electrode for direct electrochemical detection of epinephrine in pharmaceutical tablets and urine.

    Science.gov (United States)

    Koteshwara Reddy, K; Satyanarayana, M; Yugender Goud, K; Vengatajalabathy Gobi, K; Kim, Hern

    2017-10-01

    An efficient electrochemical sensor for selective detection of the neurotransmitter, epinephrine (Epn), has been fabricated with the aid of a functionalized multiwall carbon nanotube-chitosan biopolymer nanocomposite (Chit-fCNT) electrode. Multiwall carbon nanotubes (CNT) were successfully functionalized with the aid of nitric acid and confirmed by the Raman spectral data. Functionalized carbon nanotubes (fCNT) were dispersed in chitosan solution and the resulting bio-nanocomposite was used for the fabrication of sensor surface by drop and cast method. Electrochemical characteristics of the fabricated sensor were understood using cyclic, differential pulse voltammetry (CV, DPV) and electrochemical impedance analysis for the detection of Epn in phosphate buffer (pH7.4). CV and impedance analysis revealed that the Chit-fCNT modified electrode enhances the electrodic reaction of Epn and facilitated the electron transfer more readily compared to that of bare electrode. Applying DPV for the detection of Epn, achieved 30nM as the lowest detection limit in the determination range of 0.05-10μM and the analytical time as low as 10s. Selective determination of Epn against the coexistence of a number of biological electroactive interferents and reproducible results for the determination of Epn were demonstrated. The present biosensor has been found efficient for successful direct determination of Epn from pharmaceutical adrenaline formulations and urine samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. The Pulse Thermal Processing of NdFeB-Based Nanocomposite Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Z. Q. [University of Texas; Wang, Z. L. [Georgia Institute of Technology; Liu, J. P. [University of Texas; Kadolkar, Puja [ORNL; Ott, Ronald D [ORNL

    2006-01-01

    Pulse-thermal processing (PTP) based on high-density plasma arc lamp technology has been utilized to crystallize melt-spun NdFeB-based amorphous ribbons to form magnetic nanocomposites consisting of Nd{sub 2}Fe{sub 14}B and {alpha}-Fe phases. After applying suitable pulses, the NdFeB-based ribbons were developed with hard magnetic properties. The highest coercivity can be obtained for ribbons with a thickness of 40 {micro}m after PTP treatments consisting of a 400 A pulse for 0.25 s for ten times. The correlation between PTP parameters and magnetic properties indicates that PTP is an effective approach to control the structure and properties of nanostructured magnetic materials.

  8. Fabrication and in vitro degradation of porous fumarate-based polymer/alumoxane nanocomposite scaffolds for bone tissue engineering.

    NARCIS (Netherlands)

    Mistry, A.S.; Cheng, S.H.; Yeh, T.; Christenson, E.; Jansen, J.A.; Mikos, A.G.

    2009-01-01

    In this work, the fabrication and in vitro degradation of porous fumarate-based/alumoxane nanocomposites were evaluated for their potential as bone tissue engineering scaffolds. The biodegradable polymer poly (propylene fumarate)/propylene fumarate-diacrylate (PPF/PF-DA), a macrocomposite composed

  9. Adsorption of methyl violet from aqueous solution using gum xanthan/Fe3O4 based nanocomposite hydrogel

    CSIR Research Space (South Africa)

    Mittal, H

    2016-08-01

    Full Text Available This research paper reports the utilization of gum xanthan-grafted-polyacrylic acid and Fe(sub3)O(sub4) magnetic nanoparticles based nanocomposite hydrogel (NCH) for the highly effective adsorption of methyl violet (MV) from aqueous solution...

  10. A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B

    International Nuclear Information System (INIS)

    Bagheri, Habib; Daliri, Rasoul; Roostaie, Ali

    2013-01-01

    Graphical abstract: -- Highlights: •A Fe 3 O 4 –aniline-naphthylamine nanocomposite was prepared via a simple route. •The magnetic nanocomposite was applied for isolation of RhB from water. •The nanocomposite applicability was compared with other pristine polymers. •The method was applied for the determination of RhB in different samples. -- Abstract: A novel Fe 3 O 4 –poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50 nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe 3 O 4 /poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample pH, ionic strength, extraction time and stirring rate were optimized. Under the optimum condition, a linear spiked calibration curve in the range of 0.35–5.00 μg L −1 with R 2 = 0.9991 was obtained. The limits of detection (3S b ) and limits of quantification (10S b ) of the method were 0.10 μg L −1 and 0.35 μg L −1 (n = 3), respectively. The relative standard deviation for water sample with 0.5 μg L −1 of RhB was 4.2% (n = 5) and the absolute recovery was 92%. The method was applied for the determination of rhodamine B in dishwashing foam, dishwashing liquid, shampoo, pencil, matches tips and eye shadows samples and the relative recovery percentage were in the range of 94–99%

  11. A potential bioactive wound dressing based on carboxymethyl cellulose/ZnO impregnated MCM-41 nanocomposite hydrogel.

    Science.gov (United States)

    Rakhshaei, Rasul; Namazi, Hassan

    2017-04-01

    Lack of antibacterial activity, deficient water vapor and oxygen permeability, and insufficient mechanical properties are disadvantages of existing wound dressings. Hydrogels could absorb wound exudates due to their strong swelling ratio and give a cooling sensation and a wet environment. To overcome these shortcomings, flexible nanocomposite hydrogel films was prepared through combination of zinc oxide impregnated mesoporous silica (ZnO-MCM-41) as a nano drug carrier with carboxymethyl cellulose (CMC) hydrogel. Citric acid was used as cross linker to avoid the cytotoxicity of conventional cross linkers. The prepared nanocomposite hydrogel was characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Zeta potential and UV-vis spectroscopy. Results of swelling and erosion tests showed CMC/ZnO nanocomposite hydrogel disintegrated during the first hours of the test. Using MCM-41 as a substrate for ZnO nanoparticles solved this problem and the CMC/ZnO-MCM-41 showed a great improvement in tensile strength (12%), swelling (100%), erosion (53%) and gas permeability (500%) properties. Drug delivery and antibacterial properties of the nanocomposite hydrogel films studied using tetracycline (TC) as a broad spectrum antibiotic and showed a sustained TC release. This could efficiently decrease bandage exchange. Cytocompatibility of the nanocomposite hydrogel films has been analyzed in adipose tissue-derived stem cells (ADSCs) and results showed cytocompatibility of CMC/ZnO-MCM-41. Based on these results the prepared CMC nanocomposite hydrogel containing ZnO impregnated MCM-41, could serve as a kind of promising wound dressing with sustained drug delivery properties. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Effects of thermal treatment on the structure and luminescent properties of Eu3+ doped SiO2–PMMA hybrid nanocomposites prepared by a sol–gel process

    International Nuclear Information System (INIS)

    Jesus, Filipe Augusto de; Tarse Sobrinho Santos, Simei; Caiut, José Maurício Almeida; Sarmento, Victor Hugo Vitorino

    2016-01-01

    Hybrid nanocomposites are multifunctional materials and their properties are the consequence of molecular interaction between inorganic and organic phases. These materials are interesting hosts for lanthanide ions, such as Eu 3+ . The purpose of this research was to synthesize Eu 3+ doped SiO 2 –PMMA hybrid nanocomposites by a sol–gel process and to study the effects of thermal treatment on the structure and luminescent properties of the material. Structural characterization was carried out using the FTIR, TG and 29 Si NMR techniques, however, the luminescence studies were more sensitive to detect the slight structural changes resulting from the thermal treatment. The Eu 3+ ions inserted into the matrix behaved as a structural probe and make it possible to notice the symmetry change from Eu 3+ site, the decrease in the number of hydroxyl coordinated groups and the improvement in quantum efficiency as a result of the thermal treatment. In addition, the Judd–Ofelt intensity parameters were obtained and supported the interaction between the rare earth and hybrid material. The hybrid was obtained as a stable material until 200 °C and the high sensitivity of the Eu 3+ ions in the system may be used in future applications as thermal sensors, for example. - Highlights: • Eu 3+ -doped SiO 2 –PMMA hybrid nanocomposites were synthesized through a sol–gel process. • FTIR, NMR and TG techniques were used to structural characterization of the material. • Luminescence analysis showed changes in Eu 3+ coordination sphere caused by thermal treatments. • Thermal treatments increase the interaction between the lanthanide ions and the host. • There was a huge improvement in the quantum efficiency of Eu 3+ in heat treated sample.

  13. Effects of thermal treatment on the structure and luminescent properties of Eu{sup 3+} doped SiO{sub 2}–PMMA hybrid nanocomposites prepared by a sol–gel process

    Energy Technology Data Exchange (ETDEWEB)

    Jesus, Filipe Augusto de; Tarse Sobrinho Santos, Simei [Departamento de Química, Universidade Federal de Sergipe, Av. Vereador Olímpio Grande s/n, Centro, Itabaiana, SE (Brazil); Caiut, José Maurício Almeida [Departamento de Química, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, 14040-901 Ribeirão Preto, SP (Brazil); Sarmento, Victor Hugo Vitorino, E-mail: vhsarmento@ufs.br [Departamento de Química, Universidade Federal de Sergipe, Av. Vereador Olímpio Grande s/n, Centro, Itabaiana, SE (Brazil)

    2016-02-15

    Hybrid nanocomposites are multifunctional materials and their properties are the consequence of molecular interaction between inorganic and organic phases. These materials are interesting hosts for lanthanide ions, such as Eu{sup 3+}. The purpose of this research was to synthesize Eu{sup 3+} doped SiO{sub 2}–PMMA hybrid nanocomposites by a sol–gel process and to study the effects of thermal treatment on the structure and luminescent properties of the material. Structural characterization was carried out using the FTIR, TG and {sup 29}Si NMR techniques, however, the luminescence studies were more sensitive to detect the slight structural changes resulting from the thermal treatment. The Eu{sup 3+} ions inserted into the matrix behaved as a structural probe and make it possible to notice the symmetry change from Eu{sup 3+} site, the decrease in the number of hydroxyl coordinated groups and the improvement in quantum efficiency as a result of the thermal treatment. In addition, the Judd–Ofelt intensity parameters were obtained and supported the interaction between the rare earth and hybrid material. The hybrid was obtained as a stable material until 200 °C and the high sensitivity of the Eu{sup 3+} ions in the system may be used in future applications as thermal sensors, for example. - Highlights: • Eu{sup 3+}-doped SiO{sub 2}–PMMA hybrid nanocomposites were synthesized through a sol–gel process. • FTIR, NMR and TG techniques were used to structural characterization of the material. • Luminescence analysis showed changes in Eu{sup 3+} coordination sphere caused by thermal treatments. • Thermal treatments increase the interaction between the lanthanide ions and the host. • There was a huge improvement in the quantum efficiency of Eu{sup 3+} in heat treated sample.

  14. Polymer/organosilica nanocomposites based on polyimide with benzimidazole linkages and reactive organoclay containing isoleucine amino acid: Synthesis, characterization and morphology properties

    International Nuclear Information System (INIS)

    Mallakpour, Shadpour; Dinari, Mohammad

    2012-01-01

    Highlights: ► A reactive organoclay was formed using L-isoleucine amino acid as a swelling agent. ► Polyimide was synthesized from benzimidazole diamine and pyromellitic dianhydride. ► Imide and benzimidazole groups assured the thermal stability of the nanocomposites. ► Nanocomposite films were prepared by an in situ polymerization reaction. ► The TEM micrographs of nanocomposites revealed well-exfoliated structures. -- Abstract: Polyimide–silica nanocomposites are attractive hybrid architectures that possess excellent mechanical, thermal and chemical properties. But, the dispersion of inorganic domains in the polymer matrix and the compatibility between the organic and inorganic phases are critical factors in these hybrid systems. In this investigation, a reactive organoclay was prepared via ion exchange reaction between protonated form of difunctional L-isoleucine amino acid as a swelling agent and Cloisite Na + montmorillonite. Amine functional groups of this swelling agent formed an ionic bond with the negatively charged silicates, whereas the remaining acid functional groups were available for further interaction with polymer chains. Then organo-soluble polyimide (PI) have been successfully synthesized from the reaction of 2-(3,5-diaminophenyl)-benzimidazole and pyromellitic dianhydride in N,N-dimethylacetamide. Finally, PI/organoclay nanocomposite films enclosing 1%, 3%, 5%, 7% and 10% of synthesized organoclay were successfully prepared by an in situ polymerization reaction through thermal imidization. The synthesized hybrid materials were subsequently characterized by Fourier transform infrared spectroscopy, X-ray diffraction, electron microscopy, and thermogravimetric analysis techniques. The PI/organoclay nanocomposite films have good optical transparencies and the mechanical properties were substantially improved by the incorporation of the reactive organoclay.

  15. Enhancing performances of a resistivity-type hydrogen sensor based on Pd/SnO2/RGO nanocomposites.

    Science.gov (United States)

    Peng, Yitian; Zheng, Lulu; Zou, Kun; Li, Cong

    2017-05-26

    Palladium/tin oxide/reduced graphene oxide (Pd/SnO 2 /RGO) nanocomposites with Pd and SnO 2 crystalline nanoparticles of high density and uniformity coated on RGO have been synthesized by a two-step reduction process. A novel hydrogen (H 2 ) sensor based on Pd/SnO 2 /RGO nanocomposites was fabricated by placing Pd/SnO 2 /RGO nanocomposites onto a pair of gold electrodes. The Pd/SnO 2 /RGO nanocomposite-based sensor exhibited higher responses than Pd/RGO to H 2 because the introduction of SnO 2 nanoparticles enhances H 2 adsorption and forms a P-N junction with RGO. The sensor shows a high response of 55% to 10 000 ppm H 2 , and a low detection limit, fast response, good selectivity and repeatability due to a combination effect of the Pd and SnO 2 nanoparticles. The studies provide a novel strategy for great potential applications of graphene-based gas sensors.

  16. An Effective Way to Optimize the Functionality of Graphene-Based Nanocomposite: Use of the Colloidal Mixture of Graphene and Inorganic Nanosheets

    Science.gov (United States)

    Jin, Xiaoyan; Adpakpang, Kanyaporn; Young Kim, In; Mi Oh, Seung; Lee, Nam-Suk; Hwang, Seong-Ju

    2015-06-01

    The best electrode performance of metal oxide-graphene nanocomposite material for lithium secondary batteries can be achieved by using the colloidal mixture of layered CoO2 and graphene nanosheets as a precursor. The intervention of layered CoO2 nanosheets in-between graphene nanosheets is fairly effective in optimizing the pore and composite structures of the Co3O4-graphene nanocomposite and also in enhancing its electrochemical activity via the depression of interaction between graphene nanosheets. The resulting CoO2 nanosheet-incorporated nanocomposites show much greater discharge capacity of ~1750 mAhg-1 with better cyclability and rate characteristics than does CoO2-free Co3O4-graphene nanocomposite (~1100 mAhg-1). The huge discharge capacity of the present nanocomposite is the largest one among the reported data of cobalt oxide-graphene nanocomposite. Such a remarkable enhancement of electrode performance upon the addition of inorganic nanosheet is also observed for Mn3O4-graphene nanocomposite. The improvement of electrode performance upon the incorporation of inorganic nanosheet is attributable to an improved Li+ ion diffusion, an enhanced mixing between metal oxide and graphene, and the prevention of electrode agglomeration. The present experimental findings underscore an efficient and universal role of the colloidal mixture of graphene and redoxable metal oxide nanosheets as a precursor for improving the electrode functionality of graphene-based nanocomposites.

  17. Synthesis of nanocomposite coating based on TiO2/ZnAl layer double hydroxides

    International Nuclear Information System (INIS)

    Jovanov, V.; Rudic, O.; Ranogajec, J.; Fidanchevska, E.

    2017-01-01

    The aim of this investigation was the synthesis of nanocomposite coatings based on Zn-Al layered double hydroxides (Zn-Al LDH) and TiO2. The Zn-Al LDH material, which acted as the catalyst support of the active TiO2 component (in the content of 3 and 10 wt. %), was synthesized by a low super saturation co-precipitation method. The interaction between the Zn-Al LDH and the active TiO2 component was accomplished by using vacuum evaporation prior to the mechanical activation and only by mechanical activation. The final suspension based on Zn-Al LDH and 10wt. % TiO2, impregnated only by mechanical activation, showed the optimal characteristics from the aspect of particle size distribution and XRD analysis. These properties had a positive effect on the functional properties of the coatings (photocatalytic activity and self-cleaning efficiency) after the water rinsing procedure. [es

  18. Conducting polyamine nanocomposites development

    International Nuclear Information System (INIS)

    Nascimento, R.C.; Maciel, T.C.G.L.; Guimaraes, M.J.O.C.; Garcia, M.E.F.

    2010-01-01

    Polymeric nanocomposites are hybrid materials formed by the combination of inorganic nanoparticles dispersed in a polymeric matrix with, at least, one dimension in the nanometer range. It was used as nanoparticles layered and tubular clay minerals, and its insertion and dispersion were conducted through the in situ polymerization technique. As the polymer matrix, it was utilized a polyamine, which, later, will be inserted in a polyacrylamide gel for the development of a compound that aggregates both main characteristics. The nanocomposites were prepared in different polymerization conditions (temperature, concentration and nanoparticle type) and characterized by XRD and FTIR. It was observed that regarding the polymerization conditions, the temperature had influence on the kind of material obtained and on the reaction speed; the type of nanoparticle affected its interaction with the polymer matrix, predominantly providing the formation of nanocomposites by the intercalation mechanism in the layered clay. (author)

  19. Characterization of synthesized polyurethane/montmorillonite nanocomposites foams

    International Nuclear Information System (INIS)

    Ansari, Farahnaz; Njuguna, James; Sachse, Sophia; Kavosh, Masoud; Michalowski, S; Pielichowski, Krzysztof

    2014-01-01

    Nanophased hybrid composites based on polyurethane/montmorillonite (PU/MMT) have been fabricated. The nanocomposite which was formed by the addition of a polyol premix with 4,4'-diphenylmethane diisocyanate to obtain nanophased polyurethane foams which were then used for fabrication of nanocomposite panels has been shown to have raised strength, stiffness and thermal insulation properties. The nanophased polyurethane foam was characterized by means of scanning electron microscope (SEM), transmission electron microscope (TEM) measurements and X-ray diffraction (XRD). TEM and SEM analysis indicated that nanophased particles are dispersed homogeneously in the polyurethane matrix on the nanometer scale indicating that PU/MMT is an intercalated nanocomposite with a 2-3 nm nanolayer thickness

  20. Performance analysis of switching based hybrid FSO/RF transmission

    KAUST Repository

    Usman, Muneer

    2014-09-01

    Hybrid free space optical (FSO)/ radio frequency (RF) systems have emerged as a promising solution for high data rate wireless back haul.We present and analyze a switching based transmission scheme for hybrid FSO/RF system. Specifically, either FSO or RF link will be active at a certain time instance, with FSO link enjoying a higher priority. Analytical expressions have been obtained for the outage probability, average bit error rate and ergodic capacity for the resulting system. Numerical examples are presented to compare the performance of the hybrid scheme with FSO only scenario.

  1. Performance analysis of switching based hybrid FSO/RF transmission

    KAUST Repository

    Usman, Muneer; Yang, Hongchuan; Alouini, Mohamed-Slim

    2014-01-01

    Hybrid free space optical (FSO)/ radio frequency (RF) systems have emerged as a promising solution for high data rate wireless back haul.We present and analyze a switching based transmission scheme for hybrid FSO/RF system. Specifically, either FSO or RF link will be active at a certain time instance, with FSO link enjoying a higher priority. Analytical expressions have been obtained for the outage probability, average bit error rate and ergodic capacity for the resulting system. Numerical examples are presented to compare the performance of the hybrid scheme with FSO only scenario.

  2. Bond graph model-based fault diagnosis of hybrid systems

    CERN Document Server

    Borutzky, Wolfgang

    2015-01-01

    This book presents a bond graph model-based approach to fault diagnosis in mechatronic systems appropriately represented by a hybrid model. The book begins by giving a survey of the fundamentals of fault diagnosis and failure prognosis, then recalls state-of-art developments referring to latest publications, and goes on to discuss various bond graph representations of hybrid system models, equations formulation for switched systems, and simulation of their dynamic behavior. The structured text: • focuses on bond graph model-based fault detection and isolation in hybrid systems; • addresses isolation of multiple parametric faults in hybrid systems; • considers system mode identification; • provides a number of elaborated case studies that consider fault scenarios for switched power electronic systems commonly used in a variety of applications; and • indicates that bond graph modelling can also be used for failure prognosis. In order to facilitate the understanding of fault diagnosis and the presented...

  3. Preferable removal of phosphate from water using hydrous zirconium oxide-based nanocomposite of high stability.

    Science.gov (United States)

    Chen, Liang; Zhao, Xin; Pan, Bingcai; Zhang, Weixian; Hua, Ming; Lv, Lu; Zhang, Weiming

    2015-03-02

    In this study, we employed a new nanocomposite adsorbent HZO-201, which featured high stability under varying solution chemistry, for preferable removal of phosphate from synthetic solution and a real effluent. An anion exchange resin (D-201) was employed as the host of HZO-201, where nano-hydrous zirconium oxide (HZO) was encapsulated as the active species. D-201 binds phosphate through nonspecific electrostatic affinity, whereas the loaded HZO nanoparticles capture phosphate through formation of the inner-sphere complexes. Quantitative contribution of both species to phosphate adsorption was predicted based on the double-Langmuir model. Preferable removal of phosphate by HZO-201 was observed in the presence of the competing anions at higher levels (Cl(-), NO3(-), SO4(2-), HCO3(-)). Fixed-bed adsorption indicated that the effective volume capacity of a synthetic water (2.0 mg P-PO4(3-)/L) by using HZO-201 was ∼1600 BV in the first run (<0.5mg P-PO4(3-)/L), comparable to Fe(III)-based nanocomposite HFO-201 (∼1500 BV) and much larger than D-201 (<250 BV). The exhausted HZO-201 can be in situ regenerated by using a binary NaOH-NaCl solution for cyclic runs, whether fed with the synthetic solution or real effluent. In general, HZO-201 is a promising alternative to Fe(III)-based adsorbents for trace phosphate removal from effluent particularly at acidic pH. Copyright © 2014 Elsevier B.V. All rights reserved.

  4. Self-assembly of multiferroic core-shell particulate nanocomposites through DNA-DNA hybridization and magnetic field directed assembly of superstructures

    Energy Technology Data Exchange (ETDEWEB)

    Sreenivasulu, Gollapudi; Srinivasan, Gopalan, E-mail: srinivas@oakland.edu, E-mail: chavez@oakland.edu [Department of Physics, Oakland University, Rochester, MI 48309-4401 (United States); Lochbiler, Thomas A.; Panda, Manashi; Chavez, Ferman A., E-mail: srinivas@oakland.edu, E-mail: chavez@oakland.edu [Department of Chemistry, Oakland University, Rochester, MI 48309-4401 (United States)

    2016-04-15

    Multiferroic composites of ferromagnetic and ferroelectric phases are of importance for studies on mechanical strain mediated coupling between the magnetic and electric subsystems. This work is on DNA-assisted self-assembly of superstructures of such composites with nanometer periodicity. The synthesis involved oligomeric DNA-functionalized ferroelectric and ferromagnetic nanoparticles, 600 nm BaTiO{sub 3} (BTO) and 200 nm NiFe{sub 2}O{sub 4} (NFO), respectively. Mixing BTO and NFO particles, possessing complementary DNA sequences, resulted in the formation of ordered core-shell heteronanocomposites held together by DNA hybridization. The composites were imaged by scanning electron microscopy and scanning microwave microscopy. The presence of heteroassemblies along with core-shell architecture is clearly observed. The reversible nature of the DNA hybridization allows for restructuring the composites into mm-long linear chains and 2D-arrays in the presence of a static magnetic field and ring-like structures in a rotating-magnetic field. Strong magneto-electric (ME) coupling in as-assembled composites is evident from static magnetic field H induced polarization and low-frequency magnetoelectric voltage coefficient measurements. Upon annealing the nanocomposites at high temperatures, evidence for the formation of bulk composites with excellent cross-coupling between the electric and magnetic subsystems is obtained by H-induced polarization and low-frequency ME voltage coefficient. The ME coupling strength in the self-assembled composites is measured to be much stronger than in bulk composites with randomly distributed NFO and BTO prepared by direct mixing and sintering.

  5. Multidimensional Nanocomposites of Epoxy Reinforced with 1D and 2D Carbon Nanostructures for Improve Fracture Resistance

    Directory of Open Access Journals (Sweden)

    Juventino López-Barroso

    2018-03-01

    Full Text Available A hybrid nanocomposites based on epoxy reinforced with a combination of 1D and 2D carbon nanomaterials for improving impact resistance are reported. Multi-walled carbon nanotubes and oxidized-multi-walled carbon nanotubes are used as 1D nanoreinforcements, and graphene derivative materials such as graphene oxide and reduced graphene oxide are utilized as 2D nanoreinforcements. In this research, the impact resistance of epoxy matrix reinforced with 1D or 2D and the mixture of both nanomaterials is studied. The research is focused on evaluation of the influence of adding different combinations of nanomaterials into epoxy resin and their Izod impact response. Moreover, fracture surface of nanocomposites is observed by scanning electron microscopy. Images show differences between the surfaces of brittle nature on thermoset epoxy polymer and tough nanocomposites. Synergy created with 1D and 2D nanomaterials produces stable dispersions in the processing, reflected in the interface. The interactions in nanocomposites are evidenced by infrared spectra, principally on the peaks related to oxygenated functional groups present in nanomaterials and absent in polymer matrix. Consequently, an increase of 138% in fracture strength of nanocomposites is exhibited, in comparison to the neat epoxy matrix. In addition, hybrid nanocomposites were synthesized in two different methods to evaluate the influence of manufacturing method on final properties of nanocomposites.

  6. Thermoelectric-pyroelectric hybrid energy generation from thermopower waves in core-shell structured carbon nanotube-PZT nanocomposites.

    Science.gov (United States)

    Yeo, Taehan; Hwang, Hayoung; Shin, Dongjoon; Seo, Byungseok; Choi, Wonjoon

    2017-02-10

    There is an urgent need to develop a suitable energy source owing to the rapid development of various innovative devices using micro-nanotechnology. The thermopower wave (TW), which produces a high specific power during the combustion of solid fuel inside micro-nanostructure materials, is a unique energy source for unusual platforms that cannot use conventional energy sources. Here, we report on the significant enhancement of hybrid energy generation of pyroelectrics and thermoelectrics from TWs in carbon nanotube (CNT)-PZT (lead zirconate titanate, P(Z 0.5 -T 0.5 )) composites for the first time. Conventional TWs use only charge carrier transport driven by the temperature gradient along the core materials to produce voltage. In this study, a core-shell structure of CNTs-PZTs was prepared to utilize both the temperature gradient along the core material (thermoelectrics) and the dynamic change in the temperature of the shell structure (pyroelectrics) induced by TWs. The dual mechanism of energy generation in CNT-PZT composites amplified the average peak and duration of the voltage up to 403 mV and 612 ms, respectively, by a factor of 2 and 60 times those for the composites without a PZT layer. Furthermore, dynamic voltage measurements and structural analysis in repetitive TWs confirmed that CNT-PZT composites maintain the original performance in multiple TWs, which improves the reusability of materials. The advanced TWs obtained by the application of a PZT layer as a pyroelectric material contributes to the extension of the usable energy portion as well as the development of TW-based operating devices.

  7. Bio-hybrid silk fibroin/calcium phosphate/PLGA nanocomposite scaffold to control the delivery of vascular endothelial growth factor

    International Nuclear Information System (INIS)

    Farokhi, Mehdi; Mottaghitalab, Fatemeh; Shokrgozar, Mohammad Ali; Ai, Jafar; Hadjati, Jamshid; Azami, Mahmoud

    2014-01-01

    This study investigated the efficacy of bio-hybrid silk fibroin/Calcium phosphate/PLGA nanocomposite scaffold as vascular endothelial growth factor (VEGF) delivery system. The scaffold was fabricated using freeze-drying and electrospinning. Here, we highlight the structural changes of the scaffold using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and differential scanning calorimetry (DSC). The uniform dispersion of calcium phosohate (CaP) powder within silk fibroin (SF) solution was also confirmed using Zeta potential analysis. Moreover, good biocompatibility of osteoblast cells next to the scaffold was approved by cell adhesion, proliferation and alkaline phosphatase production. The release profile of VEGF during 28 days has established the efficacy of the scaffold as a sustained delivery system. The bioactivity of the released VEGF was maintained about 83%. The histology analysis has shown that the new bone tissue formation happened in the defected site after 10 weeks of implantation. Generally, our data showed that the fabricated scaffold could be considered as an effective scaffold for bone tissue engineering applications. - Highlights: • Silk fibroin/calcium phosphate/PLGA scaffold was successfully fabricated using freeze-drying and electrospinning. • The scaffold could control the release of VEGF during 28 days. • The bioactivity of electrospun VEGF was above 80%. • VEGF loaded scaffold could induce bone regeneration after 10 weeks in rabbit

  8. Bio-hybrid silk fibroin/calcium phosphate/PLGA nanocomposite scaffold to control the delivery of vascular endothelial growth factor

    Energy Technology Data Exchange (ETDEWEB)

    Farokhi, Mehdi, E-mail: mehdi13294@yahoo.com [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Mottaghitalab, Fatemeh, E-mail: fatemeh.motaghi@gmail.com [Department of Nanobiotechnology, Faculty of Biological Sciences, Tarbiat Modares University (TMU), Tehran (Iran, Islamic Republic of); Shokrgozar, Mohammad Ali, E-mail: mashokrgozar@pasteur.ac.ir [National Cell Bank of Iran, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Ai, Jafar, E-mail: jafar_ai@tums.ac.ir [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Hadjati, Jamshid; Azami, Mahmoud [Department of Tissue Engineering, School of Advanced Technologies in Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)

    2014-02-01

    This study investigated the efficacy of bio-hybrid silk fibroin/Calcium phosphate/PLGA nanocomposite scaffold as vascular endothelial growth factor (VEGF) delivery system. The scaffold was fabricated using freeze-drying and electrospinning. Here, we highlight the structural changes of the scaffold using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and differential scanning calorimetry (DSC). The uniform dispersion of calcium phosohate (CaP) powder within silk fibroin (SF) solution was also confirmed using Zeta potential analysis. Moreover, good biocompatibility of osteoblast cells next to the scaffold was approved by cell adhesion, proliferation and alkaline phosphatase production. The release profile of VEGF during 28 days has established the efficacy of the scaffold as a sustained delivery system. The bioactivity of the released VEGF was maintained about 83%. The histology analysis has shown that the new bone tissue formation happened in the defected site after 10 weeks of implantation. Generally, our data showed that the fabricated scaffold could be considered as an effective scaffold for bone tissue engineering applications. - Highlights: • Silk fibroin/calcium phosphate/PLGA scaffold was successfully fabricated using freeze-drying and electrospinning. • The scaffold could control the release of VEGF during 28 days. • The bioactivity of electrospun VEGF was above 80%. • VEGF loaded scaffold could induce bone regeneration after 10 weeks in rabbit.

  9. Antifouling activities of β-cyclodextrin stabilized peg based silver nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Punitha, N., E-mail: punithasan@gmail.com [Department of Physics, St. Joseph’s College of Engineering, Chennai 600119 (India); Saravanan, P. [Department of Chemistry, St. Joseph’s College of Engineering, Chennai 600119 (India); Mohan, R. [Department of Physics, Surya College of Engineering and Technology, Villupuram (India); Ramesh, P.S. [Department of Physics (DDE), Annamalai University, Annamalai Nagar 608002 (India)

    2017-01-15

    Highlights: • Simple, novel and cost effective. • Functionalized Ag nanocomposites exhibit enhanced biological activity. • The SNCs were crystalline nature and shows good stability. - Abstract: Self-polishing polymer composites which release metal biocide in a controlled rate have been widely used in the design of antimicrobial agents and antifouling coatings. The present work focuses on the environmental friendly green synthesis of PEG based SNCs and their application to biocidal activity including marine biofouling. Biocompatible polymer β-CD and adhesive resistance polymer PEG were used to functionalize the SNPs and the as synthesized SNCs exhibit excellent micro fouling activities. The structural and optical properties were confirmed by XRD and UV–visible techniques respectively. The particle surface and cross sectional characteristics were examined by SEM-EDS, HR-TEM, AFM and FTIR. The surface potential was evaluated using ZP analysis and assessment of antibiofouling property was investigated using static immersion method.

  10. High efficiency nanocomposite sorbents for CO2 capture based on amine-functionalized mesoporous capsules

    KAUST Repository

    Qi, Genggeng; Wang, Yanbing; Estevez, Luis; Duan, Xiaonan; Anako, Nkechi; Park, Ah-Hyung Alissa; Li, Wen; Jones, Christopher W.; Giannelis, Emmanuel P.

    2011-01-01

    A novel high efficiency nanocomposite sorbent for CO2 capture has been developed based on oligomeric amine (polyethylenimine, PEI, and tetraethylenepentamine, TEPA) functionalized mesoporous silica capsules. The newly synthesized sorbents exhibit extraordinary capture capacity up to 7.9 mmol g-1 under simulated flue gas conditions (pre-humidified 10% CO 2). The CO2 capture kinetics were found to be fast and reached 90% of the total capacities within the first few minutes. The effects of the mesoporous capsule features such as particle size and shell thickness on CO2 capture capacity were investigated. Larger particle size, higher interior void volume and thinner mesoporous shell thickness all improved the CO2 capacity of the sorbents. PEI impregnated sorbents showed good reversibility and stability during cyclic adsorption-regeneration tests (50 cycles). © 2011 The Royal Society of Chemistry.

  11. Organophilic bentonites based on Argentinean and Brazilian bentonites: part 2: potential evaluation to obtain nanocomposites

    Directory of Open Access Journals (Sweden)

    L. B. Paiva

    2012-12-01

    Full Text Available This work describes the preparation of composites of polypropylene and organophilic bentonites based on Brazilian and Argentinean bentonites. During the processing of the samples in a twin screw microextruder, torque and pressures of the extruder were accompanied and the viscosity values were calculated. No significant changes in the torque, pressure and viscosity were found for composites prepared with different bentonites. The samples were characterized by XRD and TEM to evaluate the structure and dispersion of the organophilic bentonites. Composites with exfoliated, partially exfoliated and intercalated structures were obtained and correlations between the intrinsic properties of the sodium clays and organophilic bentonites and their influence on the composites were studied. The cation exchange capacity of the sodium bentonites and the swelling capacity of the organophilic bentonites were the most important properties to obtain exfoliated structures in composites. All bentonites showed the potential to obtain polymer nanocomposites, but the ones from Argentina displayed the best results.

  12. Development of novel nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric.

    Science.gov (United States)

    Bondar, Yuliia; Kuzenko, Svetlana; Han, Do-Hung; Cho, Hyun-Kug

    2014-01-01

    A nanocomposite adsorbent based on potassium nickel hexacyanoferrate-loaded polypropylene fabric was synthesized for selective removal of Cs ions from contaminated waters by a two-stage synthesis: radiation-induced graft polymerization of acrylic acid monomer onto the nonwoven polypropylene fabric surface with subsequent in situ formation of potassium nickel hexacyanoferrate (KNiHCF) nanoparticles within the grafted chains. Data of scanning electron microscopy, X-ray diffraction, and Fourier transform infrared spectroscopy confirmed the formation of KNiHCF homogeneous phase on the fabric surface, which consisted of crystalline cubic-shaped nanoparticles (70 to 100 nm). The efficiency of the synthesized adsorbent for removal of cesium ions was evaluated under various experimental conditions. It has demonstrated a rapid adsorption process, high adsorption capacity over a wide pH range, and selectivity in Cs ion removal from model solutions with high concentration of sodium ions.

  13. Mechanical and thermomechanical properties of polycarbonate-based polyurethane-silica nanocomposites

    Directory of Open Access Journals (Sweden)

    Rafał Poręba

    2011-09-01

    Full Text Available In this work aliphatic polycarbonate-based polyurethane-silica nanocomposites were synthesized and characterized. The influence of the type and of the concentration of nanofiller differing in average particle size (7 nm for Aerosil 380 and 40 nm for Nanosilica 999 on mechanical and thermomechanical properties was investigated. DMTA measurements showed that Nanosilica 999, irrespective of its concentration, slightly increased the value of the storage shear modulus G’ but Aerosil 380 brings about a nearly opposite effect, the shear modulus in the rubber region decreases with increasing filler content. Very high elongations at break ranging from 800% to more than 1000%, as well as high tensile strengths illustrate excellent ultimate tensile properties of the prepared samples. The best mechanical and thermomechanical properties were found for the sample filled with 0.5 wt.% of Nanosilica 999.

  14. Effect of Graphene Nanoplatelets on the Physical and Antimicrobial Properties of Biopolymer-Based Nanocomposites

    Directory of Open Access Journals (Sweden)

    Roberto Scaffaro

    2016-05-01

    Full Text Available In this work, biopolymer-based nanocomposites with antimicrobial properties were prepared via melt-compounding. In particular, graphene nanoplatelets (GnPs as fillers and an antibiotic, i.e., ciprofloxacin (CFX, as biocide were incorporated in a commercial biodegradable polymer blend of poly(lactic acid (PLA and a copolyester (BioFlex®. The prepared materials were characterized by scanning electron microscopy (SEM, and rheological and mechanical measurements. Moreover, the effect of GnPs on the antimicrobial properties and release kinetics of CFX was evaluated. The results indicated that the incorporation of GnPs increased the stiffness of the biopolymeric matrix and allowed for the tuning of the release of CFX without hindering the antimicrobial activity of the obtained materials.

  15. Antifouling activities of β-cyclodextrin stabilized peg based silver nanocomposites

    International Nuclear Information System (INIS)

    Punitha, N.; Saravanan, P.; Mohan, R.; Ramesh, P.S.

    2017-01-01

    Highlights: • Simple, novel and cost effective. • Functionalized Ag nanocomposites exhibit enhanced biological activity. • The SNCs were crystalline nature and shows good stability. - Abstract: Self-polishing polymer composites which release metal biocide in a controlled rate have been widely used in the design of antimicrobial agents and antifouling coatings. The present work focuses on the environmental friendly green synthesis of PEG based SNCs and their application to biocidal activity including marine biofouling. Biocompatible polymer β-CD and adhesive resistance polymer PEG were used to functionalize the SNPs and the as synthesized SNCs exhibit excellent micro fouling activities. The structural and optical properties were confirmed by XRD and UV–visible techniques respectively. The particle surface and cross sectional characteristics were examined by SEM-EDS, HR-TEM, AFM and FTIR. The surface potential was evaluated using ZP analysis and assessment of antibiofouling property was investigated using static immersion method.

  16. High oxygen nanocomposite barrier films based on xylan and nanocrystalline cellulose

    Science.gov (United States)

    Amit Saxena; Thomas J. Elder; Jeffrey Kenvin; Arthur J. Ragauskas

    2010-01-01

    The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan, sorbitol and nanocrystalline cellulose. The morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more...

  17. An ultrasensitive electrochemical immunosensor for the detection of prostate-specific antigen based on conductivity nanocomposite with halloysite nanotubes.

    Science.gov (United States)

    Li, Yueyuan; Khan, Malik Saddam; Tian, Lihui; Liu, Li; Hu, Lihua; Fan, Dawei; Cao, Wei; Wei, Qin

    2017-05-01

    A sensitive label-free amperometric electrochemical immunosensor for detection of prostate-specific antigen (PSA) was proposed in this work. The nanocomposite of halloysite nanotubes with polypyrrole shell and palladium nanoparticles (HNTs@PPy-Pd) was used as a novel signal label. The HNTs with adequate hydroxyl groups are economically available raw materials. PPy, as an electrically conducting polymer material, can be absorbed to the surface of HNTs by in situ oxidative polymerization of the pyrrole monomer and form a shell on the HNTs. The shell of PPy could not only improve the conductivity of the nanocomposite but also absorb large amounts of Pd nanoparticles (NPs). The Pd NPs with high electrocatalytic activity toward the reduction of H 2 O 2 and the HNTs@PPy-Pd nanocomposite as the analytical signal label could improve the sensitivity of the immunosensor. Under optimal conditions, the immunosensor showed a low detection limit (0.03 pg/mL) and a wide linear range (0.0001 to 25 ng/mL) of PSA. Moreover, its merits such as good selectivity, acceptable reproducibility, and stability indicate that the fabricated immunosensor has a promising application potential in clinical diagnosis. Graphical Abstract A new label-free amperometric electrochemical immunosensor based on HNTs@PPy-Pd nanocomposite for quantitative detection of PSA.

  18. Fire and Gas Barrier Properties of Poly(styrene-co-acrylonitrile Nanocomposites Using Polycaprolactone/Clay Nanohybrid Based-Masterbatch

    Directory of Open Access Journals (Sweden)

    S. Benali

    2008-01-01

    Full Text Available Exfoliated nanocomposites are prepared by dispersion of poly(ε-caprolactone (PCL grafted montmorillonite nanohybrids used as masterbatches in poly(styrene-co-acrylonitrile (SAN. The PCL-grafted clay nanohybrids with high inorganic content are synthesized by in situ intercalative ring-opening polymerization of ε-caprolactone between silicate layers organomodified by alkylammonium cations bearing two hydroxyl functions. The polymerization is initiated by tin alcoholate species derived from the exchange reaction of tin(II bis(2-ethylhexanoate with the hydroxyl groups borne by the ammonium cations that organomodified the clay. These highly filled PCL nanocomposites (25 wt% in inorganics are dispersed as masterbatches in commercial poly(styrene-co-acrylonitrile by melt blending. SAN-based nanocomposites containing 3 wt% of inorganics are accordingly prepared. The direct blend of SAN/organomodified clay is also prepared for sake of comparison. The clay dispersion is characterized by wide-angle X-ray diffraction (WAXD, atomic force microscopy (AFM, and solid state NMR spectroscopy measurements. The thermal properties are studied by thermogravimetric analysis. The flame retardancy and gas barrier resistance properties of nanocomposites are discussed both as a function of the clay dispersion and of the matrix/clay interaction.

  19. Synthesis of ZnO nanorods and observation of resistive switching memory in ZnO based polymer nanocomposites

    Science.gov (United States)

    Nair, Manjula G.; Malakar, Meenakshi; Mohapatra, Saumya R.; Chowdhury, Avijit

    2018-05-01

    This research reports the observation of bipolar resistive switching memory in ZnO nanorod based polymer nanocomposites. We synthesized ZnO nanorods by wet-chemical method and characterized them using XRD, UV-VIS spectroscopy and SEM. The synthesized materials have hexagonal ZnO phase with grain size of 24 nm and having strong orientation along (101) direction as observed from XRD. The SEM micrograph confirms the formation of ZnO nanorods with diameter in the range of 10 to 20 nm and length of the order of 1 µm. From optical absorption spectra the band gap is estimated to be 2.42 eV. ZnO nanorods were dispersed in PVDF-HFP polymer matrix to prepare the nanocomposite. This nanocomposite was used as active layer in the devices having sandwich structure of ITO/PVDF-HFP+ZnO nanorods/Al. Bipolar non-volatile memory was observed with ON-OFF resistance ratio of the order of 103 and with a wide voltage window of 2.3V. The switching mechanism could be due to the trapping and de-trapping of electrons by the ZnO nanorods in the nanocomposite during ON and OFF states respectively.

  20. Sensors on Textile Fibres Based on Ag/a-C:H:O Nanocomposite Coatings

    Directory of Open Access Journals (Sweden)

    Martin Drabik

    2013-08-01

    Full Text Available In this contribution we present a study of the vacuum deposition process of metal/plasma polymer nanocomposite thin films monitored using plasma diagnostics (optical emission spectroscopy. We investigate\tthe\telectrical\tproperties\tof\tthe nanocomposite structures suitable for their application as\thumidity\tsensors.\tFurthermore,\tthe\tfilm microstructure is characterized by transmission electron microscopy and electron diffraction analysis. The amount of silver in the nanocomposite is evaluated using inductively coupled plasma optical emission spectrometry and the morphology of the structured\tsystem\tof\tmetal\telectrodes\tand nanocomposite films on monofilament textile fibres is visualized using scanning electron microscopy. Ageing of nanocomposite coatings and the influence of an aqueous environment on their internal structure and properties are discussed.

  1. A Hybrid Metaheuristic-Based Approach for the Aerodynamic Optimization of Small Hybrid Wind Turbine Rotors

    DEFF Research Database (Denmark)

    Herbert-Acero, José F.; Martínez-Lauranchet, Jaime; Probst, Oliver

    2014-01-01

    of the sectional blade aerodynamics. The framework considers an innovative nested-hybrid solution procedure based on two metaheuristics, the virtual gene genetic algorithm and the simulated annealing algorithm, to provide a near-optimal solution to the problem. The objective of the study is to maximize...

  2. Tribology of Nanocomposites

    CERN Document Server

    2013-01-01

    This book provides recent information on nanocomposites tribology. Chapter 1 provides information on tribology of bulk polymer nanocomposites and nanocomposite coatings. Chapter 2 is dedicated to nano and micro PTFE for surface lubrication of carbon fabric reinforced polyethersulphone composites. Chapter 3 describes Tribology of MoS2 -based nanocomposites. Chapter 4 contains information on friction and wear of Al2O2 -based composites with dispersed and agglomerated nanoparticles. Finally, chapter 5 is dedicated to wear of multi-scale phase reinforced composites. It is a useful reference for academics, materials and physics researchers, materials, mechanical and manufacturing engineers, both as final undergraduate and postgraduate levels. It is a useful reference for academics, materials and physics researchers, materials, mechanical and manufacturing engineers, both as final undergraduate and postgraduate levels.

  3. Electrochemical synthesis, in situ spectroelectrochemistry of conducting indole-titanium dioxide and zinc oxide polymer nanocomposites for rechargeable batteries

    International Nuclear Information System (INIS)

    Parvin, Mohammad Hadi; Pirnia, Mahsa; Arjomandi, Jalal

    2015-01-01

    Highlights: • Two novel hybrid materials-based conducting PIn rechargeable batteries were developed. • The charge-discharging behavior of PIn-nanocomposite batteries were studied. • The characterization of samples has been done by in situ spectroelectrochemical method. • PIn-TiO 2 and ZnO nanocomposites were synthesized electrochemically on Au and ITO. • The PIn-TiO 2 and ZnO nanocomposites resistances were less than PIn. - Abstract: Electrochemical synthesis, in situ spectroelectrochemistry of conducting polyindole (PIn), polyindole-TiO 2 (PIn-TiO 2 ) and polyindole-ZnO (PIn-ZnO) nanocomposites were investigated. The PIn and polymer nanocomposites were tested electrochemically for rechargeable batteries. The films were characterized by means of CVs, in situ UV-visible, FT-IR spectroscopies, in situ resistivity measurements, energy dispersive X-ray (EDX), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The charge-discharging behavior of a Zn/1 M ZnSO 4 /PIn cell with a capacity of around 90 Ah Kg −1 and on open circuit potential of around 1.45 V was compared with Zn/1 M ZnSO 4 /PIn-nanocomposite. The potential differences of redox couples (ΔE) for nanocomposites films show very good reversibility. A positive shift of potential was observed for polymer nanocomposites during redox scan. A significant variability was observed for in situ conductivity of the PIn and polymer nanocomposites. During in situ UV-visible and FT-IR measurements, intermediate spectroscopic behavior and positive shifts of wavelengths were observed for PIn and polymer nanocomposites. The SEM, TEM and EDX of nanocomposite films show the presence of nano particle in PIn.

  4. Quinoline-Based Hybrid Compounds with Antimalarial Activity

    Directory of Open Access Journals (Sweden)

    Xhamla Nqoro

    2017-12-01

    Full Text Available The application of quinoline-based compounds for the treatment of malaria infections is hampered by drug resistance. Drug resistance has led to the combination of quinolines with other classes of antimalarials resulting in enhanced therapeutic outcomes. However, the combination of antimalarials is limited by drug-drug interactions. In order to overcome the aforementioned factors, several researchers have reported hybrid compounds prepared by reacting quinoline-based compounds with other compounds via selected functionalities. This review will focus on the currently reported quinoline-based hybrid compounds and their preclinical studies.

  5. Synthesis and utilization of poly (methylmethacrylate nanocomposites based on modified montmorillonite

    Directory of Open Access Journals (Sweden)

    Ahmed M. Youssef

    2017-07-01

    Full Text Available Poly (methylmethacrylate nanocomposite was prepared via in-situ emulsion polymerization (PMMA/Mt-CTA. The modified montmorillonite (Mt-CTA is used as hosts for the preparation of poly (methylmethacrylate nanocomposites with basal distance 1.95 nm. Moreover, exfoliated nanocomposite was characterized by X-ray diffraction (XRD, transmission electron microscope (TEM, thermal gravimetric analysis (TGA, and differential scanning calorimetry (DSC. The fashioned nanocomposites exhibited better thermal stability than pristine PMMA which make it suitable for packaging applications. Furthermore, this nanocomposite reveals tremendous affinity for removing pesticides from aquatic solutions. The data obtained from GC/ECD gas liquid chromatography illustrated that the removal efficiency of PMMA/Mt-CTA nanocomposites for organochlorine pesticides (OCPs varied from 73.65% to 99.36% that make it as a new method for water treatment. Also, the antimicrobial activity of the Mt-CTA and PMMA/Mt-CTA nanocomposites was evaluated by the inhibitory zone tests and revealed good activity against Escherichia coli and Staphylococcus aureus, which makes it suitable materials for packaging applications.

  6. Processing and characterization of polystyrene nanocomposites based on CoAl layered double hydroxide

    Directory of Open Access Journals (Sweden)

    Kelothu Suresh

    2016-09-01

    Full Text Available The present work deals with the development of polystyrene (PS nanocomposites through solvent blending technique with diverse contents of modified CoAl layered double hydroxide (LDH. The prepared PS as well as PS/CoAl LDH (1–7 wt.% nanocomposites were characterized by X-ray diffraction (XRD, transmission electron microscopy (TEM, Fourier transform infrared spectroscopy (FTIR, rheological analysis, thermogravimetric analysis (TGA and differential scanning calorimetry (DSC. The XRD results suggested the formation of exfoliated structure, while TEM images clearly indicated the intercalated morphology of PS nanocomposites at higher loading. The presence of various functional groups in the CoAl LDH and PS/CoAl LDH nanocomposites was verified by FTIR analysis. TGA data confirmed that the thermal stability of PS composites was enhanced significantly as compared to pristine PS. While considering 15% weight loss as a reference point, it was found that the thermal degradation (Td temperature increased up to 28.5 °C for PS nanocomposites prepared with 7 wt.% CoAl LDH loading over pristine PS. All the nanocomposite samples displayed superior glass transition temperature (Tg, in which PS nanocomposites containing 7 wt.% LDH showed about 5.5 °C higher Tg over pristine PS. In addition, the kinetics for thermal degradation of the composites was studied using Coats-Redfern method. The Criado method was ultimately used to evaluate the decomposition reaction mechanism of the nanocomposites. The complex viscosity and rheological muduli of nanocomposites were found to be higher than that of pristine PS when the frequency increased from 0.01 to 100 s−1.

  7. Thermal and mechanical properties of palm oil-based polyurethane acrylate/clay nanocomposites prepared by in-situ intercalative method and electron beam radiation

    International Nuclear Information System (INIS)

    Salih, A. M.; Ahmad, Mansor Bin; Ibrahim, Nor Azowa; Dahlan, Khairul Zaman Hj Mohd; Tajau, Rida; Mahmood, Mohd Hilmi; Yunus, Wan Md. Zin Wan

    2014-01-01

    Palm oil based-polyurethane acrylate (POBUA)/clay nanocomposites were prepared via in-situ intercalative polymerization using epoxidized palm oil acrylate (EPOLA) and 4,4' methylene diphenyl diisocyante (MDI). Organically modified Montmorillonite (ODA-MMT) was incorporated in EPOLA (1, 3 and 5%wt), and then subjected to polycondensation reaction with MDI. Nanocomposites solid films were obtained successfully by electron beam radiation induced free radical polymerization (curing). FTIR results reveal that the prepolymer was obtained successfully, with nanoclay dispersed in the matrix. The intercalation of the clay in the polymer matrix was investigated by XRD and the interlayer spacing of clay was found to be increased up to 37 Å, while the structure morphology of the nanocomposites was investigated by TEM and SEM. The nanocomposites were found to be a mixture of exfoliated and intercalated morphologies. The thermal stability of the nanocomposites was significantly increased by incorporation of nanoclay into the polymer matrix. DSC results reveal that the Tg was shifted to higher values, gradually with increasing the amount of filler in the nanocomposites. Tensile strength and Young's modulus of the nanocomposites showed remarkable improvement compared to the neat POBUA

  8. Adsorption and photocatalysis for methyl orange and Cd removal from wastewater using TiO2/sewage sludge-based activated carbon nanocomposites

    Science.gov (United States)

    Rashed, M. Nageeb; Eltaher, M. A.; Abdou, A. N. A.

    2017-12-01

    Nanocomposite TiO2/ASS (TiO2 nanoparticle coated sewage sludge-based activated carbon) was synthesized by the sol-gel method. The changes in surface properties of the TiO2/ASS nanocomposite were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence. The prepared TiO2/ASS nanocomposite was applied for simultaneous removal of methyl orange dye (MO) and Cd2+ from bi-pollutant solution. The factors influencing photocatalysis (TiO2 : ASS ratios, initial pollutant concentrations, solution pH, nanocomposite dosage and UV irradiation time) w