WorldWideScience

Sample records for hybrid nanofibers prepared

  1. Preparation and Characterization of Organic/Inorganic Hybrid Nanofibers

    Institute of Scientific and Technical Information of China (English)

    WU Ning; WEI Qu-fu; LI Qi; XU Wen-zheng

    2006-01-01

    A new class of nanocomposites based on organic and inorganic species integrated at a nanoscale has obtained more attention these years. Organic-inorganic hybrids have both the advantages of organic materials, such as light weight, flexibility and good moldability, and inorganic materials, such as high strength, heat stability and chemical resistance. In this work, PVAc/TiO2 organicinorganic hybrid was prepared by sol-gel process. Electrospinning technique was used to fabricate PVAc/TiO2hybrid nanofibers. The structures and properties of the hybrid nanofibers were characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscope (AFM),Differential Scanning Calorimeter (DSC) and Fouriertransform infrared (FTIR) spectra. SEM and AFM were employed to study the topography of the hybrid nanofibers.The chemical structure of the hybrid nanofibers were examined by FTIR. The DSC scansrevealed the second order transition temperature of the hybrid materials were higher than PVAc.

  2. Preparation and characterization of UV-cured hybrid polyvinyl alcohol nanofiber membranes by electrospinning

    OpenAIRE

    2014-01-01

    The present study investigated the possibility of preparing polyvinyl alcoholic (PVA) organic-inorganic hybrid nanofiber membranes by electrospinning with UV irradiation. To this end, PVA, PVA/SiO2 organic-inorganic hybrid obtained with Geniosil® XL 33 as a SiO2 source, and imidazole-functionalized mesoporous PVA/SiO2/N=N nanofiber membranes were synthesized. These membranes were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, thermogravimetric-differen...

  3. White-light emission of polyvinyl alcohol/ZnO hybrid nanofibers prepared by electrospinning

    Science.gov (United States)

    Sui, X. M.; Shao, C. L.; Liu, Y. C.

    2005-09-01

    Polyvinyl alcohol/ZnO (PVA/ZnO) hybrid nanofibers were prepared by the electrospinning technique. The structural and spectral information of the nanofibers was characterized by scanning electron microscopy, x-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry, resonant Raman, and photoluminescence (PL). The results indicate that ZnO were successfully embedded in the one-dimensional hybrid fibers via chemical interactions between ZnO and PVA. PL results show the PVA/ZnO nanofibers have an intense white-light emission, which originates from the simultaneous emission of three bands covering from the UV to visible range. A possible PL mechanism was proposed accordingly.

  4. Biotemplated preparation of CdS nanoparticles/bacterial cellulose hybrid nanofibers for photocatalysis application.

    Science.gov (United States)

    Yang, Jiazhi; Yu, Junwei; Fan, Jun; Sun, Dongping; Tang, Weihua; Yang, Xuejie

    2011-05-15

    In this work, we describe a novel facile and effective strategy to prepare micrometer-long hybrid nanofibers by deposition of CdS nanoparticles onto the substrate of hydrated bacterial cellulose nanofibers (BCF). Hexagonal phase CdS nanocrystals were achieved via a simple hydrothermal reaction between CdCl(2) and thiourea at relatively low temperature. The prepared pristine BCF and the CdS/BCF hybrid nanofibers were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), UV-vis absorption spectroscopy (UV-vis), and X-ray photoelectron spectroscopy (XPS). The results reveal that the CdS nanoparticles were homogeneously deposited on the BCF surface and stabilized via coordination effect. The CdS/BCF hybrid nanofibers demonstrated high-efficiency photocatalysis with 82% methyl orange (MO) degradation after 90 min irradiation and good recyclability. The results indicate that the CdS/BCF hybrid nanofibers are promising candidate as robust visible light responsive photocatalysts.

  5. Preparation of Pd/Bacterial Cellulose Hybrid Nanofibers for Dopamine Detection

    Directory of Open Access Journals (Sweden)

    Dawei Li

    2016-05-01

    Full Text Available Palladium nanoparticle-bacterial cellulose (PdBC hybrid nanofibers were synthesized by in-situ chemical reduction method. The obtained PdBC nanofibers were characterized by a series of analytical techniques. The results revealed that Pd nanoparticles were evenly dispersed on the surfaces of BC nanofibers. Then, the as-prepared PdBC nanofibers were mixed with laccase (Lac and Nafion to obtain mixture suspension, which was further modified on electrode surface to construct novel biosensing platform. Finally, the prepared electrochemical biosensor was employed to detect dopamine. The analysis result was satisfactory, the sensor showed excellent electrocatalysis towards dopamine with high sensitivity (38.4 µA·mM−1, low detection limit (1.26 µM, and wide linear range (5–167 µM. Moreover, the biosensor also showed good repeatability, reproducibility, selectivity and stability and was successfully used in the detection of dopamine in human urine, thus providing a promising method for dopamine analysis in clinical application.

  6. Synthesis of organic-inorganic hybrid azobenzene materials for the preparation of nanofibers by electrospinning

    Science.gov (United States)

    Bućko, Aleksandra; Zielińska, Sonia; Ortyl, Ewelina; Larkowska, Maria; Barille, Regis

    2014-12-01

    The new photochromic hybrid materials containing different mole fractions of highly photoactive 4-[(E)-[4-[ethyl(2-hydroxyethyl)amino]phenyl]azo]-N-(4-methylpyrimidin-2-yl)benzenesulfonamide (SMERe) were prepared by a low temperature sol-gel process. The guest-host systems with triethoxyphenylsilane matrix were obtained. These materials were used to form thin transparent films by a spin-coating technique. Then the ability of thin hybrid films to reversible trans-cis photoisomerization under illumination was investigated using ellipsometry and UV-Vis spectroscopy. The reversible changes of refractive index of the films under illumination were in the range of 0.005-0.056. The maximum absorption of these materials was located at 462-486 nm. Moreover, the organic-inorganic azobenzene materials were used to form nanofibers by electrospinning using various parameters of the process. The microstructure of electrospun fibers depended on sols properties (e.g. concentration and viscosity of the sols) and process conditions (e.g. the applied voltage, temperature or type of the collector) at ambient conditions. The morphology of obtained nanofibers was analyzed by an optical microscopy and scanning electron microscopy. In most instances, the beadless fibers were obtained. The wettability of the surface of electrospun fibers deposited on glass substrates was investigated.

  7. Durable antibacterial Ag/polyacrylonitrile (Ag/PAN) hybrid nanofibers prepared by atmospheric plasma treatment and electrospinning

    Science.gov (United States)

    Durable antibacterial Ag/polyacrylonitrile (Ag/PAN) hybrid nanofibers were prepared by atmospheric plasma treatment and electrospinning. Atmospheric helium plasma treatment was first used to reduce the silver nitrate precursor in pre-electrospinning solutions into metallic silver nanoparticles, foll...

  8. Preparation and electrochemical performance of hyper-networked Li4Ti5O12/carbon hybrid nanofiber sheets for a battery-supercapacitor hybrid system.

    Science.gov (United States)

    Choi, Hong Soo; Kim, TaeHoon; Im, Ji Hyuk; Park, Chong Rae

    2011-10-07

    Hyper-networked Li(4)Ti(5)O(12)/carbon hybrid nanofiber sheets that contain both a faradaically rechargeable battery-type component, namely Li(4)Ti(5)O(12), and a non-faradaically rechargeable supercapacitor-type component, namely N-enriched carbon, are prepared by electrospinning and their dual function as a negative electrode of lithium-ion batteries (LIBs) and a capacitor is tested for a new class of hybrid energy storage (denoted BatCap). An aqueous solution composed of polyvinylpyrrolidone, lithium hydroxide, titanium(IV) bis(ammonium-lactato)dihydroxide and ammonium persulfate is electrospun to obtain hyper-networked nanofiber sheets. Next, the sheets are exposed to pyrrole monomer vapor to prepare the polypyrrole-coated nanofiber sheets (PPy-HNS). The hyper-networked Li(4)Ti(5)O(12)/N-enriched carbon hybrid nanofiber sheets (LTO/C-HNS) are then obtained by a stepwise heat treatment of the PPy-HNS. The LTO/C-HNS deliver a specific capacity of 135 mAh g(-1) at 4000 mA g(-1) as a negative electrode for LIBs. In addition, potentiodynamic experiments are performed using a full cell with activated carbon (AC) as the positive electrode and LTO/C-HNS as the negative electrode to estimate the capacitance properties. This new asymmetric electrode system exhibits a high energy density of 91 W kg(-1) and 22 W kg(-1) at power densities of 50 W kg(-1) and 4000 W kg(-1), respectively, which are superior to the values observed for the AC [symbol: see text] AC symmetric electrode system.

  9. Preparation and electrochemical performance of hyper-networked Li4Ti5O12/carbon hybrid nanofiber sheets for a battery-supercapacitor hybrid system

    Science.gov (United States)

    Choi, Hong Soo; Kim, TaeHoon; Im, Ji Hyuk; Park, Chong Rae

    2011-10-01

    Hyper-networked Li4Ti5O12/carbon hybrid nanofiber sheets that contain both a faradaically rechargeable battery-type component, namely Li4Ti5O12, and a non-faradaically rechargeable supercapacitor-type component, namely N-enriched carbon, are prepared by electrospinning and their dual function as a negative electrode of lithium-ion batteries (LIBs) and a capacitor is tested for a new class of hybrid energy storage (denoted BatCap). An aqueous solution composed of polyvinylpyrrolidone, lithium hydroxide, titanium(IV) bis(ammonium-lactato)dihydroxide and ammonium persulfate is electrospun to obtain hyper-networked nanofiber sheets. Next, the sheets are exposed to pyrrole monomer vapor to prepare the polypyrrole-coated nanofiber sheets (PPy-HNS). The hyper-networked Li4Ti5O12/N-enriched carbon hybrid nanofiber sheets (LTO/C-HNS) are then obtained by a stepwise heat treatment of the PPy-HNS. The LTO/C-HNS deliver a specific capacity of 135 mAh g - 1 at 4000 mA g - 1 as a negative electrode for LIBs. In addition, potentiodynamic experiments are performed using a full cell with activated carbon (AC) as the positive electrode and LTO/C-HNS as the negative electrode to estimate the capacitance properties. This new asymmetric electrode system exhibits a high energy density of 91 W kg - 1 and 22 W kg - 1 at power densities of 50 W kg - 1 and 4000 W kg - 1, respectively, which are superior to the values observed for the {AC} \\parallel {AC} symmetric electrode system.

  10. Nanofiber of ultra-structured aluminum and zirconium oxide hybrid.

    Science.gov (United States)

    Kim, Hae-Won; Kim, Hyoun-Ee

    2006-02-01

    An internally ultrastructured Al- and Zr-oxide hybrid was developed into a nanofiber. As a precursor for the generation of nanofiber, a hybridized sol was prepared using the Pechini-type sol-gel process, whereby the Al- and Zr-metallic ions were to be efficiently distributed and stabilized within the polymeric network. The hybridized sol was subsequently electrospun and heat treated to a nanofiber with diameters of tens to hundreds of nanometers. The internal structure of the nanofiber was organized at the molecular level, with the Al- and Zr-oxide regions being interspaced at distances of less than ten nanometers. This ultrastructured Al- and Zr-oxide hybrid nanofiber is considered to be potentially applicable in numerous fields.

  11. Chitin nanofibers: preparations, modifications, and applications

    Science.gov (United States)

    Ifuku, Shinsuke; Saimoto, Hiroyuki

    2012-05-01

    Chitin nanofibers are prepared from the exoskeletons of crabs and prawns by a simple mechanical treatment after the removal of proteins and minerals. The obtained nanofibers have fine nanofiber networks with a uniform width of approximately 10-20 nm and a high aspect ratio. The method used for chitin-nanofiber isolation is also successfully applied to the cell walls of mushrooms. They form a complex with glucans on the fiber surface. A grinder, a Star Burst atomization system, and a high speed blender are all used in the mechanical treatment to convert chitin to nanofibers. Mechanical treatment under acidic conditions is the key to facilitate fibrillation. At pH 3-4, the cationization of amino groups on the fiber surface assists nano-fibrillation by electrostatic repulsive force. By applying this finding, we also prepared chitin nanofibers from dry chitin powder. Chitin nanofibers are acetylated to modify their surfaces. The acetyl DS can be controlled from 1 to 3 by changing the reaction time. An acetyl group is introduced heterogeneously from the surface to the core. Nanofiber morphology is maintained even in the case of high acetyl DS. Optically transparent chitin nanofiber composites are prepared with 11 different types of acrylic resins. Due to the nano-sized structure, all of the composites are highly transparent. Chitin nanofibers significantly increase the Young's moduli and the tensile strengths and decrease the thermal expansion of all acrylic resins due to the reinforcement effect of chitin nanofibers. Chitin nanofibers show chiral separation ability. The chitin nanofiber membrane transports the d-isomer of glutamic acid, phenylalanine, and lysine from the corresponding racemic amino acid mixtures faster than the corresponding l-isomer. The chitin nanofibers improve clinical symptoms and suppress ulcerative colitis in a DSS-induced mouse model of acute ulcerative colitis. Moreover, chitin nanofibers suppress myeloperoxidase activation in the colon and

  12. Preparation of chitosan nanofiber tube by electrospinning.

    Science.gov (United States)

    Matsuda, Atsushi; Kagata, Go; Kino, Rikako; Tanaka, Junzo

    2007-03-01

    Water-insoluble chitosan nanofiber sheets and tubes coated with chitosan-cast film were prepared by electrospinning. When as-spun chitosan nanofiber sheets and tubes were immersed in 28% ammonium aqueous solution, they became insoluble in water and showed nanofiber structures confirmed by SEM micrography. Mechanical properties of chitosan nanofiber sheets and tubes were improved by coating with chitosan-cast film, which gave them a compressive strength higher than that of crab-tendon chitosan, demonstrating that chitosan nanofiber tubes coated with chitosan-cast film are usable as nerve-regenerative guide tubes.

  13. Multifunctional ZnO/Nylon 6 nanofiber mats by an electrospinning– electrospraying hybrid process for use in protective applications

    Science.gov (United States)

    ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacter...

  14. Preparation and electrochemical performance of hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/carbon hybrid nanofiber sheets for a battery-supercapacitor hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hong Soo; Kim, TaeHoon; Im, Ji Hyuk; Park, Chong Rae, E-mail: crpark@snu.ac.kr [Carbon Nanomaterials Design Laboratory, Global Research Laboratory, Research Institute of Advanced Materials, and Department of Materials Science and Engineering, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-744 (Korea, Republic of)

    2011-10-07

    Hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/carbon hybrid nanofiber sheets that contain both a faradaically rechargeable battery-type component, namely Li{sub 4}Ti{sub 5}O{sub 12}, and a non-faradaically rechargeable supercapacitor-type component, namely N-enriched carbon, are prepared by electrospinning and their dual function as a negative electrode of lithium-ion batteries (LIBs) and a capacitor is tested for a new class of hybrid energy storage (denoted BatCap). An aqueous solution composed of polyvinylpyrrolidone, lithium hydroxide, titanium(IV) bis(ammonium-lactato)dihydroxide and ammonium persulfate is electrospun to obtain hyper-networked nanofiber sheets. Next, the sheets are exposed to pyrrole monomer vapor to prepare the polypyrrole-coated nanofiber sheets (PPy-HNS). The hyper-networked Li{sub 4}Ti{sub 5}O{sub 12}/N-enriched carbon hybrid nanofiber sheets (LTO/C-HNS) are then obtained by a stepwise heat treatment of the PPy-HNS. The LTO/C-HNS deliver a specific capacity of 135 mAh g{sup -1} at 4000 mA g{sup -1} as a negative electrode for LIBs. In addition, potentiodynamic experiments are performed using a full cell with activated carbon (AC) as the positive electrode and LTO/C-HNS as the negative electrode to estimate the capacitance properties. This new asymmetric electrode system exhibits a high energy density of 91 W kg{sup -1} and 22 W kg{sup -1} at power densities of 50 W kg{sup -1} and 4000 W kg{sup -1}, respectively, which are superior to the values observed for the AC||AC symmetric electrode system.

  15. Graphitized carbon nanofiber-Pt nanoparticle hybrids as sensitive tool for preparation of screen printing biosensors. Detection of lactate in wines and ciders.

    Science.gov (United States)

    Loaiza, Oscar A; Lamas-Ardisana, Pedro J; Añorga, Larraitz; Jubete, Elena; Ruiz, Virginia; Borghei, Maryam; Cabañero, Germán; Grande, Hans J

    2015-02-01

    This work describes the fabrication of a new lactate biosensor. The strategy is based on the use of a novel hybrid nanomaterial for amperometric biosensors i.e. platinum nanoparticles (PtNps) supported on graphitized carbon nanofibers (PtNps/GCNF) prepared by chemical reduction of the Pt precursor at GCNF surfaces. The biosensors were constructed by covalent immobilization of lactate oxidase (LOx) onto screen printed carbon electrodes (SPCEs) modified with PtNps (PtNps/GCNF-SPCEs) using polyethyleneimine (PEI) and glutaraldehyde (GA). Experimental variables concerning both the biosensor design and the detection process were investigated for an optimal analytical performance. Lactate biosensors show good reproducibility (RSD 4.9%, n=10) and sensitivity (41,302±546) μA/Mcm(2), with a good limit of detection (6.9μM). Covalent immobilization of the enzyme allows the reuse of the biosensor for several measurements, converting them in a cheap alternative to the solid electrodes. The long-term stability of the biosensors was also evaluated. 90% of the signal was kept after 3months of storage at room temperature (RT), while 95% was retained after 18months at -20°C. These results demonstrate that the method provides sensitive electrochemical lactate biosensors where the stability of the enzymatic activity can be preserved for a long period of time in adequate storage conditions.

  16. Titanium carbide/carbon composite nanofibers prepared by a plasma process

    Energy Technology Data Exchange (ETDEWEB)

    El Mel, A A; Gautron, E; Angleraud, B; Granier, A; Tessier, P Y [Universite de Nantes, CNRS, Institut des Materiaux Jean Rouxel, UMR 6502, 2 rue de la Houssiniere BP 32229-44322 Nantes cedex 3 (France); Choi, C H [Department of Mechanical Engineering, Stevens Institute of Technology, Hoboken, NJ 07030 (United States)

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  17. Titanium carbide/carbon composite nanofibers prepared by a plasma process.

    Science.gov (United States)

    El Mel, A A; Gautron, E; Choi, C H; Angleraud, B; Granier, A; Tessier, P Y

    2010-10-29

    The incorporation of metal or metal carbide nanoparticles into carbon nanofibers modifies their properties and enlarges their field of application. The purpose of this work is to report a new non-catalytic and easy method to prepare organized metal carbide-carbon composite nanofibers on nanopatterned silicon substrates prepared by laser interference lithography coupled with deep reactive ion etching. Titanium carbide-carbon composite nanofibers were grown on the top of the silicon lines parallel to the substrate by a hybrid plasma process combining physical vapor deposition and plasma enhanced chemical vapor deposition. The prepared nanofibers were analyzed by scanning electron microscopy, x-ray photoelectron spectroscopy, Raman spectroscopy and transmission electron microscopy. We demonstrate that the shape, microstructure and the chemical composition of the as-grown nanofibers can be tuned by changing the plasma conditions.

  18. Preparation of Biopolymeric Nanofiber Containing Silica and Antibiotic

    Directory of Open Access Journals (Sweden)

    A. Bagheri Pebdeni

    2016-01-01

    Full Text Available The biocompatible and biodegradable polymer nanofiber with high potential for anti-bacterial coating are used for: multi-functional membranes, tissue engineering, wound dressings, drug delivery, artificial organs, vascular grafts and etc. Electrospinning nanofiber made of scaffolding due to characteristics such as high surface to volume ratio, high porosity and very fine pores are used for a wide range of applications. In this study, polymer composite nanofiber Silica/chitosan/poly (ethylene oxide /cefepime antibiotic synthesis and antibacterial properties will be discussed. The optimum conditions for preparation of electrospun nanofiber were: voltage; 21 kV, feed rate; 0.5 mL/h, nozzle-collector distance; 10 cm, and chitosan/poly(ethylene oxide weight ratio 90:10 and the volume ratio of chitosan/silica is 70:30.  The antibacterial activity of composite scaffolds were tested by agar plate method by two type bacteria including Escherichia coli and Staphylococcus aureus. With the addition of the silica to chitosan, the hybrid was more biodegradable and improves the mechanical properties of biopolymer.

  19. Preparation and characterization of crosslinked chitosan-based nanofibers

    Institute of Scientific and Technical Information of China (English)

    Ying Shan Zhou; Dong Zhi Yang; Jun Nie

    2007-01-01

    Crosslinked chitosan-based nanofibers were successfully prepared via electrospinning technique with heat mediated chemical crosslinking followed. The structure, morphology and mechanical property of nanofibers were characterized by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), Instron machine, respectively. The results showed that, nanofibers exhibited a smooth surface and regular morphology, and tensile strength of nanofibers improved with increasing of triethylene glycol dimethacrylate (TEGDMA) content.

  20. Electrospun MgO/Nylon 6 Hybrid Nanofib ers for Protective Clothing

    Institute of Scientific and Technical Information of China (English)

    Nattanmai Raman Dhineshbabu; Gopalu Karunakaran; Rangaraj Suriyaprabha; Palanisamy Manivasakan; Venkatachalam Rajendran

    2014-01-01

    Magnesia (MgO) nanoparticles were produced from magnesite ore (MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction analysis, transmission electron microscopy and Brunauer-Emmett-Teller method, respectively. MgO nanoparticle-incorporated nylon 6 solutions were electrospun to produce nanofiber mats. Surface morphology and internal structure of the pre-pared hybrid nanofiber mats were examined by scanning electron microscopy and high-resolution transmission electron microscopy, respectively. The fire retardancy and antibacterial activity (Staphylococcus aureus and Escherichia coli) of coated fabrics made from MgO/nylon 6 hybrid nanofiber are better than those from nylon 6 nanofiber.

  1. A hybrid biomimetic scaffold composed of electrospun polycaprolactone nanofibers and self-assembled peptide amphiphile nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Tambralli, Ajay; Blakeney, Bryan; Anderson, Joel; Kushwaha, Meenakshi; Andukuri, Adinarayana; Jun, Ho-Wook [Department of Biomedical Engineering, University of Alabama at Birmingham, 801 Shelby Building, 1825 University Boulevard, Birmingham, AL 35294 (United States); Dean, Derrick [Department of Materials Science and Engineering, University of Alabama at Birmingham, BEC 254, 1150 10th Ave South, Birmingham, AL 35294 (United States)], E-mail: hwjun@uab.edu

    2009-06-01

    Nanofibrous electrospun poly ({epsilon}-caprolactone) (ePCL) scaffolds have inherent structural advantages, but lack of bioactivity has limited their usefulness in biomedical applications. Thus, here we report the development of a hybrid, nanostructured, extracellular matrix (ECM) mimicking scaffold by a combination of ePCL nanofibers and self-assembled peptide amphiphile (PA) nanofibers. The PAs have ECM mimicking characteristics including a cell adhesive ligand (RGDS) and matrix metalloproteinase-2 (MMP-2) mediated degradable sites. Transmission electron microscope imaging verified successful PA self-assembly into nanofibers (diameters of 8-10 nm) using a solvent evaporation method. This evaporation method was then used to successfully coat PAs onto ePCL nanofibers (diameters of 300-400 nm), to develop hybrid, bioactive scaffolds. Scanning electron microscope characterization showed that the PA coatings did not interfere with the porous ePCL nanofiber network. Human mesenchymal stem cells (hMSCs) were seeded onto the hybrid scaffolds to evaluate their bioactivity. Significantly greater attachment and spreading of hMSCs were observed on ePCL nanofibers coated with PA-RGDS as compared to ePCL nanofibers coated with PA-S (no cell adhesive ligand) and uncoated ePCL nanofibers. Overall, this novel strategy presents a new solution to overcome the current bioactivity challenges of electrospun scaffolds and combines the unique characteristics of ePCL nanofibers and self-assembled PA nanofibers to provide an ECM mimicking environment. This has great potential to be applied to many different electrospun scaffolds for various biomedical applications.

  2. Synergistic tungsten oxide/organic framework hybrid nanofibers for electrochromic device application

    Science.gov (United States)

    Dulgerbaki, Cigdem; Komur, Ali Ihsan; Nohut Maslakci, Neslihan; Kuralay, Filiz; Uygun Oksuz, Aysegul

    2017-08-01

    We report the first successful applications of tungsten oxide/conducting polymer hybrid nanofiber assemblies in electrochromic devices. Poly(3,4-ethylenedioxythiophene)/tungsten oxide (PEDOT/WO3) and polypyrrole/tungsten oxide (PPy/WO3) composites were prepared by an in situ chemical oxidative polymerization of monomers in different ionic liquids; 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4), 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide (BMIMTFSI) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMPTFSI). Electrospinning process was used to form hybrid nanofibers from chemically synthesized nanostructures. The electrospun hybrid samples were compared from both morphological and electrochemical perspectives. Importantly, deposition of nanofibers from chemically synthesized hybrids can be achieved homogenously, on nanoscale dimensions. The morphologies of these assemblies were evaluated by SEM, whereas their electroactivity was characterized by cyclic voltammetry. Electrochromic devices made from hybrid nanofiber electrodes exhibited highest chromatic contrast of 37.66% for PEDOT/WO3/BMIMPF6, 40.42% for PPy/WO3/BMIMBF4 and show a strong electrochromic color change from transparent to light brown. Furthermore, the nanofiber devices exhibit outstanding stability when color switching proceeds, which may ensure a versatile platform for color displays, rear-view mirrors and smart windows.

  3. Preparation of polyvinyl alcohol/chitosan hybrid nanofibers and study on their properties%聚乙烯醇/壳聚糖复合纳米纤维的制备和性能研究

    Institute of Scientific and Technical Information of China (English)

    闫尔云; 范英梅; 郝小原; 樊姗; 张德庆

    2013-01-01

    Polyvinyl alcohol/chitosan(PVA/CS)hybrid nanofibers were prepared by electrospinning method. The morphology change of the pure PVA fibers and PVA/CS hybrid fibers was investigated via scanning electron microscopy. Studies have shown that with the increase of the concentration of electrospinning solution, the diameter of fibers became bigger, and the morphology of fibers became more regular. The PVA/CS composite nanofibers with good biocompatibility were expected to used in the field of biomedicine.%采用高压静电纺丝技术制备了聚乙烯醇/壳聚糖(PVA/CS)的复合纳米纤维。通过扫描电子显微镜考察了纯聚乙烯醇PVA纤维和PVA/CS复合纳米纤维的形貌变化。研究表明,随着纺丝溶液浓度的不断增大,所得的纤维形貌越来越规则,纤维直径也逐渐变大。这种具有良好生物相容性的PVA/CS复合纳米纤维有望在生物医学方面得到应用。

  4. Hybrid electrospun chitosan-phospholipids nanofibers for transdermal drug delivery

    DEFF Research Database (Denmark)

    Mendes, Ana Carina Loureiro; Gorzelanny, Christian; Halter, Natalia

    2016-01-01

    Chitosan (Ch) polysaccharide was mixed with phospholipids (P) to generate electrospun hybrid nanofibers intended to be used as platforms for transdermal drug delivery. Ch/P nanofibers exibithed average diameters ranging from 248 +/- 94 nm to 600 +/- 201 nm, depending on the amount of phospholipids...... used. Fourier Transformed Infra-Red (FTIR) spectroscopy and Dynamic Light Scattering (DLS) data suggested the occurrence of electrostatic interactions between amine groups of chitosan with the phospholipid counterparts. The nanofibers were shown to be stable for at least 7 days in Phosphate Buffer...

  5. UV-responsive polyvinyl alcohol nanofibers prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Khatri, Zeeshan, E-mail: zeeshan.khatri@faculty.muet.edu.pk [Department of Textile Engineering, Mehran University of Engineering and Technology, Jamshoro 76062 (Pakistan); Nano Fusion Technology Research Lab, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, 3-15-1, Tokida, Ueda, Nagano 386-8567 (Japan); Ali, Shamshad [Department of Textile Engineering, Mehran University of Engineering and Technology, Jamshoro 76062 (Pakistan); Department of Organic and Nano Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Khatri, Imran [Department of Entomology, Sindh Agriculture University, Tandojam (Pakistan); Mayakrishnan, Gopiraman [Nano Fusion Technology Research Lab, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, 3-15-1, Tokida, Ueda, Nagano 386-8567 (Japan); Kim, Seong Hun [Department of Organic and Nano Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Ick-Soo, E-mail: kim@shinshu-u.ac.jp [Nano Fusion Technology Research Lab, Division of Frontier Fibers, Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, 3-15-1, Tokida, Ueda, Nagano 386-8567 (Japan)

    2015-07-01

    Graphical abstract: - Highlights: • UV responsive PVA nanofibers were prepared via electrospinning. • Quick response codes were recorded multiple times on UV responsive nanofibers. • The rate of photo-coloration was found faster than the rate of photo-reversibility. - Abstract: We report UV-responsive polyvinyl alcohol (PVA) nanofibers for potential application for recording and erasing quick response (QR) codes. We incorporate 1′-3′-dihydro-8-methoxy-1′,3′,3′-trimethyl-6-nitrospiro [2H-1-benzopyran-2,2′-(2H)-indole] (indole) and,3-dihydro-1,3,3-trimethylspiro [2H-indole-2,3′-[3H] phenanthr [9,10-b] (1,4) oxazine] (oxazine) into PVA polymer matrix via electrospinning technique. The resultant nanofibers were measured for recording–erasing, photo-coloration and thermal reversibility. The rate of photo-coloration of PVA–indole nanofibers was five times higher than the PVA–oxazine nanofibers, whereas the thermal reversibility found to be more than twice as fast as PVA–oxazine nanofibers. Results showed that the resultant nanofibers have very good capability of recording QR codes multiple times. The FTIR spectroscopy and SEM were employed to characterize the electrospun nanofibers. The UV-responsive PVA nanofibers have great potentials as a light-driven nanomaterials incorporated within sensors, sensitive displays and in optical devices such as erasable and rewritable optical storage.

  6. Preparation of photocrosslinkable polystyrene methylene cinnamate nanofibers via electrospinning.

    Science.gov (United States)

    Yi, Chuan; Nirmala, R; Navamathavan, R; Li, Xiang-Dan; Kim, Hak-Yong

    2011-10-01

    Nanoscaled photocrosslinkable polystyrene methylene cinnamate (PSMC) nanofibers were fabricated by electrospinning. The PSMC was prepared by the modification of polystyrene as a starting material via a two-step reaction process, chloromethylation and esterification. The chemical structure of PSMC was confirmed by 1H NMR and Fourier transform infrared spectroscopy (FT-IR). The photosensitivity of the PSMC was investigated using ultraviolet (UV) spectroscopic methods. Electrospun PSMC nanofiber mat showed excellent solubility in many organic solvents. UV irradiation of the electrospun mats led to photodimerization to resist dissolving in organic solvents. The morphology of the nanofiber was observed by scanning electron microscopy (SEM) and the result indicated that the average diameter of nanofibers is 350 nm and the crosslinked nanofibers were not collapsed after dipping into organic solvent showing good solvent-stability. This photocrosslinked nanofibers has the potential application in filtration, catalyst carrier and protective coating.

  7. Preparation of natural brucite nanofibers by the dispersion method

    Institute of Scientific and Technical Information of China (English)

    Li Xu; Wen Ni; Wenping Li; Xingde Liu; Hailong Yang; Xiaoguang Yang

    2008-01-01

    The preparation of natural brucite nanofibers through dispersion by the wet process is described. The test results indicate that brucite fibers can be well dispersed by using sodium dioctyl sulfosuccinate (OT) as the dispersant at a dispersant/fiber mass ratio of 0.15:1, dispersing for 30 min at a water/solid mass ratio of 20:1. The prepared nanofibers were characterized with X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). It is shown that the prepared single brucite nanofiber is around 30 run in diameter and the talus of the nonsingle brucite nanofibers is about 50-150 nm in diameter. Natural brucite mineral fibers were treated by the dispersion method to obtain nanomaterials. These fibers have significant advantages over artificial nanofibers both in yield and in cost.

  8. Preparation, characterization of electrospun meso-hydroxylapatite nanofibers and their sorptions on Co(II)

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hualin, E-mail: hlwang@hfut.edu.cn [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China); Zhang, Peng; Ma, Xingkong; Jiang, Suwei; Huang, Yan; Zhai, Linfeng [School of Chemical Technology, Hefei University of Technology, Hefei, Anhui 230009 (China); Jiang, Shaotong [School of Biotechnology and Food Engineering, Hefei University of Technology, Hefei, Anhui 230009 (China)

    2014-01-30

    Highlights: • PVA/HA nanofibers could change into meso-HA nanofibers by calcination process. • Sorption of Co(II) on meso-HA was strongly dependent on pH and ionic strength. • Sorption kinetic data were well fitted by the pseudo-second-order rate equation. • Sorption isotherms could be well described by the Langmuir model. • Sorption process of Co(II) on meso-HA nanofibers was spontaneous and endothermic. -- Abstract: In this work, mesoporous hydroxylapatite (meso-HA) nanofibers were prepared via calcination process with polyvinyl alcohol/HA (PVA/HA) hybrid nanofibers fabricated by electrospinning technique as precursors, and the removal efficiency of meso-HA nanofibers toward Co(II) was evaluated via sorption kinetics and sorption isotherms. Furthermore, the sorption behaviors of Co(II) on meso-HA nanofibers were explored as a function of pH, ionic strength, and thermodynamic parameters. There existed hydrogen bonds between HA and PVA matrix in precursor nanofibers which could change into meso-HA nanofibers with main pore diameter at 27 nm and specific surface area at 114.26 m{sup 2}/g by calcination process. The sorption of Co(II) on meso-HA was strongly dependent on pH and ionic strength. Outer-sphere surface complexation or ion exchange was the main mechanisms of Co(II) adsorption on meso-HA at low pH, whereas inner-sphere surface complexation was the main adsorption mechanism at high pH. The sorption kinetic data were well fitted by the pseudo-second-order rate equation. The sorption isotherms could be well described by the Langmuir model. The thermodynamic parameters (ΔH°, ΔS° and ΔG°) calculated from the temperature-dependent sorption isotherms suggested that the sorption process of Co(II) on meso-HA nanofibers was spontaneous and endothermic.

  9. Fabrication of WS2 nanofibers from WO3 nanofibers prepared by an electrospinning method.

    Science.gov (United States)

    Zhu, Yajun; Zhang, Xuebin; Ji, Yi; Feng, Yi; Zhang, Jingcheng

    2013-03-01

    This paper describes a procedure of synthesizing long WS2 nanofibers. WO3 nanofibers were prepared as precursors by electrospinning of ammonium meta-tungstate (AMT), polyvinyl alcohol (PVA) and alcohol solution followed by calcination at 550 degrees C in air. WS2 nanofibers were obtained by sulfurization of the WO3 nanofibres at 800 degrees C in an argon atmosphere, with sulfur powder acting as sulfuration reducer. The nanofibres were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and transmission electron microscopy (TEM). The results show that the final products are pure WS2 nanofibres, which have high aspect ratio. The WS2 nanofibers with rough surface were formed of nanoparticles, while some nanoflakes appeared on the surface of WS2 nanofibres. The diameters of the WS2 nanofibers were between 200 and 300 nm, which is similar to WO3 nanofibers. In addition, the WS2 nanofibers were polycrystalline.

  10. Polysulfone nanofibers prepared by electrospinning and gas/jet-electrospinning

    Institute of Scientific and Technical Information of China (English)

    Yao Yongyi; Zhu Puxin; Ye Hai; Niu Anjian; Gao Xushan; Wu Dacheng

    2006-01-01

    Polysulfone nanofibers were prepared by electrospinning.The electrospinning equipment was designed in a new way,wherein the spinneret was combined with a gas jet device.The intrinsic viscosity of the used polysulfone was 0.197 dL/g in dimethyl acetamide,which was also the solvent in electrospinning.The gas used in this gas jet/electrostatic spinning was nitrogen.The relationship between the process parameters and the average diameter of polysulfone nanofibers was investigated.The main process parameters studied in this work were the voltage,the flow rate of the spinning fluid,the distance between the spinneret and the nanofiber collector and the temperature in the spinning chamber.The other important factors determining the nanometer diameter were the spinning fluid properties including its viscosity,surface tension and electrical conductivity.The average diameter and the diameter distribution of electrospinning nanofibers were measured experimentally by using scanning electron microscopy.The diameter of polysnlfone nanofibers prepared by the gas jet/electrostatic spinning was in the range 50-500 nm.It was found that the diameter of nanofibers mainly depended on high voltage,the gap between the spinneret and the collector and the concentration of polymer solutions.It is concluded that the gas-jet/electrospinning is a better method than the conventional electrospinning,in that it makes the nanofibers finer and more uniform and exhibits higher efficiency in the process of electrospinning.

  11. High performance carbon nanotube - polymer nanofiber hybrid fabrics

    Science.gov (United States)

    Yildiz, Ozkan; Stano, Kelly; Faraji, Shaghayegh; Stone, Corinne; Willis, Colin; Zhang, Xiangwu; Jur, Jesse S.; Bradford, Philip D.

    2015-10-01

    Stable nanoscale hybrid fabrics containing both polymer nanofibers and separate and distinct carbon nanotubes (CNTs) are highly desirable but very challenging to produce. Here, we report the first instance of such a hybrid fabric, which can be easily tailored to contain 0-100% millimeter long CNTs. The novel CNT - polymer hybrid nonwoven fabrics were created by simultaneously electrospinning nanofibers onto aligned CNT sheets which were drawn and collected on a grounded, rotating mandrel. Due to the unique properties of the CNTs, the hybrids show very high tensile strength, very small pore size, high specific surface area and electrical conductivity. In order to further examine the hybrid fabric properties, they were consolidated under pressure, and also calendered at 70 °C. After calendering, the fabric's strength increased by an order of magnitude due to increased interactions and intermingling with the CNTs. The hybrids are highly efficient as aerosol filters; consolidated hybrid fabrics with a thickness of 20 microns and areal density of only 8 g m-2 exhibited ultra low particulate (ULPA) filter performance. The flexibility of this nanofabrication method allows for the use of many different polymer systems which provides the opportunity for engineering a wide range of nanoscale hybrid materials with desired functionalities.Stable nanoscale hybrid fabrics containing both polymer nanofibers and separate and distinct carbon nanotubes (CNTs) are highly desirable but very challenging to produce. Here, we report the first instance of such a hybrid fabric, which can be easily tailored to contain 0-100% millimeter long CNTs. The novel CNT - polymer hybrid nonwoven fabrics were created by simultaneously electrospinning nanofibers onto aligned CNT sheets which were drawn and collected on a grounded, rotating mandrel. Due to the unique properties of the CNTs, the hybrids show very high tensile strength, very small pore size, high specific surface area and electrical

  12. Preparation and Electrochemical Properties of Silver Doped Hollow Carbon Nanofibers

    Directory of Open Access Journals (Sweden)

    LI Fu

    2016-11-01

    Full Text Available Silver doped PAN-based hollow carbon nanofibers were prepared combining co-electrospinning with in situ reduction technique subsequently heat treatment to improve the electrochemical performances of carbon based supercapacitor electrodes. The morphology, structure and electrochemical performances of the resulted nanofiber were studied. The results show that the silver nanoparticles can be doped on the surface of hollow carbon nanofibers and the addition of silver favors the improvement of the electrochemical performances, exhibiting the enhanced reversibility of electrode reaction and the capacitance and the reduced charge transfer impedance.

  13. Preparation of electrospun Ag/g-C3N4 loaded composite carbon nanofibers for catalytic applications

    Science.gov (United States)

    Yu, Bo; Liu, Yongkun; Jiang, Guohua; Liu, Depeng; Yu, Weijiang; Chen, Hua; Li, Lei; Huang, Qin

    2017-01-01

    In this paper, the electrospun Ag nanoparticles and g-C3N4 (Ag/g-C3N4) loaded composite carbon nanofibers were successfully prepared combing the electrospinning technology and carbonization treatment. The composition and microstructure of the resultant composite nanofibers were characterized by x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM) and x-ray photoelectron spectrometry (XPS). Due to the synergistic effect between catalytic activity of Ag nanoparticles (NPs) and g-C3N4 and excellent adsorption capacity of carbon nanofibers, the resultant electrospun Ag/g-C3N4 loaded composite carbon nanofibers exhibited excellent conversion of 4-nitrophenol to 4-aminophenol and benzylamine to N-benzylbenzaldimine. The resultant hybrid carbon composite nanofibers offer the significant advantages, such as low dosage, high catalytic activity, easy recycling and excellent stability.

  14. Biologically Active Polycaprolactone/Titanium Hybrid Electrospun Nanofibers for Hard Tissue Engineering

    DEFF Research Database (Denmark)

    Barakat, Nasser A. M.; Sheikh, Faheem A.; Al-Deyab, Salem S.

    2011-01-01

    In this study, a novel strategy to improve the bioactivity of polycaprolactone nanofibers is proposed. Incorporation of pure titanium nanoparticles into polycaprolactone nanofibers strongly enhances the precipitation of bone-like apatite materials when the doped nanofibers are soaked in a simulat...... nanofiber mats and the successful incorporation of the titanium nanoparticles make the prepared polycaprolactone nanofiber mat a proper candidate for the hard-tissue engineering applications....

  15. Hybrid silica-PVA nanofibers via sol-gel electrospinning.

    Science.gov (United States)

    Pirzada, Tahira; Arvidson, Sara A; Saquing, Carl D; Shah, S Sakhawat; Khan, Saad A

    2012-04-03

    We report on the synthesis of poly(vinyl alcohol) (PVA)-silica hybrid nanofibers via sol-gel electrospinning. Silica is synthesized through acid catalysis of a silica precursor (tetraethyl orthosilicate (TEOS) in ethanol-water), and fibers are obtained by electrospinning a mixture of the silica precursor solution and aqueous PVA. A systematic investigation on how the amount of TEOS, the silica-PVA ratio, the aging time of the silica precursor mixture, and the solution rheology influence the fiber morphology is undertaken and reveals a composition window in which defect-free hybrid nanofibers with diameters as small as 150 nm are obtained. When soaked overnight in water, the hybrid fibers remain intact, essentially maintaining their morphology, even though PVA is soluble in water. We believe that mixing of the silica precursor and PVA in solution initiates the participation of the silica precursor in cross-linking of PVA so that its -OH group becomes unavailable for hydrogen bonding with water. FTIR analysis of the hybrids confirms the disappearance of the -OH peak typically shown by PVA, while formation of a bond between PVA and silica is indicated by the Si-O-C peak in the spectra of all the hybrids. The ability to form cross-linked nanofibers of PVA using thermally stable and relatively inert silica could broaden the scope of use of these materials in various technologies.

  16. Formation of inorganic nanofibers by heat-treatment of poly(vinyl alcohol-zirconium compound hybrid nanofibers

    Directory of Open Access Journals (Sweden)

    Nakane K.

    2013-01-01

    Full Text Available Poly(vinyl alcohol-zirconium compound hybrid nanofibers (precursors were formed by electrospinning employing water as a solvent for the spinning solution. The precursors were converted into oxide (ZrO2, carbide (ZrC or nitride (ZrN nanofibers by heating them in air, Ar or N2 atmospheres. Monoclinic ZrO2 nanofibers with high-specific surface area were obtained by heat-treatment of the precursors in air. ZrC and ZrN nanofibers could be obtained below theoretical temperatures calculated from thermodynamics data.

  17. High performance carbon nanotube--polymer nanofiber hybrid fabrics.

    Science.gov (United States)

    Yildiz, Ozkan; Stano, Kelly; Faraji, Shaghayegh; Stone, Corinne; Willis, Colin; Zhang, Xiangwu; Jur, Jesse S; Bradford, Philip D

    2015-10-28

    Stable nanoscale hybrid fabrics containing both polymer nanofibers and separate and distinct carbon nanotubes (CNTs) are highly desirable but very challenging to produce. Here, we report the first instance of such a hybrid fabric, which can be easily tailored to contain 0-100% millimeter long CNTs. The novel CNT - polymer hybrid nonwoven fabrics were created by simultaneously electrospinning nanofibers onto aligned CNT sheets which were drawn and collected on a grounded, rotating mandrel. Due to the unique properties of the CNTs, the hybrids show very high tensile strength, very small pore size, high specific surface area and electrical conductivity. In order to further examine the hybrid fabric properties, they were consolidated under pressure, and also calendered at 70 °C. After calendering, the fabric's strength increased by an order of magnitude due to increased interactions and intermingling with the CNTs. The hybrids are highly efficient as aerosol filters; consolidated hybrid fabrics with a thickness of 20 microns and areal density of only 8 g m(-2) exhibited ultra low particulate (ULPA) filter performance. The flexibility of this nanofabrication method allows for the use of many different polymer systems which provides the opportunity for engineering a wide range of nanoscale hybrid materials with desired functionalities.

  18. Preparation and biomedical applications of chitin and chitosan nanofibers.

    Science.gov (United States)

    Azuma, Kazuo; Ifuku, Shinsuke; Osaki, Tomohiro; Okamoto, Yoshiharu; Minami, Saburo

    2014-10-01

    Chitin (β-(1-4)-poly-N-acetyl-D-glucosamine) is widely distributed in nature and is the second most abundant polysaccharide after cellulose. Chitin occurs in nature as ordered macrofibrils. It is the major structural component in the exoskeleton of crab and shrimp shells and the cell wall of fungi and yeast. As chitin is not readily dissolved in common solvents, it is often converted to its more deacetylated derivative, chitosan. Chitin, chitosan, and its derivatives are widely used in tissue engineering, wound healing, and as functional foods. Recently, easy methods for the preparation of chitin and chitosan nanofibers have been developed, and studies on biomedical applications of chitin and chitosan nanofibers are ongoing. Chitin and chitosan nanofibers are considered to have great potential for various biomedical applications, because they have several useful properties such as high specific surface area and high porosity. This review summarizes methods for the preparation of chitin and chitosan nanofibers. Further, biomedical applications of chitin and chitosan nanofibers in (i) tissue engineering, (ii) wound dressing, (iii) cosmetic and skin health, (iv) stem cell technology, (v) anti-cancer treatments and drug delivery, (vi) anti-inflammatory treatments, and (vii) obesity treatment are summarized. Many studies indicate that chitin and chitosan nanofibers are suitable materials for various biomedical applications.

  19. Preparation of polysilsesquioxane-urethaneacrylate copolymer film reinforced with chitin nanofibers.

    Science.gov (United States)

    Ifuku, Shinsuke; Ikuta, Akiko; Hosomi, Tetsuya; Kanaya, Shingo; Shervani, Zameer; Morimoto, Minoru; Saimoto, Hiroyuki

    2012-07-01

    Chitin nanofibers (CNFs) reinforced silsesquioxane-urethaneacrylate (SSQ-UA) copolymer films were prepared. CNFs-SSQ-UA nanocomposite films were highly transparent due to the filling of nanometer sized (10-20 nm) CNFs inside the hybrid organic-inorganic SSQ-UA copolymer. CNFs due to their crystalline structure drastically increased Young's moduli and the tensile strengths of the composite and decreased the thermal expansion. High thermal stability of polysilsesquioxane improved heat resistance of CNFs.

  20. PAN Nanofibers Reinforced with MMT/GO Hybrid Nanofillers

    Directory of Open Access Journals (Sweden)

    Qingqing Wang

    2014-01-01

    Full Text Available Single component nanofiller has shown some limitations in its performance, which can be overcome by hybrid nanofillers with two different components. In this work, montmorillonite (MMT/graphene oxide (GO hybrid nanofillers were formed by self-assembly and then incorporated into the polyacrylonitrile (PAN nanofibers by electrospinning process. X-ray diffraction (XRD, atomic force microscopy (AFM, and transmission electron microscopy (TEM were utilized to analyze the structures of MMT/GO hybrid nanofillers. And the effects of MMT/GO hybrid nanofillers on the morphology, thermal stability, and mechanical properties of PAN/MMT/GO composite nanofibrous membrane were examined by scanning electron microscopy (SEM, thermogravimetric analysis (TGA, and tensile test machine, respectively. The incorporation of MMT/GO hybrid nanofillers into PAN nanofibers showed a noticeable increase up to 30°C for the onset decomposition temperature and 1.32 times larger tensile strength than the pure PAN, indicating that the hybrid nanofiller is a promising candidate in improving thermal and mechanical properties of polymers.

  1. Preparation of Electrically Conductive Polystyrene/Carbon Nanofiber Nanocomposite Films

    Science.gov (United States)

    Sun, Luyi; O'Reilly, Jonathan Y.; Tien, Chi-Wei; Sue, Hung-Jue

    2008-01-01

    A simple and effective approach to prepare conductive polystyrene/carbon nanofiber (PS/CNF) nanocomposite films via a solution dispersion method is presented. Inexpensive CNF, which has a structure similar to multi-walled carbon nanotubes, is chosen as a nanofiller in this experiment to achieve conductivity in PS films. A good dispersion is…

  2. PREPARATION OF CARBON NANOFIBERS BY POLYMER BLEND TECHNIQUE

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The polymer blend technique is a novel method to produced carbon nanofibers. In this paper, we have prepared fine carbon fibers and porous carbon materials by this technique, and we will discuss the experiment results by means of SEM, TGA, Element Analysis, etc.

  3. Advances in Poly(4-aminodiphenylaniline) Nanofibers Preparation by Electrospinning Technique.

    Science.gov (United States)

    Della Pina, C; Busacca, C; Frontera, P; Antonucci, P L; Scarpino, L A; Sironi, A; Falletta, E

    2016-05-01

    Polyaniline (PANI) nanofibers are drawing a great deal of interest from academia and industry due to their multiple applications, especially in biomedical field. PANI nanofibers were successfully electrospun for the first time by MacDiarmid and co-workers at the beginning of the millennium and since then many efforts have been addressed to improve their quality. However, traditional PANI prepared from aniline monomer shows some drawbacks, such as presence of toxic (i.e., benzidine) and inorganic (salts and metals) co-products, that complicate polymer post-treatment, and low solubility in common organic solvents, making hard its processing by electrospinning technique. Some industrial sectors, such as medical and biomedical, need to employ materials free from toxic and polluting species. In this regard, the oxidative polymerization of N-(4-aminophenyl)aniline, aniline dimer, to produce poly(4-aminodiphenylaniline), P4ADA, a kind of PANI, represents an innovative alternative to the traditional synthesis because the obtained polymer results free from carcinogenic and/or polluting co-products, and, moreover, more soluble than traditional PANI. This latter feature can be exploited to obtain P4ADA nanofibers by electrospinning technique. In this paper we report the advances obtained in the P4ADA nanofibers electrospinnig. A comparison among polyethylene oxide (PEO), polymethyl methacrylate (PMMA) and polystyrene (PS), as the second polymer to facilitate the electrospinning process, is shown. In order to increase the conductivity of P4ADA nanofibers, two strategies were adopted and compared: selective insulating binder removal from electrospun nanofibers by a rinsing tratment, afterwards optimizing the minimum amount of binder necessary for the electrospinning process. Moreover, the effect of PEO/P4ADA weight ratio on the fibers morphology and conductivity was highlighted.

  4. 聚合物/TiO_2杂化纳米纤维微孔膜的制备及其在染料敏化太阳能电池中的应用%Preparation of Polymer/TiO2 Hybrid Nanofibers Microporous Membranes and Its Application in Dye-Sensitized Solar Cells

    Institute of Scientific and Technical Information of China (English)

    黄先威; 邓继勇; 许律; 沈平; 赵斌; 谭松庭

    2012-01-01

    The electrospinning technique provides a simple,cost-effective approach for producing polymeric and inorganic nanofibers with structures that vary with the processing parameters.In this paper,the polymer/TiO2 hybrid nanofibers microporous membranes were prepared from a polymer solution containing titanium(IV) butoxide(TBT) by electrospinning technique.The as-spun nanofibers microporous membranes were placed in air for 5 h to allow complete hydrolysis.The morphology of the microporous membranes was observed using electron scanning microscopy(SEM) under vacuum condition.The uptake and porosity of microporous membranes were investigated by weighting method before and after soaking electrolyte.The ionic conductivity of the microporous membranes was measured using the complex impedance technique.The blocking cell of stainless steel/microporous membranes/stainless steel was used at 1—105 Hz frequency range at 25 ℃.The AC amplitude was 5 mV.The TiO2 electrode was obtained by spreading titania paste(P25) on the conducting glass substrate using a doctor blade technique.The dye-sensitized solar cells(DSSCs) devices were fabricated based on the microporous membrane electrolyte by sandwiching a slice of the polymer/TiO2 hybrid nanofibers microporous membrane between a dye-sensitized TiO2 electrode and a Pt counter electrode.The edges of the cell were sealed with narrow strips of Surlyn hot melt.The morphology and three-dimensional structure of polymer/TiO2 hybrid nanofibers microporous membranes did not markedly change after absorbing liquid electrolyte,which indicated that the introduction of TiO2 into polymer nanofibers could improve the mechanical properties of the nanofibers.These also made the polymer/TiO2hybrid nanofibers microporous membranes possess high uptake and porosity.The TiO2 content in hybrid nanofibers was about 50 wt% according to the TG results.The wetting and diffusion properties of hybrid nanofibers microporous membranes to liquid

  5. Ethylene tetrafluoroethylene nanofibers prepared by CO2 laser supersonic drawing

    Directory of Open Access Journals (Sweden)

    A. Suzuki

    2013-06-01

    Full Text Available Ethylene tetrafluoroethylene (ETFE nanofibers were prepared by carbon dioxide (CO2 laser irradiation of asspun ETFE fibers with four different melt flow rates (MFRs in a supersonic jet that was generated by blowing air into a vacuum chamber through the fiber injection orifice. The drawability and superstructure of fibers produced by CO2 laser supersonic drawing depend on the laser power, the chamber pressure, the fiber injection speed, and the MFR. Nanofibers obtained using a laser power of 20 W, a chamber pressure of 20 kPa, and an MFR of 308 g•10 min–1 had an average diameter of 0.303 µm and a degree of crystallinity of 54%.

  6. Preparation of poly (Vinyl Alcohol) nanofibers containing silver nanoparticles by gamma-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yun Hye [AMOTECH Co., Ltd., Kimpo (Korea, Republic of); Shin, Jun Wha; An, Sung Jun; Youn, Min Ho; Lim, Youn Mook; Gwon, Hui Jeong; Nho, Young Chang [Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2008-08-15

    PVA nanofibers containing silver nanoparticles were prepared by two methods. The first method was electrospinning of irradiated solution. The prepared PVA/AgNO{sub 3} solution was irradiated by gamma-rays. And then the irradiated solution was electrospun. The second method was irradiation of electrospun nanofibers. Nanofibers prepared by electrospinning of unirradiated PVA/AgNO{sub 3} solution. The morphology of the nanofibers was observed with a SEM, TEM. When the irradiated PVA/AgNO{sub 3} solution were electrospun, the average size of the Ag nanoparticles was increased, but their number was decreased.

  7. Coaxial Electrospinning Method for the Preparation of TiO2 @CdS/PVA Composite Nanofiber Mat and Investigation on its Photodegradation Catalysis.

    Science.gov (United States)

    Luo, Yanmei; Jia, Yiru; Zhang, Dexian; Cheng, Xinjian

    2016-07-01

    TiO2 /PVA composite nanofiber mat was prepared via an electrospinning technology. SH-TiO2 -SiO2 hybrid particles and PVA solution were injected through a coaxial syringe, yielding a composite nanofiber mat. The as-prepared SH-TiO2 -SiO2 /PVA composite nanofiber mat was immersed in Cd(2+) cation solution and S(2-) anion solution in turn. Thus, yellow TiO2 @CdS/PVA composite nanofiber mats were prepared. By adjusting the number of times a mat was immersed in the Cd(2+) and S(2-) solutions, different amounts of CdS particles attaching to the mats were obtained. Both SH-TiO2 -SiO2 /PVA and TiO2 @CdS/PVA composite nanofiber mats were employed to catalyze the photodegradation of a model dye, methylene blue. The photodegradation performance could be greatly enhanced by the introduction of CdS particles anchoring onto TiO2 particles. The photodegradation efficiency reached 99.2% within 180 min. Also, the nanofiber mat could be recycled and reused at least 10 times. The photodegradation efficiency of TiO2 @CdS/PVA composite nanofiber mats remained 68.8% for 10 cycles.

  8. Preparation of Ag/HBP/PAN Nanofiber Web and Its Antimicrobial and Filtration Property

    Directory of Open Access Journals (Sweden)

    Li-Rong Yao

    2016-01-01

    Full Text Available To widen the application of nanofibers web in the field of medical health materials, a new Ag/amino-terminated hyperbranched polymer (HBP/polyacrylonitrile (PAN nanofiber web with excellent antimicrobial activity and filtration property was produced with Ag/HBP dispersion solution and PAN nanofiber. Ag/HBP dispersion solution was prepared with HBP as reducer and stabilizer, and Ag/HBP/PAN nanofiber was prepared by modifying electrospun PAN nanofiber with Ag/HBP aqueous solution. The characterization results showed that spherical Ag nanoparticles were prepared and they had a narrow distribution in HBP aqueous solution. The results of Ag/HBP/PAN nanofiber characterized with SEM and EDS showed that the content of silver nanoparticles on the surface of PAN nanofiber was on the increase when the treating temperature rose. The bacterial reduction rates of HBP-treated PAN nanofiber against S. aureus and E. coli were about 89%, while those of the Ag/HBP/PAN nanofiber against S. aureus and E. coli were 99.9% and 99.96%, respectively, due to the cooperative effects from the amino groups in HBP and Ag nanoparticles. Moreover, the small pores and high porosity in Ag/HBP/PAN nanofiber web resulted in high filtration efficiency (99.9% for removing smaller particles (0.1 μm~0.7 μm, which was much higher than that of the gauze mask.

  9. Characterization of Pullulan/Chitosan Oligosaccharide/Montmorillonite Nanofibers Prepared by Electrospinning Technique.

    Science.gov (United States)

    Rabbani, Mohammad Mahbub; Yang, Seong Baek; Park, Soo-Jin; Oh, Weontae; Yeum, Jeong Hyun

    2016-06-01

    Pullulan/Chitosan oligosaccharide (COS)/Montmorillonite (MMT) hybrid nanofibers were electrospun from their aqueous solution using different Pullulan/COS mass ratios and variable amounts of MMT. The effects of Pullulan/COS mass ratios and MMT contents on the morphologies and properties of PulluIan/COS/MMT hybrid nanofibers were investigated. The obtained nanofibers were characterized with field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), and tensile strength measurement. The Pullulan/COS mass ratio and MMT contents significantly influence the morphologies and properties of the Pullulan/COS/MMT hybrid nanofibers. Higher Pullulan contents than COS contents forms uniform and bead free nanofibers. The addition of COS to Pullulan improves the thermal stability of Pullulan/COS blend nanofibers. The incorporation of MMT to the Pullulan/COS/MMT hybrid nanofibers increase their fiber diameter, improves their thermal stability and tensile strength. These morphological changes and property enhancement depend on the amount of MMT added. The XRD and TEM results suggest the coexistence of Pullulan, COS and MMT within polymer matrix through intercalation of polymer chain between silicate layers forming well-ordered multiplayer morphology with alternating polymeric and silicate layers.

  10. Structural and mechanical properties of cellulose acetate/graphene hybrid nanofibers: Spectroscopic investigations

    Directory of Open Access Journals (Sweden)

    B. S. Kim

    2013-06-01

    Full Text Available Cellulose acetate/graphene (CA/graphene and cellulose acetate/graphene-COOH (CA/graphene-COOH hybrid nanofibers were fabricated via electrospinning technique, and their morphologies, crystallinity and mechanical properties were investigated. The added amounts of graphene and graphene-COOH were varied from 0.5 to 5.0 wt%. The crystal structures and morphologies of the resultant hybrid nanofibers were investigated by wide angle X-ray diffraction (WAXD, scanning electron microscopy (SEM and transmission electron microscopy (TEM, respectively. Graphene-COOH incorporated CA nanofiber mats showed higher Young’s modulus of about 910 MPa among than those of CA/graphene nanofibers, which is due to molecular interactions between –COOH groups in acid-treated graphene and C=O groups in CA via hydrogen bonding. This specific interaction was demonstrated by spectroscopic studies (Raman and Fourier transform infrared (FT-IR spectroscopies.

  11. Preparation and characterization of Ag nanoparticle-embedded polymer electrospun nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Dong Guoping, E-mail: guoping_dong@163.com; Xiao Xiudi; Liu, Xiaofeng; Qian Bin [Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics (China); Ma Zhijun; Ye Song [Zhejiang University, State Key Laboratory of Silicon Materials (China); Chen Danping [Chinese Academy of Sciences, Shanghai Institute of Optics and Fine Mechanics (China); Qiu Jianrong, E-mail: jrqiu@zju.edu.c [Zhejiang University, State Key Laboratory of Silicon Materials (China)

    2010-05-15

    Poly (vinyl alcohol) (PVA) and poly (vinyl pyrrolidone) (PVP) nanofibers embedding Ag nanoparticles (5-18 nm) have been prepared successfully by electrospinning at room temperature. Scanning electron microscope (SEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), Fourier transform IR spectra (FTIR), and Raman scattering were used to characterize the structure and properties of Ag nanoparticle-embedded PVA and PVP nanofibers before and after heat treatment at different temperature. The antibacterial activity of Ag nanoparticle-embedded PVP nanofibers after heat treatment was also tested, which indicated that the biological activity of yeast cells was effectively inhibited by these Ag nanoparticle-embedded PVP nanofibers.

  12. Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone composite nanofibers

    Directory of Open Access Journals (Sweden)

    Ji-Hong Chai

    2013-03-01

    Full Text Available Nanofibers containing ferrocene (Fc have been prepared for the first time by electrospinning. In this paper, Fc was dispersed uniformly throughout the poly(vinypyrrolidone (PVP matrix for the purpose of combining the properties of PVP and Fc. The effects of solvents and Fc concentration on the morphologies and diameters of nanofibers were investigated. In the DMF/ethanol solvent, the morphologies of the obtained nanofibers significantly changed with the increase of Fc concentration. The results demonstrated that the morphologies of the nanofibers could be controlled through adjusting solvents and Fc concentration. Scanning electron microscopy (SEM showed that the diameters of the obtained composite fibers were about 30–200 nm at different Fc concentrations. Thermogravimetric analysis (TGA results confirmed the presence of ferrocene within the PVP nanofibers. X-ray diffraction (XRD results showed that the crystalline structure of Fc in the fibers was amorphous after the electrospinning process. A biological evaluation of the antimicrobial activity of Fc/PVP nanofibers was carried out by using Gram-negative Escherichia coli (E. coli as model organisms. The nanofibers fabricated by this method showed obvious antibacterial activity. Electrochemical properties were characterized based on cyclic voltammetry measurements. The CV results showed redox peaks corresponding to the Fc+/Fc couple, which suggested that Fc molecules encapsulated inside PVP nanofibers retian their electrochemical activity. The properties and facile preparation method make the Fc/PVP nanofibers promising for antibacterial and sensing applications.

  13. Cell studies of hybridized carbon nanofibers containing bioactive glass nanoparticles using bone mesenchymal stromal cells

    Science.gov (United States)

    Zhang, Xiu-Rui; Hu, Xiao-Qing; Jia, Xiao-Long; Yang, Li-Ka; Meng, Qing-Yang; Shi, Yuan-Yuan; Zhang, Zheng-Zheng; Cai, Qing; Ao, Yin-Fang; Yang, Xiao-Ping

    2016-12-01

    Bone regeneration required suitable scaffolding materials to support the proliferation and osteogenic differentiation of bone-related cells. In this study, a kind of hybridized nanofibrous scaffold material (CNF/BG) was prepared by incorporating bioactive glass (BG) nanoparticles into carbon nanofibers (CNF) via the combination of BG sol-gel and polyacrylonitrile (PAN) electrospinning, followed by carbonization. Three types (49 s, 68 s and 86 s) of BG nanoparticles were incorporated. To understand the mechanism of CNF/BG hybrids exerting osteogenic effects, bone marrow mesenchymal stromal cells (BMSCs) were cultured directly on these hybrids (contact culture) or cultured in transwell chambers in the presence of these materials (non-contact culture). The contributions of ion release and contact effect on cell proliferation and osteogenic differentiation were able to be correlated. It was found that the ionic dissolution products had limited effect on cell proliferation, while they were able to enhance osteogenic differentiation of BMSCs in comparison with pure CNF. Differently, the proliferation and osteogenic differentiation were both significantly promoted in the contact culture. In both cases, CNF/BG(68 s) showed the strongest ability in influencing cell behaviors due to its fastest release rate of soluble silicium-relating ions. The synergistic effect of CNF and BG would make CNF/BG hybrids promising substrates for bone repairing.

  14. Preparation of nanofibers consisting of MnO/Mn3O4 by using the electrospinning technique: the nanofibers have two band-gap energies

    Science.gov (United States)

    Barakat, Nasser A. M.; Woo, Kee-Do; Ansari, S. G.; Ko, Jung-Ahn; Kanjwal, Muzafar A.; Kim, Hak Yong

    2009-06-01

    In the present study, nanofibers consisting of manganese monoxide (MnO), which is hard to prepare because of the chemical activity of the manganese metal, and the popular Mn3O4 have been synthesized via the electrospinning technique. The nanofibers were obtained by electrospinning of an aqueous sol-gel consisting of manganese acetate tetra-hydrate and poly(vinyl alcohol). The obtained nanofiber mats were dried in vacuum at 80°C for 24 h and then calcined in argon atmosphere at 900°C for 5 h. According to X-ray diffraction results, the obtained nanofibers contain 65% MnO. Transmission electron microscope analysis reveals good crystallinity of the produced nanofibers. UV-visible spectroscopic analysis has indicated that the produced nanofibers have two band-gap energies, 2 and 3.7 eV, which enhances utilizing of the nanofibers in different applications.

  15. Preparation of chitosan nanofibers from completely deacetylated chitosan powder by a downsizing process.

    Science.gov (United States)

    Aklog, Yihun Fantahun; Dutta, Ajoy Kumar; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki; Ifuku, Shinsuke

    2015-01-01

    Chitosan nanofibers were easily prepared from fully deacetylated chitosan dry powder using a high-pressure waterjet system. From SEM observation, after 10 cycles of treatment, most of the chitosan had been reduced to homogeneous nanofibers measuring tens of nanometers. On the other hand, further mechanical treatment did not show a significant change. Relative crystallinity of chitosan nanofibers gradually decreased as the number of passes increased since high-pressure waterjet treatment damaged the crystalline region of chitosan nanofibers. The transmittance of the chitosan nanofiber slurry increased steeply, as the number of passes increased, indicating that the chitosan fibers were disintegrated effectively. Viscosity of chitosan nanofiber slurry also showed that the chitosan disintegrated well into nanofibers up to 10 passes. Above 10 passes, disintegration efficiency was saturated. The molecular weights of the nanofibers steeply decreased due to the depolymerization of chitosan by mechanical disintegration. The Young's modulus and tensile strength of chitosan nanofiber sheets were improved as the number of treatments increased, but further treatments deteriorated the tensile strength.

  16. Preparation and Grafting Functionalization of Self-Assembled Chitin Nanofiber Film

    Directory of Open Access Journals (Sweden)

    Jun-ichi Kadokawa

    2016-07-01

    Full Text Available Chitin is a representative biomass resource comparable to cellulose. Although considerable efforts have been devoted to extend novel applications to chitin, lack of solubility in water and common organic solvents causes difficulties in improving its processability and functionality. Ionic liquids have paid much attention as solvents for polysaccharides. However, little has been reported regarding the dissolution of chitin with ionic liquids. The author found that an ionic liquid, 1-allyl-3-methylimidazolium bromide (AMIMBr, dissolved chitin in concentrations up to ~4.8 wt % and the higher contents of chitin with AMIMBr gave ion gels. When the ion gel was soaked in methanol for the regeneration of chitin, followed by sonication, a chitin nanofiber dispersion was obtained. Filtration of the dispersion was subsequently carried out to give a chitin nanofiber film. A chitin nanofiber/poly(vinyl alcohol composite film was also obtained by co-regeneration approach. Chitin nanofiber-graft-synthetic polymer composite films were successfully prepared by surface-initiated graft polymerization technique. For example, the preparation of chitin nanofiber-graft-biodegradable polyester composite film was achieved by surface-initiated graft polymerization from the chitin nanofiber film. The similar procedure also gave chitin nanofiber-graft-polypeptide composite film. The surface-initiated graft atom transfer radical polymerization was conducted from a chitin macroinitiator film derived from the chitin nanofiber film.

  17. Physicochemical and electrochemical properties of carbon nanotube/graphite nanofiber hybrid nanocomposites for supercapacitor

    Science.gov (United States)

    Ramli, Nurul Infaza Talalah; Abdul Rashid, Suraya; Sulaiman, Yusran; Mamat, Md Shuhazlly; Mohd Zobir, Syazwan Afif; Krishnan, Shutesh

    2016-10-01

    This work reports the combination of graphitic nanofibers (GNF) and carbon nanotubes (CNT) as the electrode material for supercapacitors. The hybrid CNT/GNF was prepared via a synthesis route that involved simple sonication and stirring. The loading of CNT was varied from 5 to 40% weight percentages. A specific capacitance of 174 Fg-1 has been obtained for 20 wt% CNT loading at 50 mV F g-1th 1 M H2SO4 aqueous solution as the electrolyte. The addition of 20 wt% CNT raised the specific capacitance by 87% more than the GNF electrodes. Field Emission Scanning Electron Microscopy (FESEM) and Transmission Electron Microscope (TEM) reveals the random entanglement of CNT and GNF that create diffusion paths for ion transportation. Conformational changes were monitored by Raman spectroscopy, where two dominant peaks (D and G) showed strong intensities and sharp profiles. X-ray Diffraction spectroscopy (XRD) confirmed the purity of CNT/GNF hybrid nanocomposites. 20 wt% of CNT addition also shows an outstanding thermal stability. The marked improvement of the hybrid performance was attributed to the high conductivity of the two constituent materials, coupled with sufficient accessible active sites for electrochemical reactions that resulted in a synergistic behavior of the materials.

  18. Photocurrent enhancement in hybrid cadmium sulfide/conjugated polyaniline nanofiber composites by introducing iodine

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Chenglong; Chen, Shaoyun, E-mail: cescsy@jhun.edu.cn; Peng, Sha; Liu, Xueqing; Liu, Jiyan, E-mail: liujiyan918@163.com

    2015-12-15

    Highlights: • Iodine is coated on the polyaniline nanofiber acting as an electron donor. • The photocurrent response of PANI–CdS system is enhanced by introducing iodine. • Triiodide can improve the charge transfer and slow down the recombination. - Graphical abstract: The introduction of iodide in I{sub 2}@PANI–CdS photoelectric hybrid nanocomposite greatly improves the photocurrent response by improving the charge transfer and slowing down the recombination with injected photoelectrons. The photocurrent response of as-prepared nanocomposite could be improved from 2.86 to 5.65 mA/cm{sup 2} with increasing the content of iodide from 0 to 3.0%. - Abstract: In this paper, the effect of iodine on the photocurrent of conjugated polymer/inorganic semiconductor nanocomposites is investigated. Via a redox process, iodine nanoparticles are coated on the surface of highly active nanofiber of conjugated polyaniline (PANI), forming an electron donor (i.e., I{sub 2}@PANI). After subsequent incorporation of CdS nanoparticles (serving as electron acceptors), the photocurrent of the I{sub 2}@PANI–CdS system is greatly enhanced as compared to that of the PANI–CdS hybrid. This obvious enhancement is due to the fact that the existence of I{sub 2} causes significant improvement in the charge transfer, which has favorable penetration ability into the porous semiconductor film, fast charge transfer and relatively slow recombination with injected photoelectrons. As a result, the total concentration of charge carriers in the CdS nanoparticles may increase as compared to that in bulk CdS. As a result, the photocurrent of CdS in I{sub 2}@PANI–CdS nanocomposites is remarkably enhanced.

  19. Local sustained delivery of acetylsalicylic acid via hybrid stent with biodegradable nanofibers reduces adhesion of blood cells and promotes reendothelialization of the denuded artery.

    Science.gov (United States)

    Lee, Cheng-Hung; Lin, Yu-Huang; Chang, Shang-Hung; Tai, Chun-Der; Liu, Shih-Jung; Chu, Yen; Wang, Chao-Jan; Hsu, Ming-Yi; Chang, Hung; Chang, Gwo-Jyh; Hung, Kuo-Chun; Hsieh, Ming-Jer; Lin, Fen-Chiung; Hsieh, I-Chang; Wen, Ming-Shien; Huang, Yenlin

    2014-01-01

    Incomplete endothelialization, blood cell adhesion to vascular stents, and inflammation of arteries can result in acute stent thromboses. The systemic administration of acetylsalicylic acid decreases endothelial dysfunction, potentially reducing thrombus, enhancing vasodilatation, and inhibiting the progression of atherosclerosis; but, this is weakened by upper gastrointestinal bleeding. This study proposes a hybrid stent with biodegradable nanofibers, for the local, sustained delivery of acetylsalicylic acid to injured artery walls. Biodegradable nanofibers are prepared by first dissolving poly(D,L)-lactide-co-glycolide and acetylsalicylic acid in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution is then electrospun into nanofibrous tubes, which are then mounted onto commercially available bare-metal stents. In vitro release rates of pharmaceuticals from nanofibers are characterized using an elution method, and a highperformance liquid chromatography assay. The experimental results suggest that biodegradable nanofibers release high concentrations of acetylsalicylic acid for three weeks. The in vivo efficacy of local delivery of acetylsalicylic acid in reducing platelet and monocyte adhesion, and the minimum tissue inflammatory reaction caused by the hybrid stents in treating denuded rabbit arteries, are documented. The proposed hybrid stent, with biodegradable acetylsalicylic acid-loaded nanofibers, substantially contributed to local, sustained delivery of drugs to promote re-endothelialization and reduce thrombogenicity in the injured artery. The stents may have potential applications in the local delivery of cardiovascular drugs. Furthermore, the use of hybrid stents with acetylsalicylic acid-loaded nanofibers that have high drug loadings may provide insight into the treatment of patients with high risk of acute stent thromboses.

  20. A Sustainable Approach to Fabricating Ag Nanoparticles/PVA Hybrid Nanofiber and Its Catalytic Activity

    Directory of Open Access Journals (Sweden)

    Yongde Meng

    2015-06-01

    Full Text Available Ag nanoparticles were synthesized by using Ficus altissima Blume leaf extract as a reducing agent at room temperature. The resulting Ag nanoparticles/PVA mixture was employed to create Ag nanoparticles/PVA (polyvinyl alcohol hybrid nanofibers via an electrospinning technique. The obtained nanofibers were confirmed by means of UV-Vis spectroscopy, The X-ray diffraction (XRD, Fourier transform infrared (FTIR spectroscopy, scanning electron microscopy (SEM, transmission electron microscopy (TEM, and then tested to catalyze KBH4 reduction of methylene blue (MB. The catalytic results demonstrate that the MB can be reduced completely within 15 min. In addition, the Ag nanoparticles/PVA hybrid nanofibers show reusability for three cycles with no obvious losses in degradation ratio of the MB.

  1. Preparation of porous carbon nanofibers derived from PBI/PLLA for supercapacitor electrodes

    Science.gov (United States)

    Jung, Kyung-Hye; Ferraris, John P.

    2016-10-01

    Porous carbon nanofibers were prepared by electrospinning blend solutions of polybenzimidazole/poly-L-lactic acid (PBI/PLLA) and carbonization. During thermal treatment, PLLA was decomposed, resulting in the creation of pores in the carbon nanofibers. From SEM images, it is shown that carbon nanofibers had diameters in the range of 100-200 nm. The conversion of PBI to carbon was confirmed by Raman spectroscopy, and the surface area and pore volume of carbon nanofibers were determined using nitrogen adsorption/desorption analyses. To investigate electrochemical performances, coin-type cells were assembled using free-standing carbon nanofiber electrodes and ionic liquid electrolyte. cyclic voltammetry studies show that the PBI/PLLA-derived porous carbon nanofiber electrodes have higher capacitance due to lower electrochemical impedance compared to carbon nanofiber electrode from PBI only. These porous carbon nanofibers were activated using ammonia for further porosity improvement and annealed to remove the surface functional groups to better match the polarity of electrode and electrolyte. Ragone plots, correlating energy density with power density calculated from galvanostatic charge-discharge curves, reveal that activation/annealing further improves energy and power densities.

  2. Preparation of porous carbon nanofibers derived from PBI/PLLA for supercapacitor electrodes.

    Science.gov (United States)

    Jung, Kyung-Hye; Ferraris, John P

    2016-10-21

    Porous carbon nanofibers were prepared by electrospinning blend solutions of polybenzimidazole/poly-L-lactic acid (PBI/PLLA) and carbonization. During thermal treatment, PLLA was decomposed, resulting in the creation of pores in the carbon nanofibers. From SEM images, it is shown that carbon nanofibers had diameters in the range of 100-200 nm. The conversion of PBI to carbon was confirmed by Raman spectroscopy, and the surface area and pore volume of carbon nanofibers were determined using nitrogen adsorption/desorption analyses. To investigate electrochemical performances, coin-type cells were assembled using free-standing carbon nanofiber electrodes and ionic liquid electrolyte. cyclic voltammetry studies show that the PBI/PLLA-derived porous carbon nanofiber electrodes have higher capacitance due to lower electrochemical impedance compared to carbon nanofiber electrode from PBI only. These porous carbon nanofibers were activated using ammonia for further porosity improvement and annealed to remove the surface functional groups to better match the polarity of electrode and electrolyte. Ragone plots, correlating energy density with power density calculated from galvanostatic charge-discharge curves, reveal that activation/annealing further improves energy and power densities.

  3. UV-responsive polyvinyl alcohol nanofibers prepared by electrospinning

    Science.gov (United States)

    Khatri, Zeeshan; Ali, Shamshad; Khatri, Imran; Mayakrishnan, Gopiraman; Kim, Seong Hun; Kim, Ick-Soo

    2015-07-01

    We report UV-responsive polyvinyl alcohol (PVA) nanofibers for potential application for recording and erasing quick response (QR) codes. We incorporate 1‧-3‧-dihydro-8-methoxy-1‧,3‧,3‧-trimethyl-6-nitrospiro [2H-1-benzopyran-2,2‧-(2H)-indole] (indole) and,3-dihydro-1,3,3-trimethylspiro [2H-indole-2,3‧-[3H] phenanthr [9,10-b] (1,4) oxazine] (oxazine) into PVA polymer matrix via electrospinning technique. The resultant nanofibers were measured for recording-erasing, photo-coloration and thermal reversibility. The rate of photo-coloration of PVA-indole nanofibers was five times higher than the PVA-oxazine nanofibers, whereas the thermal reversibility found to be more than twice as fast as PVA-oxazine nanofibers. Results showed that the resultant nanofibers have very good capability of recording QR codes multiple times. The FTIR spectroscopy and SEM were employed to characterize the electrospun nanofibers. The UV-responsive PVA nanofibers have great potentials as a light-driven nanomaterials incorporated within sensors, sensitive displays and in optical devices such as erasable and rewritable optical storage.

  4. Cellulose nanofiber/single-walled carbon nanotube hybrid non-woven macrofiber mats as novel wearable supercapacitors with excellent stability, tailorability and reliability

    Science.gov (United States)

    Niu, Qingyuan; Gao, Kezheng; Shao, Ziqiang

    2014-03-01

    Non-woven macrofiber mats are prepared by simply controlling the extrusion patterns of cellulose nanofiber/single-walled carbon nanotube suspensions in an ethanol coagulation bath, and drying in air under restricted conditions. These novel wearable supercapacitors based on non-woven macrofiber mats are demonstrated to have excellent tailorability, electrochemical stability, and damage reliability.Non-woven macrofiber mats are prepared by simply controlling the extrusion patterns of cellulose nanofiber/single-walled carbon nanotube suspensions in an ethanol coagulation bath, and drying in air under restricted conditions. These novel wearable supercapacitors based on non-woven macrofiber mats are demonstrated to have excellent tailorability, electrochemical stability, and damage reliability. Electronic supplementary information (ESI) available: Experimental, TEM image, IR spectra, and XRD spectra of cellulose nanofibers, photograph of the cellulose nanofiber/single-walled carbon nanotube suspension, cellulose nanofiber/single-walled carbon nanotube non-woven macrofiber mat and non-woven macrofiber mat wearable supercapacitors. The electrochemical performance of the CNF/SWCNT hybrid fiber wearable supercapacitor. Photograph of the non-woven macrofiber mat wearable supercapacitors integrated within textiles. See DOI: 10.1039/c3nr05929d

  5. Surface plasmons excited by the photoluminescence of organic nanofibers in hybrid plasmonic systems

    DEFF Research Database (Denmark)

    Sobolewska, Elzbieta; Leißner, Till; Jozefowski, Leszek

    Recent research on hybrid plasmonic systems has shown the existence of a loss channel for energy transfer between organic materials and plasmonic/metallic structured substrates. This work focuses on the exciton-plasmon coupling between para-Hexaphenylene (p-6P) organic nanofibers (ONFs) and surfa...

  6. Surface plasmons excited by the photoluminescence of organic nanofibers in hybrid plasmonic systems

    DEFF Research Database (Denmark)

    Sobolewska, Elzbieta; Leißner, Till; Jozefowski, Leszek

    2016-01-01

    Recent research on hybrid plasmonic systems has shown the existence of a loss channel for energy transfer between organic materials and plasmonic/metallic structured substrates. This work focuses on the exciton-plasmon coupling between para-Hexaphenylene (p-6P) organic nanofibers (ONFs) and surfa...

  7. Poly(hydroxybutyrate)/cellulose acetate blend nanofiber scaffolds: Preparation, characterization and cytocompatibility

    Energy Technology Data Exchange (ETDEWEB)

    Zhijiang, Cai, E-mail: caizhijiang@hotmail.com [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China); State Key Laboratory of Hollow Fiber Membrane Material and Processes, No 399 BingShuiXi Street, XiQing District, Tianjin, China, 300387 (China); Yi, Xu; Haizheng, Yang; Jia, Jianru; Liu, Yuanpei [School of Textiles, Tianjin Polytechnic University, Tianjin 300387 (China)

    2016-01-01

    Poly(hydroxybutyrate) (PHB)/cellulose acetate (CA) blend nanofiber scaffolds were fabricated by electrospinning using the blends of chloroform and DMF as solvent. The blend nanofiber scaffolds were characterized by SEM, FTIR, XRD, DSC, contact angle and tensile test. The blend nanofibers exhibited cylindrical, uniform, bead-free and random orientation with the diameter ranged from 80–680 nm. The scaffolds had very well interconnected porous fibrous network structure and large aspect surface areas. It was found that the presence of CA affected the crystallization of PHB due to formation of intermolecular hydrogen bonds, which restricted the preferential orientation of PHB molecules. The DSC result showed that the PHB and CA were miscible in the blend nanofiber. An increase in the glass transition temperature was observed with increasing CA content. Additionally, the mechanical properties of blend nanofiber scaffolds were largely influenced by the weight ratio of PHB/CA. The tensile strength, yield strength and elongation at break of the blend nanofiber scaffolds increased from 3.3 ± 0.35 MPa, 2.8 ± 0.26 MPa, and 8 ± 0.77% to 5.05 ± 0.52 MPa, 4.6 ± 0.82 MPa, and 17.6 ± 1.24% by increasing PHB content from 60% to 90%, respectively. The water contact angle of blend nanofiber scaffolds decreased about 50% from 112 ± 2.1° to 60 ± 0.75°. The biodegradability was evaluated by in vitro degradation test and the results revealed that the blend nanofiber scaffolds showed much higher degradation rates than the neat PHB. The cytocompatibility of the blend nanofiber scaffolds was preliminarily evaluated by cell adhesion studies. The cells incubated with PHB/CA blend nanofiber scaffold for 48 h were capable of forming cell adhesion and proliferation. It showed much better biocompatibility than pure PHB film. Thus, the prepared PHB/CA blend nanofiber scaffolds are bioactive and may be more suitable for cell proliferation suggesting that these scaffolds can be used for

  8. Preparations, properties and applications of chitosan based nanofibers fabricated by electrospinning

    Directory of Open Access Journals (Sweden)

    2011-04-01

    Full Text Available Chitosan is soluble in most acids. The protonation of the amino groups on the chitosan backbone inhibits the electrospinnability of pure chitosan. Recently, electrospinning of nanofibers based on chitosan has been widely researched and numerous nanofibers containing chitosan have been prepared by decreasing the number of the free amino groups of chitosan as the nanofibiers have enormous possibilities for better utilization in various areas. This article reviews the preparations and properties of the nanofibers which were electrospun from pure chitosan, blends of chitosan and synthetic polymers, blends of chitosan and protein, chitosan derivatives, as well as blends of chitosan and inorganic nanoparticles, respectively. The applications of the nanofibers containing chitosan such as enzyme immobilization, filtration, wound dressing, tissue engineering, drug delivery and catalysis are also summarized in detail.

  9. Superior hybrid hydrogels of polyacrylamide enhanced by bacterial cellulose nanofiber clusters.

    Science.gov (United States)

    Yuan, Ningxiao; Xu, Lu; Zhang, Lu; Ye, Haowen; Zhao, Jianhao; Liu, Zhong; Rong, Jianhua

    2016-10-01

    Hybrid polyacrylamide/bacterial cellulose nanofiber clusters (PAM/BC) hydrogels with high strength, toughness and recoverability were synthesized by in situ polymerization of acrylamide monomer in BC nanofiber clusters suspension. The hybrid gels exhibited an extremely large elongation at break of 2200%, and a high fracture stress of 1.35MPa. Additionally, the original length of hydrogels could be recovered after releasing the tensile force. Compressive results showed that the PAM/BC hybrid gels could reach a strain of about 99% without break, and was able to completely recover its original shape immediately after releasing the compression force. The compressive stress at 99% reached as high as 30MPa. Nearly no hysteresis in cyclic compressive tests was observed with these hybrid gels. The FT-IR, XRD and TGA analysis showed that hydrogen bonds between the PAM chains and BC nanofiber clusters mainly contributed to the superior mechanical properties of hybrid hydrogels. The cell viability results suggested that PAM/BC hybrid hydrogel was benign for biomedical application. These PAM/BC hydrogels offer a great promise as biomaterials such as bone and cartilage repair materials.

  10. Electrospinning preparation and luminescence properties of Eu(TTA)_3phen/polystyrene composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    张小萍; 温世鹏; 胡水; 张立群; 刘力

    2010-01-01

    Efficient luminescent composite nanofibers,composed of polystyrene(PS,Mw=250000) and europium complex Eu(TTA)3phen(TTA=2-thenoyltrifluoroacetone,phen=1,10-phenanthroline) with diameters ranging from 350 nm to 700 nm,were prepared by electrospinning and characterized by scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetric analysis(TG).The room-temperature fluorescence spectra of the composite nanofibers were composed of the typical E...

  11. Preparation of Mn 2O 3 and Mn 3O 4 nanofibers via an electrospinning technique

    Science.gov (United States)

    Shao, Changlu; Guan, Hongyu; Liu, Yichun; Li, Xiliang; Yang, Xinghua

    2004-07-01

    Thin PVA/manganese acetate composite fibers were prepared by using sol-gel processing and electrospinning technique. After calcinations of the above precursor fibers, Mn 2O 3 and Mn 3O 4 nanofibers with a diameter of 50-200 nm could be successfully obtained. The fibers were characterized by TG-DTA, Scanning electron microscopy, FT-IR, WAXD, respectively. The results showed that the crystalline phase and morphology of nanofibers were largely influenced by the calcination temperature.

  12. Preparation and characterization of carbon nanofiber-polymide composites

    Science.gov (United States)

    Li, Xiaobing

    Carbon nanofibers (CNFs) are potentially excellent reinforcements in polymer-based composites due to very good mechanical properties, thermal and electrical conductivity, and low cost to manufacture. The dispersion of fibers and the interfacial interaction with the polymer matrix need to be improved for CNF composites to achieve this potential. Treatment of the nanofiber surface with groups that are compatible with the polymer is key to addressing these issues. Attached functional groups may enhance the adhesion between reinforcement phase and matrix phase and reduce the slip of polymer chains on the surfaces of fibers. As a result, load can be transferred to fibers efficiently. In this investigation, CNFs were used as reinforcements in a polyimide (PI) matrix to produce a composite. To improve dispersion of fibers as well as interfacial adhesion, oxidized carbon nanofibers (OCNFs) were functionalized by covalently attaching 1,4-phenylenediamine (1,4-PDA) or polyimide oligomer to the surfaces. The functionalization with diamine was carried out either through direct reaction with OCNFs in dimethylacetimide (DMAc) solvent or through a two-step approach in which oxidized fibers were reacted with thionyl chloride (SOCl2) to improve surface reactivity followed by reaction with PDA in DMAc. The PDA was successfully bonded to the surfaces of fibers using both strategies. The further attachment of oligomer proceeded as expected in DMAc. The functionalized CNFs were characterized using Raman spectroscopy, thermal gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) to confirm the functionalization reaction. Raman spectra and XPS spectra qualitatively indicated target chemical bonds were formed in each reaction step. Quantifications of TGA and XPS consistently supported that desired chemical moieties were present on the surfaces of fibers. In short, the interfaces of fibers were tailored with groups that would mimic the structure of polyimide and can

  13. Encapsulation of amoxicillin within laponite-doped poly(lactic-co-glycolic acid) nanofibers: preparation, characterization, and antibacterial activity.

    Science.gov (United States)

    Wang, Shige; Zheng, Fuyin; Huang, Yunpeng; Fang, Yuting; Shen, Mingwu; Zhu, Meifang; Shi, Xiangyang

    2012-11-01

    We report a facile approach to encapsulating amoxicillin (AMX) within laponite (LAP)-doped poly(lactic-co-glycolic acid) (PLGA) nanofibers for biomedical applications. In this study, a synthetic clay material, LAP nanodisks, was first used to encapsulate AMX. Then, the AMX-loaded LAP nanodisks with an optimized AMX loading efficiency of 9.76 ± 0.57% were incorporated within PLGA nanofibers through electrospinning to form hybrid PLGA/LAP/AMX nanofibers. The loading of AMX within LAP nanodisks and the loading of LAP/AMX within PLGA nanofibers were characterized via different techniques. In vitro drug release profile, antimicrobial activity, and cytocompatibility of the formed hybrid PLGA/LAP/AMX nanofibers were also investigated. We show that the loading of AMX within LAP nanodisks does not lead to the change of LAP morphology and crystalline structure and the incorporation of LAP/AMX nanodisks does not significantly change the morphology of the PLGA nanofibers. Importantly, the loading of AMX within LAP-doped PLGA nanofibers enables a sustained release of AMX, much slower than that within a single carrier of LAP nanodisks or PLGA nanofibers. Further antimicrobial activity and cytocompatibility assays demonstrate that the antimicrobial activity of AMX toward the growth inhibition of a model bacterium of Staphylococcus aureus is not compromised after being loaded into the hybrid nanofibers, and the PLGA/LAP/AMX nanofibers display good cytocompatibility, similar to pure PLGA nanofibers. With the sustained release profile and the reserved drug activity, the organic/inorganic hybrid nanofiber-based drug delivery system may find various applications in tissue engineering and pharmaceutical science.

  14. Preparation and characterization of Ce-doped ZnO nanofibers by an electrospinning method

    Directory of Open Access Journals (Sweden)

    Jong-Pil Kim

    2011-02-01

    Full Text Available ZnO and Ce-doped ZnO Nanofibers on (111 Pt/SiO2/Si substrates were produced using an electrospinning technique. The as-prepared composite fibres were subjected to high-temperature calcination to produce inorganic fibers. After calcining at a temperature of 500 °C, the average diameter of the ZnO and Ce-doped ZnO nanofibers were determined to be 170 nm and 225 nm, respectively. The average grain size of the ZnO and Ce-doped ZnO nanofibers were about 50 nm and 57 nm, respectively. The microstructure, chemical bonding state and photoluminescence of the produced ZnO and Ce-doped ZnO nanofibers were investigated. The Ce-doped ZnO nanofiber can be assigned to the presence of Ce ions on substitutional sites of Zn ions and the Ce3+ state from X-ray photoelectron spectra. Compared with PL spectra of ZnO nanofibers, the peak position of the UV emission of the Ce-doped ZnO nanofibers is sharply suppressed while the green emission band is highly enhanced.

  15. Preparation of Coaxial-Electrospun Poly[bis(p-methylphenoxy]phosphazene Nanofiber Membrane for Enzyme Immobilization

    Directory of Open Access Journals (Sweden)

    Xiao-Jun Huang

    2012-11-01

    Full Text Available A core/sheath nanofiber membrane with poly[bis(p-methylphenoxy]phospha-zene (PMPPh as the sheath and easily spinnable polyacrylonitrile (PAN as the core was prepared via a coaxial electrospinning process. Field-emission scanning electron microscopy and transmission electron microscopy were used to characterize the morphology of the nanofiber membrane. It was found that the concentration of the PAN spinning solution and the ratio of the core/sheath solution flow rates played a decisive role in the coaxial electrospinning process. In addition, the stabilized core/sheath PMPPh nanofiber membrane was investigated as a support for enzyme immobilization because of its excellent biocompatibility, high surface/volume ratio, and large porosity. Lipase from Candida rugosa was immobilized on the nanofiber membrane by adsorption. The properties of the immobilized lipase on the polyphosphazene nanofiber membrane were studied and compared with those of a PAN nanofiber membrane. The results showed that the adsorption capacity (20.4 ± 2.7 mg/g and activity retention (63.7% of the immobilized lipase on the polyphosphazene nanofiber membrane were higher than those on the PAN membrane.

  16. Preparation of Amidoxime Polyacrylonitrile Chelating Nanofibers and Their Application for Adsorption of Metal Ions

    Directory of Open Access Journals (Sweden)

    You-Lo Hsieh

    2013-03-01

    Full Text Available Polyacrylonitrile (PAN nanofibers were prepared by electrospinning and they were modified with hydroxylamine to synthesize amidoxime polyacrylonitrile (AOPAN chelating nanofibers, which were applied to adsorb copper and iron ions. The conversion of the nitrile group in PAN was calculated by the gravimetric method. The structure and surface morphology of the AOPAN nanofiber were characterized by a Fourier transform infrared spectrometer (FT-IR and a scanning electron microscope (SEM, respectively. The adsorption abilities of Cu2+ and Fe3+ ions onto the AOPAN nanofiber mats were evaluated. FT-IR spectra showed nitrile groups in the PAN were partly converted into amidoxime groups. SEM examination demonstrated that there were no serious cracks or sign of degradation on the surface of the PAN nanofibers after chemical modification. The adsorption capacities of both copper and iron ions onto the AOPAN nanofiber mats were higher than those into the raw PAN nanofiber mats. The adsorption data of Cu2+ and Fe3+ ions fitted particularly well with the Langmuir isotherm. The maximal adsorption capacities of Cu2+ and Fe3+ ions were 215.18 and 221.37 mg/g, respectively.

  17. Hybrid Quantum System of a Nanofiber Mode Coupled to Two Chains of Optically Trapped Atoms

    CERN Document Server

    Zoubi, Hashem

    2010-01-01

    A tapered optical nanofiber simultaneously used to trap and optically interface of cold atoms through evanescent fields constitutes a new and well controllable hybrid quantum system. The atoms are trapped in two parallel 1D optical lattices generated by suitable far blue and red detuned evanescent field modes very close to opposite sides of the nanofiber surface. Collective electronic excitations (excitons) of each of the optical lattices are resonantly coupled to the second lattice forming symmetric and antisymmetric common excitons. In contrast to the inverse cube dependence of the individual atomic dipole-dipole interaction, we analytically find an exponentially decaying coupling strength with distance between the lattices. The resulting symmetric (bright) excitons strongly interact with the resonant nanofiber photons to form fiber polaritons, which can be observed through linear optical spectra. For large enough wave vectors the polariton decay rate to free space is strongly reduced, which should render t...

  18. Porous starch/cellulose nanofibers composite prepared by salt leaching technique for tissue engineering.

    Science.gov (United States)

    Nasri-Nasrabadi, Bijan; Mehrasa, Mohammad; Rafienia, Mohammad; Bonakdar, Shahin; Behzad, Tayebeh; Gavanji, Shahin

    2014-08-08

    Starch/cellulose nanofibers composites with proper porosity pore size, mechanical strength, and biodegradability for cartilage tissue engineering have been reported in this study. The porous thermoplastic starch-based composites were prepared by combining film casting, salt leaching, and freeze drying methods. The diameter of 70% nanofibers was in the range of 40-90 nm. All samples had interconnected porous morphology; however an increase in pore interconnectivity was observed when the sodium chloride ratio was increased in the salt leaching. Scaffolds with the total porogen content of 70 wt% exhibited adequate mechanical properties for cartilage tissue engineering applications. The water uptake ratio of nanocomposites was remarkably enhanced by adding 10% cellulose nanofibers. The scaffolds were partially destroyed due to low in vitro degradation rate after more than 20 weeks. Cultivation of isolated rabbit chondrocytes on the fabricated scaffold proved that the incorporation of nanofibers in starch structure improves cell attachment and proliferation.

  19. The Preparation of Chitosan Oligosaccharide/Alginate Sodium/Gelatin Nanofibers by Spiral-Electrospinning.

    Science.gov (United States)

    Lu, Weipeng; Xu, Haitao; Zhang, Bing; Ma, Ming; Guo, Yanchuan

    2016-03-01

    A spiral-electrospinning was used to mass-produce gelatin nanofibers with a content of chitosan oligosaccharide (COS) and alginate sodium (AS). Multiple jets were observed to form on the edges of the helix slice-spinneret simultaneously. Important electrospinning parameters, such as concentration of COS/gelatin aqueous solution, rotational velocity of spinneret and spinning distance, were examined to investigate the electrospinnability of COS/gelatin solution and the morphology of COS/gelatin nanofiber membranes. Due to the poor miscibility between COS and AS, COS/AS/gelatin nanofiber membranes were obtained from COS/gelatin solution and AS/gelatin solution by mixing electrospinning with multi-spinnerets. The novel needleless electrospinning not only avoided the possibility of nozzle-clogging, but also prepared COS/AS/gelatin nanofibers on a large scale for a wide variety of applications.

  20. Modified coaxial electrospinning for the preparation of high-quality ketoprofen-loaded cellulose acetate nanofibers.

    Science.gov (United States)

    Yu, Deng-Guang; Yu, Jia-Hui; Chen, Lan; Williams, Gareth R; Wang, Xia

    2012-10-01

    This study investigates the use of a modified coaxial electrospinning process in the production of drug-loaded cellulose acetate (CA) nanofibers. With CA employed as a filament-forming matrix and ketoprofen (KET) as an active pharmaceutical ingredient, modified coaxial processes using sheath fluids comprising only mixed solvents were undertaken. With a sheath-to-core flow rate ratio of 0.2:1, the nanofibers prepared from the coaxial process had a smaller average diameter, narrower size distribution, more uniform structures, and smoother surface morphologies than those generated from single fluid electrospinning. In addition, the coaxial fibers provided a better zero-order drug release profile. The use of a sheath solvent means that the core jet is subjected to electrical drawing for a longer period, facilitating homogeneous core jet solidification and retarding the formation of wrinkles on the surface of the nanofibers. This modified coaxial electrospinning protocol allows the systematic fabrication of functional polymer nanofibers with improved quality.

  1. A method for top down preparation of chitosan nanoparticles and nanofibers.

    Science.gov (United States)

    Wijesena, Ruchira N; Tissera, Nadeeka; Kannangara, Yasun Y; Lin, Yuan; Amaratunga, Gehan A J; de Silva, K M Nalin

    2015-03-01

    A method of top down preparation of chitosan nanoparticles and nanofibers is proposed. Chitin nanofibrils (chitin NFs) were prepared using ultrasonic assisted method from crab shells with an average diameter of 5 nm and the length less than 3 μm as analyzed by atomic force microscopy and transmission electron microscopy. These chitin nanofibers were used as the precursor material for the preparation of chitosan nanoparticles and nanofibers. The degree of deacetylation of these prepared chitosan nanostructures were found to be approximately 98%. In addition these chitosan nanostructures showed amorphous crystallinity. Transmission electron microscopic studies revealed that chitosan nanoparticles were roughly spherical in nature and had diameters less than 300 nm. These larger particles formed through self-assembly of much smaller 25 nm particles as evidenced by the TEM imaging. The diameter and the length of the chitosan nanofibers were found to be less than 100 nm and 3 μm respectively. It is envisaged that due to the cavitation effect, the deacetylated chitin nanofibers were broken down to small pieces to form seed particles. These seed particles can then be self-assembled to form larger chitosan nanoparticles.

  2. Elastin-PLGA hybrid electrospun nanofiber scaffolds for salivary epithelial cell self-organization and polarization.

    Science.gov (United States)

    Foraida, Zahraa I; Kamaldinov, Tim; Nelson, Deirdre A; Larsen, Melinda; Castracane, James

    2017-08-08

    Development of electrospun nanofibers that mimic the structural, mechanical and biochemical properties of natural extracellular matrices (ECMs) is a promising approach for tissue regeneration. Electrospun fibers of synthetic polymers partially mimic the topography of the ECM, however, their high stiffness, poor hydrophilicity and lack of in vivo-like biochemical cues is not optimal for epithelial cell self-organization and function. In search of a biomimetic scaffold for salivary gland tissue regeneration, we investigated the potential of elastin, an ECM protein, to generate elastin hybrid nanofibers that have favorable physical and biochemical properties for regeneration of the salivary glands. Elastin was introduced to our previously developed poly-lactic-co-glycolic acid (PLGA) nanofiber scaffolds by two methods, blend electrospinning (EP-blend) and covalent conjugation (EP-covalent). Both methods for elastin incorporation into the nanofibers improved the wettability of the scaffolds while only blend electrospinning of elastin-PLGA nanofibers and not surface conjugation of elastin to PLGA fibers, conferred increased elasticity to the nanofibers measured by Young's modulus. After two days, only the blend electrospun nanofiber scaffolds facilitated epithelial cell self-organization into cell clusters, assessed with nuclear area and nearest neighbor distance measurements, leading to the apicobasal polarization of salivary gland epithelial cells after six days, which is vital for cell function. This study suggests that elastin electrospun nanofiber scaffolds have potential application in regenerative therapies for salivary glands and other epithelial organs. Regenerating the salivary glands by mimicking the extracellular matrix (ECM) is a promising approach for long term treatment of salivary gland damage. Despite their topographic similarity to the ECM, electrospun fibers of synthetic polymers lack the biochemical complexity, elasticity and hydrophilicity of the

  3. Preparation and characterization of porous TiO2/ZnO composite nanofibers via electrospinning

    Institute of Scientific and Technical Information of China (English)

    Hai Ying Wang; Yang Yang; Xiang Li; Li Juan Li; Ce Wang

    2010-01-01

    Porous TiO2/ZnO composite nanofibers have been successfully prepared by electrospinning technique for the first time.It was generated by calcining TiO2/ZnCl2/PVP[PVP:poly(vinyi pyrrolidone)]nanofibers,which were electrospun from a mixture solution of TiO2,ZnCl2 and PVE Transmission electron microscopy(TEM)and X-ray diffraction(XRD)analyses were used to identify the morphology of the TiO2/ZnO nanofibers and a formation of inorganic TiO2/ZnO fibers.The porous structure of the TiO2/ZnO fbers was characterized by N2 adsoption/desorption isotherm.Surface photovoltage spectroscopy(SPS)and photo-catalytic activity measurements revealed advance properties of the porous TiO2/ZnO composite nanofibers and the results were compared with pure TiO2 nanofibers,pure ZnO nanofibers and TiO2/ZnO nanoparticles.

  4. Porous Carbon Nanofibers from Electrospun Biomass Tar/Polyacrylonitrile/Silver Hybrids as Antimicrobial Materials.

    Science.gov (United States)

    Song, Kunlin; Wu, Qinglin; Zhang, Zhen; Ren, Suxia; Lei, Tingzhou; Negulescu, Ioan I; Zhang, Quanguo

    2015-07-15

    A novel route to fabricate low-cost porous carbon nanofibers (CNFs) using biomass tar, polyacrylonitrile (PAN), and silver nanoparticles has been demonstrated through electrospinning and subsequent stabilization and carbonization processes. The continuous electrospun nanofibers had average diameters ranging from 392 to 903 nm. The addition of biomass tar resulted in increased fiber diameters, reduced thermal stabilities, and slowed cyclization reactions of PAN in the as-spun nanofibers. After stabilization and carbonization, the resultant CNFs showed more uniformly sized and reduced average diameters (226-507 nm) compared to as-spun nanofibers. The CNFs exhibited high specific surface area (>400 m(2)/g) and microporosity, attributed to the combined effects of phase separations of the tar and PAN and thermal decompositions of tar components. These pore characteristics increased the exposures and contacts of silver nanoparticles to the bacteria including Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, leading to excellent antimicrobial performances of as-spun nanofibers and CNFs. A new strategy is thus provided for utilizing biomass tar as a low-cost precursor to prepare functional CNFs and reduce environmental pollutions associated with direct disposal of tar as an industrial waste.

  5. Antibacterial continuous nanofibrous hybrid yarn through in situ synthesis of silver nanoparticles: Preparation and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Barani, Hossein, E-mail: barani@birjand.ac.ir

    2014-10-01

    Nanofibrous hybrid yarns of polyvinyl alcohol (PVA) and poly-L-lactide acid (PLLA) with the antibacterial activity were prepared that contains 0, 5, 10, 20, and 30 wt.% of silver nanoparticles according to the PVA polymer content. This was performed by electrospinning using distilled water and 2, 2, 2-trifluoroethanol as a solvent for PVA and PLLA respectively, and sodium borohydride was used as a reducing agent. The scanning electron microscope observation confirmed the formation of AgNPs into the PVA nanofiber structure, and they were uniform, bead free, cylindrical and smooth. The diameter of hybrid yarns and their nanofiber component was decreased as the silver nitrate concentration in electrospinning solutions was increased. The differential scanning calorimetry results indicated that the silver nanoparticles can form interactions with polymer chains and decrease the melting enthalpy. The mechanical analysis showed a lower stress and strain at break of the AgNP-loaded nanofibrous hybrid yarns than the unloaded hybrid yarn. However, there wasn't a statistically significant difference between the strain at break of electrospun nanofibrous hybrid yarns. Moreover, the bactericidal efficiency of all loaded samples was over 99.99%. - Highlights: • Nanofibrous hybrid yarns of PVA/PLLA with antibacterial activity were prepared. • The diameter of nanofibers was decreased as the AgNP concentration was increased. • AgNPs make interactions with amorphous phase of polymer and increase the Tg. • All loaded samples presented a good bactericidal and bacteriostatic efficiency.

  6. Local sustained delivery of acetylsalicylic acid via hybrid stent with biodegradable nanofibers reduces adhesion of blood cells and promotes reendothelialization of the denuded artery

    Directory of Open Access Journals (Sweden)

    Lee CH

    2014-01-01

    Full Text Available Cheng-Hung Lee,1,2 Yu-Huang Lin,3 Shang-Hung Chang,1 Chun-Der Tai,3 Shih-Jung Liu,2 Yen Chu,4 Chao-Jan Wang,5 Ming-Yi Hsu,5 Hung Chang,6 Gwo-Jyh Chang,7 Kuo-Chun Hung,1 Ming-Jer Hsieh,1 Fen-Chiung Lin,1 I-Chang Hsieh,1 Ming-Shien Wen,1 Yenlin Huang81Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Linkou, 2Department of Mechanical Engineering, 3Graduate Institute of Medical Mechatronics, Chang Gung University, 4Laboratory of Cardiovascular Physiology, Division of Thoracic and Cardiovascular Surgery, 5Department of Medical Imaging and Intervention, 6Hematology-Oncology Division, Department of Internal Medicine, Chang Gung Memorial Hospital, Linkou, 7Graduate Institute of Clinical Medicinal Sciences, Chang Gung University College of Medicine, Linkou, 8Department of Anatomical Pathology, Chang Gung Memorial Hospital, Linkou, Tao-Yuan, TaiwanAbstract: Incomplete endothelialization, blood cell adhesion to vascular stents, and inflammation of arteries can result in acute stent thromboses. The systemic administration of acetylsalicylic acid decreases endothelial dysfunction, potentially reducing thrombus, enhancing vasodilatation, and inhibiting the progression of atherosclerosis; but, this is weakened by upper gastrointestinal bleeding. This study proposes a hybrid stent with biodegradable nanofibers, for the local, sustained delivery of acetylsalicylic acid to injured artery walls. Biodegradable nanofibers are prepared by first dissolving poly(D,L-lactide-co-glycolide and acetylsalicylic acid in 1,1,1,3,3,3-hexafluoro-2-propanol. The solution is then electrospun into nanofibrous tubes, which are then mounted onto commercially available bare-metal stents. In vitro release rates of pharmaceuticals from nanofibers are characterized using an elution method, and a high-performance liquid chromatography assay. The experimental results suggest that biodegradable nanofibers

  7. Algae decorated TiO2/Ag hybrid nanofiber membrane with enhanced photocatalytic activity for Cr(VI) removal under visible light

    OpenAIRE

    WANG, L.; Zhang, C; Gao, F.; MAILHOT, G; Pan, G

    2016-01-01

    Algae as an abundant natural biomass, more attention has been paid to explore its potential application in environmental pollutants treatment. This work prepared the algae-TiO2/Ag bionano hybrid material by loading algae cells on the ultrafine TiO2/Ag chitosan hybrid nanofiber mat. For the first time, the synergistic photocatalytic effect of fresh algae and TiO2/Ag nanomaterial was investigated by removal of Cr(VI). The addition of algae significantly improved the photo-removal of Cr(VI) in t...

  8. Algae decorated TiO2/Ag hybrid nanofiber membrane with enhanced photocatalytic activity for Cr(VI) removal under visible light

    OpenAIRE

    Wang, L; Zhang,C.; Gao, F.; Mailhot, G.; Pan, G.

    2016-01-01

    Algae as an abundant natural biomass, more attention has been paid to explore its potential application in environmental pollutants treatment. This work prepared the algae-TiO2/Ag bionano hybrid material by loading algae cells on the ultrafine TiO2/Ag chitosan hybrid nanofiber mat. For the first time, the synergistic photocatalytic effect of fresh algae and TiO2/Ag nanomaterial was investigated by removal of Cr(VI). The addition of algae significantly improved the photo-removal of Cr(VI) in t...

  9. A Novel Route for the Preparation of Gold Nanoparticles in Polycaprolactone Nanofibers

    Directory of Open Access Journals (Sweden)

    Simón Yobanny Reyes-López

    2015-01-01

    Full Text Available A facile strategy for the fabrication of polycaprolactone (PCL nanofibers containing gold nanoparticles (AuNPs is proposed. The method is based on electrospinning nanosuspensions loaded with passivated Au nanoparticles. The optical property of gold nanoparticles synthesized was observed by UV-visible absorption spectra. Morphology and structure of the Au-PCL hybrid nanofibers were characterized by scanning electron microscopy, scanning transmission electron microscopy, and Fourier transformed infrared spectroscopy. The results of investigations by UV-visible and dynamic light scattering confirmed the presence of gold nanoparticles with diameters less than 10 nm. The STEM images show the presence of gold nanoparticles and gold agglomerates with diameter around 30 to 180 nm distributed over the surface of nanofibers, which is likely due to the increased incidence of agglomerations of AuNPs, due to drying process used.

  10. Preparation of Imprinted PVB/β-CD Nanofiber by Electrospinning Technique and Its Selective Binding Abilities for Naringin%Preparation of Imprinted PVB/β-CD Nanofiber by Electrospinning Technique and Its Selective Binding Abilities for Naringin

    Institute of Scientific and Technical Information of China (English)

    马秀玲; 陈震; 陈晓; 陈日耀; 郑曦

    2011-01-01

    A novel molecularly imprinted composite nanofiber was prepared by a simple electrospinning technique, in which polyvinylbutyral (PVB) was chosen as matrix, fl-cyclodextrin (β-CD) was used as a functional monomer and naringin (NG) as template molecules. After cross-linked by hexamethylene diisocyanate (HMDI), the composite nanofiber exhibited a high specific binding capacity. The morphological structure of the nanofibers was studied by means of infrared spectrum (IR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The β-CD molecules were mostly homogeneously distributed within the PVB nanofiber without forming phase separated crystalline aggregates. Compared with traditional imprinted β-CD polymer, the binding experiments demonstrated that the molecularly imprinted composite nanofiber shows the specific binding sites and the selective binding ability for NG. The molecularly imprinted nanofiber could be used at least six times without any loss in binding capacity.

  11. Effect of additives on the properties of polyaniline nanofibers prepared by high gravity chemical oxidative polymerization.

    Science.gov (United States)

    Zhao, Yibo; Arowo, Moses; Wu, Wei; Chen, Jianfeng

    2015-05-12

    Polyaniline (PANI) nanofibers with improved properties were prepared by high gravity chemical oxidative polymerization in a rotating packed bed with the assistance of p-aminodiphenylamine (AD) and p-phenylenediamine (AP). The effects of reactor type, additive dosage, reaction temperature, and high-gravity level on the properties of products were investigated in detail. Three conclusions were made: (1) a small amount of additive can significantly improve some properties of the nanofibers such as uniformity, specific surface area, and specific capacitance; (2) in order to obtain high-quality nanofibers, the high-gravity level should coordinate with the reaction rate; (3) the molecular weight and conductivity of PANI decrease with the increase of additive dosage. The products have larger specific surface areas of up to 73.9 and 68.4 m(2)/g and consequently improved specific capacitance of up to 527.5 and 552 F/g for the PANI nanofibers prepared with AD and AP, respectively. However, the specific surface area and specific capacitance of pure PANI are only 49.1 m(2)/g and 333.3 F/g, respectively. This research provides a simple, reliable, and scalable method to produce PANI nanofibers of high performances.

  12. Engineering hybrid polymer-protein super-aligned nanofibers via rotary jet spinning.

    Science.gov (United States)

    Badrossamay, Mohammad R; Balachandran, Kartik; Capulli, Andrew K; Golecki, Holly M; Agarwal, Ashutosh; Goss, Josue A; Kim, Hansu; Shin, Kwanwoo; Parker, Kevin Kit

    2014-03-01

    Cellular microenvironments are important in coaxing cells to behave collectively as functional, structured tissues. Important cues in this microenvironment are the chemical, mechanical and spatial arrangement of the supporting matrix in the extracellular space. In engineered tissues, synthetic scaffolding provides many of these microenvironmental cues. Key requirements are that synthetic scaffolds should recapitulate the native three-dimensional (3D) hierarchical fibrillar structure, possess biomimetic surface properties and demonstrate mechanical integrity, and in some tissues, anisotropy. Electrospinning is a popular technique used to fabricate anisotropic nanofiber scaffolds. However, it suffers from relatively low production rates and poor control of fiber alignment without substantial modifications to the fiber collector mechanism. Additionally, many biomaterials are not amenable for fabrication via high-voltage electrospinning methods. Hence, we reasoned that we could utilize rotary jet spinning (RJS) to fabricate highly aligned hybrid protein-polymer with tunable chemical and physical properties. In this study, we engineered highly aligned nanofiber constructs with robust fiber alignment from blends of the proteins collagen and gelatin, and the polymer poly-ε-caprolactone via RJS and electrospinning. RJS-spun fibers retain greater protein content on the surface and are also fabricated at a higher production rate compared to those fabricated via electrospinning. We measured increased fiber diameter and viscosity, and decreasing fiber alignment as protein content increased in RJS hybrid fibers. RJS nanofiber constructs also demonstrate highly anisotropic mechanical properties mimicking several biological tissue types. We demonstrate the bio-functionality of RJS scaffold fibers by testing their ability to support cell growth and maturation with a variety of cell types. Our highly anisotropic RJS fibers are therefore able to support cellular alignment

  13. Preparation of Co3O4 Nanofibers via an Electrospinning Technique

    Institute of Scientific and Technical Information of China (English)

    Chang Lu SHAO; Hong Yu GUAN; Shang Bin WEN; Bin CHEN; Xing Hua YANG; Jian GONG; Yi Chun LIU

    2004-01-01

    Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique.After calcination of the above precursor fibers, Co3O4 nanofibers with a diameter of 50-150 nm could be successfully obtained.The fibers were characterized by SEM, FT-IR,WAXD,respectively.

  14. Preparation and Characterization of Amphiphilic Triblock Terpolymer-Based Nanofibers as Antifouling Biomaterials

    KAUST Repository

    Cho, Youngjin

    2012-05-14

    Antifouling surfaces are critical for the good performance of functional materials in various applications including water filtration, medical implants, and biosensors. In this study, we synthesized amphiphilic triblock terpolymers (tri-BCPs, coded as KB) and fabricated amphiphilic nanofibers by electrospinning of solutions prepared by mixing the KB with poly(lactic acid) (PLA) polymer. The resulting fibers with amphiphilic polymer groups exhibited superior antifouling performance to the fibers without such groups. The adsorption of bovine serum albumin (BSA) on the amphiphilic fibers was about 10-fold less than that on the control surfaces from PLA and PET fibers. With the increase of the KB content in the amphiphilic fibers, the resistance to adsorption of BSA was increased. BSA was released more easily from the surface of the amphiphilic fibers than from the surface of hydrophobic PLA or PET fibers. We have also investigated the structural conformation of KB in fibers before and after annealing by contact angle measurements, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), and coarse-grained molecular dynamics (CGMD) simulation to probe the effect of amphiphilic chain conformation on antifouling. The results reveal that the amphiphilic KB was evenly distributed within as-spun hybrid fibers, while migrated toward the core from the fiber surface during thermal treatment, leading to the reduction in antifouling. This suggests that the antifouling effect of the amphiphilic fibers is greatly influenced by the arrangement of amphiphilic groups in the fibers. © 2012 American Chemical Society.

  15. Preparation of α-Fe2O3 Nanofiber via Electrospinning Process

    Institute of Scientific and Technical Information of China (English)

    SHAO Chang-lu; YANG Xing-hua; GUAN Hong-yu; YU Na; LIU Yi-chun

    2004-01-01

    A thin PVA/FeCl3 composite fiber was prepared by using sol-gel processing and electrospinning tech niques. A nanofiber of α-Fe2O3 with the diameter of 50-150 nm was obtained via high temperature calcina tion of the PVA/FeCl3 composite fiber. The material was characterized by infra-red(IR) spectroscopy, X-ray diffraction(XRD), and scanning electron microscopy(SEM). The results show that the fiber after the calci nation at 700 ℃ was a pure α-Fe2O3 nanofiber.

  16. Hybrid magnetic amphiphilic composites based on carbon nanotube/nanofibers and layered silicates fragments as efficient adsorbent for ethynilestradiol.

    Science.gov (United States)

    Purceno, Aluir D; Teixeira, Ana Paula C; de Souza, Nubia Janaína; Fernandez-Outon, Luis E; Ardisson, José D; Lago, Rochel M

    2012-08-01

    In this work, hybrid magnetic amphiphilic composites were prepared by the catalytic growth of carbon nanotubes (CNTs) and nanofibers CNF on layered silicates fragments. SEM, TEM, Raman, XRD, Mössbauer, TG/DTA showed that CVD with CH(4) at 800°C produced CNF and magnetic Fe cores fixed on the surface of microfragments of silicates layers. Due to the amphiphilic character, the composites can be easily dispersed in water and efficiently adsorb hydrophobic contaminant molecules. For example, the composites showed remarkable adsorption capacities for the hormone ethinylestradiol, e.g. 2-4 mg m(-2), compared to ca. 0.1 mg m(-2) obtained for high surface area activated carbon and multiwall CNT. These results are discussed in terms of a high hydrophobic exposed surface area of the CNT and CNF fixed on the layered silicates fragments surface. Moreover, the composites can be easily removed from water by a simple magnetic separation process.

  17. Silica/polyacrylonitrile hybrid nanofiber membrane separators via sol-gel and electrospinning techniques for lithium-ion batteries

    Science.gov (United States)

    Yanilmaz, Meltem; Lu, Yao; Zhu, Jiadeng; Zhang, Xiangwu

    2016-05-01

    Silica/polyacrylonitrile (SiO2/PAN) hybrid nanofiber membranes were fabricated by using sol-gel and electrospinning techniques and their electrochemical performance was evaluated for use as separators in lithium-ion batteries. The aim of this study was to design high-performance separator membranes with enhanced electrochemical performance and good thermal stability compared to microporous polyolefin membranes. In this study, SiO2 nanoparticle content up to 27 wt% was achieved in the membranes by using sol-gel technique. It was found that SiO2/PAN hybrid nanofiber membranes had superior electrochemical performance with good thermal stability due to their high SiO2 content and large porosity. Compared with commercial microporous polyolefin membranes, SiO2/PAN hybrid nanofiber membranes had larger liquid electrolyte uptake, higher electrochemical oxidation limit, and lower interfacial resistance with lithium. SiO2/PAN hybrid nanofiber membranes with different SiO2 contents (0, 16, 19 and 27 wt%) were also assembled into lithium/lithium iron phosphate cells, and high cell capacities and good cycling performance were demonstrated at room temperature. In addition, cells using SiO2/PAN hybrid nanofiber membranes with high SiO2 contents showed superior C-rate performance compared to those with low SiO2 contents and commercial microporous polyolefin membrane.

  18. Preparation and Characterization of Highly Aligned Carbon Nanotubes/Polyacrylonitrile Composite Nanofibers

    Directory of Open Access Journals (Sweden)

    Yanhua Song

    2017-01-01

    Full Text Available In the electrospinning process, a modified parallel electrode method (MPEM, conducted by placing a positively charged ring between the needle and the parallel electrode collector, was used to fabricate highly aligned carbon nanotubes/polyacrylonitrile (CNTs/PAN composite nanofibers. Characterizations of the samples—such as morphology, the degree of alignment, and mechanical and conductive properties—were investigated by a combination of scanning electron microscopy (SEM, transmission electron microscopy (TEM, universal testing machine, high-resistance meter, and other methods. The results showed the MPEM could improve the alignment and uniformity of electrospun CNTs/PAN composite nanofibers, and enhance their mechanical and conductive properties. This meant the successful preparation of highly aligned CNT-reinforced PAN nanofibers with enhanced physical properties, suggesting their potential application in appliances and communication areas.

  19. Room temperature ferromagnetism in undoped ZnO nanofibers prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Kumar Das, Arnab, E-mail: arnab.das@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Kar, Manoranjan, E-mail: mano@iitp.ac.in [Department of Physics, Indian Institute of Technology Patna, Patna 800013 (India); Srinivasan, Ananthakrishanan, E-mail: asrini@iitg.ernet.in [Department of Physics, Indian Institute of Technology Guwahati, Guwahati 781039 (India)

    2014-09-01

    We report ferromagnetic behavior in undoped ZnO nanofibers prepared by electrospinning a solution of zinc acetate and poly vinyl alcohol followed by annealing at 550 °C for about 90 min. X-ray diffraction patterns of the heat treated as-spun composite fibers reveal the formation of ZnO nanowires in wurtzite structure with no noticeable impurity phases. ZnO nanowires annealed between 500 °C and 600 °C exhibited room temperature ferromagnetism with decreasing magnetization with increasing annealing temperature. Room temperature ferromagnetism was observed in as-spun fibers annealed in air as well as under vacuum. However, vacuum annealed nanofibers show higher magnetization as compared to air annealed fibers, which indicates that oxygen vacancy is a cause for the observed room temperature ferromagnetism in the ZnO nanofibers.

  20. Preparation and characterization of ZnO nanofibers by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Siddheswaran, R. [Material Research Centre, Department of Physics, Velammal Engineering College, Chennai-600066 (India); Department of Physics, Pachaiyappa' s College, Chennai- 600 030 (India); Sankar, R.; Ramesh Babu, M.; Jayavel, R. [Crystal Growth Centre, Anna University, Chennai-600 025 (India); Rathnakumari, M.; Sureshkumar, P. [Material Research Centre, Department of Physics, Velammal Engineering College, Chennai-600066 (India); Murugakoothan, P. [Department of Physics, Pachaiyappa' s College, Chennai- 600 030 (India)

    2006-05-15

    Electrospun ZnO nanofibers were obtained by calcinating PVA/Zinc Acetate composite fibers at various temperatures. Atomic Force Microscopy (AFM) revealed that the ZnO fibers have diameters in the range of 100-200 nm. The fibers were characterized by FT- IR, TGA-DTA, and XRD studies. The XRD results showed that the crystal structure and the morphology of the fibers were largely dependent on the calcination temperature (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  1. Preparation of polyvinylidene fluoride nanofiber membrane and its antibacterial characteristics with nanosilver or graphene oxide.

    Science.gov (United States)

    Hong, Byungpyo; Jung, Hyemin; Byun, Hongsik

    2013-09-01

    Polyvinylidene fluoride (PVdF) (Kynar 761) nanofibers were prepared by electrospinning at an external voltage of 6-10 kV, a traveling distance of 7-15 cm and flow rate of 0.4-1 ml/hr. Although the diameter of the fiber was not significantly changed, the electrospinning conditions affected the overall distribution of diameter. This is probably due to the interactions, both attraction and repulsion, of positive charges on polymer solutions and the electrically grounded collector. Especially, the effect of voltage on the distribution of diameter was investigated in this study. The final PVdF nanofiber membrane showed narrow pore-size distribution and high water flux compared with the commercial MF membrane. PVdF nanofiber membranes incorporated nanosilver or graphene oxide were also prepared as nanosilver and graphene have an antibacterial activity. It was found that more than 200 ppm of silver nanoparticles in the PVdF nanofiber had 99.9% of growth inhibition of Staphylococcus aureus and Klebsiella pneumonia. It was also found that 0.2 wt% of graphene oxide in the PVdF electrospinning solution had 99.6% of disinfection property to E-Coli.

  2. Preparation and Characterization of Soluble Eggshell Membrane Protein/PLGA Electrospun Nanofibers for Guided Tissue Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    Jun Jia

    2012-01-01

    Full Text Available Guided tissue regeneration (GTR is a widely used method in periodontal therapy, which involves the placement of a barrier membrane to exclude migration of epithelium and ensure repopulation of periodontal ligament cells. The objective of this study is to prepare and evaluate a new type of soluble eggshell membrane protein (SEP/poly (lactic-co-glycolic acid (PLGA nanofibers using electrospinning method for GTR membrane application. SEP/PLGA nanofibers were successfully prepared with various blending ratios. The morphology, chemical composition, surface wettability, and mechanical properties of the nanofibers were characterized using scanning electron microscopy (SEM, contact angle measurement, Fourier transform-infrared spectroscopy (FTIR, and a universal testing machine. L-929 fibroblast cells were used to evaluate the biocompatibility of SEP/PLGA nanofibers and investigate the interaction between cells and nanofibers. Results showed that the SEP/PLGA electrospun membrane was composed of uniform, bead-free nanofibers, which formed an interconnected porous network structure. Mechanical property of SEP has been greatly improved by the addition of PLGA. The biological study results showed that SEP/PLGA nanofibers could enhance cell attachment, spreading, and proliferation. The study indicated the potential of SEP/PLGA nanofibers for GTR application and provided a basis for future optimization.

  3. New Chitosan/Poly(ethylene oxide/Thyme Nanofiber Prepared by Electrospinning Method for Antimicrobial Wound Dressing

    Directory of Open Access Journals (Sweden)

    Minoo Sadri

    2016-10-01

    Full Text Available A new natural and environmental friendly wound dressing was introduced for the first time that was prepared by electrospinning method. This new wound dressing has chitosan base, and poly (ethylene oxide was added as co-spinning agent to improve spinnability of chitosan. Moreover, thyme extract as a natural antibacterial additive was introduced in the as electrospun nanofibers scaffold in order to increase those wound healing properties. Some parameters of electrospinning such as feed rate, nozzle-collector distance, voltage and content of thyme extract in nanofiber structure were studied and optimized. The average diameters of prepared nanofibers was determined by “Clemex vision professional edition” software. Morphology and structure of electrospun nanofibers was studied with use of scaning electorn microscopy and Fourier transform infrared spectroscopy spectroscopy. The results showed that the antibacterial activity of nanofibers increased as the amount of thyme extract was increased, thus a chitosan/PEO containing 3% of thyme extract was selected as the best prepared nanofiber for wound dressing preparation. Chitosan/PEO/thyme nanofiber showed high stability in the buffer and good antibacterial activity against three understudy bacteria including Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus.

  4. Electrospun nanofibers of poly(vinyl pyrrolidone)/Eu3+ and its photoluminescence properties

    Institute of Scientific and Technical Information of China (English)

    Shan Shan Tang; Chang Lu Shao; Shou Zhu Li

    2007-01-01

    Nanofibers of poly(vinyl pyrrolidone) (PVP)/Eu3+ with diameters of 300-900 nm were prepared by using sol-gel processing and electrospinning technique. The products were characterized by scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), and photoluminescence (PL). The results indicated that, Eu3+ was successfully embedded in the onedimensional hybrid nanofibers, and the PVP/Eu3+ hybrid nanofibers had favorable photoluminescence properties.

  5. Preparation and pharmaceutical evaluation of acetaminophen nano-fiber tablets: Application of a solvent-based electrospinning method for tableting.

    Science.gov (United States)

    Hamori, Mami; Nagano, Kana; Kakimoto, Sayaka; Naruhashi, Kazumasa; Kiriyama, Akiko; Nishimura, Asako; Shibata, Nobuhito

    2016-03-01

    In this study, we developed nano-fiber-based tablets with acetaminophen (AAP; LogPow=0.51) for controlled-release delivery systems and evaluated in vitro drug dissolution and in vivo pharmacokinetics in rats. Nano-fibers made from methacrylic acid copolymer S (MAC; EUDRAGIT S100) and containing AAP were prepared using a solvent-based electrospinning (ES) method. In vitro dissolution rate profiles of AAP showed tableting pressure-dependent decreases and pH-dependent increases. The results of tablet tracking by X-ray irradiation showed tablets based on MAC nano-fibers did not disintegrate in the upper intestinal lumen and had the properties of a long-term-acting tablet. In addition, the in vitro release profiles of AAP from nano-fiber tablets prepared by dissolving MAC with AAP (NFT), nano-fiber tablets prepared by adsorbing AAP to drug-free MAC nano-fibers (NFTadso), and tablets prepared by adsorbing half the amount of AAP to MAC nano-fibers containing the remaining amount of AAP (NFThalf) showed independent controlled-release aspects of AAP compared with physical mixture tablets (PMT). In vivo pharmacokinetic studies in rats after intraduodenal administration of 14 mg/rat AAP in NFT, NFTadso, and NFThalf demonstrated that all these tablets based on MAC nano-fibers showed sustained-release profiles compared with PMT, and showed ultra-sustained release properties for AAP. These new tablets based on MAC nano-fibers did not disintegrate in the intestine in the lower pH region, and the tablets could regulate the release of AAP in a pH-dependent manner. The ES method is a useful technique to prepare nano-fibers and showed promising results as an oral delivery system for sustained-release regulation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  6. PANI-nanofibers/polyethylene blends: preparation and properties; Blendas de nanofibras de PANI/polietileno: preparacao e propriedades

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, F.; Hubler, R.; Basso, N.R.S., E-mail: nrbass@pucrs.b [Pontificia Universidade Catolica do Rio Grande do Sul (PUC-RS), Porto Alegre, RS (Brazil); Fim, F.C.; Galland, G.B. [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil)

    2010-07-01

    In this work polyaniline nanofibers (PANI-nanofibers) were prepared via interfacial polymerization. The PANI-nanofibers were dispersed in polyethylene (PE) matrix by in situ polymerization of ethylene using Cp{sub 2}ZrCl{sub 2} [bis(cyclopentadienyl) zirconium(IV) dichloride)] and methylaluminoxane as catalytic system. The composites were characterized by infra-red spectroscopy, X-ray diffraction, thermal analysis, transmission electron microscopy and scanning electron microscopy. The results show that nanofibers with average diameters of 200 nm were synthesized and that it was obtained well dispersed PE/PANI nanocomposites. The PANI-nanofibers load did not affect the catalytic activity, but it decreased crystallinity degree of nanocomposites. (author)

  7. Preparation and Characterization of Cellulose Nanofibers from Two Commercial Hardwood and Softwood Pulps

    DEFF Research Database (Denmark)

    Stelte, Wolfgang; Sanadi, Anand R.

    2009-01-01

    The aim of this work was to study the mechanical fibrillation process for the preparation of cellulose nanofibers from two commercial hard- and softwood cellulose pulps. The process consisted of initial refining and subsequent high-pressure homogenization. The progress in fibrillation was studied...... using different microscopy techniques, mechanical testing, and fiber density measurements of cellulose films prepared after different processing stages. The mechanical properties of cellulose films showed an increase in strength and stiffness with decreasing fiber size, and this stabilized after...... a certain number of passes in the homogenizer. Atomic force microscopy studies showed that the obtained cellulose nanofibers had diameters in the 10−25-nm range. The significant difference between the two samples was that the ultimate failure strain for cellulose films made of softwood fibers increased...

  8. Hybrid self-healing matrix using core-shell nanofibers and capsuleless microdroplets.

    Science.gov (United States)

    Lee, Min Wook; An, Seongpil; Lee, Changmin; Liou, Minho; Yarin, Alexander L; Yoon, Sam S

    2014-07-01

    In this work, we developed novel self-healing anticorrosive hierarchical coatings that consist of several components. Namely, as a skeleton we prepared a core-shell nanofiber mat electrospun from emulsions of cure material (dimethyl methylhydrogen siloxane) in a poly(acrylonitrile) (PAN) solution in dimethylformamide. In these nanofibers, cure is in the core, while PAN is in the shell. The skeleton deposited on a protected surface is encased in an epoxy-based matrix, which contains emulsified liquid droplets of dimethylvinyl-terminated dimethylsiloxane resin monomer. When such hierarchical coatings are damaged, cure is released from the nanofiber cores and the resin monomer, released from the damaged matrix, is polymerized in the presence of cure. This polymerization and solidification process takes about 1-2 days and eventually heals the damaged material when solid poly(dimethylsiloxane) resin is formed. The self-healing effect was demonstrated using an electrochemical analogue of the scanning vibrating electrode technique. Damaged samples were left for 2 days. After that, the electric current through a damaged coating was found to be negligibly small for the samples with self-healing properties. On the other hand, for the samples without self-healing properties, the electric current was significant.

  9. Surface plasmons excited by the photoluminescence of organic nanofibers in hybrid plasmonic systems

    Science.gov (United States)

    Sobolewska, ElŻbieta K.; Leißner, Till; Jozefowski, Leszek; Brewer, Jonathan; Rubahn, Horst-Günter; Adam, Jost; Fiutowski, Jacek

    2016-04-01

    Recent research on hybrid plasmonic systems has shown the existence of a loss channel for energy transfer between organic materials and plasmonic/metallic structured substrates. This work focuses on the exciton-plasmon coupling between para-Hexaphenylene (p-6P) organic nanofibers (ONFs) and surface plasmon polaritons (SPPs) in organic/dielectric/metal systems. We have transferred the organic p-6P nanofibers onto a thin silver film covered with a dielectric (silicon dioxide) spacer layer with varying thicknesses. Coupling is investigated by two-photon fluorescence-lifetime imaging microscopy (FLIM) and leakage radiation spectroscopy (LRS). Two-photon excitation allows us to excite the ONFs with near-infrared light and simultaneously avoids direct SPP excitation on the metal layer. We observe a strong dependence of fluorescence lifetime on the type of underlying substrate and on the morphology of the fibers. The experimental findings are complemented via finite-difference time-domain (FDTD) modeling. The presented results lead to a better understanding and control of hybrid-mode systems, which are crucial elements in future low-loss energy transfer devices.

  10. Preparation of flexible zinc oxide/carbon nanofiber webs for mid-temperature desulfurization

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Soojung; Bajaj, Bharat [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Byun, Chang Ki; Kwon, Soon-Jin [Department of Chemical Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Joh, Han-Ik [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Yi, Kwang Bok, E-mail: cosy32@cnu.ac.kr [Department of Chemical Engineering Education, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 305-764 (Korea, Republic of); Lee, Sungho, E-mail: sunghol@kist.re.kr [Carbon Convergence Materials Research Center, Institute of Advanced Composite Materials, Korea Institute of Science and Technology, San 101, Eunha-ri, Bongdong-eup, Wanju-gun, Jeollabuk-do 565-905 (Korea, Republic of); Department of Nano Material Engineering, University of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791 (Korea, Republic of)

    2014-11-30

    Graphical abstract: - Highlights: • Polyacrylonitrile (PAN) and zinc precursor were electrospun and heat-treated for preparing zinc oxide (ZnO) modified carbon nanofibers (CNF). • A facile synthesis of composite webs resulted in uniformly loaded ZnO on the surface of CNFs. • The composites showed significant hydrogen sulfide adsorption efficiency at 300 °C. • The flexible webs can be applied for mid-temperature desulfurization. - Abstract: Polyacrylonitrile (PAN) derived carbon nanofiber (CNF) webs loaded with zinc oxide (ZnO) were synthesized using electrospinning and heat treatment at 600 °C. Uniformly dispersed ZnO nanoparticles, clarified by X-ray diffraction and scanning electron microscopy, were observed on the surface of the nanofiber composites containing 13.6–29.5 wt% of ZnO. The further addition of ZnO up to 34.2 wt% caused agglomeration with a size of 50–80 nm. Higher ZnO contents led the concentrated ZnO nanoparticles on the surface of the nanofibers rather than uniform dispersion along the cross-section of the fiber. The flexible composite webs were crushed and tested for hydrogen sulfide (H{sub 2}S) adsorption at 300 °C. Breakthrough experiments with the ZnO/CNF composite containing 25.7 wt% of ZnO for H{sub 2}S adsorption showed three times higher ZnO utilization efficiency compared to pure ZnO nano powders, attributed to chemisorption of the larger surface area of well dispersed ZnO particles on nanofibers and physical adsorption of CNF.

  11. Preparation and Characterization of Novel Electrospinnable PBT/POSS Hybrid Systems Starting from c-PBT

    Directory of Open Access Journals (Sweden)

    Lorenza Gardella

    2015-01-01

    Full Text Available Novel hybrid systems based on poly(butyleneterephthalate (PBT and polyhedral oligomeric silsesquioxanes (POSS have been prepared by applying the ring-opening polymerization of cyclic poly(butyleneterephthalate oligomers. Two types of POSS have been used: one characterized by hydroxyl functionalities (named POSS-OH and another without specific reactive groups (named oib-POSS. It was demonstrated that POSS-OH acts as an initiator for the polymerization reaction, leading to the direct insertion of the silsesquioxane into the polymer backbone. Among the possible applications of the PBT/POSS hybrid system, the possibility to obtain nanofibers has been assessed in this work.

  12. Hybrid matrices of ZnO nanofibers with silicone for high water flux photocatalytic degradation of dairy effluent

    DEFF Research Database (Denmark)

    Kanjwal, Muzafar Ahmad; Shawabkeh, Ali Qublan; Alm, Martin

    2016-01-01

    Zinc oxide (ZnO) nanofibers were produced by electrospinning technique and surface coated on silicone elastomer substrate (diameter: 10.0 mm; thickness: 2.0 mm) by a dipcoating method. The obtained hybrid nanoporous matrices were investigated by scanning and transmission electron microscopy (SEM,...

  13. Preparation of core-shell PAN nanofibers encapsulated α-tocopherol acetate and ascorbic acid 2-phosphate for photoprotection.

    Science.gov (United States)

    Wu, Xiao-Mei; Branford-White, Christopher J; Yu, Deng-Guang; Chatterton, Nicholas P; Zhu, Li-Min

    2011-01-01

    Magnesium l-ascorbic acid 2-phosphate (MAAP) and α-tocopherol acetate (α-TAc), as the stable vitamin C and vitamin E derivative, respectively, are often applied to skin care products for reducing UV damage. The encapsulation of MAAP (0.5%, g/mL) and α-TAc (5%, g/mL) together within the polyacrylonitrile (PAN) nanofibers was demonstrated using a coaxial electrospinning technique. The structure and morphology characterizations of the core-shell fibers MAAP/α-TAc-PAN were investigated by SEM, FTIR and XRD. As a negative control, the blend nanofibers MAAP/α-TAc/PAN were prepared from a normal electrospinning method. The results from SEM indicated that the morphology and diameter of the nanofibers were influenced by concentration of spinning solution, the polymer component of the shell, the carrying agent of the core and the fabricating methods, and the core-shell nanofibers obtained at the concentration of 8% had finer and uniform structure with the average diameters of 200 ± 15nm. From in vitro release studies it could be seen that both different fiber specimens showed a gradual increase in the amount of α-TAc or MAAP released from the nanofibers. Furthermore, α-TAc and MAAP released from the blend nanofibers showed the burst release at the maximum release of ∼15% and ∼40% during the first 6h, respectively, but their release amount from the core-shell nanofibers was only 10-12% during the initial part of the process. These results showed that core-shell nanofibers alleviated the initial burst release and gave better sustainability compared to that of the blend nanofibers. The present study would provide a basis for further optimization of processing conditions to obtain desired structured core-shell nanofibers and release kinetics for practical applications in dermal tissue.

  14. Preparation of ZnO/CdS/BC Photocatalyst Hybrid Fiber and Research of Its Photocatalytic Properties

    Directory of Open Access Journals (Sweden)

    Beibei Dai

    2015-01-01

    Full Text Available An environment-friendly biomaterial bacterial cellulose (BC is introduced to substitute general organic polymers to assist the preparation of ZnO/CdS/BC photocatalyst hybrid nanofiber through coprecipitation method under the low-temperature condition. The XRD, XPS, and SEM results show that high load of ZnO/CdS/BC ternary hybrid fiber can be produced. TGA curves scan shows that ZnO/CdS/BC hybrid fiber has better thermal properties than bacterial cellulose. The UV-Vis spectra of the ZnO/CdS/BC hybrid nanofiber (0, 10, 20, and 50 wt%, resp. show that photocatalytic activities of ZnO/CdS/BC are influenced by the added amount of CdS. The degradation curve of methyl shows that ZnO/CdS/BC nanohybrid fibers exhibit excellent photocatalytic efficiency.

  15. Protein/CaCO3/Chitin Nanofiber Complex Prepared from Crab Shells by Simple Mechanical Treatment and Its Effect on Plant Growth

    Directory of Open Access Journals (Sweden)

    Yihun Fantahun Aklog

    2016-09-01

    Full Text Available A protein/CaCO3/chitin nanofiber complex was prepared from crab shells by a simple mechanical treatment with a high-pressure water-jet (HPWJ system. The preparation process did not involve chemical treatments, such as removal of protein and calcium carbonate with sodium hydroxide and hydrochloric acid, respectively. Thus, it was economically and environmentally friendly. The nanofibers obtained had uniform width and dispersed homogeneously in water. Nanofibers were characterized in morphology, transparency, and viscosity. Results indicated that the shell was mostly disintegrated into nanofibers at above five cycles of the HPWJ system. The chemical structure of the nanofiber was maintained even after extensive mechanical treatments. Subsequently, the nanofiber complex was found to improve the growth of tomatoes in a hydroponics system, suggesting the mechanical treatments efficiently released minerals into the system. The homogeneous dispersion of the nanofiber complex enabled easier application as a fertilizer compared to the crab shell flakes.

  16. Preparation of animal polysaccharides nanofibers by electrospinning and their potential biomedical applications.

    Science.gov (United States)

    Zhao, Wen; Liu, Wenlong; Li, Jiaojiao; Lin, Xiao; Wang, Ying

    2015-02-01

    Animal polysaccharides belong to a class of biological macromolecules. They are natural biopolymers with numerous advantages for biomedical applications, such as biocompatibility, biodegradability, non-antigenicity and non-toxicity. Electrospinning is a versatile and facile technique which can produce continuous fibers with nanoscale from a wide range of natural and synthetic polymers. The review aims to provide an up-to-date overview of the preparation of animal polysaccharides nanofibers by electrospinning and their potential biomedical applications such as tissue engineering, wound healing, and drug delivery. Various animal polysaccharides including chitin and chitosan (CS), hyaluronic acid (HA), heparin and heparan sulfate (HS), and chondroitin sulfate (ChS), are discussed. The challenges and some useful strategies in electrospinning of animal polysaccharides also are summarized. In addition, future study of animal polysaccharides nanofibers by electrospinning is proposed.

  17. Polymer nanofibers prepared by low-voltage near-field electrospinning

    Institute of Scientific and Technical Information of China (English)

    Zheng Jie; Long Yun-Ze; Sun Bin; Zhang Zhi-Hua; Shao Feng; Zhang Hong-Di; Zhang Zhi-Ming; Huang Jia-Yin

    2012-01-01

    Electrospinning is a straightforward method to produce micro/nanoscale fibers from polymer solutions typically using an operating voltage of 10 kV-30 kV and spinning distance of 10 cm-20 cm.In this paper,polyvinyl pyrrolidone (PVP) non-woven nanofibers with diameters of 200 nm-900 nm were prepared by low-voltage near-field electrospinning with a working voltage of less than 2.8 kV and a spinning distance of less than 10 mm.Besides the uniform fibers,beaded-fibers were also fabricated and the formation mechanism was discussed.Particularly,a series of experiments were carried out to explore the influence of processing variables on the formation of near-field electrospun PVP nanofibers,including concentration,humidity,collecting position,and spinning distance.

  18. Adsorption behavior of Cu(II) onto titanate nanofibers prepared by alkali treatment.

    Science.gov (United States)

    Li, Nian; Zhang, Lide; Chen, Yongzhou; Tian, Yue; Wang, Huimin

    2011-05-15

    Novel low-cost adsorbents of titanate nanofibers with formula Na(x)H(2-x)Ti(3)O(7) · nH(2)O have been prepared by alkali treatment for Cu(II) removal from aqueous solutions. The nanofibers have structures in which three edge-shared TiO(6) octahedras join at the corners to form stepped, zigzag Ti(3)O(7)(2-) layers. The sodium cations located between the layers are exchangeable. The results of batch adsorption experiments suggest that the nanofibers with high sodium content can be effective adsorbents for Cu(II) removal. Effects of several important factors such as Na amount in adsorbents, pH, temperature, contact time and initial concentration are systematically studied. Results show that the adsorption is highly pH-dependent and the removal is almost complete (99.8%) for initial concentration under 100mg/l at pH 4. Equilibrium adsorption follows Langmuir isotherms well and the maximum Cu(II) uptake calculated is 167.224 mg/g. The adsorption kinetics can be explained by pseudo-second-order model well and the time needed for equilibrium is 180 min. Thermodynamic study indicates that the adsorption is spontaneous and endothermic. Desorption of Cu(II) from adsorbents using EDTA-2Na solutions exhibits a high efficiency and the adsorbents can be used repeatedly. These results demonstrate that the titanate nanofibers are readily prepared, enabling promising applications for the removal of Cu(II) from aqueous solutions.

  19. Adsorption behavior of Cu(II) onto titanate nanofibers prepared by alkali treatment

    Energy Technology Data Exchange (ETDEWEB)

    Li, Nian [Key Laboratory of Materials Physics, Anhui Key laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhang, Lide, E-mail: ldzhang@issp.ac.cn [Key Laboratory of Materials Physics, Anhui Key laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Chen, Yongzhou; Tian, Yue; Wang, Huimin [Key Laboratory of Materials Physics, Anhui Key laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2011-05-15

    Novel low-cost adsorbents of titanate nanofibers with formula Na{sub x}H{sub 2-x}Ti{sub 3}O{sub 7}.nH{sub 2}O have been prepared by alkali treatment for Cu(II) removal from aqueous solutions. The nanofibers have structures in which three edge-shared TiO{sub 6} octahedras join at the corners to form stepped, zigzag Ti{sub 3}O{sub 7}{sup 2-} layers. The sodium cations located between the layers are exchangeable. The results of batch adsorption experiments suggest that the nanofibers with high sodium content can be effective adsorbents for Cu(II) removal. Effects of several important factors such as Na amount in adsorbents, pH, temperature, contact time and initial concentration are systematically studied. Results show that the adsorption is highly pH-dependent and the removal is almost complete (99.8%) for initial concentration under 100 mg/l at pH 4. Equilibrium adsorption follows Langmuir isotherms well and the maximum Cu(II) uptake calculated is 167.224 mg/g. The adsorption kinetics can be explained by pseudo-second-order model well and the time needed for equilibrium is 180 min. Thermodynamic study indicates that the adsorption is spontaneous and endothermic. Desorption of Cu(II) from adsorbents using EDTA-2Na solutions exhibits a high efficiency and the adsorbents can be used repeatedly. These results demonstrate that the titanate nanofibers are readily prepared, enabling promising applications for the removal of Cu(II) from aqueous solutions.

  20. Preparation of LiCoO2 nanofibers by electrospinning technique

    Science.gov (United States)

    Shao, Changlu; Yu, Na; Liu, Yichun; Mu, Rixiang

    2006-07-01

    Using a sol gel processing and electrospinning technique, extrathin fibers of PVA (polyvinyl alcohol)/lithium chloride/cobalt acetate composite were prepared. After calcinations of the above precursor fibers at 600°C, LiCoO2 nanofibers with a diameter of 100 150 nm, were successfully obtained. Measurements of TG/DTA, IR, XRD, Raman, SEM, EDS, respectively, were performed to characterize the properties of the as-prepared materials. We observed a strong correlation between crystalline phase and morphology of the fibers and calcinations temperature.

  1. Preparation of Polyacrylonitrile/Ferrous Chloride Composite Nanofibers by Electrospinning for Efficient Reduction of Cr(VI).

    Science.gov (United States)

    Zhou, Shilin; Liu, Fang; Zhang, Qian; Chen, Bor-Yann; Lin, Chin-Jung; Chang, Chang-Tang

    2015-08-01

    In this study, A novel adsorbent material of polyacrylonitrile (PAN)/ferrous chloride (FeCl2) composite nanofibers is prepared by electrospinning, a simple and effective method. The obtained composite nanofibers have a non-uniform morphology and structure and a large specific surface area of 13.8 m2 g-1. Fourier transform infrared spectroscopy (FTIR) revealed that Fe2+ was successful introduced into the composite nanofibers. Furthermore, the PAN/FeC12 composite nanofibers exhibited excellent performance in Cr removal, especially when reacted with reduction from a Cr(VI) standard containing solution, which has much faster removal efficiency than the previous report of Lin et al. (2011). The results of the adsorption isotherm show that the data fitted well to the Langmuir isotherm model. The maximum adsorption of chromium ions composite nanofibers is 108 mgCr/gFeCl2. An attempted model prediction of the transient dynamics of adsorption-desorption elucidated the feasible kinetic analysis of Cr6+ from the PAN/FeCl2 composite nanofibers. This kinetic modeling can be used both for adsorption of heavy metals wastewater and for organic-adsorption and biosorption of diverse wastewaters. The PAN/FeCl2 composite nanofibers producted in this study exhibit high efficiency in Cr(VI) removal from wastewater, and may be used as a reference for future investigation.

  2. Functionalized hybrid nanofibers to mimic native ECM for tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Karuppuswamy, Priyadharsini [Center for Nanofibers and Nanotechnology, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, Singapore (Singapore); Department Physics and Nanotechnology, SRM University, Kattankulathur, Chennai (India); Department of Engineering and System Science, National Tsing Hua University, Hsinchu 30013, Taiwan (China); Venugopal, Jayarama Reddy, E-mail: nnijrv@nus.edu.sg [Center for Nanofibers and Nanotechnology, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, Singapore (Singapore); Navaneethan, Balchandar [Center for Nanofibers and Nanotechnology, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, Singapore (Singapore); Department Physics and Nanotechnology, SRM University, Kattankulathur, Chennai (India); Laiva, Ashang Luwang; Sridhar, Sreepathy; Ramakrishna, Seeram [Center for Nanofibers and Nanotechnology, Nanoscience and Nanotechnology Initiative, Faculty of Engineering, National University of Singapore, Singapore (Singapore)

    2014-12-15

    Highlights: • Functionalized hybrid polymer mats fabricated for tissue engineering. • Hybrid polymer mats showed high surface area, high porosity and good wettability. • Incorporation of natural polymers modified the properties of nanofiber mats more biologically favorable for biomedical applications. - Abstract: Nanotechnology being one of the most promising technologies today shows an extremely huge potential in the field of tissue engineering to mimic the porous topography of natural extracellular matrix (ECM). Natural polymers are incorporated into the synthetic polymers to fabricate functionalized hybrid nanofibrous scaffolds, which improve cell and tissue compatibility. The present study identified the biopolymers – aloe vera, silk fibroin and curcumin incorporated into polycaprolactone (PCL) as suitable substrates for tissue engineering. Different combinations of PCL with natural polymers – PCL/aloe vera, PCL/silk fibroin, PCL/aloe vera/silk fibroin, PCL/aloe vera/silk fibroin/curcumin were electrospun into nanofibrous scaffolds. The fabricated two dimensional nanofibrous scaffolds showed high surface area, appropriate mechanical properties, hydrophilicity and porosity, required for the regeneration of diseased tissues. The nanofibrous scaffolds were characterized by Scanning electron microscope (SEM), porometry, Instron tensile tester, VCA optima contact angle measurement and FTIR to analyze the fiber diameter and morphology, porosity and pore size distribution, mechanical strength, wettability, chemical bonds and functional groups, respectively. The average fiber diameter of obtained fibers ranged from 250 nm to 350 nm and the tensile strength of PCL scaffolds at 4.49 MPa increased upto 8.3 MPa for PCL/silk fibroin scaffolds. Hydrophobicity of PCL decreased with the incorporation of natural polymers, especially for PCL/aloe vera scaffolds. The properties of as-spun nanofiber scaffolds showed their potential as promising scaffold materials in

  3. Layer-by-Layer assembled hybrid multilayer thin film electrodes based on transparent cellulose nanofibers paper for flexible supercapacitors applications

    Science.gov (United States)

    Wang, Xi; Gao, Kezheng; Shao, Ziqiang; Peng, Xiaoqing; Wu, Xue; Wang, Feijun

    2014-03-01

    Cellulose nanofibers (CNFs) paper with low thermal expansion and electrolyte absorption properties is considered to be a good potential substrate for supercapacitors. Unlike traditional substrates, such as glass or plastic, CNFs paper saves surfaces pretreatment when Layer-by-Layer (LbL) assembly method is used. In this study, negatively charged graphene oxide (GO) nanosheets and poly(3,4-ethylenedioxythiophene: poly(styrene sulfonate)) (PEDOT:PSS) nanoparticles are deposited onto CNFs paper with positively charged polyaniline (PANI) nanowires as agents to prepare multilayer thin film electrodes, respectively. Due to the different nanostructures of reduced graphene oxide (RGO) and PEDOT:PSS, the microstructures of the electrodes are distinguishing. Our work demonstrate that CNFs paper/PANI/RGO electrode provides a more effective pathway for ion transport facilitation compared with CNFs paper/PANI/PEDOT:PSS electrode. The supercapacitor fabricated by CNFs/[PANI-RGO]8 (S-PG-8) exhibits an excellent areal capacitance of 5.86 mF cm-2 at a current density of 0.0043 mA cm-2, and at the same current density the areal capacitance of the supercapacitor fabricated by CNFs/[PANI-PEDOT:PSS]8 (S-PP-8) is 4.22 mF cm-2. S-PG-8 also exhibits good cyclic stability. This study provides a novel method using CNFs as substrate to prepare hybrid electrodes with diverse microstructures that are promising for future flexible supercapacitors.

  4. Graphitic Carbon-Coated FeSe2 Hollow Nanosphere-Decorated Reduced Graphene Oxide Hybrid Nanofibers as an Efficient Anode Material for Sodium Ion Batteries

    Science.gov (United States)

    Cho, Jung Sang; Lee, Jung-Kul; Kang, Yun Chan

    2016-04-01

    A novel one-dimensional nanohybrid comprised of conductive graphitic carbon (GC)-coated hollow FeSe2 nanospheres decorating reduced graphene oxide (rGO) nanofiber (hollow nanosphere FeSe2@GC-rGO) was designed as an efficient anode material for sodium ion batteries and synthesized by introducing the nanoscale Kirkendall effect into the electrospinning method. The electrospun nanofibers transformed into hollow nanosphere FeSe2@GC-rGO hybrid nanofibers through a Fe@GC-rGO intermediate. The discharge capacities of the bare FeSe2 nanofibers, nanorod FeSe2-rGO-amorphous carbon (AC) hybrid nanofibers, and hollow nanosphere FeSe2@GC-rGO hyrbid nanofibers at a current density of 1 A g-1 for the 150th cycle were 63, 302, and 412 mA h g-1, respectively, and their corresponding capacity retentions measured from the 2nd cycle were 11, 73, and 82%, respectively. The hollow nanosphere FeSe2@GC-rGO hybrid nanofibers delivered a high discharge capacity of 352 mA h g-1 even at an extremely high current density of 10 A g-1. The enhanced electrochemical properties of the hollow nanosphere FeSe2@GC-rGO composite nanofibers arose from the synergetic effects of the FeSe2 hollow morphology and highly conductive rGO matrix.

  5. In situ self-assembly of polarizing chromogen nanofibers catalyzed with hybrid films of gold nanoparticles and cellulose

    Science.gov (United States)

    Liu, Zhiming; Wu, Wenjian

    2017-09-01

    Hybrid materials of metal nanoparticles and biopolymers with catalytic properties are very promising to be used as detectors in biochemical reactions. In this work, the catalytic properties and relevant in situ self-assembly abilities of hybrid films of gold nanoparticles (GNPs) and cellulose for the oxidation of benign chromogen 3,3‧,5,5‧-tetramethylbenzidine (TMB) with hydrogen peroxide (H2O2) are revealed for the first time. The peroxidase-like properties of hybrid films are inherited from those of colloidal GNPs and increase with their contents of GNPs. It is discovered that the oxidized products of TMB grow in situ and assemble into rod-like and tumbleweed-like nanofiber assemblies on hybrid films. The rod-like nanofibers show a magnificent polarizing phenomenon under polarized light because of polycrystalline globular nanoparticles inside. The in situ self-assembly of polarizing nanofibers of chromogen catalyzed with hybrid films creates an opportunity for the synthesis of novel organic nanomaterials and the enhanced detection of biochemical products under polarized light.

  6. Preparation and electrochemical properties of carbon-coated LiFePO4 hollow nanofibers

    Science.gov (United States)

    Wei, Bin-bin; Wu, Yan-bo; Yu, Fang-yuan; Zhou, Ya-nan

    2016-04-01

    Carbon-coated LiFePO4 hollow nanofibers as cathode materials for Li-ion batteries were obtained by coaxial electrospinning. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller specific surface area analysis, galvanostatic charge-discharge, and electrochemical impedance spectroscopy (EIS) were employed to investigate the crystalline structure, morphology, and electrochemical performance of the as-prepared hollow nanofibers. The results indicate that the carbon-coated LiFePO4 hollow nanofibers have good long-term cycling performance and good rate capability: at a current density of 0.2C (1.0C = 170 mA·g-1) in the voltage range of 2.5-4.2 V, the cathode materials achieve an initial discharge specific capacity of 153.16 mAh·g-1 with a first charge-discharge coulombic efficiency of more than 97%, as well as a high capacity retention of 99% after 10 cycles; moreover, the materials can retain a specific capacity of 135.68 mAh·g-1, even at 2C.

  7. Preparation and electrochemical properties of carbon-coated LiFePO4 hollow nanofibers

    Institute of Scientific and Technical Information of China (English)

    Bin-bin Wei; Yan-bo Wu; Fang-yuan Yu; Ya-nan Zhou

    2016-01-01

    Carbon-coated LiFePO4 hollow nanofibers as cathode materials for Li-ion batteries were obtained by coaxial electrospinning. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller specific surface area analysis, galvanostatic charge–discharge, and electrochemical impedance spectroscopy (EIS) were employed to investigate the crystalline structure, morphology, and electrochemical performance of the as-prepared hollow nanofibers. The results indicate that the carbon-coated LiFePO4 hollow nanofibers have good long-term cycling performance and good rate capability:at a current density of 0.2C (1.0C=170 mA·g−1) in the voltage range of 2.5–4.2 V, the cathode materials achieve an initial discharge specific capacity of 153.16 mAh·g−1 with a first charge–discharge coulombic efficiency of more than 97%, as well as a high capacity retention of 99%after 10 cycles;moreover, the materi-als can retain a specific capacity of 135.68 mAh·g−1, even at 2C.

  8. Preparation of asiaticoside-loaded coaxially electrospinning nanofibers and their effect on deep partial-thickness burn injury.

    Science.gov (United States)

    Zhu, Lifei; Liu, Xiaoyan; Du, Lina; Jin, Yiguang

    2016-10-01

    Sodium alginate and chitosan were in favor of wound healing. However, the two polymers were not compatible in one formulation due to the electrostatic interaction. Coaxially electrospinning technology could make two or more noneletrospun polymers to be electrospun in independent core and shell layer. Asiaticoside-loaded coaxially electrospinning nanofibers of alginate, polyvinyl alcohol (PVA) and chitosan (alginate/PVA/chitosan) were prepared and evaluated. Morphologies and microstructure of nanofibers were observed with scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Drug release in vitro of coaxial nanofibers was also evaluated. Deep partial-thickness burn injury were established and used to evaluate the improved healing effect of asiaticoside-loaded coaxial nanofibers. Drug-loaded coaxial nanofibers prepared with the optimized formulations and technologies had the obvious core-shell structure. Coaxial nanofibers showed faster drug release profiles in vitro and this facilitated wound healing. Its healing effect on rats with deep partial-thickness burn injury was also significant based on morphology, wound healing ratio, and pathological sections. Positive expression of vascular endothelial growth factor (VEGF), cluster of differentiation 31 (CD31), and proliferating cell nuclear antigen (PCNA), and down regulation of tumor necrosis factor (TNF) and interleukin-6 (IL-6) also validated the improved effect of wound healing. In general, the asiaticoside-loaded coaxial nanofibers had obvious core-shell structure with smooth surface and uniform diameter. Its healing effect on deep partial-thickness burn injury of rats was obvious. Asiaticoside-loaded coaxial nanofibers provide a novel promising option for treatment of deep partial-thickness burn injury.

  9. High Yield Preparation Method of Thermally Stable Cellulose Nanofibers

    Directory of Open Access Journals (Sweden)

    Hongli Zhu

    2014-02-01

    Full Text Available The preparation of nanocellulose fibers (NFs is achieved through pretreating cellulose in a NaOH/urea/thiourea solution, and then defibrillating the fibers through ultrasonication, resulting in a high yield of 85.4%. Extensive work has been done to optimize the preparation parameters. The obtained NFs are about 30 nm in diameter with cellulose II crystal structure. They possess high thermal stability with an onset of thermal degradation at 270 °C and a maximum degradation temperature of 370 °C. Such NFs have potential applications in transistors and batteries with high thermal stability. NFs-H were obtained by homogenizing undefibrillated fibers separated from the preparation of NFs. NFs-H were also in cellulose II crystal form but with lower thermal stability due to low crystallinity. They can be applied to make highly transparent paper.

  10. Preparation of an imogolite/poly(acrylic acid) hybrid gel.

    Science.gov (United States)

    Lee, Hoik; Ryu, Jungju; Kim, Donghyun; Joo, Yongho; Lee, Sang Uck; Sohn, Daewon

    2013-09-15

    Many efforts in the field of hydrogels have been focused toward increasing the mechanical strength of the gel using inorganic materials. In this study, we synthesized a hydrogel that has excellent mechanical properties using surface-modified inorganic nanofibers composed of imogolite (Al2SiO3(OH)4), which is a hydrated aluminum silicate that has a hollow tube structure. Gamma ray radiation generates peroxide radicals on the nanofibers (imogolite), resulting in an additive free hybrid hydrogel. Structural optimization was carried out by changing the composition of imogolite and poly(acrylic acid). Chemical bonding between the nanofiber and the polymer was simulated by a cluster model and characterized by wide area Raman spectroscopy. The results indicate that imogolite embedded in a polymer matrix can align along the direction of an elongational force, as confirmed by small angle X-ray scattering (SAXS).

  11. Preparation and evaluation of electrospun nanofibers containing pectin and time-dependent polymers aimed for colonic drug delivery of celecoxib

    Directory of Open Access Journals (Sweden)

    A. Akhgari

    2016-01-01

    Full Text Available Objective(s:The aim of this study was to prepare electrospun nanofibers of celecoxib using combination of time-dependent polymers with pectin to achieve a colon-specific drug delivery system for celecoxib. Materials and Methods:Formulations were produced based on two multilevel 22 full factorial designs. The independent variables were the ratio of drug:time-dependent polymer (X1 and the amount of pec­tin in formulations (X2. Electrospinning process was used for preparation of nanofibers. The spinning solutions were loaded in 5 mL syringes. The feeding rate was fixed by a syringe pump at 2.0 mL/h and a high voltage supply at range 10-18 kV was applied for electrospinning. Electrospun nanofibers were collected and evaluated by scanning electron microscopy and drug release in the acid and buffer with pH 6.8 with and without pectinase. Results:Electrospun nanofibers of celecoxib with appropriate morphological properties were produced via electrospinning process. Drug release from electrospun nanofibers was very low in the acidic media; while, drug release in the simulated colonic media was the highest from formulations containing pectin. Conclusion: Formulation F2 (containing drug:ERS with the ratio of 1:2 and 10% pectin exhibited acceptable morphological characteristics and protection of drug in the upper GI tract and could be a good candidate as a colonic drug delivery system for celecoxib.

  12. First Introduction of NiSe2 to Anode Material for Sodium-Ion Batteries: A Hybrid of Graphene-Wrapped NiSe2/C Porous Nanofiber

    Science.gov (United States)

    Cho, Jung Sang; Lee, Seung Yeon; Kang, Yun Chan

    2016-03-01

    The first-ever study of nickel selenide materials as efficient anode materials for Na-ion rechargeable batteries is conducted using the electrospinning process. NiSe2-reduced graphene oxide (rGO)-C composite nanofibers are successfully prepared via electrospinning and a subsequent selenization process. The electrospun nanofibers giving rise to these porous-structured composite nanofibers with optimum amount of amorphous C are obtained from the polystyrene to polyacrylonitrile ratio of 1/4. These composite nanofibers also consist of uniformly distributed single-crystalline NiSe2 nanocrystals that have a mean size of 27 nm. In contrast, the densely structured bare NiSe2 nanofibers formed via selenization of the pure NiO nanofibers consist of large crystallites. The initial discharge capacities of the NiSe2-rGO-C composite and bare NiSe2 nanofibers at a current density of 200 mA g-1 are 717 and 755 mA h g-1, respectively. However, the respective 100th-cycle discharge capacities of the former and latter are 468 and 35 mA h g-1. Electrochemical impedance spectroscopy measurements reveal the structural stability of the composite nanofibers during repeated Na-ion insertion and extraction processes. The excellent Na-ion storage properties of these nanofibers are attributed to this structural stability.

  13. Effects of Electrode Reversal on the Distribution of Naproxen in the Electrospun Cellulose Acetate Nanofibers

    Directory of Open Access Journals (Sweden)

    Zhuang Li

    2014-01-01

    Full Text Available Naproxen (NAP/cellulose acetate hybrid nanofibers were prepared by positive and reversed emitting electrodes electrospinning setups. The morphology and structure of the resultant nanofibers were characterized, and the NAP release behaviors were investigated. It was found that NAP dispersed in the CA matrix in molecular level, and no aggregation and dimers of NAP were found in the resultant NAP/CA hybrid nanofibers due to the formation of hydrogen bonds between NAP and CA. The nanofibers obtained by reversed emitting electrode electrospinning setup have a thicker diameter and a faster NAP release rate compared with those obtained by positive emitting electrode electrospinning setup. The faster drug release of NAP from nanofibers prepared by reversed emitting electrode electrospinning is due to the fact that the concentration of NAP molecules near the surface of the nanofibers is relatively higher than that of the nanofibers prepared by positive emitting electrode electrospinning setup. The effects of the electrode polarity on the distribution of drugs in nanofibers can be used to prepare hybrid electrospun fibers of different drug release rates, which may found applications in biomedical materials.

  14. Fabrication and optical properties of Y2O3: Eu3+ nanofibers prepared by electrospinning.

    Science.gov (United States)

    Dong, Guoping; Chi, Yingzhi; Xiao, Xiudi; Liu, Xiaofeng; Qian, Bin; Ma, Zhijun; Wu, E; Zeng, Heping; Chen, Danping; Qiu, Jianrong

    2009-12-07

    Y(2)O(3): Eu(3+) nanofibers with the average diameter of ~300 nm were in situ fabricated by electrospinning. X-ray diffraction (XRD) pattern confirmed that the Y(2)O(3): Eu(3+) nanofibers were composed of pure body-centered cubic (bcc) Y(2)O(3) phase. High-resolution transmission electron microscopy (HRTEM) results indicated that Y(2)O(3): Eu(3+) nanofibers were constituted of nonspherical crystalline grains, and these crystalline grains were orderly arranged along the axial direction of single nanofiber. These Y(2)O(3): Eu(3+) nanofibers showed a partially polarized photoluminescence (PL). The arrangement of crystalline grains and the mismatch of dielectric constant between Y(2)O(3): Eu(3+) nanofiber and its environment probably contributed together to the polarized PL from Y(2)O(3): Eu(3+) nanofiber.

  15. Fabrication and durable antibacterial properties of electrospun chitosan nanofibers with silver nanoparticles.

    Science.gov (United States)

    Liu, Yanan; Liu, Yang; Liao, Nina; Cui, Fuhai; Park, Mira; Kim, Hak-Yong

    2015-08-01

    Non-precipitation chitosan/silver nanoparticles (AgNPs) in 1% acetic acid aqueous solution was prepared from chitosan colloidal gel with various contents of silver nitrate via electron beam irradiation (EBI). Electrospun chitosan-based nanofibers decorated with AgNPs were successfully performed by blending poly(vinyl alcohol). The morphology of as-prepared nanofibers and the size of AgNPs in the nanofibers were investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The presence of AgNPs in as-obtained nanofibers was also confirmed by ultraviolet-visible spectroscopy (UV), Fourier transform infrared (FT-IR) spectroscopy, EDX spectrum and metal mapping. Silver ion release behavior indicated that these hybrid nanofibers continually release adequate silver to exhibit antibacterial activity over 16 days. These biocomposite nanofibers showed pronounced antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli).

  16. Functionalized hybrid nanofibers to mimic native ECM for tissue engineering applications

    Science.gov (United States)

    Karuppuswamy, Priyadharsini; Venugopal, Jayarama Reddy; Navaneethan, Balchandar; Laiva, Ashang Luwang; Sridhar, Sreepathy; Ramakrishna, Seeram

    2014-12-01

    Nanotechnology being one of the most promising technologies today shows an extremely huge potential in the field of tissue engineering to mimic the porous topography of natural extracellular matrix (ECM). Natural polymers are incorporated into the synthetic polymers to fabricate functionalized hybrid nanofibrous scaffolds, which improve cell and tissue compatibility. The present study identified the biopolymers - aloe vera, silk fibroin and curcumin incorporated into polycaprolactone (PCL) as suitable substrates for tissue engineering. Different combinations of PCL with natural polymers - PCL/aloe vera, PCL/silk fibroin, PCL/aloe vera/silk fibroin, PCL/aloe vera/silk fibroin/curcumin were electrospun into nanofibrous scaffolds. The fabricated two dimensional nanofibrous scaffolds showed high surface area, appropriate mechanical properties, hydrophilicity and porosity, required for the regeneration of diseased tissues. The nanofibrous scaffolds were characterized by Scanning electron microscope (SEM), porometry, Instron tensile tester, VCA optima contact angle measurement and FTIR to analyze the fiber diameter and morphology, porosity and pore size distribution, mechanical strength, wettability, chemical bonds and functional groups, respectively. The average fiber diameter of obtained fibers ranged from 250 nm to 350 nm and the tensile strength of PCL scaffolds at 4.49 MPa increased upto 8.3 MPa for PCL/silk fibroin scaffolds. Hydrophobicity of PCL decreased with the incorporation of natural polymers, especially for PCL/aloe vera scaffolds. The properties of as-spun nanofiber scaffolds showed their potential as promising scaffold materials in tissue engineering applications.

  17. Synthesis and Catalytic Features of Hybrid Metal Nanoparticles Supported on Cellulose Nanofibers

    Directory of Open Access Journals (Sweden)

    Hirotaka Koga

    2011-11-01

    Full Text Available The structural and functional design of metal nanoparticles has recently allowed remarkable progress in the development of high-performance catalysts. Gold nanoparticles (AuNPs are among the most innovative catalysts, despite bulk Au metal being regarded as stable and inactive. The hybridization of metal NPs has attracted major interest in the field of advanced nanocatalysts, due to electro-mediated ligand effects. In practical terms, metal NPs need to be supported on a suitable matrix to avoid any undesirable aggregation; many researchers have reported the potential of polymer-supported AuNPs. However, the use of conventional polymer matrices make it difficult to take full advantage of the inherent properties of the metal NPs, since most of active NPs are imbedded inside the polymer support. This results in poor accessibility for the reactants. Herein, we report the topochemical synthesis of Au and palladium (Pd bimetallic NPs over the surfaces of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO-oxidized cellulose nanofibers (TOCNs, and their exceptional catalytic performance. Highly-dispersed AuPdNPs were successfully synthesized in situ on the crystal surfaces of TOCNs with a very high density of carboxylate groups. The AuPdNPs@TOCN nanocomposites exhibit excellent catalytic efficiencies in the aqueous reduction of 4-nitrophenol to 4-aminophenol, depending on the molar ratios of Au and Pd.

  18. Preparation of Electrospun Nanocomposite Nanofibers of Polyaniline/Poly(methyl methacrylate with Amino-Functionalized Graphene

    Directory of Open Access Journals (Sweden)

    Hanan Abdali

    2017-09-01

    Full Text Available In this paper we report upon the preparation and characterization of electrospun nanofibers of doped polyaniline (PANI/poly(methyl methacrylate (PMMA/amino-functionalized graphene (Am-rGO by electrospinning technique. The successful functionalization of rGO with amino groups is examined by Fourier transforms infrared (FTIR, X-ray photoelectron spectroscopy (XPS and Raman microspectrometer. The strong electric field enables the liquid jet to be ejected faster and also contributes to the improved thermal and morphological homogeneity of PANI/PMMA/Am-rGO. This results in a decrease in the average diameter of the produced fibers and shows that these fibers can find promising uses in many applications such as sensors, flexible electronics, etc.

  19. Preparation and photoluminescence characteristics of Tb-, Sm- and Dy-doped Y{sub 2}O{sub 3} nanofibers by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoyan; Chen Yuming [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China); Qian Qingrong, E-mail: qrqian@fjnu.edu.cn [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China); Liu Xinping; Xiao Liren [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China); Chen Qinghua, E-mail: cqhuar@pub5.fz.fj.cn [College of Chemistry and Materials Science, College of Environmental Science and Engineering, Fujian Normal University, Fuzhou 350007 (China); Fujian Modified Plastic Institute of Research and Technology Development, Fuzhou 350007 (China); Fujian Engineering Research Center of Environment-friendly Polymer Material, Fuzhou 350007 (China)

    2012-01-15

    An electrospinning-calcination strategy was established to fabricate Y{sub 2}O{sub 3} nanofibers doped with rare earth ions (Tb, Sm and Dy) using electrospun PVA/RE(NO{sub 3}){sub x}/Y(NO{sub 3}){sub 3} composite nanofibers as precursors (x=3.4). The prepared nanofibers were characterized by XRD, FESEM, EDS, (HR)TEM and PL analyses. Based on the experimental results, a solid-solid growth mechanism (SS) was proposed to describe the formation of inorganic crystalline fibers from organic/inorganic composite nanofibers by calcination. It was determined that carbonaceous nanoparticles that were formed in the process of pre-carbonization adsorbed Y{sub 2}O{sub 3}:RE nanoparticles to grow Y{sub 2}O{sub 3}:RE crystal, and the resultant nanofibers exhibited a typical crystalline domain with grain boundary. The obtained Y{sub 2}O{sub 3}:RE nanofibers possessed excellent luminescent characteristics and could be used as an appreciable luminescent material. - Highlights: > Fabricate Y{sub 2}O{sub 3}:RE fibers by the calcination of electrospun PVA/Y(NO{sub 3}){sub 3}/RE(NO{sub 3}){sub 3} composite nanofibers. > Prepared Y{sub 2}O{sub 3}:RE nanofibers display more intensive photoluminescence performance than the bulk materials. > Propose a solid-solid growth mechanism for the formation of inorganic crystalline fibers via calciation.

  20. Preparation and Photocatalysis of Mesoporous TiO2 Nanofibers via an Electrospinning Technique

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; YUAN Qing; CHI Yue; SHAO Chang-lu; LI Nan; LI Xiao-tian

    2012-01-01

    Mesoporous TiO2 nanofibers have been synthesized by a new method that combines sol-gel chemistry and electrospinning technique.The obtained mesoporous TiO2 nanofibers were characterized with scanning electron microscopy(SEM),X-ray diffraction(XRD),transmission electron microscopy(TEM) and nitrogen adsorptiondesorption isotherms.The photocatalytic performance was evaluated by the photocatalytic degradation of Rhodamine B undcr UV light irradiation.The results show that mesoporous TiO2 nanofibers exhibit higher photocatalytic activity compared with nonporous TiO2 nanofibers.

  1. Hybrid matrices of TiO2 and TiO2–Ag nanofibers with silicone for high water flux photocatalytic degradation of dairy effluent

    DEFF Research Database (Denmark)

    Kanjwal, Muzafar Ahmad; Alm, Martin; Thomsen, Peter

    2016-01-01

    TiO2 and TiO2–Ag nanofibers were produced by electrospinning technique and surface coated on silicone elastomer (diameter: 10.0 mm; thickness: 2.0 mm) by dipcoating method. These coated hybrid nanoporous matrices were characterized by various morphological and physicochemical techniques (like SEM......, TEM, XRD, FTIR, EDS and UV). These characterizations reveal that the surface morphology of electrospun nanofibers remain intact by the dipcoating technique. The produced hybrid matrices of TiO2 and TiO2–Ag silicone were utilized as photocatalysts to degrade dairy waste water with an efficient water...

  2. Highly Efficient Photocatalytic Hydrogen Evolution in Ternary Hybrid TiO2/CuO/Cu Thoroughly Mesoporous Nanofibers.

    Science.gov (United States)

    Hou, Huilin; Shang, Minghui; Gao, Fengmei; Wang, Lin; Liu, Qiao; Zheng, Jinju; Yang, Zuobao; Yang, Weiyou

    2016-08-10

    Development of novel hybrid photocatalysts with high efficiency and durability for photocatalytic hydrogen generation is highly desired but still remains a grand challenge currently. In the present work, we reported the exploration of ternary hybrid TiO2/CuO/Cu thoroughly mesoporous nanofibers via a foaming-assisted electrospinning technique. It is found that by adjusting the Cu contents in the solutions, the unitary (TiO2), binary (TiO2/CuO, TiO2/Cu), and ternary (TiO2/CuO/Cu) mesoporous products can be obtained, enabling the growth of TiO2/CuO/Cu ternary hybrids in a tailored manner. The photocatalytic behavior of the as-synthesized products as well as P25 was evaluated in terms of their hydrogen evolution efficiency for the photodecomposition water under Xe lamp irradiation. The results showed that the ternary TiO2/CuO/Cu thoroughly mesoporous nanofibers exhibit a robust stability and the most efficient photocatalytic H2 evolution with the highest release rate of ∼851.3 μmol g(-1) h(-1), which was profoundly enhanced for more than 3.5 times with respect to those of the pristine TiO2 counterparts and commercial P25, suggesting their promising applications in clean energy production.

  3. Hybrid matrices of ZnO nanofibers with silicone for high water flux photocatalytic degradation of dairy effluent

    Energy Technology Data Exchange (ETDEWEB)

    Kanjwal, Muzafar A., E-mail: kanjwalmuzafar@gmail.com [Nano-Bio Science Research Group, DTU-Food Technical University of Denmark, Soltofts Plads, B 227, 2800 Kgs. Lyngby (Denmark); Dept. of Chemical Engineering, College of Engineering, University of Hail, Hail 81451 (Saudi Arabia); Shawabkeh, Ali Qublan [Dept. of Chemical Engineering, College of Engineering, University of Hail, Hail 81451 (Saudi Arabia); Alm, Martin; Thomsen, Peter [BioModics ApS, Gregersensvej 7, DK-2630 Taastrup (Denmark); Barakat, Nasser A.M. [Department of Textile Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Chronakis, Ioannis S., E-mail: ioach@food.dtu.dk [Nano-Bio Science Research Group, DTU-Food Technical University of Denmark, Soltofts Plads, B 227, 2800 Kgs. Lyngby (Denmark)

    2016-09-15

    Zinc oxide (ZnO) nanofibers were produced by electrospinning technique and surface coated on silicone elastomer substrate (diameter: 10.0 mm; thickness: 2.0 mm) by a dipcoating method. The obtained hybrid nanoporous matrices were investigated by scanning and transmission electron microscopy (SEM, TEM), X-ray diffraction (XRD) and Fourier transformation infrared techniques (FTIR). These characterizations reveal that the surface morphology of electrospun nanofibers remained intact by the dipcoating technique. The produced hybrid matrices showed high water flux of 9407 L/m{sup 2}h, 38% removal rate of dairy effluent (DE) and 2298 ml/g h rate of hydrogen production. - Highlights: • Hybrid ZnO silicon nanoporous matrices are introduced. • The water flux is high 9407 L/m{sup 2}h for ZnO silicon nanoporous matrices. • The ZnO silicon nanoporous matrices showed good photocatalytic properties. • The ZnO nanoporous matrices showed 2298 ml/g h rate of hydrogen production.

  4. Preparation and Application as the Filler for Elastomers of Flake-Shaped Cellulose Particles and Nanofibers

    Science.gov (United States)

    Nagatani, Asahiro; Lee, Seung-Hwan; Endo, Takashi; Tanaka, Tatsuya

    Fibrous cellulose made from wood pulp was mechanically milled into flake-shaped cellulose particles(FS-CPs) using a planetary ball mill with additives under several conditions. The average particle diameter of the FS-CPs was ca. 15μm, and the particles were available in a variety of thicknesses by changing the kind of the additives used in the milling process. FS-CPs-reinforced olefinic thermoplastic elastomer composites were prepared under melt mixing and passed through an open roll to orient the particles. The tensile modulus of the composites with a compatibilizer increased with increasing the particle content. The damping properties of the composites improved, compared to the neat elastomer. On the other hand, the fibrous cellulose was suspended in water, followed by wet disk-milled to prepare cellulose nanofibers(CNFs). The wet ground products showed nanoscopic fine morphology. CNFs-reinforced natural rubber(NR) composites were prepared by mixing the water suspension of CNFs with NR latex using a homogenizer. Then, it was dried in an oven and mixed again with vulcanizing ingredients of rubber using an open roll. The tensile properties of the composites improved remarkably by the addition of small amount of CNFs.

  5. Characterization and application of zeolitic imidazolate framework-8@polyvinyl alcohol nanofibers mats prepared by electrospinning

    Science.gov (United States)

    Fan, Xiaoxiao; Yu, Linling; Li, Lianghao; Yang, Cao; Wen, Junjie; Ye, Xiaokun; Cheng, Jianhua; Hu, Yongyou

    2017-02-01

    In this study, Zeolitic imidazolate framework-8@polyvinyl alcohol (ZIF-8@PVA) nanofibers were creatively fabricated by electrospinning technique, and the nanofibers membranes were characterized by SEM, TEM, XRD, FTIR, TG, DSC, DTA, BET. Its thermal stability, mechanical property, water stability and adsorption nature were also performed. The optimized fabrication parameter of the ZIF-8@PVA was 10 wt% and the uniform diameters of the nanofibers has been obtained. In addition, the ZIF-8@PVA nanofibers displayed unique properties such as a water stable and flexible structure. The adsorption test for Congo red treatment revealed that the nanofibers had a great adsorption performance. The results indicated that the nonwoven fiber mats had a great potential as a new type of membrane adsorbents in wastewater purification. The possible mechanism of CR adsorption onto ZIF-8@PVA was researched.

  6. Synthesis and characterization of electrospun PVdF-HFP/silane-functionalized ZrO2 hybrid nanofiber electrolyte with enhanced optical and electrochemical properties

    Science.gov (United States)

    Puguan, John Marc C.; Chung, Wook-Jin; Kim, Hern

    2016-12-01

    A facile method to produce a hybrid of organic-inorganic nanofiber electrolyte via electrospinning is hereby presented. The incorporation of functionalized zirconium oxide (ZrO2) nanoparticles into poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) and complexed with lithium trifluoromethanesulfonate (LiCF3SO3) provided an enhanced optical transmissivity and ionic conductivity. The dependence of the nanofiber's morphology, optical and electrochemical properties on the various ZrO2 loading was studied. Results show that while nanofiller content was increased, the diameter of the nanofibers was reduced. The improved bulk ionic conductivity of the nanofiber electrolyte was at 1.96 × 10-5 S cm-1. Owing to the enhanced dispersibility of the 3-(trimethoxysilyl)propyl methacrylate (MPS) functionalized ZrO2, the optical transmissivity of the nanofiber electrolyte was improved significantly. This new nanofiber composite electrolyte membrane with further development has the potential to be next generation electrolyte for energy efficient windows like electrochromic devices.

  7. Release of Bacteriocins from Nanofibers Prepared with Combinations of Poly(D,L-lactide (PDLLA and Poly(Ethylene Oxide (PEO

    Directory of Open Access Journals (Sweden)

    Leon Dicks

    2011-03-01

    Full Text Available Plantaricin 423, produced by Lactobacillus plantarum, and bacteriocin ST4SA produced by Enterococcus mundtii, were electrospun into nanofibers prepared from different combinations of poly(D,L-lactide (PDLLA and poly(ethylene oxide (PEO dissolved in N,N-dimethylformamide (DMF. Both peptides were released from the nanofibers with a high initial burst and retained 88% of their original antimicrobial activity at 37 °C. Nanofibers have the potential to serve as carrier matrix for bacteriocins and open a new field in developing controlled antimicrobial delivery systems for various applications.

  8. Release of bacteriocins from nanofibers prepared with combinations of poly(d,l-lactide) (PDLLA) and poly(ethylene oxide) (PEO).

    Science.gov (United States)

    Heunis, Tiaan; Bshena, Osama; Klumperman, Bert; Dicks, Leon

    2011-01-01

    Plantaricin 423, produced by Lactobacillus plantarum, and bacteriocin ST4SA produced by Enterococcus mundtii, were electrospun into nanofibers prepared from different combinations of poly(d,l-lactide) (PDLLA) and poly(ethylene oxide) (PEO) dissolved in N,N-dimethylformamide (DMF). Both peptides were released from the nanofibers with a high initial burst and retained 88% of their original antimicrobial activity at 37 °C. Nanofibers have the potential to serve as carrier matrix for bacteriocins and open a new field in developing controlled antimicrobial delivery systems for various applications.

  9. Environmental remediation and superhydrophilicity of ultrafine antibacterial tungsten oxide-based nanofibers under visible light source

    Energy Technology Data Exchange (ETDEWEB)

    Srisitthiratkul, Chutima; Yaipimai, Wittaya [Nano Functional Textile Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand); Intasanta, Varol, E-mail: varol@nanotec.or.th [Nano Functional Textile Laboratory, National Nanotechnology Center (NANOTEC), National Science and Technology Development Agency (NSTDA), 111 Thailand Science Park, Phahonyothin Rd., Klong 1, Klong Luang, Pathumthani 12120 (Thailand)

    2012-10-15

    Graphical abstract: Nanosilver-decorated WO{sub 3} photocatalytic nanofibers are antibacterial and superhydrophilic under a visible light source. Highlights: Black-Right-Pointing-Pointer Deposition of nanosilver onto electrospun WO{sub 3} nanofibers' surface was done exploiting visible or UV light driven photoreduction of silver ion. Black-Right-Pointing-Pointer Nanofibers showed antibacterial characteristics. Black-Right-Pointing-Pointer Nanofibers degraded a model toxin effectively. Black-Right-Pointing-Pointer Nanofibers showed superhydrophilicity under a visible light source. - Abstract: Fabrication of nanosilver-decorated WO{sub 3} nanofibers was successfully performed. First, deposition of nanosilver onto electrospun WO{sub 3} nanofibers' surface was done via photoreduction of silver ion under visible or UV light. The resulting hybrid nanofibers not only revealed antibacterial characteristics but also maintained their photocatalytic performance towards methylene blue decomposition. Unexpectedly, the nanofibrous layers prepared from these nanofibers showed superhydrophilicity under a visible light source. The nanofibers might be advantageous in environmental and hygienic nanofiltration under natural light sources, where the self-cleaning characteristics could be valuable in maintenance processes.

  10. Antibacterial Properties of Novel Bacterial Cellulose Nanofiber Containing Silver Nanoparticles

    Institute of Scientific and Technical Information of China (English)

    杨加志; 刘晓丽; 黄立勇; 孙东平

    2013-01-01

    In this work, we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers (BCF) as a template. Silver (Ag) nanoparticles with an average di-ameter of 1.5 nm were well dispersed on BCF via a simple in situ chemical-reduction between AgNO3 and NaBH4 at a relatively low temperature. A growth mechanism is proposed that Ag nanoparticles are uniformly anchored onto BCF by coordination with BC-containing hydroxyl groups. The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by several techniques including transmission electron microscopy, X-ray diffraction, thermogra-vimetric analyses, and ultraviolet-visible (UV-Vis) absorption spectra. The antibacterial properties of Ag/BCF hybrid nanofibers against Escherichia coli (E. coli, Gram-negative) and Staphylococcu saureus (S. saureus, Gram-positive) bacteria were evaluated by using modified Kirby Bauer method and colony forming count method. The results show that Ag nanoparticles are well dispersed on BCF surface via in situ chemical-reduction. The Ag/BCF hybrid nanofiber presents strong antibacterial property and thus offers its candidature for use as functional antimicrobial agents.

  11. Preparation of Pt/TiO2 hollow nanofibers with highly visible light photocatalytic activity

    Science.gov (United States)

    Yang, Ziling; Lu, Jing; Ye, Weichun; Yu, Chushu; Chang, Yanlong

    2017-01-01

    The Pt/TiO2 hollow nanofibers (HNFs) as a photocatalyst have been successfully prepared by a uniaxial electrospinning method combined with photo-deposition. The as-synthesized photocatalysts were characterized by TEM, XRD, SAED, EDX, XPS, N2 adsorption-desorption, and UV-vis DRS. The TiO2 HNFs were composed of an anatase-rutile mixed phase, with the ratio of ∼70:30. The band gap of TiO2 HNFs decreased from 3.09 down to 2.77 eV with 2 wt.% Pt loading, this led to an enhanced photocatalytic performance under visible light. By evaluating the degradation of azo dye Orange II, the pseudo-first-rate constant (k) of Pt/350-TiO2 HNFs system was 0.0069 min-1, which was 11.5 and 3.63 times higher than for TiO2 HNFs and Pt/P25, respectively. The main factors affecting the photocatalytic activity were further investigated, these included the loading amount of Pt, the calcination temperature of TiO2 HNFs, the pH of initial solution and the light source. The results of repeated use of the Pt/TiO2 HNFs demonstrated that the photocatalysts exhibited an excellent stability even after ten cycles. The possible degradation mechanism was also studied. It was shown that rad O2- radicals were the main reactive oxygen species for the degradation of Orange II.

  12. Zwitterionic phosphorylcholine grafted chitosan nanofiber: Preparation, characterization and in-vitro cell adhesion behavior.

    Science.gov (United States)

    Oktay, Burcu; Kayaman-Apohan, Nilhan; Süleymanoğlu, Mediha; Erdem-Kuruca, Serap

    2017-04-01

    In this study, zwitterionic phosphorylcholine grafted electrospun chitosan fiber was accomplished in three steps: (1) Azide groups on the chitosan were regioselectively replaced with hydroxyl side group and then the product was electrospun. (2) Chitosan based macroinitiator was prepared using an azide-alkyne click reaction from azide-functionalized electrospun chitosan fiber. (3) Poly(2-methacryloyloxyethyl phosphorylcholine) (MPC) was grafted onto the electrospun chitosan fiber by atom transfer radical polymerization (ATRP) in order to enhance cellular viability and proliferation of 3T3, ECV and Saos. The structure of surface modified chitosan was characterized by Fourier transform infrared spectrometer (FT-IR) and (1)H nuclear magnetic resonance ((1)H NMR). The surface morphology of the nanofibers was investigated by scanning electron microscope (SEM). In-vitro cellular attachment and spreading experiments of 3T3, ECV304 and Saos were performed on electrospun chitosan fibers in the presence and the absence of MPC grafting. Poly(MPC) grafted electrospun fiber showed an excellent performance due to phosphorylcholine groups mimicking the natural phospholipid. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Preparation of antibacterial PVA and PEO nanofibers containing Lawsonia Inermis (henna) leaf extracts.

    Science.gov (United States)

    Avci, H; Monticello, R; Kotek, R

    2013-01-01

    Concerns about health issues and environmental pollution stimulate research to find new health and hygiene related products with healing properties and minimum negative effect on the environment. Development of new, natural antibacterial agents has become one of the most important research areas to combat some pathogens such as Gram- positive and Gram-negative bacteria, fungi, algae, yeast, and some microorganisms which cause serious human infections. Lawsonia Inermis (henna) leaf extracts for preparation of antibacterial poly(ethylene oxide) (PEO) and poly(vinyl alcohol) (PVA) nanofibers via electrospinning technique were investigated. PEO and PVA based electrospun fibers containing henna extract were verified by the appearance of FTIR peaks corresponding to the pure extract. Our study demonstrates that 2.793 wt.% Li in PVA and PEO based solutions showed bactericidal effects against Staphylococcus aureus and bacteriostatic action to Escherichia coli. Concentrations of henna leaf extract strongly impacted antibacterial activities against both bacteria. Henna leaves have a great potential to be used as a source of a potent eco-friendly antimicrobial agent.

  14. Preparation and characterization of naproxen-loaded electrospun thermoplastic polyurethane nanofibers as a drug delivery system.

    Science.gov (United States)

    Akduman, Cigdem; Özgüney, Işık; Kumbasar, E Perrin Akcakoca

    2016-07-01

    The design and production of drug-loaded nanofiber based materials produced by electrospinning is of interest for use in innovative drug delivery systems. In the present study, ultra-fine fiber mats of thermoplastic polyurethane (TPU) containing naproxen (NAP) were successfully prepared by electrospinning from 8 and 10% (w/w) TPU solutions. The amount of NAP in the solutions was 10 and 20% based on the weight of TPU. The collection period of the drug-loaded electrospun TPU fibers was 5, 10 and 20h, and they were characterized by FTIR, DSC and TGA analysis. The morphology of the NAP-loaded electrospun TPU fiber mats was smooth, and the average diameters of these fibers varied between 523.66 and 723.50nm. The release characteristics of these fiber mats were determined by the total immersion method in the phosphate buffer solution at 37°C. It was observed that the collection period in terms of the mat thickness played a major role in the release rate of NAP from the electrospun TPU mats.

  15. Preparation and Performance of Inorganic Heat Insulation Panel Based on Sepiolite Nanofibers

    Directory of Open Access Journals (Sweden)

    Fei Wang

    2014-01-01

    Full Text Available High efficiency and low cost thermal insulation energy saving panel materials containing sepiolite nanofibers were developed by means of the synergistic action of inorganic adhesive, curing agent, and hydrogen peroxide. The water soluble sodium silicate was used as inorganic adhesive, and the sodium fluorosilicate was chosen as curing agent. Moreover, appropriate amount of hydrogen peroxide was added in order to decrease the bulk density and improve the heat insulation performance of panel materials. The results showed that the synergistic action of inorganic adhesive, curing agent, and hydrogen peroxide could make thermal insulation energy saving panel materials have low bulk density and high mechanical performance, and the optimal process was as follows: 120°C of drying temperature, 1.6% of sodium silicate as inorganic adhesive, 12% of sodium fluorosilicate as curing agent in sodium silicate, and 2.5% of hydrogen peroxide. The thermal insulation energy saving panel materials as prepared could arrest heat transmission and resist external force effectively.

  16. Preparation of supramolecular hydrogel-enzyme hybrids exhibiting biomolecule-responsive gel degradation.

    Science.gov (United States)

    Shigemitsu, Hajime; Fujisaku, Takahiro; Onogi, Shoji; Yoshii, Tatsuyuki; Ikeda, Masato; Hamachi, Itaru

    2016-09-01

    Hydrogelators are small, self-assembling molecules that form supramolecular nanofiber networks that exhibit unique dynamic properties. Development of supramolecular hydrogels that degrade in response to various biomolecules could potentially be used for applications in areas such as drug delivery and diagnostics. Here we provide a synthetic procedure for preparing redox-responsive supramolecular hydrogelators that are used to create hydrogels that degrade in response to oxidizing or reducing conditions. The synthesis takes ∼2-4 d, and it can potentially be carried out in parallel to prepare multiple hydrogelator candidates. This described solid-phase peptide synthesis protocol can be used to produce previously described hydrogelators or to construct a focused molecular library to efficiently discover and optimize new hydrogelators. In addition, we describe the preparation of redox-responsive supramolecular hydrogel-enzyme hybrids that are created by mixing aqueous solutions of hydrogelators and enzymes, which requires 2 h for completion. The resultant supramolecular hydrogel-enzyme hybrids exhibit gel degradation in response to various biomolecules, and can be rationally designed by connecting the chemical reactions of the hydrogelators with enzymatic reactions. Gel degradation in response to biomolecules as triggers occurs within a few hours. We also describe the preparation of hydrogel-enzyme hybrids arrayed on flat glass slides, enabling high-throughput analysis of biomolecules such as glucose, uric acid, lactate and so on by gel degradation, which is detectable by the naked eye. The protocol requires ∼6 h to prepare the hydrogel-enzyme hybrid array and to complete the biomolecule assay.

  17. Facile Preparation of Optically Tailored Hybrid Nanocomposite

    Directory of Open Access Journals (Sweden)

    Susana Fernández de Ávila

    2014-01-01

    Full Text Available Lead sulfide nanoparticles (PbS NPs have been synthesized directly in poly[2-methoxy-5-(3′,7′-dimethyloctyloxy-1,4-phenylenevinylene] (MDMO-PPV semiconducting polymer by a simple low temperature method. Hybrid solutions with different concentrations of PbS with respect to the polymer have been prepared and characterized first in solution and then as thin film nanocomposites deposited on quartz substrates by spin coating. Quenching of photoluminescence emission is observed both in solutions and thin films when the ratio of PbS NPs increases with respect to the polymer, suggesting the occurrence of Dexter energy transfer from the polymer to the PbS NPs. Optical absorption is markedly increased for hybrid solutions compared to pure polymer. In thin nanocomposite films an enhancement of absorbance is observed with increasing PbS NPs concentration, which is more pronounced below 400 nm. The reported results could lead to the development of a method for tailoring the optical response of devices based on PbS NP-polymer nanocomposite by controlling the PbS NP concentration inside the polymer matrix.

  18. In-vitro anticancer and antimicrobial activities of PLGA/silver nanofiber composites prepared by electrospinning.

    Science.gov (United States)

    Almajhdi, Fahad N; Fouad, H; Khalil, Khalil Abdelrazek; Awad, Hanem M; Mohamed, Sahar H S; Elsarnagawy, T; Albarrag, Ahmed M; Al-Jassir, Fawzi F; Abdo, Hany S

    2014-04-01

    In the present work, a series of 0, 1 and 7 wt% silver nano-particles (Ag NPs) incorporated poly lactic-co-glycolic acid (PLGA) nano-fibers were synthesized by the electrospinning process. The PLGA/Ag nano-fibers sheets were characterized using SEM, TEM and DSC analyses. The three synthesized PLGA/silver nano-fiber composites were screened for anticancer activity against liver cancer cell line using MTT and LDH assays. The anticancer activity of PLGA nano-fibers showed a remarkable improvement due to increasing the concentration of the Ag NPs. In addition to the given result, PLGA nano-fibers did not show any cytotoxic effect. However, PLGA nano-fibers that contain 1 % nano silver showed anticancer activity of 8.8 %, through increasing the concentration of the nano silver to 7 % onto PLGA nano-fibers, the anticancer activity was enhanced to a 67.6 %. Furthermore, the antibacterial activities of these three nano-fibers, against the five bacteria strains namely; E.coli o157:H7 ATCC 51659, Staphylococcus aureus ATCC 13565, Bacillus cereus EMCC 1080, Listeria monocytogenes EMCC 1875 and Salmonella typhimurium ATCC25566 using the disc diffusion method, were evaluated. Sample with an enhanced inhibitory effect was PLGA/Ag NPs (7 %) which inhibited all strains (inhibition zone diameter 10 mm); PLGA/Ag NPs (1 %) sample inhibited only one strain (B. cereus) with zone diameter 8 mm. The PLGA nano-fiber sample has not shown any antimicrobial activity. Based on the anticancer as well as the antimicrobial results in this study, it can be postulated that: PLGA nanofibers containing 7 % nano silver are suitable as anticancer- and antibiotic-drug delivery systems, as they will increase the anticancer as well as the antibiotic drug potency without cytotoxicity effect on the normal cells. These findings also suggest that Ag NPs, of the size (5-10 nm) evaluated in the present study, are appropriate for therapeutic application from a safety standpoint.

  19. Preparation of Surface Adsorbed and Impregnated Multi-walled Carbon Nanotube/Nylon-6 Nanofiber Composites and Investigation of their Gas Sensing Ability.

    Science.gov (United States)

    Lala, Neeta L; Thavasi, Velmurugan; Ramakrishna, Seeram

    2009-01-01

    We have prepared electrospun Nylon-6 nanofibers via electrospinning, and adsorbed multi-walled carbon nanotubes (MWCNTs) onto the surface of Nylon-6 fibers using Triton(®) X-100 to form a MWCNTs/Nylon-6 nanofiber composite. The dispersed MWCNTs have been found to be stable in hexafluoroisopropanol for several months without precipitation. A MWCNTs/Nylon-6 nanofiber composite based chemical sensor has demonstrated its responsiveness towards a wide range of solvent vapours at room temperature and only mg quantities of MWCNTs were expended. The large surface area and porous nature of the electrospun Nylon-6/MWCNT nanofibers facilitates greater analyte permeability. The experimental analysis has indicated that the dipole moment, functional group and vapour pressure of the analytes determine the magnitude of the responsiveness.

  20. Preparation of Surface Adsorbed and Impregnated Multi-walled Carbon Nanotube/Nylon-6 Nanofiber Composites and Investigation of their Gas Sensing Ability

    Directory of Open Access Journals (Sweden)

    Velmurugan Thavasi

    2009-01-01

    Full Text Available We have prepared electrospun Nylon-6 nanofibers via electrospinning, and adsorbed multi-walled carbon nanotubes (MWCNTs onto the surface of Nylon-6 fibers using Triton® X-100 to form a MWCNTs/Nylon-6 nanofiber composite. The dispersed MWCNTs have been found to be stable in hexafluoroisopropanol for several months without precipitation. A MWCNTs/Nylon-6 nanofiber composite based chemical sensor has demonstrated its responsiveness towards a wide range of solvent vapours at room temperature and only mg quantities of MWCNTs were expended. The large surface area and porous nature of the electrospun Nylon-6/MWCNT nanofibers facilitates greater analyte permeability. The experimental analysis has indicated that the dipole moment, functional group and vapour pressure of the analytes determine the magnitude of the responsiveness.

  1. Highly efficient hybrid energy generator: coupled organic photovoltaic device and randomly oriented electrospun poly(vinylidene fluoride) nanofiber.

    Science.gov (United States)

    Park, Boongik; Lee, Kihwan; Park, Jongjin; Kim, Jongmin; Kim, Ohyun

    2013-03-01

    A hybrid architecture consisting of an inverted organic photovoltaic device and a randomly-oriented electrospun PVDF piezoelectric device was fabricated as a highly-efficient energy generator. It uses the inverted photovoltaic device with coupled electrospun PVDF nanofibers as tandem structure to convert solar and mechanical vibrations energy to electricity simultaneously or individually. The power conversion efficiency of the photovoltaic device was also significantly improved up to 4.72% by optimized processes such as intrinsic ZnO, MoO3 and active layer. A simple electrospinning method with the two electrode technique was adopted to achieve a high voltage of - 300 mV in PVDF piezoelectric fibers. Highly-efficient HEG using voltage adder circuit provides the conceptual possibility of realizing multi-functional energy generator whenever and wherever various energy sources are available.

  2. Preparation and Characterization of Polyaniline Nanofibers by Template-free Method

    Institute of Scientific and Technical Information of China (English)

    Xuemei GUO; Kun LUO; Nanlin SHI

    2005-01-01

    In the presence of p-toluene sulfonic acid (TSA) as a dopant, polyaniline (PAni) nanofibers, (about 80~165 nm in diameter) were successfully synthesized with a chemical template-free method. It was found that the formation probability, morphology, and diameter of the resulting PAni-TSA nanofibers were sensitive to the synthetic conditions,such as reaction temperature, the molar ratio of TSA to aniline, and the concentration of TSA in the polymerization media. The molecular structure was characterized by using the FT-IR, Raman spectra and X-ray diffraction, which shows that the main chain structure of PAni-TSA nanofibers was in agreement with that of granular PAni.

  3. Preparation of NiO-CuO-MgO fine powders by ultrasonic spray pyrolysis for carbon nanofibers synthesis

    Science.gov (United States)

    Krasnikova, Irina V.; Mishakov, Ilya V.; Bauman, Yury I.; Karnaukhov, Timofey M.; Vedyagin, Aleksey A.

    2017-09-01

    Carbon nanofibers with uniform diameter distribution are of great importance to be applied in composite materials production. Characteristics of the final carbon product obtained via catalytic chemical vapour deposition are known to be determined by the catalyst characteristics and the process conditions. In this work, ultrasonic spray pyrolysis was used for the preparation of uniform-sized NiO-CuO-MgO fine powders. Spherical particles of 170-340 nm in diameter were obtained in a temperature range of 400-600 °C. Synthesized powders exhibited high catalytic activity in CCVD of ethylene with the formation of CNF with relatively narrow diameter distribution (60 ± 20 nm).

  4. Fabrication of a TiO2@porphyrin nanofiber hybrid material: a highly efficient photocatalyst under simulated sunlight irradiation

    Science.gov (United States)

    La, Duong Duc; Rananaware, Anushri; Phuong Nguyen Thi, Hoai; Jones, Lathe; Bhosale, Sheshanath V.

    2017-03-01

    The solar spectrum consists of 8% UV radiation, while 45% of solar energy is from visible light. It is therefore desirable to fabricate a hybrid material which is able to harvest energy from a wide range of photons from the sun for applications such as solar cells, photovoltaics, and photocatalysis. In this study we report on the fabrication of a TiO2@porphyrin hybrid material by surfactant-assisted co-assembly of monomeric porphyrin molecules with TiO2 nanoparticles. The obtained TiO2@porphyrin composite shows excellent integration of TiO2 particles with diameters of 15–30 nm into aggregated porphyrin nanofibers, which have a width of 70–90 nm and are several µm long. SEM, XPS, XRD, FTIR, UV–Vis and fluorescence spectroscopy were employed to characterize the TiO2@TCPP hybrid material. This material exhibits efficient photocatalytic performance under simulated sunlight, due to synergistic photocatalytic activities of the porphyrin aggregates in visible light and TiO2 particles in the UV region. A plausible mechanism for photocatalytic degradation is also proposed and discussed.

  5. Preparation and characterization of poly(vinyl alcohol)/graphene nanofibers synthesized by electrospinning

    Science.gov (United States)

    Barzegar, Farshad; Bello, Abdulhakeem; Fabiane, Mopeli; Khamlich, Saleh; Momodu, Damilola; Taghizadeh, Fatemeh; Dangbegnon, Julien; Manyala, Ncholu

    2015-02-01

    We report on the synthesis and characterization of electrospun polyvinyl alcohol (PVA)/graphene nanofibers. The samples produced were characterized by Raman spectroscopy for structural and defect density analysis, scanning electron microscopy (SEM) for morphological analysis, and thermogravimetric (TGA) for thermal analysis. SEM measurements show uniform hollow PVA fibers formation and excellent graphene dispersion within the fibers, while TGA measurements show the improved thermal stability of PVA in the presence of graphene. The synthesized polymer reinforced nanofibers have potential to serve in many different applications such as thermal management, supercapacitor electrodes and biomedical materials for drug delivery.

  6. Preparation of paclitaxel/chitosan co-assembled core-shell nanofibers for drug-eluting stent

    Science.gov (United States)

    Tang, Jing; Liu, Yongjia; Zhu, Bangshang; Su, Yue; Zhu, Xinyuan

    2017-01-01

    The paclitaxel/chitosan (PTX/CS) core-shell nanofibers (NFs) are easily prepared by co-assembly of PTX and CS and used in drug-eluting stent. The mixture solution of PTX (dissolved in ethanol) and CS (dissolved in 1% acetic acid water solution) under sonication will make the formation of NFs, in which small molecule PTX co-assembles with biomacromolecular CS through non-covalent interactions. The obtained NFs are tens to hundreds nanometers in diameter and millimeter level in length. Furthermore, the structure of PTX/CS NFs was characterized by confocal laser scanning microscopy (CLSM), zeta potential, X-ray photoelectron spectroscopy (XPS) and nanoscale infra-red (nanoIR), which provided evidences demonstrated that PTX/CS NFs are core-shell structures. The 'shell' of CS wrapped outside of the NFs, while PTX is located in the core. Thus it resulted in high drug loading content (>40 wt.%). The well-controlled drug release, low cytotoxicity and good haemocompatibility were also found in drug carrier system of PTX/CS NFs. In addition, the hydrophilic and flexible properties of NFs make them easily coating and filming on stent to prepare drug-eluting stent (DES). Therefore, this study provides a convenient method to prepare high PTX loaded NFs, which is a promising nano-drug carrier used for DES and other biomedical applications. The possible molecular mechanism of PTX and CS co-assembly and core-shell nanofiber formation is also explored.

  7. Electrospinning preparation, characterization and magnetic properties of cobalt-nickel ferrite (Co(1-x)Ni(x)Fe2)O4) nanofibers.

    Science.gov (United States)

    Xiang, Jun; Chu, Yanqiu; Shen, Xiangqian; Zhou, Guangzhen; Guo, Yintao

    2012-06-15

    Uniform Co(1-)(x)Ni(x)Fe(2)O(4) (x=0.0, 0.2, 0.4, 0.6, 0.8 and 1.0) nanofibers with average diameter of 110 nm and length up to several millimeters were prepared by calcination of electrospun precursor nanofibers containing polymer and inorganic salts. The as-spun and calcined nanofibers were characterized in detail by TG-DTA, XRD, FE-SEM, TEM, SAED and VSM, respectively. The effect of composition of the nanofibers on the structure and magnetic properties were investigated. The nanofibers are formed through assembling magnetic nanoparticles with poly(vinyl pyrrolidone) as the structure-directing template. The structural characteristics and magnetic properties of the resultant nanofibers vary with chemical composition and can be tuned by adjusting the Co/Ni ratio. Both lattice parameter and particle size decrease gradually with increasing nickel concentration. The saturation magnetization and coercivity lie in the range 29.3-56.4 emu/g and 210-1255 Oe, respectively, and both show a monotonously decreasing behavior with the increase in nickel concentration. Such changes in magnetic properties can mainly be attributed to the lower magnetocrystalline anisotropy and the smaller magnetic moment of Ni(2+) ions compared to Co(2+) ions. Furthermore, the coercivity of Co-Ni ferrite nanofibers is found to be superior to that of the corresponding nanoparticle counterparts, presumably due to their large shape anisotropy. These novel one-dimensional Co-Ni ferrite magnetic nanofibers can potentially be used in micro-/nanoelectronic devices, microwave absorbers and sensing devices. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Electrospun chitosan nanofibers with controlled levels of silver nanoparticles. Preparation, characterization and antibacterial activity.

    Science.gov (United States)

    Lee, Sang Jin; Heo, Dong Nyoung; Moon, Ji-Hoi; Ko, Wan-Kyu; Lee, Jung Bok; Bae, Min Soo; Park, Se Woong; Kim, Ji Eun; Lee, Dong Hyun; Kim, Eun-Cheol; Lee, Chang Hoon; Kwon, Il Keun

    2014-10-13

    The ideal wound dressing would have properties that allow for absorption of exudates, and inhibition of microorganism for wound protection. In this study, we utilized an electrospinning (ELSP) technique to design a novel wound dressing. Chitosan (CTS) nanofibers containing various ratios of silver nanoparticles (AgNPs) were obtained. AgNPs were generated directly in the CTS solution by using a chemical reduction method. The formation and presence of AgNPs in the CTS/AgNPs composite was confirmed by x-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV) and thermogravimetric analysis (TGA). The electrospun CTS/AgNPs nanofibers were characterized morphologically by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). These nanofibers were subsequently tested to evaluate their antibacterial activity against gram-negative Pseudomonas aeruginosa (P. aeruginosa) and gram-positive Methicillin-resistant Staphylococcus aureus (MRSA). Results of this antibacterial testing suggest that CTS/AgNPs nanofibers may be effective in topical antibacterial treatment in wound care.

  9. Functionalized polymer-iron oxide hybrid nanofibers: Electrospun filtration devices for metal oxyanion removal.

    Science.gov (United States)

    Peter, Katherine T; Johns, Adam J; Myung, Nosang V; Cwiertny, David M

    2017-06-15

    Via a single-pot electrospinning synthesis, we developed a functionalized polymer-metal oxide nanofiber filter for point of use (POU) water treatment of metal oxyanions (e.g., arsenate and chromate). Polyacrylonitrile (PAN) functionalization was accomplished by inclusion of surface-active, quaternary ammonium salts (QAS) [cetyltrimethylammonium bromide (CTAB) or tetrabutylammonium bromide (TBAB)] that provide strong base ion exchange sites. Embedded iron oxide [ferrihydrite (Fh)] nanoparticles were used for their established role as metal sorbents. We examined the influence of QAS and Fh loading on composite properties, including nanofiber morphology, surface area, surface chemical composition, and the accessibility of embedded nanoparticles to solution. Composite performance was then evaluated using kinetic, isotherm, and pH-edge sorption experiments with arsenate and chromate, and benchmarked to unmodified PAN nanofibers and freely dispersed Fh nanoparticles. We also assessed the long-term stability of QAS in the composite matrix. For composites containing QAS or Fh nanoparticles, increasing QAS/Fh nanoparticle loading generally yielded increasing metal oxyanion uptake. The optimized composite (PAN 7 wt%, Fh 3 wt%, TBAB 1 wt%) exhibited two distinct sites for simultaneous, non-competitive metal binding (i.e., iron oxide sites for arsenate removal via sorption and well-retained QAS sites for chromate removal via ion exchange). Moreover, surface-segregating QAS enriched Fh abundance at the nanofiber surface, allowing immobilized nanoparticles to exhibit reactivity comparable to that of unsupported (i.e., suspended or freely dispersed) nanoparticles. To simulate POU application, the optimized composite was tested in a dead-end, flow-through filtration system for arsenate and chromate removal at environmentally relevant concentrations (e.g., μg/L) in both idealized and simulated tap water matrices. Performance trends indicate that dual mechanisms for uptake are

  10. Processing and Structure of Carbon Nanofiber Paper

    Directory of Open Access Journals (Sweden)

    Zhongfu Zhao

    2009-01-01

    Full Text Available A unique concept of making nanocomposites from carbon nanofiber paper was explored in this study. The essential element of this method was to design and manufacture carbon nanofiber paper with well-controlled and optimized network structure of carbon nanofibers. In this study, carbon nanofiber paper was prepared under various processing conditions, including different types of carbon nanofibers, solvents, dispersants, and acid treatment. The morphologies of carbon nanofibers within the nanofiber paper were characterized with scanning electron microscopy (SEM. In addition, the bulk densities of carbon nanofiber papers were measured. It was found that the densities and network structures of carbon nanofiber paper correlated to the dispersion quality of carbon nanofibers within the paper, which was significantly affected by papermaking process conditions.

  11. A wave-shaped hybrid piezoelectric and triboelectric nanogenerator based on P(VDF-TrFE) nanofibers.

    Science.gov (United States)

    Chen, Xuexian; Han, Mengdi; Chen, Haotian; Cheng, Xiaoliang; Song, Yu; Su, Zongming; Jiang, Yonggang; Zhang, Haixia

    2017-01-19

    A wave-shaped hybrid nanogenerator (NG) with mutually enhanced piezoelectric and triboelectric output is presented in this work. By sandwiching piezoelectric P(VDF-TrFE) nanofibers between wave-shaped Kapton films, the device forms a three-layer structure, which can generate piezoelectric and triboelectric outputs simultaneously in one press and release cycle. Through systematic situational analysis and experimental validation, the three-layer structure can achieve obvious improvement of the output performance for both parts. When triggered with 4 Hz external force, the piezoelectric part generates a peak output and current of 96 V and 3.8 μA, which is ∼2 times higher than its initial output. Meanwhile, the performance of triboelectric parts also increases 8 V and 16 V with the assistance of piezoelectric potential. The enhanced high output enables the hybrid nanogenerator to instantaneously light up LEDs and charges capacitors quickly, which shows extensive application prospects in the field of self-powered systems or sensor networks.

  12. Preparation and luminescence properties of La6MoO12:Eu3+/PVA nanofibers by Pechini/electrospinning process.

    Science.gov (United States)

    Qin, Chuanxiang; Gu, Mingbo; Huang, Yanlin; Dai, Lixing; Chen, Guoqiang; Shi, Liang; Qiao, Xuebin; Seo, Hyo Jin

    2011-11-01

    The 20% concentration Eu3+-based red-emitting phosphor, nano-sized La6MoO12:Eu3+ was prepared by the Pechini method. X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG-DTA), scanning electron microscopy (SEM), photoluminescence (PL), and decay curves were used to characterize the resulting samples. The phosphor can be efficiently excited by near UV light and exhibits an intense red luminescence corresponding to the electric dipole transition 5D0 --> 7F2 at 615 nm. When the phosphor was mixed into poly(vinyl alcohol) aqueous solution, the fluorescent nanofibers could be prepared by electrospinning process. It was suggested that the La6MoO12:Eu3+ phosphor would be a promising red component for solid-state lighting devices based on InGaN or GaN light-emitting diodes.

  13. Preparation and characterization of chitosan/Aloe Vera composite nanofibers generated by electrostatic spinning

    Science.gov (United States)

    Ibrahim, Illani; Sekak, Khairunnadim Ahmad; Hasbullah, Norazurean

    2015-08-01

    Researches on the fabrication of nanostructured based membrane have attracted great attention amongst scientists due to their wide potential applications on medical application. In this work, Chitosan and Aloe Vera sol-gel solution were electrospun using 20 kV DC supply at room temperature. Morphological structure and functional group of nanofibers were characterized using field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FT-IR) respectively. The optimum parameter obtained at 90% concentration of acetic acid, 0.3 ml/h of solution flow rate and 10 cm distance of nozzle to collector. The fiber diameters were analyzed using the ImageJ software. Average diameters of the Chitosan/Aloe Vera composite nanofibers is 183nm in ranges of 140-260nm.

  14. Preparation and characterization of chitosan/Aloe Vera composite nanofibers generated by electrostatic spinning

    Energy Technology Data Exchange (ETDEWEB)

    Ibrahim, Illani; Sekak, Khairunnadim Ahmad; Hasbullah, Norazurean [Center of Physics and Material Studies, Faculty of Applied Sciences, Universiti Teknologi Mara (UiTM) 40450 Shah Alam, Selangor (Malaysia)

    2015-08-28

    Researches on the fabrication of nanostructured based membrane have attracted great attention amongst scientists due to their wide potential applications on medical application. In this work, Chitosan and Aloe Vera sol-gel solution were electrospun using 20 kV DC supply at room temperature. Morphological structure and functional group of nanofibers were characterized using field emission scanning electron microscopy (FESEM) and Fourier-transform infrared spectroscopy (FT-IR) respectively. The optimum parameter obtained at 90% concentration of acetic acid, 0.3 ml/h of solution flow rate and 10 cm distance of nozzle to collector. The fiber diameters were analyzed using the ImageJ software. Average diameters of the Chitosan/Aloe Vera composite nanofibers is 183nm in ranges of 140–260nm.

  15. Preparation of methacrylic acid copolymer S nano-fibers using a solvent-based electrospinning method and their application in pharmaceutical formulations.

    Science.gov (United States)

    Hamori, Mami; Shimizu, Yuki; Yoshida, Kaori; Fukushima, Keizo; Sugioka, Nobuyuki; Nishimura, Asako; Naruhashi, Kazumasa; Shibata, Nobuhito

    2015-01-01

    In this study, we applied an electrospinning (ES) method, which is mainly employed in the textile industry, to the field of pharmaceuticals. We developed and modified an ES instrument and then utilized it to produce methacrylic acid copolymer S (MAC) nano-fibers to prepare tablets. By attaching a conductor rod made from stainless steel to the central part of the nano-fiber-collection plate of the ES apparatus, a MAC nano-fiber sheet could be produced effectively. In addition, we studied various operating conditions for this new ES method, including needle gauge, voltage between the electrodes, distance between the needle and nano-fiber-collection plate and the flow rate of MAC polymer solution, but these had no significant effect on the diameter of MAC nano-fibers. On the other hand, the viscosity (concentration) of MAC polymer solution and permittivity of solvent used to dilute MAC were closely related to the mean diameter of the nano-fibers. Tableting of MAC nano-fibers was performed using a tableting machine without lubricants, and addition of Tween 20 to the tablets enabled regulation of the release profile of a water-soluble drug. The modified ES method reported here is a useful technique for the controlled-release of drugs and has wide-ranging potential for pharmaceutical applications.

  16. Preparation of Aligned Ultra-long and Diameter-controlled Silicon Oxide Nanotubes by Plasma Enhanced Chemical Vapor Deposition Using Electrospun PVP Nanofiber Template

    Directory of Open Access Journals (Sweden)

    Zhou Ming

    2009-01-01

    Full Text Available Abstract Well-aligned and suspended polyvinyl pyrrolidone (PVP nanofibers with 8 mm in length were obtained by electrospinning. Using the aligned suspended PVP nanofibers array as template, aligned ultra-long silicon oxide (SiOx nanotubes with very high aspect ratios have been prepared by plasma-enhanced chemical vapor deposition (PECVD process. The inner diameter (20–200 nm and wall thickness (12–90 nm of tubes were controlled, respectively, by baking the electrospun nanofibers and by coating time without sacrificing the orientation degree and the length of arrays. The micro-PL spectrum of SiOx nanotubes shows a strong blue–green emission with a peak at about 514 nm accompanied by two shoulders around 415 and 624 nm. The blue–green emission is caused by the defects in the nanotubes.

  17. Preparation of PAA/AM/MMT Hybrid by Intercalation Polymerization

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Over the last few years, Montmorillonite (MMT) was widely used as a special inorganic material for preparing Polymer/MMT nanocompsites. MMT is a clay imineral consisting of stacked silicate sheets whose thickness is about 10A. Through intercalation a large number of polymer-clay nanocomposites have been prepared such as Nylon-clay hybrid [1], PS-clay hybrid [2], Poly (methyl methacrylate) (PMMA)-clay hybrid [3], etc. In this article, the synthesis and properties of Poly (acrylic acid/acrylamide)/MMT hybrid (PAAAM/MMT) were studied. X-ray diffraction and Transmission electron microscopy were used to characterize the hybrid material. DSC has been used to study its property. Results showed that the intercalating reagents have entered the space of MMT's layers and enlarged them. At the same time, the MMT dispersed homogeneously in acrylic acid and acrylamide monomers that allow MMT to disperse in PAAAM matrix in the monolayer form.

  18. Carbon-coated SnSb nanoparticles dispersed in reticular structured nanofibers for lithium-ion battery anodes

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Xiao [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education, Shanghai 201620 (China); Zhou, Huimin; Li, Zhiyong; Shan, Xiaohong [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Xia, Xin, E-mail: xjxiaxin@163.com [College of Textiles and Clothing, Xin Jiang University, Xinjiang, Urumqi 830046 (China); Key Laboratory of Textile Science and Technology, Donghua University, Ministry of Education, Shanghai 201620 (China)

    2015-01-25

    Highlights: • Sn{sub 0.92}Sb{sub 0.08}O{sub 2.04} nanoparticles as SnSb alloy precursor. • Carbon-coated SnSb nanoparticles were prepared and then embedded in carbon nanofibers. • The synergic effect of carbon coating and special structure improved cycling stability. - Abstract: Carbon coating and carbon nanofiber processes were used to enhance the cycling performance of SnSb alloys. Carbon-coated SnSb alloys were firstly prepared by a simple hydrothermal method to build the first protection, and then carbon-coated SnSb nanoparticles were embedded in carbon nanofibers via single-spinneret electrospinning followed by carbonization. The crystal structure of carbon-coated SnSb/C hybrid nanofibers was characterized by X-ray diffraction (XRD). The morphologies of carbon-coated SnSb alloys and hybrid nanofibers were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The thermal stability of hybrid nanofibers were determined by thermogravimetric analysis (TGA). The electrochemical properties were investigated as a potential high-capacity anode material for lithium-ion batteries. The results showed that the hybrid nanofibers exhibited excellent electrochemical performance due to the special structure. The carbon shell can effectively hinder the agglomeration of SnSb alloys, while maintaining electronic conduction as well as accommodating drastic volume changes during lithium insertion and extraction and carbon nanofibers formed a further protection. The resultant carbon-coated SnSb nanoparticles dispersed in carbon nanofibers deliver a high capacity of 674 mA h g{sup −1} and a good capacity retention of 68.7% after 50 cycles.

  19. Drug loaded homogeneous electrospun PCL/gelatin hybrid nanofiber structures for anti-infective tissue regeneration membranes.

    Science.gov (United States)

    Xue, Jiajia; He, Min; Liu, Hao; Niu, Yuzhao; Crawford, Aileen; Coates, Phil D; Chen, Dafu; Shi, Rui; Zhang, Liqun

    2014-11-01

    Infection is the major reason for guided tissue regeneration/guided bone regeneration (GTR/GBR) membrane failure in clinical application. In this work, we developed GTR/GBR membranes with localized drug delivery function to prevent infection by electrospinning of poly(ε-caprolactone) (PCL) and gelatin blended with metronidazole (MNA). Acetic acid (HAc) was introduced to improve the miscibility of PCL and gelatin to fabricate homogeneous hybrid nanofiber membranes. The effects of the addition of HAc and the MNA content (0, 1, 5, 10, 20, 30, and 40 wt.% of polymer) on the properties of the membranes were investigated. The membranes showed good mechanical properties, appropriate biodegradation rate and barrier function. The controlled and sustained release of MNA from the membranes significantly prevented the colonization of anaerobic bacteria. Cells could adhere to and proliferate on the membranes without cytotoxicity until the MNA content reached 30%. Subcutaneous implantation in rabbits for 8 months demonstrated that MNA-loaded membranes evoked a less severe inflammatory response depending on the dose of MNA than bare membranes. The biodegradation time of the membranes was appropriate for tissue regeneration. These results indicated the potential for using MNA-loaded PCL/gelatin electrospun membranes as anti-infective GTR/GBR membranes to optimize clinical application of GTR/GBR strategies.

  20. Enhancement of chondrogenic differentiation of rabbit mesenchymal stem cells by oriented nanofiber yarn-collagen type I/hyaluronate hybrid

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Xianyou; Wang, Wei; Liu, Shen [Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, 600 Yishan Road, Shanghai 200233 (China); Wu, Jinglei [Biomaterials and Tissue Engineering Laboratory, College of Chemistry and Chemical Engineering and Biological Engineering, Donghua University, Shanghai 201620 (China); Li, Fengfeng [Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, 600 Yishan Road, Shanghai 200233 (China); Cao, Lei [Shanghai Key Laboratory of Orthopaedic Implants, Department of Orthopaedics, Shanghai Ninth People' s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhizaoju Road, Shanghai 200011 (China); Liu, Xu-dong [Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, 600 Yishan Road, Shanghai 200233 (China); Mo, Xiumei, E-mail: xmm@dhu.edu.cn [Biomaterials and Tissue Engineering Laboratory, College of Chemistry and Chemical Engineering and Biological Engineering, Donghua University, Shanghai 201620 (China); Fan, Cunyi, E-mail: fancunyish@126.com [Department of Orthopaedics, Shanghai Jiao Tong University Affiliated Sixth People' s Hospital, 600 Yishan Road, Shanghai 200233 (China)

    2016-01-01

    Cartilage defects cause joint pain and loss of mobility. It is crucial to induce the chondrogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by both biological and structural signals in cartilage tissue engineering. Sponge-like scaffolds fabricated using native cartilage extracellular matrix components can induce the BMSC differentiation by biological signals and limited structural signals. In this study, an oriented poly(L-lactic acid)-co-poly(ε-caprolactone) P(LLA-CL)/collagen type I (Col-I) nanofiber yarn mesh, fabricated by dynamic liquid electrospinning served as a skeleton for a freeze-dried Col-I/hyaluronate (HA) chondral phase (SPONGE) containing both structural and biological signals to guide BMSC chondrogenic differentiation. In vitro results show that the Yarn Col-I/HA hybrid scaffold (Yarn-CH) promotes orientation, adhesion and proliferation of BMSCs better than SPONGE. Furthermore, BMSCs seeded on the Yarn-CH scaffold demonstrated a large increase in the glycosaminoglycan content and expression of collagen type II following a 21-day culture. - Highlights: • An oriented yarn was used as the skeleton of the sponge-like scaffold. • Both structural and biological signals were given for BMSC chondrogenic differentiation. • Yarn-CH promotes orientation and chondrogenesis differentiation of BMSCs. • Yarn-CH reproduces the superficial zone of the cartilage.

  1. Polymer structure and antimicrobial activity of polyvinylpyrrolidone-based iodine nanofibers prepared with high-speed rotary spinning technique.

    Science.gov (United States)

    Sebe, István; Szabó, Barnabás; Nagy, Zsombor K; Szabó, Dóra; Zsidai, László; Kocsis, Béla; Zelkó, Romána

    2013-12-15

    Poly(vinylpyrrolidone)/poly(vinylpyrrolidone-vinylacetate)/iodine nanofibers of different polymer ratios were successfully prepared by a high-speed rotary spinning technique. The obtained fiber mats were subjected to detailed morphological analysis using an optical and scanning electron microscope (SEM), while the supramolecular structure of the samples was analyzed by positron annihilation lifetime spectroscopy (PALS). The maximum dissolved iodine of the fiber samples was determined, and microbiological assay was carried out to test their effect on the bacterial growth. SEM images showed that the polymer fibers were linear, homogenous, and contained no beads. The PALS results, both the o-positronium (o-Ps) lifetime values and distributions, revealed the changes of the free volume holes of fibers as a function of their composition and the presence of iodine. The micro- and macrostructural characterisation of polymer fiber mats enabled the selection of the required composition from the point of their applicability as a wound dressing.

  2. Preparation of polyacrylnitrile (PAN)/ Manganese oxide based activated carbon nanofibers (ACNFs) for adsorption of Cadmium (II) from aqueous solution

    Science.gov (United States)

    Abdullah, N.; Yusof, N.; Jaafar, J.; Ismail, AF; Che Othman, F. E.; Hasbullah, H.; Salleh, W. N. W.; Misdan, N.

    2016-06-01

    In this work, activated carbon nanofibers (ACNFs) from precursor polyacrylnitrile (PAN) and manganese oxide (MnO2) were prepared via electrospinning process. The electrospun PAN/MnO2-based ACNFs were characterised in term of its morphological structure and specific surface area using SEM and BET analysis respectively. The comparative adsorption study of cadmium (II) ions from aqueous solution between the neat ACNFs, composite ACNFs and commercial granular activated carbon was also conducted. SEM analysis illustrated that composite ACNFs have more compact fibers with presence of MnO2 beads with smaller fiber diameter of 437.2 nm as compared to the neat ACNFs which is 575.5 nm. BET analysis elucidated specific surface area of ACNFs/MnO2 to be 67 m2/g. Under adsorption study, it was found out that Cd (II) removal by ACNFs/MnO2 was the highest (97%) followed by neat ACNFs (96%) and GAC (74%).

  3. Preparation and characterization of a Lithium-ion battery separator from cellulose nanofibers

    Directory of Open Access Journals (Sweden)

    Hongfeng Zhang

    2015-10-01

    Full Text Available Optimizing the desired properties for stretch monolayer separators used in Lithium-ion batteries has been a challenge. In the present study a cellulose nanofiber/PET nonwoven composite separator is successfully fabricated, using a wet-laid nonwoven (papermaking process, which can attain optimal properties in wettability, mechanical strength, thermal resistance, and electrochemical performance simultaneously. The PET nonwoven material, which is fabricated from ultrafine PET fibers by a wet-laid process, is a mechanical support layer. The porous structure of the composite separator was created by cellulose nanofibers coating the PET in a papermaking process. Cellulose nanofibers (CNFs, which are an eco-friendly sustainable resource, have been drawing considerable attention due to their astounding properties, such as: incredible specific surface area, thermal and chemical stability, high mechanical strength and hydrophilicity. The results show that the CNF separator exhibits higher porosity (70% than a PP (polypropylene separator (40%. The CNF separator can also be wetted by electrolyte in a few seconds while a PP separator cannot be entirely wetted after 1 min. The CNF separator has an electrolyte uptake of 250%, while a PP separator has only 65%. Another notable finding is that the CNF separator has almost no shrinkage when exposed to 180 °C for 1 h, whereas a PP separator shrinks by more than 50%. Differential Scanning Calorimetry (DSC shows that the CNF separator has a higher melting point than a PP separator. These findings all indicate that the CNF 29 separator will be more favorable than stretch film for use in Lithium-ion batteries.

  4. Cell-adhesive RGD peptide-displaying M13 bacteriophage/PLGA nanofiber matrices for growth of fibroblasts.

    Science.gov (United States)

    Shin, Yong Cheol; Lee, Jong Ho; Jin, Linhua; Kim, Min Jeong; Oh, Jin-Woo; Kim, Tai Wan; Han, Dong-Wook

    2014-01-01

    M13 bacteriophages can be readily fabricated as nanofibers due to non-toxic bacterial virus with a nanofiber-like shape. In the present study, we prepared hybrid nanofiber matrices composed of poly(lactic-co-glycolic acid, PLGA) and M13 bacteriophages which were genetically modified to display the RGD peptide on their surface (RGD-M13 phage). The surface morphology and chemical composition of hybrid nanofiber matrices were characterized by scanning electron microscopy (SEM) and Raman spectroscopy, respectively. Immunofluorescence staining was conducted to investigate the existence of M13 bacteriophages in RGD-M13 phage/PLGA hybrid nanofibers. In addition, the attachment and proliferation of three different types of fibroblasts on RGD-M13 phage/PLGA nanofiber matrices were evaluated to explore how fibroblasts interact with these matrices. SEM images showed that RGD-M13 phage/PLGA hybrid matrices had the non-woven porous structure, quite similar to that of natural extracellular matrices, having an average fiber diameter of about 190 nm. Immunofluorescence images and Raman spectra revealed that RGD-M13 phages were homogeneously distributed in entire matrices. Moreover, the attachment and proliferation of fibroblasts cultured on RGD-M13 phage/PLGA matrices were significantly enhanced due to enriched RGD moieties on hybrid matrices. These results suggest that RGD-M13 phage/PLGA matrices can be efficiently used as biomimetic scaffolds for tissue engineering applications.

  5. Preparation and characterization of doped TiO{sub 2} nanofibers by coaxial electrospining combined with sol–gel process

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Haixia, E-mail: tonghaixia@126.com; Tao, Xican; Wu, Daoxin; Zhang, Xiongfei; Li, Dan; Zhang, Ling

    2014-02-15

    Graphical abstract: The surface of the precursor of Fe/TiO{sub 2} nanofibers are smoother than that of Fe /TiO{sub 2} nanofibers. After calcined at 500 °C, the tubers on the surface of the nanofibers become more obvious, and which also provides a direct proof for the dopant of Fe element. -- Highlights: • N, Fe, and W doped TiO{sub 2} nanofibers have been fabricated by coaxial electrospining. • The dopant has obvious influences on the surface topographies and crystal structures. • Fe doping can make remarkable topography changes and easy formation of rutile TiO{sub 2}. • The maximum doping amount of W in TiO{sub 2} nanofibers is less than 10% under 500 °C. -- Abstract: N, Fe, and W doped TiO{sub 2} nanofibers were fabricated by coaxial electrospining and directly annealing polyvinylpyrrolidone (PVP)/Tetrabutyl titanate (TBT) composite nanofibers. The crystal structure, morphology, and surface composition of the doped TiO{sub 2} nanofibers were investigated by the X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) respectively. The results show that the dopants have different influence on the surface topographies, the crystal structures and the transformation of anatase to rutile of TiO{sub 2} nanofibers. Fe dopant promotes bigger influence on topographies, phase transformation and crystallite growth of TiO{sub 2} nanofibers than that of either N or W dopant.

  6. Enhanced Wettability and Thermal Stability of a Novel Polyethylene Terephthalate-Based Poly(Vinylidene Fluoride) Nanofiber Hybrid Membrane for the Separator of Lithium-Ion Batteries.

    Science.gov (United States)

    Zhu, Chunhong; Nagaishi, Tomoki; Shi, Jian; Lee, Hoik; Wong, Pok Yin; Sui, Jianhua; Hyodo, Kenji; Kim, Ick Soo

    2017-08-09

    In this study, a novel membrane for the separator in a lithium-ion (Li-ion) battery was proposed via a mechanically pressed process with a poly(vinylidene fluoride) (PVDF) nanofiber subject and polyethylene terephthalate (PET) microfiber support. Important physical properties, such as surface morphology, wettability, and heat stability were considered for the PET-reinforced PVDF nanofiber (PRPN) hybrid separator. Images of scanning electron microscopy (SEM) showed that the PRPN hybrid separator had a homogeneous pore size and high porosity. It can wet out in battery electrolytes completely and quickly, satisfying wettability requirements. Moreover, the electrolyte uptake was higher than that of dry-laid and wet-laid nonwovens. For heat stability, no shrink occurred even when the heating temperature reached 135 °C, demonstrating thermal and dimensional stability. Moreover, differential scanning calorimetry (DSC) showed that the PRPN hybrid separator possessed a shutdown temperature of 131 °C, which is the same as conventional separators. Also, the meltdown temperature reached 252 °C, which is higher than the shutdown temperature, and thus can protect against internal cell shorts. The proposed PRPN hybrid separator is a strong candidate material for utilization in Li-ion batteries.

  7. Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples.

    Science.gov (United States)

    Bagheri, Habib; Aghakhani, Ali; Baghernejad, Masoud; Akbarinejad, Alireza

    2012-02-24

    A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2-10 ng L(-1). The relative standard deviations (RSD) (n=3) at the concentration level of 1.7-6.7 ng mL(-1) were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27-1330 ng L(-1) for phenol and monochlorophenols and 7-1000 ng L(-1) for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%. Copyright © 2011

  8. Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples

    Energy Technology Data Exchange (ETDEWEB)

    Bagheri, Habib, E-mail: bagheri@sharif.edu [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of); Aghakhani, Ali; Baghernejad, Masoud; Akbarinejad, Alireza [Environmental and Bio-Analytical Laboratories, Department of Chemistry, Sharif University of Technology, Azadi Av., P.O. Box 11365-9516, Tehran (Iran, Islamic Republic of)

    2012-02-24

    A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200 nm for polyamide nanofibers with a homogeneous and porous surface structure. The extraction efficiency of new coating was investigated for headspace solid-phase microextraction (HS-SPME) of some environmentally important chlorophenols from aqueous samples followed by gas chromatography-mass spectrometry (GC-MS) analysis. Effect of different parameters influencing the extraction efficiency including extraction temperature, extraction time, ionic strength and polyamide amount were investigated and optimized. In order to improve the chromatographic behavior of phenolic compounds, all the analytes were derivatized prior to the extraction process using basic acetic anhydride. The detection limits of the method under optimized conditions were in the range of 2-10 ng L{sup -1}. The relative standard deviations (RSD) (n = 3) at the concentration level of 1.7-6.7 ng mL{sup -1} were obtained between 1 and 7.4%. The calibration curves of chlorophenols showed linearity in the range of 27-1330 ng L{sup -1} for phenol and monochlorophenols and 7-1000 ng L{sup -1} for dichloro and trichlorophenols. Also, the proposed method was successfully applied to the extraction of phenol and chlorophenols from real water samples and relative recoveries were between 84 and 98% for all the selected analytes except for 2,4,6 tricholophenol which was between 72 and 74%.

  9. Electrospun carbon nanofibers/electrocatalyst hybrids as asymmetric electrodes for vanadium redox flow battery

    Science.gov (United States)

    Wei, Guanjie; Fan, Xinzhuang; Liu, Jianguo; Yan, Chuanwei

    2015-05-01

    To improve the electrochemical activity of polyacrylonitrile (PAN)-based electrospun carbon nanofibers (ECNFs) toward vanadium redox couples, the multi-wall carbon nanotubes (CNTs) and Bi-based compound as electrocatalyst have been embedded in the ECNFs to make composite electrode, respectively. The morphology and electrochemical properties of pristine ECNFs, CNTs/ECNFs and Bi/ECNFs have been characterized. Among the three kinds of electrodes, the CNTs/ECNFs show best electrochemical activity toward VO2+/VO2+ redox couple, while the Bi/ECNFs present the best electrochemical activity toward V2+/V3+ redox couple. Furthermore, the high overpotential of hydrogen evolution on Bi/ECNFs makes the side-reaction suppressed. Because of the large property difference between the two composite electrodes, the CNTs/ECNFs and Bi/ECNFs are designed to act as positive and negative electrode for vanadium redox flow battery (VRFB), respectively. It not only does improve the kinetics of two electrode reactions at the same time, but also reduce the kinetics difference between them. Due to the application of asymmetric electrodes, performance of the cell is improved greatly.

  10. Preparation of graphene oxide/poly (3,4-ethylenedioxytriophene): Poly (styrene sulfonate) (PEDOT:PSS) electrospun nanofibers

    Science.gov (United States)

    Widianto, Eri; Efelina, Vita; Rusdiana, Dadi; Nugroho, A. A.; Kusumaatmaja, Ahmad; Triyana, Kuwat; Santoso, Iman

    2016-04-01

    Graphene oxide (GO)/Poly (3,4-Ethylenedioxytriophene):Poly (styrene Sulfonate) (PEDOT:PSS)nanofibers have been successfully fabricated by a simple electrospinning technique to develop conductive nanofibers with polyvinyl alcohol (PVA) act as a carrier solution. Graphene oxide hasbeen synthesized by Hummer's method and has been confirmed by Raman Spectroscopy, FTIR, and UV-Vis Spectroscopy. The structural and morphological properties of GO/PEDOT:PSS composite nanofiberswere characterized by Scanning Electron Microscopy (SEM). The result of SEM showed that GO/PEDOT:PSS nanofibers have a relatively uniform morphology nanofiber with adiameterof 180 nm - 340 nm with smooth nanofiber surface. The produced nanofibers from this study can be utilized for various applicationssuch as aflexible, conductive and transparent electrode.

  11. Bubbfil electrospinning of PA66/Cu nanofibers

    Directory of Open Access Journals (Sweden)

    Li Ya

    2016-01-01

    Full Text Available Different PA66/Cu nanofibers were prepared under various electrospinning parameters through bubbfil electrospinning. The process parameters were determined. Cuprum particles with different size were added to PA66 solution to produce PA6/66-Cu composite nanofibers. The influence of cuprum nanoparticle size on the PA66 nanofibers was analyzed.

  12. Preparation of mesohollow and microporous carbon nanofiber and its application in cathode material for lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Yuanhe; Gao, Mingxia, E-mail: gaomx@zju.edu.cn; Li, Xiang; Liu, Yongfeng; Pan, Hongge, E-mail: hgpan@zju.edu.cn

    2014-09-01

    Highlights: • Mesohollow and microporous carbon fibers were prepared via electrospinning and carbonization. • Sulfur (S) incorporated into the porous fibers by thermal heating in 60 wt.%, forming composite. • S fills fully in the micropores and partially in the mesohollows of the carbon fibers. • The composite shows high capacity and capacity retention as cathode material for Li–S batteries. • Mesohollow and microporous structure is effective in improving the property of S cathode. - Abstract: Mesohollow and microporous carbon nanofibers (MhMpCFs) were prepared by a coaxial electrospinning with polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) as outer and inner spinning solutions followed by a carbonization. The carbon fibers were thermal treated with sublimed sulfur to form S/MhMpCFs composite, which was used as cathode material for lithium–sulfur batteries. Electrochemical study shows that the S/MhMpCFs cathode material provides a maximum capacity of 815 mA h/g after several cycles of activation, and the capacity retains 715 mA h/g after 70 cycles, corresponding to a retention of 88%. The electrochemical property of the S/MhMpCFs composite is much superior than the S-incorporated solid carbon fibers prepared from electrospinning of single PAN. The mechanism of the enhanced electrochemical property of the S/MhMpCFs composite is discussed.

  13. Integrated fast assembly of free-standing lithium titanate/carbon nanotube/cellulose nanofiber hybrid network film as flexible paper-electrode for lithium-ion batteries.

    Science.gov (United States)

    Cao, Shaomei; Feng, Xin; Song, Yuanyuan; Xue, Xin; Liu, Hongjiang; Miao, Miao; Fang, Jianhui; Shi, Liyi

    2015-05-27

    A free-standing lithium titanate (Li4Ti5O12)/carbon nanotube/cellulose nanofiber hybrid network film is successfully assembled by using a pressure-controlled aqueous extrusion process, which is highly efficient and easily to scale up from the perspective of disposable and recyclable device production. This hybrid network film used as a lithium-ion battery (LIB) electrode has a dual-layer structure consisting of Li4Ti5O12/carbon nanotube/cellulose nanofiber composites (hereinafter referred to as LTO/CNT/CNF), and carbon nanotube/cellulose nanofiber composites (hereinafter referred to as CNT/CNF). In the heterogeneous fibrous network of the hybrid film, CNF serves simultaneously as building skeleton and a biosourced binder, which substitutes traditional toxic solvents and synthetic polymer binders. Of importance here is that the CNT/CNF layer is used as a lightweight current collector to replace traditional heavy metal foils, which therefore reduces the total mass of the electrode while keeping the same areal loading of active materials. The free-standing network film with high flexibility is easy to handle, and has extremely good conductivity, up to 15.0 S cm(-1). The flexible paper-electrode for LIBs shows very good high rate cycling performance, and the specific charge/discharge capacity values are up to 142 mAh g(-1) even at a current rate of 10 C. On the basis of the mild condition and fast assembly process, a CNF template fulfills multiple functions in the fabrication of paper-electrode for LIBs, which would offer an ever increasing potential for high energy density, low cost, and environmentally friendly flexible electronics.

  14. Novel preparation and characterization of human hair-based nanofibers using electrospinning process.

    Science.gov (United States)

    Park, Mira; Shin, Hye Kyoung; Panthi, Gopal; Rabbani, Mohammad Mahbub; Alam, Al-Mahmnur; Choi, Jawun; Chung, Hea-Jong; Hong, Seong-Tshool; Kim, Hak-Yong

    2015-05-01

    Human hair-based biocomposite nanofibers (NFs) have been fabricated by an electrospinning technique. Aqueous keratin extracted from human hair was successfully blended with poly(vinyl alcohol) (PVA). The focus here is on transforming into keratin/PVA nanofibrous membranes and insoluble property of electrospun NFs. The resulting hair-based NFs were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning colorimetry (DSC), and thermogravimetric analysis (TGA). Toward the potential use of these NFs after cross-linking with various weight fractions of glyoxal, its physicochemical properties, such as morphology, mechanical strength, crystallinity, and chemical structure were investigated. Keratin/PVA ratio of 2/1 NFs with 6 wt%-glyoxal showed good uniformity in fiber morphology and suitable mechanical properties, and excellent antibacterial activity providing a potential application of hair-based NFs in biomedical field.

  15. Templates for integrated nanofiber growth

    DEFF Research Database (Denmark)

    Oliveira Hansen, Roana Melina de

    Para-hexaphenylene (p6P) molecules have the ability to self-assemble into organic nanofibers. These nanofibers hold unique optoelectronic properties, which make them interesting candidates as elements in electronic and optoelectronic devices. Typically these nanofibers are grown on specific single......, high-volume integration. Besides such single-crystalline templates, the nanofibers can also be grown on non-crystalline gold surfaces, on which the orientation of the nanofibers can be manipulated by structuring the gold surface prior to p6P deposition. In this work, a novel method for in-situ growth...... of p6P nanofibers on nano-structured gold surfaces is presented. The substrates are prepared by conventional nanofabrication techniques such as e-beam lithography and metal deposition, which increase their potential as device platforms. Some of the results presented here demonstrate, that both...

  16. Ultrasonic dyeing of cellulose nanofibers.

    Science.gov (United States)

    Khatri, Muzamil; Ahmed, Farooq; Jatoi, Abdul Wahab; Mahar, Rasool Bux; Khatri, Zeeshan; Kim, Ick Soo

    2016-07-01

    Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing.

  17. Preparation and up-conversion luminescence properties of LaOBr:Yb3+/Er3+ nanofibers via electrospinning.

    Science.gov (United States)

    Ma, Wenwen; Yu, Wensheng; Dong, Xiangting; Wang, Jinxian; Liu, Guixia

    2014-11-01

    LaOBr:Yb(3+)/Er(3+) nanofibers were synthesized for the first time by calcinating electrospun PVP/[La(NO3)3 + Er(NO3)3 + Yb(NO3)3 + NH4 Br] composites. The morphology and properties of the final products were investigated in detail using scanning electron microscopy (SEM), energy dispersion spectroscopy (EDS), X-ray diffractometry (XRD) and fluorescence spectroscopy. The results indicate that LaOBr:Yb(3+)/Er(3+) nanofibers are tetragonal in structure with a space group of P4/nmm. The diameter of LaOBr:Yb(3+)/Er(3+) nanofibers is ~ 147 nm. Under the excitation of a 980-nm diode laser, LaOBr:Yb(3+)/Er(3+) nanofibers emit strong green and red up-conversion emission centering at 519, 541 and 667 nm, ascribed to the (2)H11/2, (4)S3/2 → (4) I(15/2) and (4)F9/2 → (4)I(15/2) energy-level transitions of Er(3+) ions, respectively. The up-conversion luminescent mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is advanced. Moreover, near-infrared emission of LaOBr:Yb(3+)/Er(3+) nanofibers is obtained under the excitation of a 532-nm laser. The formation mechanism of LaOBr:Yb(3+)/Er(3+) nanofibers is proposed. LaOBr:Yb(3+)/Er(3+) nanofibers could be important up-conversion luminescent materials.

  18. Gold nanorods contained polyvinyl alcohol/chitosan nanofiber matrix for cell imaging and drug delivery

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Eryun, E-mail: yaney359@126.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Cao, Minglu [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006 (China); Wang, Yuwei; Hao, Xiaoyuan [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China); Pei, Shichun; Gao, Jianwei; Wang, Yan [College of Food and Biological Engineering, Qiqihar University, Qiqihar 161006 (China); Zhang, Zhuanfang [College of Chemistry and Chemical Engineering, Qiqihar University, Qiqihar 161006 (China); Zhang, Deqing, E-mail: zhdqing@163.com [College of Materials Science and Engineering, Qiqihar University, Qiqihar 161006 (China)

    2016-01-01

    Gold nanorods (AuNRs) that contained polyvinyl alcohol/chitosan (PVA/CS) hybrid nanofibers with dual functions are successfully fabricated by a simple electrospinning method. The results of transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy dispersive X-ray (EDX) spectroscopy indicate that AuNRs are indeed encapsulated into the PVA/CS hybrid nanofibers. FTIR spectra results demonstrate that the chemical structures of PVA and CS are not affected when the AuNRs are introduced into the fibers. In vitro cytotoxicity test reveals that the hybrid fibers involving AuNRs are completely biocompatible. The as-prepared fibers can be used as a carrier for anticancer agent doxorubicin (DOX), and the drug is delivered into the cell nucleus. The AuNRs and DOX incorporated fibers are effective for inhibiting the growth and proliferation of ovary cancer cells and they can also be used as the cell imaging agent due to the unique optical properties of AuNRs. The nanofiber matrix combining two functions of cell imaging and drug delivery may be of great application potential in biomedical-related areas. - Highlights: • The AuNRs contained PVA/CS nanofibers are fabricated by electrospinning. • The hybrid fibers involving AuNRs are completely biocompatible. • The DOX loaded fibers are effective for inhibiting the proliferation of cancer cells. • The nanofibers combined two functions of cell imaging and drug delivery.

  19. Preparation of a novel composite nanofiber gel-encapsulated human placental extract through layer-by-layer self-assembly.

    Science.gov (United States)

    Liu, Guohui; Chen, X I; Zhou, W U; Yang, Shuhua; Ye, Shunan; Cao, Faqi; Liu, Y I; Xiong, Yuan

    2016-04-01

    Aqueous human placenta extract (HPE) has been previously used to treat chronic soft tissue ulcer; however, the optimal dosage of HPE has yet to be elucidated. The present study investigated a novel nanofiber gel composed through layer-by-layer (LbL) self-assembly, in which HPE was encapsulated. IKVAV, RGD, RAD16 and FGL-PA were screened and combined to produce an optimal vehicle nanofiber gel through LbL assembly. Subsequently, the aqueous HPE was encapsulated into this nanofiber at the appropriate concentration, and the morphology, particle size, drug loading efficacy, encapsulation rate, release efficiency and structure validation were detected. The encapsulation efficiency of all three HPE samples was >90%, the nanofiber gel exhibited a slow releasing profile, and the structure of HPE encapsulated in the nanofiber gel was unvaried. In conclusion, this type of novel composite nanocapsules may offer a promising delivery system for HPE.

  20. Fluorescence In Situ Hybridization Probe Preparation.

    Science.gov (United States)

    Tolomeo, Doron; Stanyon, Roscoe R; Rocchi, Mariano

    2017-01-01

    The public human genome sequencing project utilized a hierarchical approach. A large number of BAC/PAC clones, with an insert size approximate from 50 kb to 300 kb, were identified and finely mapped with respect to the Sequence Tagged Site (STS) physical map and with respect to each other. A "golden path" of BACs, covering the entire human genome, was then selected and each clone was fully sequenced. The large number of remaining BACs was not fully sequenced, but the availability of the end sequence (~800-1000 bp) at each end allowed them to be very precisely mapped on the human genome.The search for copy number variations of the human genome used several strategies. One of these approaches took advantage of the fact that fosmid clones, contrary to BAC/PAC clones, have a fixed insert size (~40 kb) (Kidd et al., Nature 453: 56-64, 2008). In this context, the ends of ~7 million fosmid clones were sequenced, and therefore it was possible to precisely map these clones on the human genome.In summary, a large number of genomic clones (GC) are available for FISH experiments. They usually yield bright FISH signals and are extremely precious for molecular cytogenetics, and in particular cancer cytogenetics. The already-labeled probes available commercially are usually based on a combination of such GCs. The present chapter summarizes the protocols for extracting, labeling, and hybridization onto slides of DNA obtained from GC.

  1. Biodegradable conductive composites of poly(3-hydroxybutyrate and polyaniline nanofibers: Preparation, characterization and radiolytic effects

    Directory of Open Access Journals (Sweden)

    2011-01-01

    Full Text Available Poly(3-hydroxybutyrate is a biodegradable polyester produced by microorganisms under nutrient limitation conditions. We obtained a biodegradable poly(3-hydroxybutyrate composite having 8 to 55% of chemically in situ polymerized hydrochloric acid-doped polyaniline nanofibers (70-100 nm in diameter. Fourier transform infrared spectroscopy and X-rays diffractometry data did not show evidence of significant interaction between the two components of the nanocomposite, and polyaniline semiconductivity was preserved in all studied compositions. Gamma-irradiation at 25 kGy absorbed dose on the semiconductive composite presenting 28% of doped polyaniline increased its conductivity from 4.6*10-2 to 1.1 S/m, while slightly decreasing its biodegradability. PANI-HCl biodegradation is negligible when compared to PHB biodegradability in an 80 day timeframe. Thus, this unprecedented all-polymer nanocomposite presents, at the same time, semiconductivity and biodegradability and was proven to maintain these properties after gamma irradiation. This new material has many potential applications in biological science, engineering, and medicine.

  2. Preparation of PAA/AM/MMT Hybrid by Intercalation Polymerization

    Institute of Scientific and Technical Information of China (English)

    WANG; YunPu

    2001-01-01

    Over the last few years, Montmorillonite (MMT) was widely used as a special inorganic material for preparing Polymer/MMT nanocompsites. MMT is a clay imineral consisting of stacked silicate sheets whose thickness is about 10A. Through intercalation a large number of polymer-clay nanocomposites have been prepared such as Nylon-clay hybrid [1], PS-clay hybrid [2], Poly (methyl methacrylate) (PMMA)-clay hybrid [3], etc.  In this article, the synthesis and properties of Poly (acrylic acid/acrylamide)/MMT hybrid (PAAAM/MMT) were studied. X-ray diffraction and Transmission electron microscopy were used to characterize the hybrid material. DSC has been used to study its property. Results showed that the intercalating reagents have entered the space of MMT's layers and enlarged them. At the same time, the MMT dispersed homogeneously in acrylic acid and acrylamide monomers that allow MMT to disperse in PAAAM matrix in the monolayer form.  ……

  3. Preparation and Characterization of Vancomycin-Loaded Electrospun Rana chensinensis Skin Collagen/Poly(L-lactide Nanofibers for Drug Delivery

    Directory of Open Access Journals (Sweden)

    Mei Zhang

    2016-01-01

    Full Text Available Collagen was extracted from abandoned Rana chensinensis skin in northeastern China via an acid enzymatic extraction method for the use of drug carriers. In this paper we demonstrated two different nanofiber-vancomycin (VCM systems, that is, VCM blended nanofibers and core-shell nanofibers with VCM in the core. Rana chensinensis skin collagen (RCSC and poly(L-lactide (PLLA (3 : 7 were blended in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP at a concentration of 10% (g/mL to fabricate coaxial and blend nanofibers, respectively. Coaxial and blend electrospun RCSC/PLLA nanofibers containing VCM (5 wt% were evaluated for the local and temporal delivery of VCM. The nanofiber scaffolds were characterized by environmental scanning electron microscope (ESEM, transmission electron microscopy (TEM, Fourier transform infrared spectra (FTIR, differential scanning calorimeter (DSC, water contact angle (WCA, and mechanical tests. The drug release of VCM in these two systems was compared by using UV spectrophotometer. The empirical result indicated that both the blend and coaxial RCSC/PLLA scaffolds followed sustained control release for a period of 80 hours, but the coaxial nanofiber might be a potential drug delivery material for its better mechanical properties and sustained release effect.

  4. Hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nanofibers modified with CdS nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Shingchung Lo; Zhike Liu; Jinhua Li; Helen Laiwa Chan; Feng Yann

    2013-01-01

    Organic-inorganic hybrid solar cells based on poly(3-hexylthiophene) and electrospun TiO2 nanofibers were fabricated by solution process. The efficiency of the device was improved by modifying CdS nanoparticles on the surface of TiO2 by electrochemical method. The CdS layer can lead to the increase of both open circuit voltage and short circuit current of the device, which are attributed to enhanced exciton dissociation and light absorption and suppressed carrier recombination by CdS at the heterojunction. However, too thick CdS layer led to increased series resistance and decreased efficiency of the device. Therefore, the optimum condition of the CdS deposition was obtained, which increased the power conversion efficiency of the device for about 50%. Our results indicate that the surface modification on the inorganic semiconductor layer is an effect way to improve the performance of the hybrid solar cells.

  5. Research Update: Polyimide/CaCu3Ti4O12 nanofiber functional hybrid films with improved dielectric properties

    Science.gov (United States)

    Yang, Yang; Wang, Ziyu; Ding, Yi; Lu, Zhihong; Sun, Haoliang; Li, Ya; Wei, Jianhong; Xiong, Rui; Shi, Jing; Liu, Zhengyou; Lei, Qingquan

    2013-11-01

    This work reports the excellent dielectric properties of polyimide (PI) embedded with CaCu3Ti4O12 (CCTO) nanofibers. The dielectric behaviors were investigated over a frequency of 100 Hz-1 MHz. It is shown that embedding CCTO nanofibers with high aspect ratio (67) is an effective means to enhance the dielectric permittivity and reduce the percolation threshold. The dielectric permittivity of PI/CCTO nanofiber composites is 85 with 1.5 vol.% loading of filler, also the dielectric loss is only 0.015 at 100 Hz. Monte Carlo simulation was used to investigate the percolation threshold of CCTO nanofibers reinforced polyimide matrix by using excluded volume theory and soft, hard-core models. The results are in good agreement with the percolation theory and the hard-core model can well explain the percolation phenomena in PI/CCTO nanofiber composites. The dielectric properties of the composites will meet the practical requirements for the application in high dielectric constant capacitors and high energy density materials.

  6. Research Update: Polyimide/CaCu3Ti4O12 nanofiber functional hybrid films with improved dielectric properties

    Directory of Open Access Journals (Sweden)

    Yang Yang

    2013-11-01

    Full Text Available This work reports the excellent dielectric properties of polyimide (PI embedded with CaCu3Ti4O12 (CCTO nanofibers. The dielectric behaviors were investigated over a frequency of 100 Hz–1 MHz. It is shown that embedding CCTO nanofibers with high aspect ratio (67 is an effective means to enhance the dielectric permittivity and reduce the percolation threshold. The dielectric permittivity of PI/CCTO nanofiber composites is 85 with 1.5 vol.% loading of filler, also the dielectric loss is only 0.015 at 100 Hz. Monte Carlo simulation was used to investigate the percolation threshold of CCTO nanofibers reinforced polyimide matrix by using excluded volume theory and soft, hard-core models. The results are in good agreement with the percolation theory and the hard-core model can well explain the percolation phenomena in PI/CCTO nanofiber composites. The dielectric properties of the composites will meet the practical requirements for the application in high dielectric constant capacitors and high energy density materials.

  7. Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Jordi Puiggalí

    2013-09-01

    Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  8. Electrospinning of Nanofibers for Energy Applications.

    Science.gov (United States)

    Sun, Guiru; Sun, Liqun; Xie, Haiming; Liu, Jia

    2016-07-02

    With global concerns about the shortage of fossil fuels and environmental issues, the development of efficient and clean energy storage devices has been drastically accelerated. Nanofibers are used widely for energy storage devices due to their high surface areas and porosities. Electrospinning is a versatile and efficient fabrication method for nanofibers. In this review, we mainly focus on the application of electrospun nanofibers on energy storage, such as lithium batteries, fuel cells, dye-sensitized solar cells and supercapacitors. The structure and properties of nanofibers are also summarized systematically. The special morphology of nanofibers prepared by electrospinning is significant to the functional materials for energy storage.

  9. Electrospinning of Nanofibers for Energy Applications

    Directory of Open Access Journals (Sweden)

    Guiru Sun

    2016-07-01

    Full Text Available With global concerns about the shortage of fossil fuels and environmental issues, the development of efficient and clean energy storage devices has been drastically accelerated. Nanofibers are used widely for energy storage devices due to their high surface areas and porosities. Electrospinning is a versatile and efficient fabrication method for nanofibers. In this review, we mainly focus on the application of electrospun nanofibers on energy storage, such as lithium batteries, fuel cells, dye-sensitized solar cells and supercapacitors. The structure and properties of nanofibers are also summarized systematically. The special morphology of nanofibers prepared by electrospinning is significant to the functional materials for energy storage.

  10. A novel method for preparing Co{sub 3}O{sub 4} nanofibers by using electrospun PVA/cobalt acetate composite fibers as precursor

    Energy Technology Data Exchange (ETDEWEB)

    Guan Hongyu; Shao Changlu; Wen Shangbin; Chen Bin; Gong Jian; Yang Xinghua

    2003-12-20

    Thin PVA/cobalt acetate composite fibers were prepared by using sol-gel processing and electrospinning technique. After calcination of the above precursor fibers, Co{sub 3}O{sub 4} nanofibers with a diameter of 50-200 nm were successfully obtained. The fibers were characterized by scanning electron microscopy, FT-IR, wide-angle X-ray diffraction, respectively. The results showed that the crystalline phase and morphology of the as-prepared fibers were largely influenced by the calcination temperature.

  11. Preparation, Characterization and Properties of Graphene-silver Sulphide Hybrid

    Institute of Scientific and Technical Information of China (English)

    CHEN Guang-yi; WEI Zhi-yong; LIANG Ce; WANG De-jin; LIANG Ji-cai; ZHANG Wan-xi

    2012-01-01

    A facile and efficient strategy was reported for the preparation of graphene nanosheets-Ag2S hybrid by a simple hydrothermal process.First,Ag2S particles deposited on the surface of graphene oxide(GO) sheet.GO was then reduced by hydrazine hydrate to graphcne.The results of X-ray diffraction(XRD) and Fourier transform infrared(FTIR) demonstrated the efficient reduction of GO to graphene.Transmission electron microscopy(TEM) image of the sample reveals the morphology of the architecture of graphene-Ag2S hybrid.Ultraviolet-visible spectroscopy(UV-Vis) and photoluminescence(PL) measurement were further employed to study the optical properties of the obtained nanocomposite.This work can be extended to design other graphene-based hybrid nanomaterials,and the as-grown architectures may hold promise for many applications.

  12. Preparation of hybrid biomaterials for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Vilma Conceição Costa

    2007-03-01

    Full Text Available Tissue engineering has evolved from the use of biomaterials for bone substitution that fulfill the clinical demands of biocompatibility, biodegradability, non-immunogeneity, structural strength and porosity. Porous scaffolds have been developed in many forms and materials, but few reached the need of adequate physical, biological and mechanical properties. In the present paper we report the preparation of hybrid porous polyvinyl alcohol (PVA/bioactive glass through the sol-gel route, using partially and fully hydrolyzed polyvinyl alcohol, and perform structural characterization. Hybrids containing PVA and bioactive glass with composition 58SiO2-33CaO-9P2O5 were synthesized by foaming a mixture of polymer solution and bioactive glass sol-gel precursor solution. Sol-gel solution was prepared from mixing tetraethoxysilane (TEOS, triethylphosphate (TEP, and calcium chloride as chemical precursors. The hybrid composites obtained after aging and drying at low temperature were chemically and morphologically characterized through infrared spectroscopy and scanning electron microscopy. The degree of hydrolysis of PVA, concentration of PVA solution and different PVA-bioglass composition ratios affect the synthesis procedure. Synthesis parameters must be very well combined in order to allow foaming and gelation. The hybrid scaffolds obtained exhibited macroporous structure with pore size varying from 50 to 600 µm.

  13. Preparation of Pure and Stable Chitosan Nanofibers by Electrospinning in the Presence of Poly(ethylene oxide).

    Science.gov (United States)

    Mengistu Lemma, Solomon; Bossard, Frédéric; Rinaudo, Marguerite

    2016-10-26

    Electrospinning was employed to obtain chitosan nanofibers from blends of chitosans (CS) and poly(ethylene oxide) (PEO). Blends of chitosan (MW (weight-average molecular weight) = 102 kg/mol) and PEO (M (molecular weight) = 1000 kg/mol) were selected to optimize the electrospinning process parameters. The PEO powder was solubilized into chitosan solution at different weight ratios in 0.5 M acetic acid. The physicochemical changes of the nanofibers were determined by scanning electron microscopy (SEM), swelling capacity, and nuclear magnetic resonance (NMR) spectroscopy. For stabilization, the produced nanofibers were neutralized with K₂CO₃ in water or 70% ethanol/30% water as solvent. Subsequently, repeated washings with pure water were performed to extract PEO, potassium acetate and carbonate salts formed in the course of chitosan nanofiber purification. The increase of PEO content in the blend from 20 to 40 w% exhibited bead-free fibers with average diameters 85 ± 19 and 147 ± 28 nm, respectively. Their NMR analysis proved that PEO and the salts were nearly completely removed from the nanostructure of chitosan, demonstrating that the adopted strategy is successful for producing pure chitosan nanofibers. In addition, the nanofibers obtained after neutralization in ethanol-aqueous solution has better structural stability, at least for six months in aqueous solutions (phosphate buffer (PBS) or water).

  14. Preparation and Property of the Water Absorbent Hybrid Resin

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@ Water absorption material has been attracted much more attention for its wide use in soil and water conservation, agriculture, etc. But this material will actually apply in agriculture, soil and water conservation only when it is cheap enough. Pulp fiber and starch to prepare high absorbing-water resin is a good method for decreasing the cost [1,2]. However, it still has a long way to turn it into reality. Now the montmorillonite is widely used in preparing nanocomposites [3]. But used it in preparing absorbing-water resin has little report. In this article the water absorption hybrid resin has been prepared by one step intercalation polymerization method. In the process of intercalation the partly neutralization acrylic acid and urea have been used as intercalating reagent. Beside that, the urea also has been used as cross-linking agent.

  15. Preparation and Property of the Water Absorbent Hybrid Resin

    Institute of Scientific and Technical Information of China (English)

    WANG; YunPu

    2001-01-01

    Water absorption material has been attracted much more attention for its wide use in soil and water conservation, agriculture, etc. But this material will actually apply in agriculture, soil and water conservation only when it is cheap enough. Pulp fiber and starch to prepare high absorbing-water resin is a good method for decreasing the cost [1,2]. However, it still has a long way to turn it into reality.  Now the montmorillonite is widely used in preparing nanocomposites [3]. But used it in preparing absorbing-water resin has little report. In this article the water absorption hybrid resin has been prepared by one step intercalation polymerization method. In the process of intercalation the partly neutralization acrylic acid and urea have been used as intercalating reagent. Beside that, the urea also has been used as cross-linking agent.   ……

  16. Preparation and characterization of PVA/Au composite nanofiber%PVA/Au纳米复合纤维的制备及表征

    Institute of Scientific and Technical Information of China (English)

    吴涛; 钱琛

    2011-01-01

    以聚乙烯醇(PVA)为还原剂和保护剂,采用PVA还原氯金酸(HAuCl4)制备纳米金(Au),一步法制备PVA/Au溶液,通过静电纺丝制备了PVA/Au纳米复合纤维.利用紫外可见光谱仪、透明电镜和扫描电镜对PVA/Au纳米复合纤维进行了表征.结果表明:随着HAuCl4浓度的增加,Au纳米粒子的粒径逐渐增大;HAuCl4的浓度对纳米复合纤维的形貌影响较大,在HAuCl4浓度较低或较高时,均可以获得直径较为均一的PVA/Au纳米复合纤维;低电导率和高粘度的PVA/Au溶液可得到纤维直径均一的纳米复合纤维.%Using polyvinyl alcohol (PVA) as a reductant and a protectant, gold (Au) mmoparticles were produced from gold chloric acid ( HauCl4 ), from which PVA/Au solution was prepared by one-step process and was spun into PVA/Au composite nanofiber via electrospinning process. PVA/Au composite nanofiber was characterized with ultraviolet-visible spectroscope, transparent electron microscope and scanning electron microscope. The results showed that the Au runoparticle size gradually increased with the increase of HAuCl4 concentration. The HAuCl4 concentration had a great effect on the morphology of the composite nanofiber. PVA/Au composite nanofiber with uniform diameter can be obtained from PVA/Au solution with low conductivity and high viscosity at relatively high or low HAuCl4 concentration.

  17. Preparation of Aluminum Nanoparticles/Nitrocellulose Nanofibers%含纳米铝粉的纳米NC纤维的制备

    Institute of Scientific and Technical Information of China (English)

    谢龙; 邵自强; 王文俊; 王飞俊; 王慧庆

    2011-01-01

    In order to overcome the agglomeration of aluminum nanoparticles(AlNPs) in the propellant processing,the smooth and uniform nanofibers of AlNPs/nitrocellulose(NC) have been successfully fabricated by simple adding AlNPs to NC solution before electrospinning.The effect of electrospinning technique on the morphology and diameter of the nitrocellulose nanofibers were investigated by SEM.The suitable electrospinning conditions were as follows: water content, 10 % - 15 %, nitrocellulose solution concentration, 5 % - 10 %, voltage, 25 - 30 kV and extrusion rate,0.5~4 mL/h.The AlNPs/NC nanofibers prepared in the above-mentioned feasible condition reveal that AlNPs distribute uniformly in nanofibers matrix.%为了克服纳米铝粉在推进剂使用过程中分散不均匀的问题,采用静电纺丝技术制备了材料表面光滑、直径均匀、且纳米铝粉分散均匀的纳米NC纤维.用扫描电镜研究了含水率、溶液浓度、电压和挤出速率对纤维形态和直径的影响,得到静电纺丝最佳工艺条件:含水率为10%~15%,NC纺丝液质量分数5%~10%,电压25~30kV,挤出速率0.5~4mL/h.在此工艺条件下,制备出含纳米铝粉的纳米硝化棉纤维,显示纳米铝粉均匀地分散在硝化棉纤维中.

  18. A flexible triboelectric-piezoelectric hybrid nanogenerator based on P(VDF-TrFE) nanofibers and PDMS/MWCNT for wearable devices

    Science.gov (United States)

    Wang, Xingzhao; Yang, Bin; Liu, Jingquan; Zhu, Yanbo; Yang, Chunsheng; He, Qing

    2016-11-01

    This paper studied and realized a flexible nanogenerator based on P(VDF-TrFE) nanofibers and PDMS/MWCNT thin composite membrane, which worked under triboelectric and piezoelectric hybrid mechanisms. The P(VDF-TrFE) nanofibers as a piezoelectric functional layer and a triboelectric friction layer are formed by electrospinning process. In order to improve the performance of triboelectric nanogenerator, the multiwall carbon nanotubes (MWCNT) is doped into PDMS patterned films as the other flexible friction layer to increase the initial capacitance. The flexible nanogenerator is fabricated by low cost MEMS processes. Its output performance is characterized in detail and structural optimization is performed. The device’s output peak-peak voltage, power and power density under triboelectric mechanism are 25 V, 98.56 μW and 1.98 mW/cm3 under the pressure force of 5 N, respectively. The output peak-peak voltage, power and power density under piezoelectric working principle are 2.5 V, 9.74 μW, and 0.689 mW/cm3 under the same condition, respectively. We believe that the proposed flexible, biocompatible, lightweight, low cost nanogenerator will supply effective power energy sustainably for wearable devices in practical applications.

  19. Preparation and characterization of multi-layer biodegradable nanofibers by coaxial electrospinning and their potential for tissue engineering

    Science.gov (United States)

    Liu, Wenwen

    As an evolution of conventional electrospinning, coaxial electrospinning became popular soon after its debut as a novel way to develop nanofibers with special structures, such as core-shell and hollow interior. In recent years, there has been an increasing interest in a modified coaxial electrospinning, tri-layer coaxial electrospinning, to develop more complex structures, such as multi-layer and nanowire-in-microtube. Previous studies have primarily concentrated on the fabrication of tri-layered inorganic fibers while studies on tri-layered coaxial polymeric fibers has not been reported until very recently. Our research focuses on the fabrication of core-shell and tri-layer structured biodegradable polymeric nanofibers with coaxial electrospinning. Different characterization methods have been applied to observe the internal structure in single nanofibers and the potential application of tri-layer coaxial electrospinning has been discussed. The material system consists of biodegradable natural polymer gelatin, synthetic polymers poly (epsilon-caprolactone) (PCL) and poly (lactic-co-glycolic acid) (PLGA). A uniquely designed three-needle concentric spinneret is developed to perform tri-layer coaxial electrospinning. Different kinds of core-shell structured nanofibers, including gelatin/PCL, PCL/gelatin, gelatin/PLGA and PCL/PLGA, have been fabricated with a customized coaxial electrospinning apparatus. Two kinds of tri-layer coaxial nanofibers, two-component ABA structured gelatin/PCL/gelatin biodegradable nanofibers and tri-component ABC structured gelatin/PCL/PLGA biodegradable nanofibers, have been developed with the customized three needle coaxial electrospinning setup. The core-shell and tri-layered structures of electrospun nanofibers have been characterized by several commonly used techniques, such as laser scanning confocal microscopy (LSCM) and transmission electron microscopy (TEM). Besides the conventional methods, other newer techniques, including

  20. Insights to Advanced Inorganic Nanoparticles,Nanorods,Nanofibers and Nanotubes:Preparation and Applications

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Quasi one-dimensional nanostructured materials have received considerable attention due to their unique optical and electrical properties and potential applications in nanodevices.Much effort has been directed toward exploring novel synthetic methods and understanding the chemical and physical properties of these nanostructures.The chemical vapor deposition and thermal evaporation,are proved to be efficient for the preparation of wirelike nanomaterials,however these methods are quite energy co...

  1. Magnetic and electrical properties of oxygen stabilized nickel nanofibers prepared by the borohydride reduction method

    Energy Technology Data Exchange (ETDEWEB)

    Srinivas, V. [Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur West Bengal 721 302 India (India)], E-mail: veeturi@phy.iitkgp.ernet.in; Barik, S.K.; Bodo, Bhaskarjyoti [Department of Physics and Meteorology, Indian Institute of Technology, Kharagpur West Bengal 721 302 India (India); Karmakar, Debjani; Chandrasekhar Rao, T.V. [Technical Physics and Prototype Engineering Division, Bhabha Atomic Research Centre, Bombay 400085 India (India)

    2008-03-15

    Fine nickel fibers have been synthesized by chemical reduction of nickel ions in aqueous medium with sodium borohydride. The thermal stability and relevant properties of these fibers, as-prepared as well as air-annealed, have been investigated by structural, magnetic and electrical measurements. As-prepared samples appear to have a novel crystal structure due to the presence of interstitial oxygen. Upon annealing in air, the fcc-Ni phase emerges out initially and develops into a nanocomposite subsequently by retaining its fiber-like structure in nano phase. The as-prepared sample is observed to be weakly magnetic at room temperature, but attains surprisingly high magnetization values at low temperatures. This is attributed to the modified spin structure, presumably due to the presence of interstitial oxygen in the lattice. Development of a weakly ferromagnetic and electrically conducting phase upon annealing in air is attributed to the formation of the fcc-Ni phase. The structural phase transformations corroborate well with magnetic and electrical measurements.

  2. Electrospun non-woven nanofibrous hybrid mats based on chitosan and PLA for wound-dressing applications.

    Science.gov (United States)

    Ignatova, Milena; Manolova, Nevena; Markova, Nadya; Rashkov, Iliya

    2009-01-09

    Continuous defect-free nanofibers containing chitosan (Ch) or quaternized chitosan (QCh) were successfully prepared by one-step electrospinning of Ch or QCh solutions mixed with poly[(L-lactide)-co-(D,L-lactide)] in common solvent. XPS revealed the surface chemical composition of the bicomponent electrospun mats. Crosslinked Ch- and QCh-containing nanofibers exhibited higher kill rates against bacteria S. aureus and E. coli than the corresponding solvent-cast films. SEM observations showed that hybrid mats were very effective in suppressing the adhesion of pathogenic bacteria S. aureus. The hybrid nanofibers are promising for wound-healing applications.

  3. A simple and effective route for the preparation of poly(vinylalcohol) (PVA) nanofibers containing gold nanoparticles by electrospinning method

    Science.gov (United States)

    Bai, Jie; Li, Yaoxian; Yang, Songtao; Du, Jianshi; Wang, Shugang; Zheng, Jifu; Wang, Yongzhi; Yang, Qingbiao; Chen, Xuesi; Jing, Xiabin

    2007-02-01

    Poly(vinylalcohol) (PVA) nanofibers containing gold nanoparticles have been simply obtained by electrospinning a solution containing gold nanoparticles without the additional step of introducing other stabilizing agents. The optical property of gold nanoparticles in PVA aqueous solution was observed by UV-visible absorption spectra. Morphology of the Au/PVA nanofibers and distribution of the gold nanoparticles were characterized by transmission electron microscopy (TEM). The structure transformation was characterized from PVA to PVA/Au composite by Fourier transform infrared spectroscopy (FTIR).

  4. Effect of airflow on nanofiber yarn spinning

    Directory of Open Access Journals (Sweden)

    He Jian-Xin

    2015-01-01

    Full Text Available The paper proposes a new air-jet spinning method for the preparation of continuous twisted nanofiber yarns. The nozzle-twisting device is designed to create the 3-D rotating airflow to twist nanofiber bundles. The airflow characteristics inside the twisting chamber are studied numerically. The airflow field distribution and its effect on nanofiber yarn spinning at different pressures are also discussed.

  5. Preparation, in vitro mineralization and osteoblast cell response of electrospun 13-93 bioactive glass nanofibers.

    Science.gov (United States)

    Deliormanlı, Aylin M

    2015-08-01

    In this study, silicate based 13-93 bioactive glass fibers were prepared through sol-gel processing and electrospinning technique. A precursor solution containing poly (vinyl alcohol) and bioactive glass sol was used to produce fibers. The mixture was electrospun at a voltage of 20 kV by maintaining tip to a collector distance of 10 cm. The amorphous glass fibers with an average diameter of 464±95 nm were successfully obtained after calcination at 625 °C. Hydroxyapatite formation on calcined 13-93 fibers was investigated in simulated body fluid (SBF) using two different fiber concentrations (0.5 and 1 mg/ml) at 37 °C. When immersed in SBF, conversion to a calcium phosphate material showed a strong dependence on the fiber concentration. At 1mg/ml, the surface of the fibers converted to the hydroxyapatite-like material in SBF only after 30 days. At lower solid concentrations (0.5 mg/ml), an amorphous calcium phosphate layer formation was observed followed by the conversion to hydroxyapatite phase after 7 days of immersion. The XTT (2,3-Bis-(2-Methoxy-4-Nitro-5-Sulfophenyl)-2H-Tetrazolium-5-Carboxanilide) assay was conducted to evaluate the osteoblast cell response to the bioactive glass fibers. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Preparation of Ionic Silsesquioxanes with Regular Structures and Their Hybridization

    Directory of Open Access Journals (Sweden)

    Yoshiro Kaneko

    2012-01-01

    Full Text Available This paper deals with our recent studies on the preparation of ionic silsesquioxanes (SQs with regular structures. Cationic ladder-like polySQs (PSQs with hexagonally stacked structures were successfully prepared by the sol-gel reactions of amino group-containing organotrialkoxysilanes in strong acid aqueous solutions. Self-organization of an ion pair (a salt prepared from the amino group in the organotrialkoxysilane and an acid is the key factor for the formation of such regular structures of the PSQs. It is also reported that the control of the conformational structure of the PSQs was performed by the introduction of the chiral moieties. In addition, we investigated the correlation between the of acid-catalysts and the structures of SQs prepared by the hydrolytic condensation of amino group-containing organotrialkoxysilane, that is, the use of the superacid aqueous solution resulted in the formation of cage-like octaSQ, while the ladder-like PSQs with hexagonally stacked structures were formed from the strong acid aqueous solutions under the same reaction conditions. Furthermore, anion-exchange behaviors of the cationic ladder-like PSQ were investigated with various organic and inorganic compounds, such as anionic surfactants, a polymer, and layered clay minerals, to obtain the functional hybrid materials.

  7. Preparation and Study of Electromagnetic Interference Shielding Materials Comprised of Ni-Co Coated on Web-Like Biocarbon Nanofibers via Electroless Deposition

    Directory of Open Access Journals (Sweden)

    Xiaohu Huang

    2015-01-01

    Full Text Available Electromagnetic interference (EMI shielding materials made of Ni-Co coated on web-like biocarbon nanofibers were successfully prepared by electroless plating. Biocarbon nanofibers (CF with a novel web-like structure comprised of entangled and interconnected carbon nanoribbons were obtained using bacterial cellulose pyrolyzed at 1200°C. Paraffin wax matrix composites filled with different loadings (10, 20, and 30 wt%, resp. of CF and Ni-Co coated CF (NCCF were prepared. The electrical conductivities and electromagnetic parameters of the composites were investigated by the four-probe method and vector network analysis. From these results, the EMI shielding efficiencies (SE of NCCF composites were shown to be significantly higher than that of CF at the same mass fraction. The paraffin wax composites containing 30 wt% NCCF showed the highest EMI SE of 41.2 dB (99.99% attenuation, which are attributed to the higher electrical conductivity and permittivity of the NCCF composites than the CF composites. Additionally, EMI SE increased with an increase in CF and NCCF loading and the absorption was determined to be the primary factor governing EMI shielding. This study conclusively reveals that NCCF composites have potential applications as EMI shielding materials.

  8. Nickel nanofibers synthesized by the electrospinning method

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Yi [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China); Zhang, Xuebin, E-mail: zzhhxxbb@126.com [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China); Zhu, Yajun; Li, Bin; Wang, Yang; Zhang, Jingcheng; Feng, Yi [School of Materials Science and Engineering, Hefei University of Technology, Anhui 230000 (China)

    2013-07-15

    Highlights: ► The nickel nanofibers have been obtained by electrospinning method. ► The nickel nanofibers had rough surface which was consisted of mass nanoparticles. ► The average diameter of nickel nanofibers is about 135 nm and high degree of crystallization. ► The Hc, Ms, and Mr were estimated to be 185 Oe, 51.9 and 16.9 emu/g respectively. - Abstract: In this paper, nickel nanofibers were prepared by electrospinning polyvinyl alcohol/nickel nitrate precursor solution followed by high temperature calcination in air and deoxidation in hydrogen atmosphere. The thermal stability of the as-electrospun PVA/Ni(NO{sub 3}){sub 2} composite nanofibers were characterized by TG–DSC. The morphologies and structures of the as-prepared samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field-emission scanning electronmicroscope (FE-SEM) and field-emission transmission electron microscopy (FE-TEM). The hysteresis loops (M–H loops) were measured by Physical Property Measurement System (PPMS). The results indicate that: the PVA and the nickel nitrate were almost completely decomposed at 460 °C and the products were pure nickel nanofibers with face-centered cubic (fcc) structure. Furthermore, the as-prepared nickel nanofibers had a continuous structure with rough surface and high degree of crystallization. The average diameter of nickel nanofibers was about 135 nm. The nanofibers showed a stronger coercivity of 185 Oe than value of bulk nickel.

  9. Hybrid Filter Membrane

    Science.gov (United States)

    Laicer, Castro; Rasimick, Brian; Green, Zachary

    2012-01-01

    Cabin environmental control is an important issue for a successful Moon mission. Due to the unique environment of the Moon, lunar dust control is one of the main problems that significantly diminishes the air quality inside spacecraft cabins. Therefore, this innovation was motivated by NASA s need to minimize the negative health impact that air-suspended lunar dust particles have on astronauts in spacecraft cabins. It is based on fabrication of a hybrid filter comprising nanofiber nonwoven layers coated on porous polymer membranes with uniform cylindrical pores. This design results in a high-efficiency gas particulate filter with low pressure drop and the ability to be easily regenerated to restore filtration performance. A hybrid filter was developed consisting of a porous membrane with uniform, micron-sized, cylindrical pore channels coated with a thin nanofiber layer. Compared to conventional filter media such as a high-efficiency particulate air (HEPA) filter, this filter is designed to provide high particle efficiency, low pressure drop, and the ability to be regenerated. These membranes have well-defined micron-sized pores and can be used independently as air filters with discreet particle size cut-off, or coated with nanofiber layers for filtration of ultrafine nanoscale particles. The filter consists of a thin design intended to facilitate filter regeneration by localized air pulsing. The two main features of this invention are the concept of combining a micro-engineered straight-pore membrane with nanofibers. The micro-engineered straight pore membrane can be prepared with extremely high precision. Because the resulting membrane pores are straight and not tortuous like those found in conventional filters, the pressure drop across the filter is significantly reduced. The nanofiber layer is applied as a very thin coating to enhance filtration efficiency for fine nanoscale particles. Additionally, the thin nanofiber coating is designed to promote capture of

  10. Tailoring Supramolecular Nanofibers for Air Filtration Applications.

    Science.gov (United States)

    Weiss, Daniel; Skrybeck, Dominik; Misslitz, Holger; Nardini, David; Kern, Alexander; Kreger, Klaus; Schmidt, Hans-Werner

    2016-06-15

    The demand of new materials and processes for nanofiber fabrication to enhance the performance of air filters is steadily increasing. Typical approaches to obtain nanofibers are based on top-down processes such as melt blowing, centrifugal spinning, and electrospinning of polymer materials. However, fabrication of polymer nanofibers is limited with respect to either a sufficiently high throughput or the smallest achievable fiber diameter. This study reports comprehensively on a fast and simple bottom-up process to prepare supramolecular nanofibers in situ inside viscose/polyester microfiber nonwovens. Here, selected small molecules of the materials class of 1,3,5-benzenetrisamides are employed. The microfiber-nanofiber composites exhibit a homogeneous nanofiber distribution and morphology throughout the entire nonwoven scaffold. Small changes in molecular structure and processing solvent have a strong influence on the final nanofiber diameter and diameter distribution and, consequently, on the filtration performance. Choosing proper processing conditions, microfiber-nanofiber composites with surprisingly high filtration efficiencies of particulate matter are obtained. In addition, the microfiber-nanofiber composite integrity at elevated temperatures was determined and revealed that the morphology of supramolecular nanofibers is maintained compared to that of the utilized polymer nonwoven.

  11. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Science.gov (United States)

    Liu, Huan; Xu, Bin; Jia, Mengqiu; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-01

    A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO3 templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g-1 at a current load of 0.1 A g-1 with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  12. Preparation and Characterization of Cyclic N-halamine Modified Chitosan/PVA Nanofibers%环状卤胺化合物改性壳聚糖/PVA纳米纤维的制备与表征

    Institute of Scientific and Technical Information of China (English)

    李蓉; 刘喆; 任学宏

    2013-01-01

    Antibacterial nanofibers were prepared by electrospinning the mixtures of 3-glycidyl-5,5-dimethylhydantoin modified chitosan (CTS-GH) and poly(vinyl alcohol) (PVA).The structures and thermo properties of electro-spun nanofibers were measured by SEM,FT-IR,and TGA.The effect of the spinning flow rates on the diameters and chlorine loadings of nanofibers were investigated.The results show that the diameter of nanofibers decreased with the increase of the flow rate.The high chlorine contents of the nanofibers indicate that the nanofibers have excellent antibacterial property after chlorination.These nanofibers may serve as potential materials for filtration and biomedical applications.%以易于纺丝的聚乙烯醇(PVA)为纤维基材,添加3-环氧丙基-5,5-二甲基海因改性壳聚糖(CTS-GH),利用静电纺丝法制备出具有高效抗茵效果的纳米纤维.采用扫描电镜、红外光谱、热重分析仪表征和分析了纳米纤维的结构和热性能,考察了纺丝液流量对纳米纤维结构和氯含量的影响.结果表明,纳米纤维的直径随着纺丝速度的加快而减小.利用碘量法测定了纳米纤维的氯含量,说明该纳米纤维经过氯化处理后具有很好的抗茵效果.该纳米纤维可用于抗茵过滤材料、生物医药等方面.

  13. Preparation and characterization of electrospun PLCL/Poloxamer nanofibers and dextran/gelatin hydrogels for skin tissue engineering.

    Directory of Open Access Journals (Sweden)

    Jian-feng Pan

    Full Text Available In this study, two different biomaterials were fabricated and their potential use as a bilayer scaffold for skin tissue engineering applications was assessed. The upper layer biomaterial was a Poly(ε-caprolactone-co-lactide/Poloxamer (PLCL/Poloxamer nanofiber membrane fabricated using electrospinning technology. The PLCL/Poloxamer nanofibers (PLCL/Poloxamer, 9/1 exhibited strong mechanical properties (stress/strain values of 9.37 ± 0.38 MPa/187.43 ± 10.66% and good biocompatibility to support adipose-derived stem cells proliferation. The lower layer biomaterial was a hydrogel composed of 10% dextran and 20% gelatin without the addition of a chemical crosslinking agent. The 5/5 dextran/gelatin hydrogel displayed high swelling property, good compressive strength, capacity to present more than 3 weeks and was able to support cells proliferation. A bilayer scaffold was fabricated using these two materials by underlaying the nanofibers and casting hydrogel to mimic the structure and biological function of native skin tissue. The upper layer membrane provided mechanical support in the scaffold and the lower layer hydrogel provided adequate space to allow cells to proliferate and generate extracellular matrix. The biocompatibility of bilayer scaffold was preliminarily investigated to assess the potential cytotoxicity. The results show that cell viability had not been affected when cocultured with bilayer scaffold. As a consequence, the bilayer scaffold composed of PLCL/Poloxamer nanofibers and dextran/gelatin hydrogels is biocompatible and possesses its potentially high application prospect in the field of skin tissue engineering.

  14. Novel flavonolignan hybrid antioxidants: From enzymatic preparation to molecular rationalization.

    Science.gov (United States)

    Vavříková, Eva; Křen, Vladimír; Jezova-Kalachova, Lubica; Biler, Michal; Chantemargue, Benjamin; Pyszková, Michaela; Riva, Sergio; Kuzma, Marek; Valentová, Kateřina; Ulrichová, Jitka; Vrba, Jiří; Trouillas, Patrick; Vacek, Jan

    2017-02-15

    A series of antioxidants was designed and synthesized based on conjugation of the hepatoprotective flavonolignan silybin with l-ascorbic acid, trolox alcohol or tyrosol via a C12 aliphatic linker. These hybrid molecules were prepared from 12-vinyl dodecanedioate-23-O-silybin using the enzymatic regioselective acylation procedure with Novozym 435 (lipase B) or with lipase PS. Voltammetric analyses showed that the silybin-ascorbic acid conjugate exhibited excellent electron donating ability, in comparison to the other conjugates. Free radical scavenging, antioxidant activities and cytoprotective action were evaluated. The silybin-ascorbic acid hybrid exhibited the best activities (IC50 = 30.2 μM) in terms of lipid peroxidation inhibition. The promising protective action of the conjugate against lipid peroxidation can be attributed to modulated electron transfer abilities of both the silybin and ascorbate moieties, but also to the hydrophobic C12 linker facilitating membrane insertion. This was supported experimentally and theoretically by density functional theory (DFT) and molecular dynamics (MD) calculations. The results presented here can be used in the further development of novel multipotent antioxidants and cytoprotective agents, in particular for substances acting at an aqueous/lipid interface. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  15. Heterojunctions of p-BiOI Nanosheets/n-TiO2 Nanofibers: Preparation and Enhanced Visible-Light Photocatalytic Activity

    Directory of Open Access Journals (Sweden)

    Kexin Wang

    2016-01-01

    Full Text Available p-BiOI nanosheets/n-TiO2 nanofibers (p-BiOI/n-TiO2 NFs have been facilely prepared via the electrospinning technique combining successive ionic layer adsorption and reaction (SILAR. Dense BiOI nanosheets with good crystalline and width about 500 nm were uniformly assembled on TiO2 nanofibers at room temperature. The amount of the heterojunctions and the specific surface area were well controlled by adjusting the SILAR cycles. Due to the synergistic effect of p-n heterojunctions and high specific surface area, the obtained p-BiOI/n-TiO2 NFs exhibited enhanced visible-light photocatalytic activity. Moreover, the p-BiOI/n-TiO2 NFs heterojunctions could be easily recycled without decreasing the photocatalytic activity owing to their one-dimensional nanofibrous structure. Based on the above, the heterojunctions of p-BiOI/n-TiO2 NFs may be promising visible-light-driven photocatalysts for converting solar energy to chemical energy in environment remediation.

  16. Influence of graphene oxide doping on the morphology and the magnetic properties of Ni0.8Gd0.2Fe2O4 nanofibers prepared by electrospinning

    Science.gov (United States)

    Mansour, Michel; Bechelany, Mikhael; Habchi, Roland; Eid, Cynthia

    2017-02-01

    Nickel-gadolinium ferrite nanofibers doped with graphene oxide (GO) were prepared for the first time by the electrospinning technique. The structure and morphology of the as-obtained composites were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy, X-ray diffractometer, Fourier transform infrared spectra, and Raman spectroscopy. The magnetic properties were analyzed by Quantum design MPMS-XL magnetometer. A transition from a 'fiber' morphology to a 'ribbon' morphology was detected for the samples doped with GO. Also, an increase in the magnetic saturation was found when the GO amount increases. Therefore, doping with GO influences both the morphology and the magnetic properties of the electrospun nickel-gadolinium ferrite nanofibers. These results provide a promising lead for the future synthesis of a variety of GO doped ferrites nanofiber morphologies with controllable magnetic properties.

  17. Hybrid layer thickness and morphology: Influence of cavity preparation with air abrasion.

    Science.gov (United States)

    Barceleiro, Marcos Oliveira; de Mello, Jose Benedicto; Porto, Celso Luis de Angelis; Dias, Katia Regina Hostilio Cervantes; de Miranda, Mauro Sayao

    2011-01-01

    Dentinal surfaces prepared with air abrasion have considerably different characteristics from those prepared with conventional instruments. Different hybrid layer morphology and thickness occur, which can result in differences in the quality of restorations placed on dentinal surfaces prepared with a diamond bur compared to surfaces prepared using air abrasion. The objective of this study was to compare the hybrid layer thickness and morphology formed utilizing Scotchbond Multi-Purpose Plus (SBMP) on dentin prepared with a diamond bur in a high-speed handpiece and on dentin prepared using air abrasion. Flat dentin surfaces obtained from five human teeth were prepared using each method, then treated with the dentin adhesive system according to manufacturer's instructions. After a layer of composite was applied, specimens were sectioned, flattened, polished, and prepared for scanning electron microscopy. Ten different measurements of hybrid layer thickness were obtained along the bonded surface in each specimen. SBMP produced a 3.43 ± 0.75 µm hybrid layer in dentin prepared with diamond bur. This hybrid layer was regular and found consistently. In the air abrasion group, SBMP produced a 4.94 ± 1.28 µm hybrid layer, which was regular and found consistently. Statistical ANOVA (P = 0.05) indicated that there was a statistically significant difference between the groups. These data indicate that the air abrasion, within the parameters used in this study, provides a thick hybrid layer formation.

  18. Preparation of Magnesium Hydroxide and Nanofiber Polymer Composites to Reduce the Flammability and Melt Dripping Behaviour of Polymers

    Directory of Open Access Journals (Sweden)

    S. S. Raza

    2014-12-01

    Full Text Available Nanoscale alumina fibers reduce the flammability and melt dripping behaviour of polymers. Magnesium hydroxide breaks the agglomerates by generating shear and iterative forces. Mixing was done with Brabender Plasticoder. The temperature and time of mixing greatly affects the mixing behaviour. At higher temperatures blow holes were observed. By increasing the mixing time agglomerates were broken to a greater extent. Different concentrations of nanofibers, Magnesium hydroxide and surface treatments are used to investigate the properties of polymer. Thermogravimetric analysis (TGA, optical microscopy and flame test was done to see the effect of different parameters on mixing and flame retardancy behaviour.

  19. Polyaniline nanofiber/large mesoporous carbon composites as electrode materials for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Huan; Xu, Bin; Jia, Mengqiu, E-mail: jiamq@mail.buct.edu.cn; Zhang, Mei; Cao, Bin; Zhao, Xiaonan; Wang, Yu

    2015-03-30

    Highlights: • The composites of polyaniline nanofiber and large mesoporous carbon were prepared for supercapacitors. • The large mesoporous carbons were simply prepared by nano-CaCO{sub 3} template method. • The composites exhibit high capacitance and good rate capability and cycle stability. - Abstract: A composite of polyaniline nanofiber/large mesoporous carbon (PANI-F/LMC) hybrid was prepared by an in situ chemical oxidative polymerization of aniline monomer with nano-CaCO{sub 3} templated LMC as host matrix for supercapacitors. The morphology, composition and electronic structure of the composites (PANI-F/LMC) together with pure PANI nanofibers and the LMC were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), FT-IR, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). It is found that the PANI nanofibers were incorporated into the large mesochannels of LMC with interpenetrating framework formed. Such unique structure endows the PANI-F/LMC composite with a high capacitance of 473 F g{sup −1} at a current load of 0.1 A g{sup −1} with good rate performance and cycling stability, suggesting its potential application in the electrode material for supercapacitors.

  20. Photocatalytic Performance Investigation of TiO2/PVA Nanofibers Prepared by Electrospinning%静电纺制备TiO2/PVA复合纳米纤维及其光催化性能研究

    Institute of Scientific and Technical Information of China (English)

    丁源维; 王騊; 姚菊明; 王晟

    2013-01-01

    通过静电纺丝的方法制备一种以二氧化钛(TiO2)为催化剂,聚乙烯醇(PVA)为载体的TiO2/PVA复合纳米纤维光催化材料.使用FE-SEM,XRD,Tg,FTIR对制备的TiO2/PVA复合纳米纤维膜进行了表征,并考察了其紫外光照射下光催化降解罗丹明B(Rh B)的能力.结果表明:制备的TiO2/PVA复合纳米纤维具有较高的光催化活性.%This paper prepares TiO2/PVA nanofibers via electrospinning and by using TiO2 as photo-catalysts and PVA as carriers. The as-prepared TiO2/PVA nanofibers are characterized by FE-SEM, XRD, TG and FT-IR. Furthermore, under UV light irradiation, the authors investigate the photodecom-position of Rhodamine B solution by applying TiO2/PVA nanofibers as photocatalysts. The results indicate that TiCWPVA nanofibers are efficient photocatalysts.

  1. Preparation and application of amino functionalized mesoporous nanofiber membrane via electrospinning for adsorption of Cr3+ from aqueous solution

    Institute of Scientific and Technical Information of China (English)

    Ahmed A.Taha; Junlian Qiao; Fengting Li; Bingru Zhang

    2012-01-01

    Novel amino (-NH2) functionalized mesoporous polyvinyl pyrrolidone (PVP)/SiO2 composite nanofiber membranes were fabricated by a one-step electrospinning method using poly (vinyl alcohol) and tetraethyl orthosilicate (TEOS) mixed with cationic surfactant,cetyltrimethyl ammonium bromide (CTAB) as the structure directing agent.Ureidopropyltriethoxysilane was used for functionalization of the internal pore surfaces.The membranes were characterized by scanning electron microscopy (SEM),high-resolution transmission electron microscopy (HRTEM) images,X-ray diffraction (XRD),Fourier-transform infrared spectroscopy (FT-IR),element analyzer and N2 adsorption-desorption isotherms.The nanofiber diameters,average pore diameters and surface areas were 100-700 nm,2.86 nm and 873.62 m2/g,respectively.These mesoporous membranes functionalized with -NH2 groups exhibited very high adsorptions properties based on the adsorption of Cr3+ from an aqueous solution.Equilibrium adsorption was achieved after approximately 20 min and more than 97% of chromium ions in the solution were removed.The membrane could be regenerated through acidification.

  2. Alkylated graphene nanosheet composites with polyaniline nanofibers.

    Science.gov (United States)

    Grinou, Ali; Yun, Young Soo; Cho, Se Youn; Jin, Hyoung-Joon

    2011-07-01

    We demonstrate a simple method to prepare alkylated graphene/polyaniline composites (a-GR/PANI) using solution mixing of exfoliated alkyl Iodododecane treated graphene oxide sheets with polyaniline nanofiber; polyaniline nanofibers (PANI) prepared by using rapid mixing polymerization significantly improve the processibility of polyaniline and its performance in many conventional applications. Also, polyaniline nanofibers exhibit excellent water dispersibility due to their uniform nanofiber morphology. Morphological study using SEM and TEM analysis showed that the fibrous PANI in the composites a-GR/PANI mainly adsorbed onto the surface or intercalated between the graphene sheets, due especially to the good interfacial interaction between the alkylated gaphene and the polyaniline nanofibers. The existence of polyaniline nanofibers on the surface of the garphene and the alkylated graphene sheets was confirmed by using FT-IR, FT-Raman and X-ray diffraction analysis. Due to the good interfacial interaction between the alkylated graphene and the polyanilines nanofibers, the composite (a-GR/PANI) exhibited excellent dispersion stability in DMF compared to the same composite (GR/PANI) without alkylation. The electrical conductivity of the (GR/PANI) composite was 9% higher than that of pure PANI and the same weight percent for the composite after alkylation was 13% higher than that of pure PANI nanofibers.

  3. Preparation of hybrid scaffold from fibrin and biodegradable polymer fiber.

    Science.gov (United States)

    Hokugo, Akishige; Takamoto, Tomoaki; Tabata, Yasuhiko

    2006-01-01

    A biodegradable hybrid scaffold was prepared from fibrin and poly(glycolic acid) (PGA) fiber. Mixed fibrinogen and thrombin solution homogeneously dispersed in the presence of various amounts (0, 1.5, 3.0, and 6.0mg) of PGA fiber was freeze-dried to obtain fibrin sponges with or without PGA fiber incorporation. By scanning electron microscopy observation, the fibrin sponges had an interconnected pore structure, irrespective of the amount of PGA fiber incorporated. PGA fiber incorporation enabled the fibrin sponges to significantly enhance their compression strength. In vitro cell culture studies revealed that the number of L929 fibroblasts initially attached was significantly larger for any fibrin sponge with PGA fiber incorporation than for the fibrin sponge without PGA fiber. The shrinkage of sponges after cell seeding was suppressed by fiber incorporation. It is possible that the shrinkage suppression of sponges maintains their intraspace, resulting in the superior cell attachment of a sponge with PGA fiber incorporation. After subcutaneous implantation into the backs of mice, the residual volume of a fibrin sponge with PGA fiber incorporation was significant compared with that of a fibrin sponge without PGA fiber. Larger number of cells infiltrated deep inside the fibrin sponges with PGA fiber incorporation implanted subcutaneously. It is concluded that the fibrin sponge reinforced by fiber incorporation is a promising three-dimensional scaffold of cells for tissue engineering.

  4. Preparation and characterization of polyimide/silica hybrid films

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ming-yan; ZENG Shu-jin; DONG Tie-quan; ZHOU Sheng; FAN Yong; ZHANG Xiao-hong; LEI Qing-quan

    2006-01-01

    A kind of hybrid polyimide films was prepared by synthesizing poly( amic acid ) /Silica matrix resin through sol-gel technique and then followed by positing it on a silex glass plate and drying at high temperature.The effect of silica content on the corona-resistant property of the films was studied. The miscibility between the organic and inorganic phases and its effect on the corona-resistant property were investigated with aminopropyltriethoxysilane, which served as a coupling agent, added into the polyimide composite system. The chemical structure and the surface morphology of the films were characterized by FTIR and AFM respectively. The corona-resistant property of the films was tested by a rod-plate electrode. It proved that the corona-resistant property was enhanced with silica content. It also turned ont that the improvement of the miscibility between the two phases due to the presence of covalent force as a result of the addition of the coupling agent had, to some extent,effect on the corona-resistant property of the films. Furthermore, a theory on the corona-resistant property was put forward preliminarily.

  5. The generation of hybrid electrospun nanofiber layer with extracellular matrix derived from human pluripotent stem cells, for regenerative medicine applications.

    Science.gov (United States)

    Shtrichman, Ronit; Zeevi-Levin, Naama; Zaid, Rinat; Barak, Efrat; Fishman, Bettina; Ziskind, Anna; Shulman, Rita; Novak, Atara; Avrahami, Ron; Livne, Erella; Lowenstein, Lior; Zussman, Eyal; Itskovitz-Eldor, Joseph

    2014-10-01

    Extracellular matrix (ECM) has been utilized as a biological scaffold for tissue engineering applications in a variety of body systems, due to its bioactivity and biocompatibility. In the current study we developed a modified protocol for the efficient and reproducible derivation of mesenchymal progenitor cells (MPCs) from human embryonic stem cells as well as human induced pluripotent stem cells (hiPSCs) originating from hair follicle keratinocytes (HFKTs). ECM was produced from these MPCs and characterized in comparison to adipose mesenchymal stem cell ECM, demonstrating robust ECM generation by the excised HFKT-iPSC-MPCs. Exploiting the advantages of electrospinning we generated two types of electrospun biodegradable nanofiber layers (NFLs), fabricated from polycaprolactone (PCL) and poly(lactic-co-glycolic acid) (PLGA), which provide mechanical support for cell seeding and ECM generation. Elucidating the optimized decellularization treatment we were able to generate an available "off-the-shelf" implantable product (NFL-ECM). Using rat subcutaneous transplantation model we demonstrate that this stem-cell-derived construct is biocompatible and biodegradable and holds great potential for tissue regeneration applications.

  6. 二氧化硅@聚合物同轴纳米纤维%Silica@Polymers Coaxial Nanofibers

    Institute of Scientific and Technical Information of China (English)

    洪友良; 商铁存; 靳玉伟; 杨帆; 王策

    2005-01-01

    The preparation and formation mechamsm ot silica/polyvinylpyrrolidone(PAN) coaxial nanofibers were presented in this paper. The PVP-PAN composite nanofibers were obtained via an electrospinning technique, while SiO2 nanoparticles were prepared according to a Stoeher method. The measurements of water contact angle(WCA), the compared results of silica coating PVPPAN composite nanofibers with PAN nanofibers indicate that much PVP resided on the composite nanofiber surface, which resuks in the occurrence of SiO2@polymer coaxial nanofibers due to the formation of hydrogen bonding between silica and composite nanofibers and subsequent adsorption of silica on the fiber surface.

  7. Biomolecular hybrid material and process for preparing same and uses for same

    Science.gov (United States)

    Kim, Jungbae [Richland, WA

    2010-11-23

    Disclosed is a composition and method for fabricating novel hybrid materials comprised of, e.g., carbon nanotubes (CNTs) and crosslinked enzyme clusters (CECs). In one method, enzyme-CNT hybrids are prepared by precipitation of enzymes which are subsequently crosslinked, yielding crosslinked enzyme clusters (CECs) on the surface of the CNTs. The CEC-enzyme-CNT hybrids exhibit high activity per unit area or mass as well as improved enzyme stability and longevity over hybrid materials known in the art. The CECs in the disclosed materials permit multilayer biocatalytic coatings to be applied to surfaces providing hybrid materials suitable for use in, e.g., biocatalytic applications and devices as described herein.

  8. Synthesis and electrochemical properties of polyaniline nanofibers by interfacial polymerization.

    Science.gov (United States)

    Manuel, James; Ahn, Jou-Hyeon; Kim, Dul-Sun; Ahn, Hyo-Jun; Kim, Ki-Won; Kim, Jae-Kwang; Jacobsson, Per

    2012-04-01

    Polyaniline nanofibers were prepared by interfacial polymerization with different organic solvents such as chloroform and carbon tetrachloride. Field emission scanning electron microscopy and transmission electron microscopy were used to study the morphological properties of polyaniline nanofibers. Chemical characterization was carried out using Fourier transform infrared spectroscopy, UV-Vis spectroscopy, and X-ray diffraction spectroscopy and surface area was measured using BET isotherm. Polyaniline nanofibers doped with lithium hexafluorophosphate were prepared and their electrochemical properties were evaluated.

  9. Preparation and characterization of bioactive composite scaffolds from polycaprolactone nanofibers-chitosan-oxidized starch for bone regeneration.

    Science.gov (United States)

    Nourmohammadi, Jhamak; Ghaee, Azadeh; Liavali, Samira Hosseini

    2016-03-15

    The objective of this study was to fabricate and investigate the characteristics of a suitable scaffold for bone regeneration. Therefore, chitosan was combined with various amounts of oxidized starch through reductive alkylation process. Afterwards, chopped CaP-coated PCL nanofibers were added into the chitosan-starch composite scaffolds in order to obtain bioactivity and mimic bone extracellular matrix structure. Scanning electron microscopy confirmed that all scaffolds had well-interconnected porous structure. The mean pore size, porosity, and water uptake of the composite scaffolds increased by incorporation of higher amounts of starch, while this trend was opposite for compressive modulus and strength. Osteoblast-like cells (MG63) culturing on the scaffolds demonstrated that higher starch content could improve cell viability. Moreover, the cells spread and anchored well on the scaffolds, on which the surface was covered with a monolayer of cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Influence of graphene oxide doping on the morphology and the magnetic properties of Ni{sub 0.8}Gd{sub 0.2}Fe{sub 2}O{sub 4} nanofibers prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Mansour, Michel [EC2M, Faculty of Sciences 2, and Research Platform for Nanoscience and Nanotechnologies, Campus Pierre Gemayel, Fanar, Lebanese University, 90656 (Lebanon); Institut Européen des Membranes, UMR 5635 ENSCM UM CNRS, Université du Montpellier, Place Eugène Bataillon, 34095 Montpellier (France); Bechelany, Mikhael [Institut Européen des Membranes, UMR 5635 ENSCM UM CNRS, Université du Montpellier, Place Eugène Bataillon, 34095 Montpellier (France); Habchi, Roland [EC2M, Faculty of Sciences 2, and Research Platform for Nanoscience and Nanotechnologies, Campus Pierre Gemayel, Fanar, Lebanese University, 90656 (Lebanon); Eid, Cynthia, E-mail: cynthia.eid@ul.edu.lb [EC2M, Faculty of Sciences 2, and Research Platform for Nanoscience and Nanotechnologies, Campus Pierre Gemayel, Fanar, Lebanese University, 90656 (Lebanon)

    2017-02-12

    Nickel–gadolinium ferrite nanofibers doped with graphene oxide (GO) were prepared for the first time by the electrospinning technique. The structure and morphology of the as-obtained composites were characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy, X-ray diffractometer, Fourier transform infrared spectra, and Raman spectroscopy. The magnetic properties were analyzed by Quantum design MPMS-XL magnetometer. A transition from a ‘fiber’ morphology to a ‘ribbon’ morphology was detected for the samples doped with GO. Also, an increase in the magnetic saturation was found when the GO amount increases. Therefore, doping with GO influences both the morphology and the magnetic properties of the electrospun nickel–gadolinium ferrite nanofibers. These results provide a promising lead for the future synthesis of a variety of GO doped ferrites nanofiber morphologies with controllable magnetic properties. - Highlights: • Graphene oxide doped nickel–gadolinium nanofibers are obtained by the low cost method of electrospinning. • With higher GO amounts, higher magnetic saturation was obtained. • Total conversion from the fiber morphology to ribbon morphology was observed starting from a doping rate of 12%.

  11. Preparation of Bacterial Cellulose Nanofiber Through Electrospinning%静电纺丝法制备细菌纤维素纳米纤维

    Institute of Scientific and Technical Information of China (English)

    关晓辉; 于磊; 鲁敏; 张月明

    2013-01-01

    Using bacterial cellulose (BC) as raw material,room temperature ionic liquid AMIMCL as a solution system,the bacterial cellulose nanofibers were prepared through electrospinning technology.Co-solvent N,N-dimethyl formamide (DMF) was added to reduce the viscosity of spinning fluid,and a rotating drum collector was designed and applied.The influences of BC mass fraction,DMF amount,voltage,and curing distance on the spinning process were investigated.The electrospun nanofibers were analyzed by optical microscope,SEM and XRD.The experimental results showed that,when BC mass fraction,ratio of AMIMCL to DMF,voltage,curing distance,and environmental humidity were 5%,1:2.5,23 kV,12 cm,and 60%-80%,respectively,the electrospun B(nanofibers were continuous and the diameter was 500-800 nm.The crystal structure of BC was cellulose of type-Ⅰ,but after BC was dissolved by ionic liquid and electrospun into nanofibers,its crystal structure conversed into cellulose type-Ⅱ.%利用静电纺丝技术,以实验室自制的细菌纤维素(BC)为原材料,选择室温离子液体1-烯丙基-3-甲基咪唑氯化物(AMIMCL)为溶解体系,制备出细菌纤维素纳米纤维.实验中通过添加助溶剂N,N-二甲基甲酰胺(DMF)降低纺丝液的粘度,并设计了转动的滚筒收集器,考察了BC质量分数、DMF的添加量、电压、固化距离等因素对静电纺丝的影响,利用光学显微镜、扫描电子显微镜(SEM)以及X射线衍射(XRD)对纺丝进行分析.研究表明,在BC质量分数为5%、AMIMCL与DMF的质量比为1:2.5、电压为23 kV、固化距离为12 cm、环境湿度为60%~80%的条件下能够制备出连续的、直径为500~800nm的细菌纤维素纳米纤维;BC的晶体结构为纤维素Ⅰ型,而BC经离子液体溶解并静电纺丝后其结构转化为纤维素Ⅱ型.

  12. Fabrication of nanofiber mats from electrospinning of functionalized polymers

    Science.gov (United States)

    Oktay, Burcu; Kayaman-Apohan, Nilhan; Erdem-Kuruca, Serap

    2014-08-01

    Electrospinning technique enabled us to prepare nanofibers from synthetic and natural polymers. In this study, it was aimed to fabricate electrospun poly(vinyl alcohol) (PVA) based nanofibers by reactive electrospinning process. To improve endurance of fiber toward to many solvents, PVA was functionalized with photo-crosslinkable groups before spinning. Afterward PVA was crosslinked by UV radiation during electrospinning process. The nanofiber mats were characterized by scanning electron microscopy (SEM). The results showed that homogenous, uniform and crosslinked PVA nanofibers in diameters of about 200 nm were obtained. Thermal stability of the nanofiber mat was investigated with thermal gravimetric analysis (TGA). Also the potential use of this nanofiber mats for tissue engineering was examined. Osteosarcoma (Saos) cells were cultured on the nanofiber mats.

  13. Novel continuous carbon and ceramic nanofibers and nanocomposites

    Science.gov (United States)

    Wen, Yongkui

    2004-12-01

    studied. In Chapter 6, ZrO2 nanofibers were prepared using commercial and novel polymer-containing sol-gel precursors. The ZrO2 nanofibers were continuous, circular in cross section, and had diameters as small as 80 mn. Aligned ZrO2 nanofibers were prepared using newly developed polymer containing composite precursor for the first time. The possibility of nanomanufacturing of nanocrystalline continuous nanofibers was demonstrated. The results of this dissertation will have an impact in the field of high performance fibers and nanocomposites. This study is expected to catalyze research on advanced continuous nanofibers and may pave way for consideration of continuous advanced electrospun nanofibers as reinforcement in the next generation nanocomposites. (Abstract shortened by UMI.)

  14. Preparing Students for Success in Hybrid Learning Environments with Academic Resource Centers

    Science.gov (United States)

    Newman, Daniel; Dickinson, Michael

    2017-01-01

    This chapter describes institutional and andragogical best practices for preparing students to succeed in hybrid courses through the programming of academic resource centers, offers information on how to create peer support systems for students, and outlines some of the common pitfalls for students encountering a hybrid course for the first time.

  15. Preparation and characterization of functional silica hybrid magnetic nanoparticles

    Science.gov (United States)

    Digigow, Reinaldo G.; Dechézelles, Jean-François; Dietsch, Hervé; Geissbühler, Isabelle; Vanhecke, Dimitri; Geers, Christoph; Hirt, Ann M.; Rothen-Rutishauser, Barbara; Petri-Fink, Alke

    2014-08-01

    We report on the synthesis and characterization of functional silica hybrid magnetic nanoparticles (SHMNPs). The co-condensation of 3-aminopropyltriethoxysilane (APTES) and tetraethyl orthosilicate (TEOS) in presence of superparamagnetic iron oxide nanoparticles (SPIONs) leads to hybrid magnetic silica particles that are surface-functionalized with primary amino groups. In this work, a comprehensive synthetic study is carried out and completed by a detailed characterization of hybrid particles' size and morphology, surface properties, and magnetic responses using different techniques. Depending on the mass ratio of SPIONs and the two silanes (TEOS and APTES), we were able to adjust the number of surface amino groups and tune the magnetic properties of the superparamagnetic hybrid particles.

  16. Preparation and characterization of perfluorosulfonic resin/titania hybrid transparent films

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Preparation and characterization of perfluorosulfonic resin/titania organic-inorganic hybrid films were presented. The transparent hybrid films were prepared by hydrothermal treatment at low temperature of a mixed solution of tetrabutyl titanate and perfluorosulfonic resin with the help of acetylacetone. The characterization was carried out by SEM,XRD,FT-IR,UV-Vis and TGA. The results showed that the perfluorosulfonic resin/titania hybrid transparent films were composed of titania particles dispersed in the perfluorosulfonic resin matrix very well and the titania was of anatase phase. Its diameter de-creased with increasing weight ratio of titania to perfluorosulfonic resin.

  17. Preparation and characterization of perfluorosulfonic resin/titania hybrid transparent films

    Institute of Scientific and Technical Information of China (English)

    LI JianMei; XUE MinZhao; ZHANG YongMing; LIU YanGang

    2007-01-01

    Preparation and characterization of perfluoroaulfonic resin/titaniaorganic-inorganic hybrid films were presented. The transparent hybrid films were prepared by hydrothermal treatment at low temperature of a mixed solution of tetrabutyl titanata and perfluorosulfonic resin with the help of acetylacetone. The charactarization was carried out by SEM, XRD, FT-IR, UV-Vis and TGA. The results showed that the perfiuorosulfonic resin/titania hybrid transparent films were composed of titania particles dispersed in the perfluorosulfonic resin matrix very well and the titania was of anatase phase. Its diameter decreased with increasing weight ratio of titania to perfluorosulfonic resin.

  18. Facile approach to prepare Pt decorated SWNT/graphene hybrid catalytic ink

    Energy Technology Data Exchange (ETDEWEB)

    Mayavan, Sundar, E-mail: sundarmayavan@cecri.res.in [Centre for Innovation in Energy Research, CSIR–Central Electrochemical Research Institute, Karaikudi 630006, Tamil Nadu (India); Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of); Mandalam, Aditya; Balasubramanian, M. [Centre for Innovation in Energy Research, CSIR–Central Electrochemical Research Institute, Karaikudi 630006, Tamil Nadu (India); Sim, Jun-Bo [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of); Choi, Sung-Min, E-mail: sungmin@kaist.ac.kr [Department of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, Daejeon, 305-701 (Korea, Republic of)

    2015-07-15

    Highlights: • Pt NPs were in situ synthesized onto CNT–graphene support in aqueous solution. • The as-prepared material was used directly as a catalyst ink without further treatment. • Catalyst ink is active toward methanol oxidation. • This approach realizes both scalable and greener production of hybrid catalysts. - Abstract: Platinum nanoparticles were in situ synthesized onto hybrid support involving graphene and single walled carbon nanotube in aqueous solution. We investigate the reduction of graphene oxide, and platinum nanoparticle functionalization on hybrid support by X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The as-prepared platinum on hybrid support was used directly as a catalyst ink without further treatment and is active toward methanol oxidation. This work realizes both scalable and greener production of highly efficient hybrid catalysts, and would be valuable for practical applications of graphene based fuel cell catalysts.

  19. Carbon Supported Engineering NiCo2O4 Hybrid Nanofibers with Enhanced Electrocatalytic Activity for Oxygen Reduction Reaction

    Directory of Open Access Journals (Sweden)

    Diab Hassan

    2016-09-01

    Full Text Available The design of cheap and efficient oxygen reduction reaction (ORR electrocatalysts is of a significant importance in sustainable and renewable energy technologies. Therefore, ORR catalysts with superb electrocatalytic activity and durability are becoming a necessity but still remain challenging. Herein, we report C/NiCo2O4 nanocomposite fibers fabricated by a straightforward electrospinning technique followed by a simple sintering process as a promising ORR electrocatalyst in alkaline condition. The mixed-valence oxide can offer numerous accessible active sites. In addition, the as-obtained C/NiCo2O4 hybrid reveals significantly remarkable electrocatalytic performance with a highly positive onset potential of 0.65 V, which is only 50 mV lower than that of commercially available Pt/C catalysts. The analyses indicate that C/NiCo2O4 catalyst can catalyze O2-molecules via direct four electron pathway in a similar behavior as commercial Pt/C catalysts dose. Compared to single NiCo2O4 and carbon free NiCo2O4, the C/NiCo2O4 hybrid displays higher ORR current and more positive half-wave potential. The incorporated carbon matrices are beneficial for fast electron transfer and can significantly impose an outstanding contribution to the electrocatalytic activity. Results indicate that the synthetic strategy hold a potential as efficient route to fabricate highly active nanostructures for practical use in energy technologies.

  20. Conjugated polymers/semiconductor nanocrystals hybrid materials--preparation, electrical transport properties and applications.

    Science.gov (United States)

    Reiss, Peter; Couderc, Elsa; De Girolamo, Julia; Pron, Adam

    2011-02-01

    This critical review discusses specific preparation and characterization methods applied to hybrid materials consisting of π-conjugated polymers (or oligomers) and semiconductor nanocrystals. These materials are of great importance in the quickly growing field of hybrid organic/inorganic electronics since they can serve as active components of photovoltaic cells, light emitting diodes, photodetectors and other devices. The electronic energy levels of the organic and inorganic components of the hybrid can be tuned individually and thin hybrid films can be processed using low cost solution based techniques. However, the interface between the hybrid components and the morphology of the hybrid directly influences the generation, separation and transport of charge carriers and those parameters are not easy to control. Therefore a large variety of different approaches for assembling the building blocks--conjugated polymers and semiconductor nanocrystals--has been developed. They range from their simple blending through various grafting procedures to methods exploiting specific non-covalent interactions between both components, induced by their tailor-made functionalization. In the first part of this review, we discuss the preparation of the building blocks (nanocrystals and polymers) and the strategies for their assembly into hybrid materials' thin films. In the second part, we focus on the charge carriers' generation and their transport within the hybrids. Finally, we summarize the performances of solar cells using conjugated polymer/semiconductor nanocrystals hybrids and give perspectives for future developments.

  1. Chemistry on electrospun polymeric nanofibers: merely routine chemistry or a real challenge?

    Science.gov (United States)

    Agarwal, Seema; Wendorff, Joachim H; Greiner, Andreas

    2010-08-03

    Nanofiber-based non-wovens can be prepared by electrospinning. The chemical modification of such nanofibers or chemistry using nanofibers opens a multitude of application areas and challenges. A wealth of chemistry has been elaborated in recent years on and with electrospun nanofibers. Known methods as well as new methods have been applied to modify the electrospun nanofibers and thereby generate new materials and new functionalities. This Review summarizes and sorts the chemistry that has been reported in conjunction with electrospun nanofibers. The major focus is on catalysis and nanofibers, enzymes and nanofibers, surface modification for biomedical and specialty applications, coatings of fibers, crosslinking, and bulk modifications. A critical focus is on the question: what could make chemistry on or with nanofibers different from bulk chemistry?

  2. Preparation of amide-t-butylcalix[8] arene/polyacrylonitrile nanofibers by electrospinning%对叔丁基酰胺化杯[8]芳烃/聚丙烯腈纳米纤维的制备

    Institute of Scientific and Technical Information of China (English)

    高春; 房伟; 陈铭; 刁国旺

    2012-01-01

    Amide-t-butylcalix[8] arene/polyacrylonitrile (Amide-Cal[8]/PAN) nanofibers were prepared by electrospinning. The nanofibers were characterized by fourier transform infrared spectros-copy (FTIR), field emission scanning electron microscope (FE-SEM), conductivity meter, torque rheometer. The results showed that Amide-Cal[8]/PAN was successfully prepared by electrospinning. The diameter of nanofibers was smaller than that of the blank PAN nanofibers. Moreover, the surface of nanofibers was smooth and uniform, but with the Amide-Cal[8] content increased, diameter of nanofibers and the surface roughness were increased. Rheometer results indicated that the viscosities of Amide-Cal[8]/PAN spinning solutions were increased with the increase of Amide-Cal[8] content. Conductivity results showed that the electrical conductivities of Amide-Cal[8]/ PAN spinning solution were higher than that of pure PAN solution and it was conducive to electrospinning.%采用静电纺丝技术制备了对叔丁基酰胺化杯[8]芳烃/聚丙烯腈(Amide-Cal[8]/PAN)复合纳米纤维,并通过傅里叶变换红外光谱(FTIR)仪、场发射扫描电镜(FE-SEM)、电导率仪、转矩流变仪对其结构与性质进行表征.实验结果表明:①Amide-Cal[8]/PAN纳米纤维的直径较空白的PAN纳米纤维小;②随着Amide-Cal[8]含量的增加,纳米纤维的直径先减小后增大,且纤维表面的粗糙程度逐渐增加,粗细不均;Amide-Cal[8]/PAN电纺溶液的黏度随着Amide-Cal[8]含量的增加而线性增大;③Amide-Cal[8]/PAN电纺溶液比PAN溶液的电导率大,有利于静电纺丝.

  3. RGO/InVO{sub 4} hollowed-out nanofibers: Electrospinning synthesis and its application in photocatalysis

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Dong [Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); College of Resource and Environment, Qingdao Agricultural University, Qingdao 266109 (China); Zhang, Yanxiang [College of Environmental Science and Engineering, Shandong University, Jinan 250100 (China); Gao, Mengchun, E-mail: mengchungao@outlook.com [Key Lab of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao 266100 (China); Xin, Yanjun; Wu, Juan [College of Resource and Environment, Qingdao Agricultural University, Qingdao 266109 (China); Bao, Nan [College of Environmental Science and Engineering, Shandong University, Jinan 250100 (China)

    2015-10-30

    Graphical abstract: - Highlights: • RGO/InVO{sub 4} hollow-out nanofibers were obtained by electrospinning method. • The properties of InVO{sub 4} hollow-out nanofibers were deeply influenced by RGO. • RGO could reduce recombination of e{sup −}–h{sup +} pairs to improve photocatalytic activity. • Photo-induced h{sup +} and e{sup −} are the two main reactive species for RhB degradation. - Abstract: A composite of reduced graphene oxide (RGO) and InVO{sub 4} nanofiber was successfully synthesized by an electrospinning technique. The as-collected fibers were calcined at 420 °C in air and then calcined at 550 °C in nitrogen gas to remove polyvinyl pyrrolidone (PVP), which could enable InVO{sub 4} to crystallize and protect the RGO from oxidation. The InVO{sub 4} in the composite illustrated a hollowed-out fibrous morphology and orthorhombic phase, and RGO nanosheets were nested in the InVO{sub 4} nanofibers. The hybrid RGO could produce more hydroxyl groups and a higher oxygen vacancy density on the surface of RGO/InVO{sub 4} composite. Compared with pure InVO{sub 4}, the light absorption range of the as-prepared RGO/InVO{sub 4} composite was expanded. In Rh B degradation, the RGO/InVO{sub 4} hybrid nanofibers displayed a higher photocatalytic activity than pure InVO{sub 4} nanofibers. The enhanced photocatalytic activity might be ascribed to the role of RGO as an electron transporter and acceptor in the composite, which could effectively inhibit the charge recombination and facilitate the charge transfer. The exported electron could attack an O{sub 2} molecule to facilitate the generation of • O{sub 2}{sup −} and • OH for the photodegradation process of Rh B.

  4. Fabrication of Conductive Polypyrrole Nanofibers by Electrospinning

    Directory of Open Access Journals (Sweden)

    Yiqun Cong

    2013-01-01

    Full Text Available Electrospinning is employed to prepare conductive polypyrrole nanofibers with uniform morphology and good mechanical strength. Soluble PPy was synthesized with NaDEHS as dopant and then applied to electrospinning with or without PEO as carrier. The PEO contents had great influence on the morphology and conductivity of the electrospun material. The results of these experiments will allow us to have a better understanding of PPy electrospun nanofibers and will permit the design of effective electrodes in the BMIs fields.

  5. Doubly curved nanofiber-reinforced optically transparent composites

    Science.gov (United States)

    Shams, Md. Iftekhar; Yano, Hiroyuki

    2015-11-01

    Doubly curved nanofiber-reinforced optically transparent composites with low thermal expansion of 15 ppm/k are prepared by hot pressing vacuum-filtered Pickering emulsions of hydrophobic acrylic resin monomer, hydrophilic chitin nanofibers and water. The coalescence of acrylic monomer droplets in the emulsion is prevented by the chitin nanofibers network. This transparent composite has 3D shape moldability, making it attractive for optical precision parts.

  6. SEM evaluation of the hybrid layer after cavity preparation with Er:YAG laser.

    Science.gov (United States)

    de Barceleiro, Marcos Oliveira; Dias, Kátia Regina Hostílio Cervantes; Sales, Helena Xavier; Silva, Bárbara Carvalho; Barceleiro, Cristiane Gomes

    2008-01-01

    This study compared the thickness of the hybrid layer formed using Scotchbond Multi-Purpose Plus, Single Bond 2, Prime & Bond 2.1 and Xeno III on a dentin surface prepared with a diamond bur in a high speed handpiece or prepared with an Er:YAG laser used with two parameters of pulse energy (200 and 400 mJ) and two parameters of frequency (4 and 6 Hz). Flat dentin surfaces obtained from 20 human third molars were treated with the two methods and were then prepared with the dentin adhesive systems according to the manufacturers' instructions. After a layer of composite was applied, the specimens were sectioned, flattened, polished and prepared for Scanning Electronic Microscopy observation. Five different measurements of the hybrid layer thickness were obtained along the bonded surface in each specimen. The results were statistically analyzed using Analysis of Variance and Student-Newman-Keuls tests (p cavity preparation method, four groups were formed: Group I (diamond bur) > Group II (Laser 200 mJ/4 Hz) = Group III (Laser 200 mJ/6 Hz) > Group IV (Laser 400 mJ/4 Hz) > Group V (Laser 400 mJ/6 Hz). When comparing the dentin adhesive systems, there were no statistically significant differences. These results showed that the four tested dentin adhesive systems produced a 2.90 +/- 1.71 microm hybrid layer in dentin prepared with a diamond bur. This hybrid layer was regular and routinely found. In the laser groups, the dentin adhesive systems produced hybrid layers ranging from 0.41 +/- 1.00 microm to 2.06 +/- 2.49 microm, which were very irregular and not routinely found. It was also concluded that the Er:YAG laser, with the parameters used in this experiment, has a negative influence on the formation of a hybrid layer and cavity preparation methods influence formation of the hybrid layer.

  7. Adsorption of Th4+, U6+, Cd2+, and Ni2+ from aqueous solution by a novel modified polyacrylonitrile composite nanofiber adsorbent prepared by electrospinning

    Science.gov (United States)

    Dastbaz, Abolfazl.; Keshtkar, Ali Reza.

    2014-02-01

    In this study, SiO2 nanoparticles were modified by 3-aminopropyltriethoxysilane (APTES) and then applied to prepare a novel polyacrylonitrile (PAN) composite nanofiber adsorbent by the electrospinning method. In addition, the adsorbent was characterized by SEM, BET, and FTIR analyses. Then the effects of pH, SiO2 and APTES content, adsorbent dosage, contact time and temperature were investigated. Moreover, adsorption experiments were carried out with initial concentrations in the range of 30-500 mg L-1 and the adsorbent affinity for metal ions was in order of Th4+ > U6+ > Cd2+ > Ni2+. Furthermore, it was observed that the optimum pH for adsorption was different for each metal. Some isotherm and kinetic models were applied to analyze the experimental data, among which the Langmuir and pseudo-second order models were better than the others. The regeneration study showed that the adsorbent could be used for industrial processes repeatedly without any significant reduction in its adsorption capacity. Based on the Langmuir model, the maximum adsorption capacity of Th4+, U6+, Cd2+, and Ni2+ at 45 °C was 249.4, 193.1, 69.5 and 138.7 mg g-1, respectively. Besides, the calculated thermodynamic parameters showed an endothermic as well as chemical nature through the adsorption process.

  8. Microwave-assisted preparation of carbon nanofiber-functionalized graphite felts as electrodes for polymer-based redox-flow batteries

    Science.gov (United States)

    Schwenke, A. M.; Janoschka, T.; Stolze, C.; Martin, N.; Hoeppener, S.; Schubert, U. S.

    2016-12-01

    A simple and fast microwave-assisted protocol to functionalize commercially available graphite felts (GFs) with carbon nanofibers (CNFs) for the application as electrode materials in redox-flow batteries (RFB) is demonstrated. As catalyst for the CNF synthesis nickel acetate is applied and ethanol serves as the carbon source. By the in-situ growth of CNFs, the active surface of the electrodes is increased by a factor of 50, which is determined by the electrochemical double layer capacities of the obtained materials. Furthermore, the morphology of the CNF-coating is investigated by scanning electron microscopy. Subsequently, the functionalized electrodes are applied in a polymer-based redox-flow battery (pRFB) using a TEMPO- and a viologen polymer as active materials. Due to the increased surface area as compared to an untreated graphite felt electrode, the current rating is improved by about 45% at 80 mA cm-2 and, furthermore, a decrease in overpotentials is observed. Thus, using this microwave-assisted synthesis approach, CNF-functionalized composite electrodes are prepared with a very simple protocol suitable for real life applications and an improvement of the overall performance of the polymer-based redox-flow battery is demonstrated.

  9. Fast preparation of PtRu catalysts supported on carbon nanofibers by the microwave-polyol method and their application to fuel cells.

    Science.gov (United States)

    Tsuji, Masaharu; Kubokawa, Masatoshi; Yano, Ryuto; Miyamae, Nobuhiro; Tsuji, Takeshi; Jun, Mun-Suk; Hong, Seonghwa; Lim, Seongyop; Yoon, Seong-Ho; Mochida, Isao

    2007-01-16

    PtRu alloy nanoparticles (24 +/- 1 wt %, Ru/Pt atomic ratios = 0.91-0.97) supported on carbon nanofibers (CNFs) were prepared within a few minutes by using a microwave-polyol method. Three types of CNFs with very different surface structures, such as platelet, herringbone, and tubular ones, were used as new carbon supports. The dependence of particles sizes and electrochemical properties on the structures of CNFs was examined. It was found that the methanol fuel cell activities of PtRu/CNF catalysts were in the order of platelet > tubular > herringbone. The methanol fuel cell activities of PtRu/CNFs measured at 60 degrees C were 1.7-3.0 times higher than that of a standard PtRu (29 wt %, Ru/Pt atomic ratio = 0.92) catalyst loaded on carbon black (Vulcan XC72R) support. The best electrocatalytic activity was obtained for the platelet CNF, which is characterized by its edge surface and high graphitization degree.

  10. 锐钛矿相TiO2纳米纤维制备与摩擦学性能%Preparation of Anatase TiO2 Nanofiber and Its Tribological Properties as Additive in Liquid Paraffin

    Institute of Scientific and Technical Information of China (English)

    刘琳; 阴翔宇; 张月; 钱建华

    2013-01-01

    Anatase TiO2 nanofiber was prepared via an available alkaline hydrothermal method and surface modified. The obtained products were characterized by using X-ray diffraction (XRD), scanning electron microscope (SEM) measurements and Fourier transform infrared spectroscopy (FT-IR). The as-prepared TiO2 nanofiber could be well dispersed in liquid paraffin, and its tribological properties as additive were evaluated with a four-ball tester. The results showed that the as-prepared TiO2 nanofiber exhibited good performance in anti-wear and friction-reduction, load-carrying capacity, and extreme pressure properties. When addition amount of the as-prepared TiO2 nanofiber was 1.5% of mass fraction in liquid paraffin, the best anti-friction wear reducing and bearing capacity enhancing were obtained, which made the TiO2 nanofiber promising for green lubricating oil additives.%采用简便且可重复性较好的碱熔法制备锐钛矿相TiO2,采用简便的表面修饰技术对其进行表面改性,得到TiO2纳米纤维,并采用XRD、SEM和FT-IR方法对其进行表征.利用四球摩擦试验机考察其作为油品润滑添加剂的摩擦学性能.结果表明,所合成的TiO2纳米纤维为锐钛矿相结构,结晶度和纯度较高,而且在油品中具有良好的分散性;TiO2纳米纤维具有良好的抗磨减摩性能,并能够很好地提高油品承载能力,当其加入量为1.5%(质量分数)时,抗磨减摩以及提高承载能力的效果最好.这些特性使得锐钛矿相TiO2纳米纤维有望在未来成为绿色润滑油添加剂.

  11. Preparation and Characterization of Wheat Protein/PVA Blend Composite Nanofiber%小麦蛋白/聚乙烯醇复合纳米纤维的制备及其表征

    Institute of Scientific and Technical Information of China (English)

    潘丽军; 张黎黎; 姜绍通; 王华

    2012-01-01

    Wheat protein/PVA composite nanofiber was prepared via electrospining technique. The effects of total concentration of the solution, voltages, tip to collector distance and structure of the nanofibers were investigated by scanning electron microscopy (SEM), fourier transform infratred (FT-IR) and X-ray diffraction (XRD). The results indicated that the uniform and smooth wheat protein/PVA composite nanofiber with average diameter of 280 nm could be prepared with following optimal process parameters: total concentration of the solution 10 %, weight ratio of wheat protein to PVA 8:2, applied voltage 12 kV, and the tip-to-collector distance 10 cm. There were hydrogen bonds between wheat protein and PVA in the composite nanofibers.%以小麦蛋白、聚乙烯醇(PVA)为原料,采用静电纺丝法制备小麦蛋白/PVA共混复合纳米纤维,重点研究纺丝液质量分数、电压、接收距离对纤维形态的影响,利用扫描电镜、傅里叶变换红外光谱、X-射线衍射光谱对纤维的形态与结构进行表征.结果表明:在纺丝液质量分数10%、小麦蛋白与PVA质量比8∶2、电压12 kV、接收距离10 cm的条件下,可以制备平均直径为280 nm左右的均一、表面光滑的纳米纤维.小麦蛋白与PVA复合后,分子间以氢键结合.

  12. 电纺CoFe2O4纳米纤维及其磁性研究%Electrospinning preparation and magnetic properties of CoFe2O4 nanofibers

    Institute of Scientific and Technical Information of China (English)

    韩丽艳; 于娜; 邵长路

    2012-01-01

    PVA/FeCl3/Co (CH3COO)2 composite nanofibers were synthesized by using sol-gel processing combination with electrospinning technology,where polyacrylonitrile and manganese acetate were used as precursors. After high temperature calcination, CoFe2O4 nanofibers were successful prepared. The samples were characterized by scanning electron microscopy (SEM) ,fourier transform infrared ( FT-IR) spectroscopy, thermogravimetry-differential thermal ( TG-DTA) and X-ray diffraction (XRD) analysis, respectively. The results showed that CoPe2O4 nanofibers with one-dimensional structure had been prepared uniformly. And,magnetic property measurements suggested that the CoFe2O4 nanofibers exhibited ferromagnetic paramagnetic.%采用溶胶-凝胶过程和静电纺丝技术,以三氯化铁(FeCl3·6H2O)、醋酸钴(Co(CH3COO)2·4H2O)和聚乙烯醇(PVA)为前驱物,制得PVA/FeCl3/Co(CH3COO)2复合纳米纤维.经高温煅烧,制备了CoFe2O4纳米纤维.利用扫描电镜(SEM)、红外光谱(FT-IR)、差热-热重(TG-DTA)和X射线衍射(XRD)等分析测试手段对样品进行了表征,并研究了其磁性质.结果表明:静电纺丝技术制备的CoFe2O4纳米纤维为规则的一维结构,直径分布均匀,具有良好的铁磁性.

  13. DC Electrical Conductivity Retention, Optical Properties and Ammonia Sensing Analysis of Naturally Degraded CSA-Doped Graphene/polyaniline Composite Nanofibers Prepared with CTAB

    Science.gov (United States)

    Ghazali, Sayyed; Hossain, Muhammad M.; Khan, Abuzar; Khan, Mohd Y.; Hasan, Mudassir

    2016-09-01

    In this paper, we report surfactant-mediated synthesis of camphor sulfonic acid (CSA)-doped polyaniline/graphene (PANI/GN) composite nanofibers as an electrical conductor and excellent ammonia sensor. The synthesis was mediated by cetyltrimethylammonium bromide as surfactant. The as-synthesized composite nanofibers were characterized by Raman spectroscopy, scanning electron microscopy, tunneling electron microscopy, x-ray diffraction, diffused reflectance spectroscopy and differential scanning calorimetry. The electrical conductivity of the CSA-doped PANI/GN composite nanofibers was found to be remarkably enhanced as compared to the CSA-doped PANI. The boost in electronic conductivity could be attributed to an improved electronic interaction between CSA-doped PANI backbone and GN present in the composite system. The naturally degraded CSA-doped PANI/GN composite nanofibers showed a decrease in electrical conductivity but worked as a good ammonia sensor in open atmospheric conditions.

  14. DC Electrical Conductivity Retention, Optical Properties and Ammonia Sensing Analysis of Naturally Degraded CSA-Doped Graphene/polyaniline Composite Nanofibers Prepared with CTAB

    Science.gov (United States)

    Ghazali, Sayyed; Hossain, Muhammad M.; Khan, Abuzar; Khan, Mohd Y.; Hasan, Mudassir

    2017-01-01

    In this paper, we report surfactant-mediated synthesis of camphor sulfonic acid (CSA)-doped polyaniline/graphene (PANI/GN) composite nanofibers as an electrical conductor and excellent ammonia sensor. The synthesis was mediated by cetyltrimethylammonium bromide as surfactant. The as-synthesized composite nanofibers were characterized by Raman spectroscopy, scanning electron microscopy, tunneling electron microscopy, x-ray diffraction, diffused reflectance spectroscopy and differential scanning calorimetry. The electrical conductivity of the CSA-doped PANI/GN composite nanofibers was found to be remarkably enhanced as compared to the CSA-doped PANI. The boost in electronic conductivity could be attributed to an improved electronic interaction between CSA-doped PANI backbone and GN present in the composite system. The naturally degraded CSA-doped PANI/GN composite nanofibers showed a decrease in electrical conductivity but worked as a good ammonia sensor in open atmospheric conditions.

  15. Fabrication of Poly(4-vinylpyridine) Nanofiber and Fluorescent Poly(4-vinylpyridine)/Porphyrin Nanofiber by Electrospinning

    Institute of Scientific and Technical Information of China (English)

    SONG Yan; ZHAN Nai-qian; YU Miao; YANG Qing-biao; ZHANG Chao-qun; WANG Heng-guo; LI Yao-xian

    2008-01-01

    Poly(4-vinylpyridine)(P4-VP) nanofiber and fluoresent poly(4-vinylpyridine)/porphyrin(P4-VP/TPPA) nanofiber were respectively prepared by electrospinning.The effect of the concentration of P4-VP/dimethylformamide (DMF) electrospinning solutions on the morphology of P4-VP nanofiber was investigated and it was found that the average diameter of the nanofiber of P4-VP/DMF increased with the increase of the concentration of the spinning solution.After the addition of TPPA to the P4-VP/DMF spinning solution,the diameter of P4-VP/TPPA nanofiber became even due to the increase of the conductivity of the P4-VP/DMF-TPPA solution.The photoluminescent(PL) spectral analysis indicates that the emission peak position of P4-VP/TPPA nanofiber is almost the same as that of pure TPPA at about 650 nm without peak shift,and when it was stored for 20 days,the emission peak of P4-VP/TPPA nanofiber is also at 650 rim,indicating that the fuorescent property of P4-VP/TPPA nanofiber is stable.Fourier-transform infrared(FTIR) spectrum confirms the chemical composition of the resulting P4-VP/TPPA composite nanoflber.

  16. Novel Nanofiber-based Membrane Separators for Lithium-Ion Batteries

    Science.gov (United States)

    Yanilmaz, Meltem

    Lithium-ion batteries have been widely used in electronic devices including mobile phones, laptop computers, and cameras due to their high specific energy, high energy density, long cycling lifetime, and low self-discharge rate. Nowadays, lithium-ion batteries are finding new applications in electric/hybrid vehicles and energy storage for smart grids. To be used in these new applications, novel battery components are needed so that lithiumion batteries with higher cell performance, better safety, and lower cost can be developed. A separator is an important component to obtain safe batteries and its primary function is to prevent electronic contact between electrodes while regulating cell kinetics and ionic flow. Currently, microporous membranes are the most commonly used separator type and they have good mechanical properties and chemical stability. However, their wettability and thermal stabilities are not sufficient for applications that require high operating temperature and high performance. Due to the superior properties such as large specific surface area, small pore size and high porosity, electrospun nanofiber membranes can be good separator candidate for highperformance lithium-ion batteries. In this work, we focus our research on fabricating nanofiber-based membranes to design new high-performance separators with good thermal stability, as well as superior electrochemical performance compared to microporous polyolefin membranes. To combine the good mechanical strength of PP nonwovens with the excellent electrochemical properties of SiO2/polyvinylidene fluoride (PVDF) composite nanofibers, SiO 2/PVDF composite nanofiber-coated PP nonwoven membranes were prepared. It was found that the addition of SiO2 nanoparticles played an important role in improving the overall performance of these nanofiber-coated nonwoven membranes. Although ceramic/polymer composites can be prepared by encapsulating ceramic particles directly into polymer nanofibers, the performance

  17. Fabrication of Cellulose Nanofiber/AlOOH Aerogel for Flame Retardant and Thermal Insulation

    OpenAIRE

    Bitao Fan; Shujun Chen; Qiufang Yao; Qingfeng Sun; Chunde Jin

    2017-01-01

    Cellulose nanofiber/AlOOH aerogel for flame retardant and thermal insulation was successfully prepared through a hydrothermal method. Their flame retardant and thermal insulation properties were investigated. The morphology image of the cellulose nanofiber/AlOOH exhibited spherical AlOOH with an average diameter of 0.5 μm that was wrapped by cellulose nanofiber or adhered to them. Cellulose nanofiber/AlOOH composite aerogels exhibited excellent flame retardant and thermal insulation propertie...

  18. Preparation and Characterization of Organic-Inorganic Hybrid Hydrogel Electrolyte Using Alkaline Solution

    Directory of Open Access Journals (Sweden)

    Masanobu Chiku

    2011-09-01

    Full Text Available Organic-inorganic hybrid hydrogel electrolytes were prepared by mixing hydrotalcite, cross-linked potassium poly(acrylate and 6 M KOH solution. The organic-inorganic hybrid hydrogel electrolytes had high ionic conductivity (0.456–0.540 S cm−1 at 30 °C. Moreover, the mechanical strength of the hydrogel electrolytes was high enough to form a 2–3 mm thick freestanding membrane because of the reinforcement with hydrotalcite.

  19. Preparation and properties of a POSS-containing organic-inorganic hybrid crosslinked polymer

    Institute of Scientific and Technical Information of China (English)

    Wang Yan Nie; Gang Li; Yang Li; Hong Yao Xu

    2009-01-01

    A novel POSS-containing organic-inorganic hybrid crosslinked polymer was prepared by hydrosilylation reaction of octahydridosilsesquioxane (T8H8) with 4,4'-bis(4-allyloxybenzoyloxy)phenyl (diene A). Its structure and property was character-ized by FTIR, 29Si NMR, TGA and ellipsometer, respectively. The results show that the hybrid polymer possesses high thermal stability and low dielectric constant of 1.97 at optical frequencies.

  20. Polyurethane nanofibers containing copper nanoparticles as future materials

    DEFF Research Database (Denmark)

    Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Saran, Saurabh

    2011-01-01

    In the present study, we aimed to represent a novel approach to fabricate polyurethane nanofibers containing copper nanoparticles (NPs) by simple electrospinning process. A simple method, not depending on additional foreign chemicals, has been employed to utilize prepared copper NPs in polyurethane...... nanofibers. Typically, a colloidal gel consisting of copper NPs and polyurethane has been electrospun. SEM-EDX and TEM results confirmed well oriented nanofibers and good dispersion of pure copper NPs. Copper NPs have diameter in the range of 5–10nm. The thermal stability of the synthesized nanofibers...

  1. Synthesis of Uniform Polyaniline Nanofibers through Interfacial Polymerization

    Directory of Open Access Journals (Sweden)

    Shahrir Hashim

    2012-08-01

    Full Text Available The present paper aims to study the preparation of polyaniline nanofibers through simple interfacial polymerization. Ammonium persulfate, hydrochloric acid and chloroform were used as oxidant, dopant and organic solvent respectively. Field Emission Scanning Electron Microscopy (FESEM, X-ray diffraction and Fourier Transform Infrared Spectroscopy (FTIR techniques were used to analyze the product. FESEM results show that polyaniline has nano-fiber morphology. XRD results show the crystalline properties of polyaniline nanofiber, and FTIR results confirmed the formation of polyaniline in different monomer/oxidant molar ratios. This study provides a better understanding on the synthesis of uniform polyaniline nanofibers through interfacial polymerization.

  2. NiB/PVDF-PVA纳米纤维催化剂的制备及其应用%Preparation and application of NiB/PVDF-PVA nanofiber catalyst

    Institute of Scientific and Technical Information of China (English)

    李芳; 郑权; 李其明; 付琛; 郭瑞东

    2015-01-01

    NiCl2/PVDF-PVA composite nanofibers were prepared via electrospinning technique, and then NiB/PVDF-PVA nanofiber catalyst can be prepared by in-situ reduction. This catalyst was applied in hydro-gen production from hydrolysis of NaBH4 . SEM characterization showed that the well-defined nanoscaled mi-crostructure can be obtained for NiB/PVDF-PVA composite nanofiber,which possesses uniform nanofiber diameter (50~200 nm) . TG analysis revealed that NiB/PVDF-PVA nanofiber catalyst can be stable up to approximately 390 ℃ which is suitable to be used in hydrolysis of NaBH4 . The measurement of water con-tact angle indicated that the wettability of PVDF-PVA nanofiber is better than that of pure PVDF nanofiber due to hydrophilic PVA doping. The results showed that the catalytic activity of NiB/PVDF-PVA composite catalyst can be remarkably improved through the doping of hydrophilic PVA compared with NiB/PVDF cat-alysts. Hence,NiB/PVDF-PVA nanofiber catalyst has an extensive application prospect.%通过静电纺丝技术首先制备了NiCl2/PVDF-PVA复合高分子纳米纤维,通过原位还原法得到了PVDF-PVA复合纳米纤维负载NiB的非晶态合金催化剂,并把该催化剂用于 NaBH4水解制氢反应。 SEM 表征表明, NiCl2/PVDF-PVA复合纳米纤维具有纤细微观纳米形貌,纤维直径均匀,介于50~200 nm。 TG分析表明, NiCl2/PVDF-PVA纳米纤维可以稳定到大约390℃,超过该温度纳米纤维开始发生热解,说明该纳米纤维催化剂载体具有适于硼氢化钠水解反应的热稳定性。接触角测试表明,PVA共纺显著提高了PVDF纳米纤维的亲水性,有利于NaBH4和水分子在催化剂表面上的接触反应。水解制氢实验表明,PVA共混静电纺丝法得到的NiB /PVDF-PVA较NiB/PVDF催化剂催化活性显著提高,该催化剂具有较好的应用前景。

  3. Preparation and applications of hybrid organic-inorganic monoliths: a review.

    Science.gov (United States)

    Zhu, Tao; Row, Kyung Ho

    2012-06-01

    This review presents an overview of the properties of hybrid organic-inorganic monolithic materials and summarizes the recent developments in the preparation and applications of these hybrid monolithic materials. Hybrid monolithic materials with porosities, surface functionalities, and fast dynamic transport have developed rapidly, and have been used in a wide range of applications owing to the low cost, good stability, and excellent performance. Basically, these materials can be divided into two major types according to the chemical composition: hybrid silica-based monolith (HSM) and hybrid polymer-based monolith (HPM). Compared to the HPM, HSM monolith has been attracting most wide attentions, and it is commonly synthesized by the sol-gel process. The conventional preparation procedures of two type's hybrid organic-inorganic monoliths are addressed. Applications of hybrid organic-inorganic monoliths in optical devices, capillary microextraction (CME), capillary electrochromatography (CEC), high performance liquid chromatography (HPLC), and chiral separation are also reviewed. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The synthesis of titanium carbide-reinforced carbon nanofibers.

    Science.gov (United States)

    Zhu, Pinwen; Hong, Youliang; Liu, Bingbing; Zou, Guangtian

    2009-06-24

    Tailoring hard materials into nanoscale building blocks can greatly extend the applications of hard materials and, at the same time, also represents a significant challenge in the field of nanoscale science. This work reports a novel process for the preparation of carbon-based one-dimensional hard nanomaterials. The titanium carbide-carbon composite nanofibers with an average diameter of 90 nm are prepared by an electrospinning technique and a high temperature pyrolysis process. A composite solution containing polyacrylonitrile and titanium sources is first electrospun into the composite nanofibers, which are subsequently pyrolyzed to produce the desired products. The x-ray diffraction pattern and transmission electron microscopy results show that the main phase of the as-synthesized nanofibers is titanium carbide. The Raman analyses show that the composite nanofibers have low graphite clusters in comparison with the pure carbon nanofibers originating from the electrospun polyacrylonitrile nanofibers. The mechanical property tests demonstrate that the titanium carbide-carbon nanofiber membranes have four times higher tensile strength than the carbon nanofiber membranes, and the Young's modulus of the titanium carbide-carbon nanofiber membranes increases in direct proportion to the titanium quantity.

  5. Chitosan-nanosilica hybrid materials: Preparation and properties

    Energy Technology Data Exchange (ETDEWEB)

    Podust, T.V., E-mail: tania_list@yahoo.com [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Kulik, T.V., E-mail: tanyakulyk@i.ua [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Palyanytsya, B.B.; Gun’ko, V.M. [Chuiko Institute of Surface Chemistry, 17 General Naumov Street, Kyiv 03164 (Ukraine); Tóth, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Mikhalovska, L. [School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Menyhárd, A. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary); Institute of Materials Science and Environmental Chemistry, Research Centre for Natural Sciences, Hungarian Academy of Sciences (Hungary); László, K. [Department of Physical Chemistry and Material Science, Budapest University of Technology and Economics, H-1521 Budapest (Hungary)

    2014-11-30

    Highlights: • Hybrid chitosan-nanosilica materials were synthesized using an adsorption modification method. • The chitosan adsorption capacity is higher on the silica/titania and silica/alumina than on the fumed silica. • Nanosilicas undergo structural and textural alterations due to modification by chitosan. • The more severe chitosan thermodestruction occurs on the silica/titania and silica/alumina surfaces than on the plain silica surface. - Abstract: The research focuses on the synthesis of novel organic–inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO{sub 2}, TiO{sub 2}/SiO{sub 2} and Al{sub 2}O{sub 3}/SiO{sub 2}). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area S{sub BET} of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface.

  6. Wet-Laid Meets Electrospinning: Nonwovens for Filtration Applications from Short Electrospun Polymer Nanofiber Dispersions.

    Science.gov (United States)

    Langner, Markus; Greiner, Andreas

    2016-02-01

    Dispersions of short electrospun fibers are utilized for the preparation of nanofiber nonwovens with different weight area on filter substrates. The aerosol filtration efficiencies of suspension-borne nanofiber nonwovens are compared to nanofiber nonwovens prepared directly by electrospinning with similar weight area. The filtration efficiencies are found to be similar for both types of nonwovens. With this, a large potential opens for processing, design, and application of new nanofiber nonwovens obtained by wet-laying of short electrospun nanofiber suspensions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Biologic effect of a hybrid preparation of human chorionic gonadotropin in human subjects.

    Science.gov (United States)

    Rosemberg, E

    1982-01-01

    Alpha and beta-hCG subunits were recombined generating a hybrid hCG preparation (AB1ER-CR-2XY) which met the required specifications of a pharmaceutical product. The biologic activity contained in each vial of AB1ER-CR-2XY was equivalent to 10 000IU of hCG-IS. This preparation was given as a single dose of 10 000IU by the i.m. route to four female subjects presenting unexplained infertility. The hCG hybrid was demonstrated to effect gonadal stimulation in humans.

  8. Chitosan-nanosilica hybrid materials: Preparation and properties

    Science.gov (United States)

    Podust, T. V.; Kulik, T. V.; Palyanytsya, B. B.; Gun'ko, V. M.; Tóth, A.; Mikhalovska, L.; Menyhárd, A.; László, K.

    2014-11-01

    The research focuses on the synthesis of novel organic-inorganic hybrid materials based on polysaccharide chitosan and nanosilicas (SiO2, TiO2/SiO2 and Al2O3/SiO2). The chitosan modified nanooxides were obtained by the equilibrium adsorption method. The chitosan adsorption capacities of silica/titania and silica/alumina are higher than of the plain silica due to the additional active sites present on the surfaces of the mixed oxides. The hybrid materials were characterized by low-temperature nitrogen adsorption/desorption, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM), thermogravimetry (TG/DTG) and temperature-programmed desorption with mass spectrometry control (TPD MS) methods. The chitosan treatment only modestly influences the surface area SBET of the nanooxides but the rearrangement of the secondary and tertiary structures (aggregates and agglomerates) results in an enhancement of the mesoporosity and affects the size of the aggregates. The more severe thermodestruction of the polysaccharide desorbing from the modified mixed silicas indicates a stronger interaction between the chitosan and the mixed oxides compared to the silanol groups of the plain silica surface.

  9. Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Liang; Gong, Jie [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China); Zeng, Changfeng [College of Mechanic and Power Engineering, Nanjing University of Technology, Nanjing 210009 (China); Zhang, Lixiong, E-mail: lixiongzhang@yahoo.com [State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing 210009 (China)

    2013-10-15

    Zeolite-A/chitosan hybrid composites with zeolite contents of 20–55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation–gelation–hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry. Their in vitro bioactivities were examined using as-synthesized and Ca{sup 2+}-exchanged hybrid composites in simulated body fluid (SBF) for hydroxyapatite (HAP) growth. Their antimicrobial activities for Escherichia coli (E. coli) in trypticase soy broth (TSB) were evaluated using Ag{sup +}-exchanged hybrid composites. The zeolite-A/chitosan hybrid composites could be prepared as various shapes, including cylinders, plates and thin films. They possessed macropores with pore sizes ranging from 100 to 300 μm and showed compressive mechanical strength as high as 3.2 MPa when the zeolite content was 35 wt.%. Fast growth on the Ca{sup 2+}-exchanged hybrid composites was observed with the highest weight gain of 51.4% in 30 days. The 35 wt.% Ag{sup +}-exchanged hybrid composite showed the highest antimicrobial activity, which could reduce the 9 × 10{sup 6} CFU mL{sup −1}E. coli concentration to zero within 4 h of incubation time with the Ag{sup +}-exchanged hybrid composite amount of 0.4 g L{sup −1}. The bioactivity and antimicrobial activity could be combined by ion-exchanging the composites first with Ca{sup 2+} and then with Ag{sup +}. These zeolite-A/chitosan hybrid composites have potential applications on tissue engineering and antimicrobial food packaging. - Graphical abstract: Zeolite A/chitosan hybrid composites were prepared by in situ transformation of precursors in the chitosan matrix, which possess macroporous structures and exhibit superior bioactivity and antimicrobial activity and potential biomedical

  10. Preparation of CuO/NiO composite nanofibers by electrospinning and their application for electro-catalytic oxidation of hydrazine

    Science.gov (United States)

    Hosseini, Sayed Reza; Ghasemi, Shahram; Kamali-Rousta, Mina

    2017-03-01

    In present work, polyvinyl alcohol/copper acetate-nickel acetate composite nanofibers (PVA/Cu(OAc)2-Ni(OAc)2 NFs) with various weight percentages of Cu(OAc)2:Ni(OAc)2 such as 25:75, 50:50 and 75:25 are fabricated by electrospinning method. After this, the CuO/NiO composite NFs are produced after thermal treatment. A calcination temperature at about 600 °C is determined by thermal gravimetric analysis. Field-emission scanning electron microscopy (FE-SEM) for morphology characterization indicates that large quantities of the prepared PVA/Cu(OAc)2-Ni(OAc)2 composite fibers have smooth and bead-free surfaces. Fourier transform infrared spectroscopy, FE-SEM and energy dispersive X-ray spectroscopy are used to characterize the CuO/NiO composites. According to FE-SEM results, with increasing of Cu(OAc)2 content in polymeric solution, the fibers don't remain as continuous structures after calcination and accumulate in the form of nanoparticles. Also, a carbon paste electrode (CPE) bulky modified with CuO/NiO composites is used for investigation of the electro-catalytic oxidation of hydrazine hydrate in NaOH solution. The catalytic activities of the synthesized catalysts are studied through cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopy. The obtained results demonstrate that the most appropriate proportion of Cu(OAc)2:Ni(OAc)2 in electrospinning solution to enhance the electro-catalytic ability is 25:75.

  11. Preparing photochromic nanofibers and animal cells using a photochromic compound of 1',3',3'-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2'-indoline).

    Science.gov (United States)

    Li, Xiaoqiang; Lin, Lin; Kanjwal, Muzafar A; Chronakis, Ioannis S; Liu, Shuiping; Chen, Yanmo

    2012-01-01

    In this work, the photochromic compound 1',3',3'-trimethyl-6-nitrospiro (2H-1-benzopyran-2,2'-indoline) (NOSP) was synthesized by a two step process. The photochromic properties of NOSP were investigated by ultraviolet-visible (UV-Vis) spectrophotometry. The results showed that NOSP was very sensitive to UV irradiation with absorption peaks at about 336 nm and 567 nm. Our hypothesis was that both photochromic nanofibers and photochromic living animal cells could be obtained by combining them with NOSP. To test the hypothesis, photochromic nanofibers were fabricated by electrospinning from various mixed solutions of NOSP and polymers (including a synthetic polymer of poly(methyl methacrylate) and a natural polymer of gelatin); NOSP/ethanol solution was dissolved in culture medium to stain pig iliac endothelial cells (PIEC) and endow them with photochromic capability. Polymer nanofibers from electrospinning were characterized by water contact angle measurements, ultraviolet-visible (UV-Vis) spectrophotometry and fluorescence microscopy. Morphology of photochromic PIEC was observed by fluorescence microscopy after being irradiated. It was shown that nanofibers from electrospun polymers and NOSP-treated PIEC had photochromic properties. The bio-toxicity of the photochromic compound was also evaluated and it was shown that ~50% of PIEC remained viable for at least 20 min. The photochromic compound NOSP could be a potentially powerful tool for development of multi-functional nanofibers and biological applications.

  12. Preparation of Coaxial-Line and Hollow Mn2O3 Nanofibers by Single-Nozzle Electrospinning and Their Catalytic Performances for Thermal Decomposition of Ammonium Perchlorate.

    Science.gov (United States)

    Liang, Jiyuan; Yang, Jie; Cao, Weiguo; Guo, Xiangke; Guo, Xuefeng; Ding, Weiping

    2015-09-01

    Coaxial-line and hollow Mn2O3 nanofibers have been synthesized by a simple single-nozzle electrospinning method without using a complicated coaxial jet head, combined with final calcination. The crystal structure and morphology of the Mn2O3 nanofibers were investigated by using the X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The results indicate that the electrospinning distance has important influence on the morphology and structure of the obtained Mn2O3 nanofibers, which changes from hollow fibers for short electrospinning distance to coaxial-line structure for long electrospinning distance after calcination in the air. The formation mechanisms of different structured Mn2O3 fibers are discussed in detail. This facile and effective method is easy to scale up and may be versatile for constructing coaxial-line and hollow fibers of other metal oxides. The catalytic activity of the obtained Mn2O3 nanofibers on thermal decomposition of ammonium perchlorate (AP) was studied by differential scanning calorimetry (DSC). The results show that the hollow Mn2O3 nanofibers have good catalytic activity to promote the thermal decomposition of AP.

  13. Ammonia Sensing Behaviors of TiO2-PANI/PA6 Composite Nanofibers

    Science.gov (United States)

    Wang, Qingqing; Dong, Xianjun; Pang, Zengyuan; Du, Yuanzhi; Xia, Xin; Wei, Qufu; Huang, Fenglin

    2012-01-01

    Titanium dioxide-polyaniline/polyamide 6 (TiO2-PANI/PA6) composite nanofibers were prepared by in situ polymerization of aniline in the presence of PA6 nanofibers and a sputtering-deposition process with a high purity titanium sputtering target. TiO2-PANI/PA6 composite nanofibers and PANI/PA6 composite nanofibers were fabricated for ammonia gas sensing. The ammonia sensing behaviors of the sensors were examined at room temperature. All the results indicated that the ammonia sensing property of TiO2-PANI/PA6 composite nanofibers was superior to that of PANI/PA6 composite nanofibers. TiO2-PANI/PA6 composite nanofibers had good selectivity to ammonia. It was also found that the content of TiO2 had a great influence on both the morphology and the sensing property of TiO2-PANI/PA6 composite nanofibers. PMID:23235446

  14. Ammonia Sensing Behaviors of TiO2-PANI/PA6 Composite Nanofibers

    Directory of Open Access Journals (Sweden)

    Fenglin Huang

    2012-12-01

    Full Text Available Titanium dioxide-polyaniline/polyamide 6 (TiO2-PANI/PA6 composite nanofibers were prepared by in situ polymerization of aniline in the presence of PA6 nanofibers and a sputtering-deposition process with a high purity titanium sputtering target. TiO2-PANI/PA6 composite nanofibers and PANI/PA6 composite nanofibers were fabricated for ammonia gas sensing. The ammonia sensing behaviors of the sensors were examined at room temperature. All the results indicated that the ammonia sensing property of TiO2-PANI/PA6 composite nanofibers was superior to that of PANI/PA6 composite nanofibers. TiO2-PANI/PA6 composite nanofibers had good selectivity to ammonia. It was also found that the content of TiO2 had a great influence on both the morphology and the sensing property of TiO2-PANI/PA6 composite nanofibers.

  15. Transparent Conductive Films Fabricated from Polythiophene Nanofibers Composited with Conventional Polymers

    Directory of Open Access Journals (Sweden)

    Borjigin Aronggaowa

    2013-11-01

    Full Text Available Transparent, conductive films were prepared by compositing poly(3-hexylthiophene (P3HT nanofibers with poly(methyl methacrylate (PMMA. The transparency, conductivity, atmospheric stability, and mechanical strength of the resulting nanofiber composite films when doped with AuCl3 were evaluated and compared with those of P3HT nanofiber mats. The conductivity of the nanofiber composite films was 4.1 S∙cm−1, which is about seven times less than that which was previously reported for a nanofiber mat with the same optical transmittance (~80% reported by Aronggaowa et al. The time dependence of the transmittance, however, showed that the doping state of the nanofiber composite films in air was more stable than that of the nanofiber mats. The fracture stress of the nanofiber composite film was determined to be 12.3 MPa at 3.8% strain.

  16. Facile preparation of hybrid core-shell nanorods for photothermal and radiation combined therapy

    Science.gov (United States)

    Deng, Yaoyao; Li, Erdong; Cheng, Xiaju; Zhu, Jing; Lu, Shuanglong; Ge, Cuicui; Gu, Hongwei; Pan, Yue

    2016-02-01

    The hybrid platinum@iron oxide core-shell nanorods with high biocompatibility were synthesized and applied for combined therapy. These hybrid nanorods exhibit a good photothermal effect on cancer cells upon irradiation with a NIR laser. Furthermore, due to the presence of a high atomic number element (platinum core), the hybrid nanorods show a synergistic effect between photothermal and radiation therapy. Therefore, the as-prepared core-shell nanorods could play an important role in facilitating synergistic therapy between photothermal and radiation therapy to achieve better therapeutic efficacy.The hybrid platinum@iron oxide core-shell nanorods with high biocompatibility were synthesized and applied for combined therapy. These hybrid nanorods exhibit a good photothermal effect on cancer cells upon irradiation with a NIR laser. Furthermore, due to the presence of a high atomic number element (platinum core), the hybrid nanorods show a synergistic effect between photothermal and radiation therapy. Therefore, the as-prepared core-shell nanorods could play an important role in facilitating synergistic therapy between photothermal and radiation therapy to achieve better therapeutic efficacy. Electronic supplementary information (ESI) available: Details of general experimental procedures. See DOI: 10.1039/c5nr09102k

  17. Novel Cu@SiO{sub 2}/bacterial cellulose nanofibers: Preparation and excellent performance in antibacterial activity

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Bo [Chemicobiology and Functional Materials Institute of Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing 210094 (China); Department of Life Sciences of Lianyungang Teacher' s College, Sheng Hu Lu 28, Lianyungang 222006 (China); Huang, Yang; Zhu, Chunlin; Chen, Chuntao; Chen, Xiao; Fan, Mengmeng [Chemicobiology and Functional Materials Institute of Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing 210094 (China); Sun, Dongping, E-mail: sundpe301@163.com [Chemicobiology and Functional Materials Institute of Nanjing University of Science and Technology, Xiao Ling Wei 200, Nanjing 210094 (China)

    2016-05-01

    The antibacterial composite based on bacterial cellulose (BC) was successfully prepared by in-situ synthesis of SiO{sub 2} coated Cu nanoparticles (Cu@SiO{sub 2}/BC) and its properties were characterized. Its chemical structures and morphologies were evaluated by Fourier transformation infrared spectrum (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results demonstrated that the SiO{sub 2} coated Cu particles were well homogeneously precipitated on the surface of BC. The Cu@SiO{sub 2}/BC was more resistant to oxidation than the Cu nanoparticles impregnated into BC (Cu/BC) and then Cu@SiO{sub 2}/BC could prolong the antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). - Graphical abstract: Schematic illustration of the preparation of Cu@SiO{sub 2}/BC. Due to its unique structure, the Cu@SiO{sub 2}/BC membrane shows excellent antibacterial effects and can be used for a long time. - Highlights: • This work paves the novel way to fabricate antibacterial nanomaterial with good efficiency. • We prepare the antibacterial membrane based on bacterial cellulose by in-situ synthesis of SiO{sub 2}-coated Cu nanoparticles. • The antibacterial membrane is more resistant to oxidation and can prolong the antimicrobial activity.

  18. Preparation, characterisation, engine performance and emission characteristics of coconut oil based hybrid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pranil J.; Singh, Anirudh [Division of Physics, School of Engineering and Physics, Faculty of Science, Technology and Environment, University of the South Pacific, 325 Fletcher Road, Suva (Fiji); Khurma, Jagjit [Division of Chemistry, School of Biological, Chemical and Environmental Sciences, Faculty of Science, Technology and Environment, University of the South Pacific, Suva (Fiji)

    2010-09-15

    In this study, hybrid fuels consisting of coconut oil, aqueous ethanol and a surfactant (butan-1-ol) were prepared and tested as a fuel in a direct injection diesel engine. After determining fuel properties such as the density, viscosity and gross calorific values of these fuels, they were used to run a diesel engine. The engine performance and exhaust emissions were investigated and compared with that of diesel. The experimental results show that the efficiency of the hybrid fuels is comparable to that of diesel. As the viscosity of the hybrid fuels decreased and approached that of diesel, the efficiency increased progressively towards that of diesel. The exhaust emissions were lower than those for diesel, except carbon monoxide emissions, which increased. Hence, it is concluded that these hybrid fuels can be used successfully as an alternative fuel in diesel engines without any modifications. Their completely renewable nature ensures that they are environmentally friendly with regard to their emissions characteristics. (author)

  19. Preparation of stable food-grade double emulsions with a hybrid premix membrane emulsification system

    NARCIS (Netherlands)

    Eisinaite, Viktorija; Juraite, Dovile; Schroën, Karin; Leskauskaite, Daiva

    2016-01-01

    In this study we demonstrate that food-grade double emulsions can be successfully prepared using a hybrid premix emulsification system. A coarse emulsion containing beetroot juice as inner water phase, sunflower oil as oil phase and 0.5% or 1.0% whey protein isolate solution as outer water phase

  20. Structure of hybrid organic-inorganic sols for the preparation of hydrothermally stable membranes

    NARCIS (Netherlands)

    Castricum, H.L.; Sah, A.; Geenevasen, J.A.J.; Kreiter, R.; Blank, D.H.A.; Vente, J.F.; ten Elshof, J.E.

    2008-01-01

    A procedure for the preparation of hybrid sols for the synthesis of organic-inorganic microporous materials and thin film membranes is reported. We describe silane reactivity and sol structure for acid-catalysed colloidal sols from mixtures of either tetraethylorthosilicate (TEOS) and methyltriethox

  1. Preparation and characterization of cellulose acetate organic/inorganic hybrid films

    Science.gov (United States)

    Saeed S. Shojaie; Timothy G. Rials; Stephen S. Kelley

    1995-01-01

    A series of organic/inorganic hybrid (OIH) films were prepared using cellulose acetate (CA) as the organic component and tetraethyl orthosilicate (TEOS) as the inorganic component. The chemical, morphological, and mechanical properties of these films were evaluated with a variety of analytical techniques. The results of these evaluations showed that crosslinked CA OIH...

  2. Preparation and Characterization of Hybrid Luminescence Mesoporous MCM-48 Doped with Eu( Ⅲ ) Complex

    Institute of Scientific and Technical Information of China (English)

    Meng Qingguo; Li Huanrong; Peng Chunyun; Zhang Hongjie; Boutinaud P; Franville A C; Mahiou R

    2004-01-01

    The preparation of hybrid mesoporous MCM-48 grafted by vinyl group via post-grafting process was reported and studied by X-ray diffraction, BET and 29Si solid MAS NMR.An organic β-diketonate Europium complex the corresponding luminescence property was characterized.

  3. Metal nanoparticle deposited inorganic nanostructure hybrids, uses thereof and processes for their preparation

    Science.gov (United States)

    Tenne, Reshef; Tsverin, Yulia; Burghaus, Uwe; Komarneni, Mallikharjuna Rao

    2016-01-26

    This invention relates to a hybrid component comprising at least one nanoparticle of inorganic layered compound (in the form of fullerene-like structure or nanotube), and at least one metal nanoparticle, uses thereof as a catalyst, (e.g. photocatalysis) and processes for its preparation.

  4. Silicon nanoparticles encapsulated in hollow graphitized carbon nanofibers for lithium ion battery anodes

    Science.gov (United States)

    Kong, Junhua; Yee, Wu Aik; Wei, Yuefan; Yang, Liping; Ang, Jia Ming; Phua, Si Lei; Wong, Siew Yee; Zhou, Rui; Dong, Yuliang; Li, Xu; Lu, Xuehong

    2013-03-01

    Silicon (Si) is a promising material for lithium ion battery (LIB) anodes due to its high specific capacity. To overcome its shortcomings such as insulation property and large volume change during the charge-discharge process, a novel hybrid system, Si nanoparticles encapsulated in hollow graphitized carbon nanofibers, is studied. First, electrospun polyacrylonitrile (PAN)-Si hybrid nanofibers were obtained using water as the collector. The loose nanofiber lumps suspended in water have large inter-fiber distance, allowing in situ coating of a thin layer of polydopamine (PDA), the source for graphitized carbon, uniformly throughout the system. The designed morphology and structure were then realized by etching and calcination, and the morphology and structure were subsequently verified by various analytical techniques. Electrochemical measurements show that the resulting hollow hybrid nanofibers (C-PDA-Si NFs) exhibit much better cycling stability and rate capacity than conventional C/Si nanofibers derived by electrospinning of PAN-Si followed by calcination. For instance, the capacity of C-PDA-Si NFs is as high as 72.6% of the theoretical capacity after 50 cycles, and a high capacity of 500 mA h g-1 can be delivered at a current density of 5 A g-1. The significantly improved electrochemical properties of C-PDA-Si NFs are due to the excellent electrical conductivity of the carbonized PDA (C-PDA) shell that compensates for the insulation property of Si, the high electrochemical activity of C-PDA, which has a layered structure and is N-doped, the hollow nature of the nanofibers and small size of Si nanoparticles that ensure smooth insertion-extraction of lithium ions and more complete alloying with them, as well as the buffering effect of the remaining PAN-derived carbon around the Si nanoparticles, which stabilizes the structure.Silicon (Si) is a promising material for lithium ion battery (LIB) anodes due to its high specific capacity. To overcome its shortcomings

  5. Effect of probiotic preparation for chemical composition of meat cocks different combinations of hybrid chicks

    Directory of Open Access Journals (Sweden)

    Peter Haščík

    2011-01-01

    Full Text Available In the experiment were verified the application of probiotic preparation through a water supply for feeding of cock’s hybrids Ross 308, Hubbard JV and Cobb 500 in the chemical composition of the most valuable parts of the carcass. Probiotic was based on the strain Lactobacillus fermentum with containing of 1.109 cfu.g−1 and potentially components of maltodextrin and oligofructose in 1% concentration. Length of feeding period was 42 days. Cocks were fed an ad libitum with the same starter mixture HYD-01 to 21th day and from 22nd to 42nd day of feeding with mixture HYD-02 in powdery form. The average of protein content of breast muscle was highest in Hubbard JV hybrid (23.93 g.100 g−1, lower in Cobb 500 hybrid (23.90 g.100 g−1 and lowest in Ross 308 hybrid (23.73 g.100 g−1, without significant differences (P ≥ 0.05 between hybrids and hybrids groups. Effect of probiotics had increased the protein content (P ≥ 0.05 in breast muscle of Ross 308 and Cobb 500 cocks and at the Hubbard JV only lower doses application during the feeding. The average of fat content in 100 g of breast muscle was lowest in Cobb 500 hybrid (1.09 g, higher in Hubbard JV hybrid (1.28 g and highest in Ross 308 hybrid (1.35 g. Effect of probiotic to reduce fat content in breast muscle of cocks was at Ross 308 hybrid (1.33 and 1.23 g.100 g−1, Cobb 500 hybrid (0.98 and 1.02 g.100 g−1 and in second experimental group at Hubbard JV hybrid (1.03 g.100 g−1 statistically significant (P ≥ 0.05 in compared with control group, but significantly (P ≤ 0.05 between hybrids Cobb 500 and Hubbard JV in the first test groups. The average of energy value in 100 g of breast muscle was highest in Hubbard JV hybrid (449.24 kJ, lower in Ross 308 hybrid (448.40 kJ and lowest in Cobb 500 hybrid (441.45 kJ, without significant differences (P ≥ 0.05 between hybrids and hybrids groups. The average of protein content of the femur was highest in Ross 308 hybrid (18.56 g.100

  6. Functionalized electrospun nanofibers as bioseparators in microfluidic systems.

    Science.gov (United States)

    Matlock-Colangelo, Lauren; Cho, Daehwan; Pitner, Christine L; Frey, Margaret W; Baeumner, Antje J

    2012-05-01

    Functionalized electrospun nanofibers were integrated into microfluidic channels to serve as on-chip bioseparators. Specifically, poly(vinyl alcohol) (PVA) nanofiber mats were shown to successfully serve as bioseparators for negatively charged nanoparticles. Nanofibers were electrospun onto gold microelectrodes, which were incorporated into poly(methyl methacrylate) (PMMA) microfluidic devices using UV-assisted thermal bonding. PVA nanofibers functionalized with poly(hexadimethrine bromide) (polybrene) were positively charged and successfully filtered negatively charged liposomes out of a buffer solution, while negatively charged nanofibers functionalized with Poly(methyl vinyl ether-alt-maleic anhydride) (POLY(MVE/MA)) were shown to repel the liposomes. The effect of fiber mat thickness was studied using confocal fluorescence microscopy, determining a quite broad optimal range of thicknesses for specific liposome retention, which simplifies fiber mat production with respect to retention reliability. Finally, it was demonstrated that liposomes bound to positively charged nanofibers could be selectively released using a 4-(2-Hydroxyethyl)piperazine-1-ethanesulfonic acid (HEPES)-sucrose-saline (HSS) solution of pH 9, which dramatically changes the nanofiber zeta potential and renders the positively charged nanofibers negatively charged. This is the first demonstration of functional electrospun nanofibers used to enable sample preparation procedures of isolation and concentration in lab-on-a-chip devices. This has far reaching impact on the ability to integrate functional surfaces and materials into microfluidic devices and to significantly expand their ability toward simple lab-on-a-chip devices.

  7. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Science.gov (United States)

    Afshari, Esmail; Mazinani, Saeedeh; Ranaei-Siadat, Seyed-Omid; Ghomi, Hamid

    2016-11-01

    Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO2, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  8. Evaluation of the genotoxicity of cellulose nanofibers

    Directory of Open Access Journals (Sweden)

    de Lima R

    2012-07-01

    Full Text Available Renata de Lima,1 Leandro Oliveira Feitosa,1 Cintia Rodrigues Maruyama,1 Mariana Abreu Barga,1 Patrícia Cristina Yamawaki,1 Isolda Jesus Vieira,1 Eliangela M Teixeira,2 Ana Carolina Corrêa,2 Luiz Henrique Caparelli Mattoso,2 Leonardo Fernandes Fraceto31Department of Biotechnology, University of Sorocaba, Sorocaba, 2Embrapa Instrumentation (CNPDIA, National Nanotechnology Laboratory for Agriculture (LNNA, São Carlos, 3Department of Environmental Engineering, State University of São Paulo (UNESP, Sorocaba, SP, BrazilBackground: Agricultural products and by products provide the primary materials for a variety of technological applications in diverse industrial sectors. Agro-industrial wastes, such as cotton and curaua fibers, are used to prepare nanofibers for use in thermoplastic films, where they are combined with polymeric matrices, and in biomedical applications such as tissue engineering, amongst other applications. The development of products containing nanofibers offers a promising alternative for the use of agricultural products, adding value to the chains of production. However, the emergence of new nanotechnological products demands that their risks to human health and the environment be evaluated. This has resulted in the creation of the new area of nanotoxicology, which addresses the toxicological aspects of these materials.Purpose and methods: Contributing to these developments, the present work involved a genotoxicological study of different nanofibers, employing chromosomal aberration and comet assays, as well as cytogenetic and molecular analyses, to obtain preliminary information concerning nanofiber safety. The methodology consisted of exposure of Allium cepa roots, and animal cell cultures (lymphocytes and fibroblasts, to different types of nanofibers. Negative controls, without nanofibers present in the medium, were used for comparison.Results: The nanofibers induced different responses according to the cell type used. In

  9. Myocardial Cell Pattern on Piezoelectric Nanofiber Mats for Energy Harvesting

    Science.gov (United States)

    Liu, X.; Wang, X.; Zhao, H.; Du, Y.

    2014-11-01

    The paper presents in vitro contractile myocardial cell pattern on piezoelectric nanofiber mats with applications in energy harvesting. The cell-based energy harvester consists of myocardial cell sheet and a PDMS substrate with a PVDF nanofiber mat on. Experimentally, cultured on specifically distributed nanofiber mats, neonatal rat ventricular cardiomyocytes are characterized with the related morphology and contraction. Previously, we have come up with the concept of energy harvesting from heart beating using piezoelectric material. A bio-hybrid energy harvester combined living cardiomyocytes, PDMS polymer substrate and piezoelectric PVDF film with the electrical output of peak current 87.5nA and peak voltage 92.3mV. However, the thickness of the cardiomyocyte cultured on a two-dimensional substrate is much less than that of the piezoelectric film. The Micro Contact Printing (μCP) method used in cell pattern on the PDMS thin film has tough requirement for the film surface. As such, in this paper we fabricated nanofiber-constructed PDMS thin film to realize cell pattern due to PVDF nanofibers with better piezoelectricity and microstructures of nanofiber mats guiding cell distribution. Living cardiomyocytes patterned on those distributed piezoelectric nanofibers with the result of the same distribution as the nanofiber pattern.

  10. Polymer/Carbon-Based Hybrid Aerogels: Preparation, Properties and Applications

    Directory of Open Access Journals (Sweden)

    Lizeng Zuo

    2015-10-01

    Full Text Available Aerogels are synthetic porous materials derived from sol-gel materials in which the liquid component has been replaced with gas to leave intact solid nanostructures without pore collapse. Recently, aerogels based on natural or synthetic polymers, called polymer or organic aerogels, have been widely explored due to their porous structures and unique properties, such as high specific surface area, low density, low thermal conductivity and dielectric constant. This paper gives a comprehensive review about the most recent progresses in preparation, structures and properties of polymer and their derived carbon-based aerogels, as well as their potential applications in various fields including energy storage, adsorption, thermal insulation and flame retardancy. To facilitate further research and development, the technical challenges are discussed, and several future research directions are also suggested in this review.

  11. Preparation of a Novel Coal Gangue-Polyacrylamide Hybrid Flocculant and Its Flocculation Performance

    Institute of Scientific and Technical Information of China (English)

    Xiangao Quan; Huiyun Wang

    2014-01-01

    A novel flocculant based on hybrid coal gangue-polyacrylamide (HCGPAM) has been prepared by using modified coal gangue and polyacrylamide. Factors related to the preparation such as reaction time, temperature, concentration of the polymer monomer and ratio of initiators are investigated. The product is characterized by infrared spectra (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), aswell as viscometry. The flocculating tests on oilfield drilling wastewater show that the removal efficiency is 85.5% and the light transmittance is 53.6%. The results indicate that the coal gangue could be used for the preparation of inorganic-organic hybrid flocculant and the removal efficiency is much higher than that of commercial polyacrylamide (PAM) or PAM/ coal gangue blend.

  12. Polyurethane nanofibers containing copper nanoparticles as future materials

    Science.gov (United States)

    Sheikh, Faheem A.; Kanjwal, Muzafar A.; Saran, Saurabh; Chung, Wook-Jin; Kim, Hern

    2011-01-01

    In the present study, we aimed to represent a novel approach to fabricate polyurethane nanofibers containing copper nanoparticles (NPs) by simple electrospinning process. A simple method, not depending on additional foreign chemicals, has been employed to utilize prepared copper NPs in polyurethane nanofibers. Typically, a colloidal gel consisting of copper NPs and polyurethane has been electrospun. SEM-EDX and TEM results confirmed well oriented nanofibers and good dispersion of pure copper NPs. Copper NPs have diameter in the range of 5-10 nm. The thermal stability of the synthesized nanofibers was examined for identifying the proper settlement of copper NPs among the nanofibers, according to the concentrations used in original solutions. Furthermore, XRD results well demonstrated crystalline feature of copper NPs. Model microorganisms Escherichia coli and Bacillus subtillus had been used to check the antimicrobial efficacy of these nanofiber mats. Subsequently, antimicrobial tests have indicated that the prepared nanofibers do posses good bactericidal effect. Accordingly, it is noted that the obtained nanofiber mats can be used as future filter membranes with good antimicrobial activities.

  13. The Electrochemical Characteristics of Hybrid Capacitor Prepared by Chemical Activation of NaOH

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jeong Eun; Bae, Ga Yeong; Yang, Jeong Min; Lee, Jong Dae [Chungbuk National Univ., Chungju (Korea, Republic of)

    2013-06-15

    Active carbons with high specific surface area and micro pore structure were prepared from the coconut shell char using the chemical activation method of NaOH. The preparation process has been optimized through the analysis of experimental variables such as activating chemical agents to char ratio and the flow rate of gas during carbonization. The active carbons with the surface area (2,481m{sup 2}/g) and mean pore size (2.32 nm) were obtained by chemical activation with NaOH. The electrochemical performances of hybrid capacitor were investigated using LiMn{sub 2}O{sub 4}, LiCoO{sub 2} as the positive electrode and prepared active carbon as the negative electrode. The electrochemical behaviors of hybrid capacitor using organic electrolytes (LiPF{sub 6}, TEABF{sub 4}) were characterized by constant current charge/discharge, cyclic voltammetry, cycle and leakage tests. The hybrid capacitor using LiMn{sub 2}O{sub 4}/AC electrodes had better capacitance than other hybrid systems and was able to deliver a specific energy as high as 131 Wh/kg at a specific power of 1,448 W/kg.

  14. Preparation of Magnetic Hybrid Microspheres with Well-Defined Yolk-Shell Structure

    Directory of Open Access Journals (Sweden)

    Yuan Zhao

    2016-01-01

    Full Text Available A facile and efficient route was reported to prepare a kind of yolk-shell magnetic hybrid microspheres by suspension polymerization and calcinations method. The morphology, structure, and composition of the magnetic microspheres were characterized by FTIR, XRD, TEM, SEM, and TGA analysis. The vibrating-sample magnetometry (VSM results clearly showed that the magnetic particles were superparamagnetic with saturation magnetization of 32.82 emu/g which makes the microcomposites easily controlled by an external magnetic field. The results revealed that the magnetic hybrid microspheres might have important applications in magnetic bioseparation and drug delivery.

  15. Sol-gel Process in Preparation of Organic-inorganic Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Macan, J

    2008-07-01

    Full Text Available Organic-inorganic hybrid materials are a sort of nanostructured material in which the organic and inorganic phases are mixed at molecular level. The inorganic phase in hybrid materials is formed by the sol-gel process, which consists of reactions of hydrolysis and condensation of metal (usually silicon alkoxides. Flexibility of sol-gel process enables creation of hybrid materials with varying organic and inorganic phases in different ratios, and consequently fine-tuning of their properties. In order to obtain true hybrid materials, contact between the phases should be at molecular level, so phase separation between thermodynamically incompatible organic and inorganic phases has to be prevented. Phase interaction can be improved by formation of hydrogen or covalent bonds between them during preparation of hybrid materials. Covalent bond can be introduced by organically modified silicon alkoxides containing a reactive organic group (substituent capable of reacting with the organic phase. In order to obtain hybrid materials with desired structures, a detailed knowledge of hydrolysis and condensation mechanism is necessary. The choice of catalyst, whether acid or base, has the most significant influence on the structure of the inorganic phase. Other important parameters are alkoxide concentration, water: alkoxide ratio, type of alkoxide groups, solvent used, temperature, purity of chemicals used, etc. Hydrolysis and condensation of organically modified silicon alkoxides are additionally influenced by nature and size of the organic supstituent.

  16. Influences of Silver-Doping on the Crystal Structure, Morphology and Photocatalytic Activity of TiO2 Nanofibers

    DEFF Research Database (Denmark)

    Barakat, Nasser A. M.; Kanjwal, Muzafar Ahmed; Al-Deyab, Salem S.

    2011-01-01

    activity of titanium oxide nanofibers has been studied. Sil-ver-doped TiO2 nanofibers having different silver contents were prepared by calcination of electrospun nanofiber mats consisting of silver nitrate, titanium isopropoxide and poly(vinyl acetate) at 600°C. The results affirmed formation of silver...

  17. Preparation of hybrid nano biocomposite κ-carrageenan/cellulose nanocrystal/nanoclay

    Science.gov (United States)

    Zakuwan, Siti Zarina; Ahmad, Ishak; Ramli, Nazaruddin

    2013-11-01

    Biodegradable composites film based on κ-carrageenan and nano particles as filler was prepared to study the mechanical strength of carrageenan composites. Solution casting technique was used to prepare_this biocomposite. Preparation of composite film and nano filler involve two stages, preparation of cellulose nanocrystals (CNC) from kenaf with alkali treatment, bleaching, and hydrolysis followed by the preparation of two types of nano composite. Tensile test was carried on the composite film based on κ-carrageenan with the variation percentage of CNC and nano clay to obtain the optimum CNC and nano clay loading. After that hybrid nano-biocomposite film based on κ-carrageenan with the variation percentage of CNC/nano clay (OMMT) according to optimum value of composite carrageenan/CNC and composite carrageenan/nano clay film was prepared. The effect of nano filler on the mechanical properties of carrageenan films was examined. κ-carrageenan biocomposite increased with the optimum at 4% CNC and nano clay composition. Additional improvement of tensile strength with hybridization of CNC and nanoclay indicated better mechanical properties.

  18. Electrospun Perovskite Nanofibers

    Science.gov (United States)

    Chen, Dongsheng; Zhu, Yanyan

    2017-02-01

    CH3NH3PbI3 perovskite nanofibers were synthesized by versatile electrospinning techniques. The synthetic CH3NH3PbI3 nanofibers were characterized by X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and photoluminescence. As counter electrodes, the synthesized nanofibers increased the performance of the dye-sensitized solar cells from 1.58 to 2.09%. This improvement was attributed to the enhanced smoothness and efficiency of the electron transport path. Thus, CH3NH3PbI3 perovskites nanofibers are potential alternative to platinum counter electrodes in dye-sensitized solar cells.

  19. PEG/PVA相变复合纳米纤维的制备及其性能研究%Prepare PVA/PEG phase change composite nanofibers and study its characteristics

    Institute of Scientific and Technical Information of China (English)

    张梅; 刘永佳; 栾加双; 徐天宇; 孙大辉

    2012-01-01

    在室温下制得了PEG/PVA相变复合纳米纤维。探讨了PVA/PEG和PEG2000/PEG4000各自不同质量分数、外加电压、接收距离、外加盐离子等参数对纤维直径和纤维网形态的影响。结果表明PEG/PVA为60/40,电压为15kV,接受距离为10cm时,成纤较好。运用DSC测试复合纳米纤维的可逆相转变特性,Tm和TC值与PEG2000/PEG4000的比例有关。%In this work,PVA /PEG phase change composite nanofibers were prepared by electrospinning at room temperature.The diameter and morphology of PVA / PEG nanofibers were studied by scanning electron microscopy(SEM) to research the relationship with different weight content,applied voltage,collect distance and added ionic salt on fiber diameter and fiber network morphology.Experimental results showed that PVA/PEG blend solution of 4∶6 weight content,a fixed electric field of 15kV/10cm was the best process parameters.Using DSC method,the phase change characteristics of PVA/PEG composite nanofibers has been tested.Tm and TC values are affected by different ratios of PEG component(Mw = 2000,4000).

  20. Preparation and Photochromic Properties of Hybrid Thin Films Based on Heteropolyoxometallate and Polyacrylamide

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    series of photochromic hybrid films were prepared through entrapping Dawson type tungsten heteropolyoxometallates (P2W18O626-) and molybdenum heteropolyoxometallate (P2Mo18O626-) into polyacrylamide matrix. FTIR results showed that the Dawson geometry of heteropolyoxometallates is still preserved inside the composites and strong coulombic interaction is built between heteropolyoxometallates and polyacrylamide via hydrogen bonding. Irradiated with ultraviolet light, the transparent films change from colorless to blue and show reversible photochromism.The bleaching process occurs when the films are in contact with air or O2 in the dark. The molybdenum heteropolyoxometallate hybrid film has higher photochromic efficiency and slower bleaching reaction than tungsten heteropolyoxometallate hybrid film. ESR results indicated that polyacrylamide is a hydrogen donor and the photoreduced process is in accordance with the radical mechanism.

  1. Preparation and gas sensing properties of novel CdS-supramolecular organogel hybrid films

    Science.gov (United States)

    Xia, Huiyun; Peng, Junxia; Liu, Kaiqiang; Li, Chen; Fang, Yu

    2008-05-01

    A novel CdS-supramolecular organogel hybrid film with unusual morphology has been fabricated by exposing a supramolecular organogel film containing Cd(Ac)2 in an H2S atmosphere at room temperature. The organogel film was prepared by spin-coating a LMOG (low-molecular weight organic gelator) gel of dmethyl sulfoxide onto a glass plate substrate. XRD, SEM, EDS, TG-DTA, UV-vis, PL (photoluminescence) spectroscopy and PL lifetime measurements were employed to characterize the film. It was shown that the organogel film had functioned as a template to control the morphology of the final hybrid film. The quantities and sizes of the CdS particles embedded in the organogel films can be easily altered by varying the initial concentration of Cd(Ac)2. Importantly, the PL of the hybrid film is sensitive to the presence of some volatile organic monoamines and diamines. The selectivity and reversibility of the sensing process were investigated.

  2. Fluorescence in situ hybridization of old G-banded and mounted chromosome preparations

    DEFF Research Database (Denmark)

    Gerdes, A M; Pandis, N; Bomme, L;

    1997-01-01

    , that the amount of added probe is increased approximately 2.5 times, and that the amplification of signals is performed twice. The applicability of the method, which allows double painting with two differently labeled probes using two differently fluorescing colors, was tested on 11 cases involving different......An improved method for fluorescence in situ hybridization (FISH) investigation of old, previously G-banded, mounted chromosome preparations with chromosome specific painting probes and centromere-specific probes is described. Before hybridization, the slides are incubated in xylene until...... the coverslips detach spontaneously; any mechanical manipulation will jeopardize the results. The success of chromosome painting is improved by excluding the regular RNase treatment step prior to hybridization. Additional changes compared with standard FISH protocols are that the 2 x SSC step is omitted...

  3. High Sensitive Sensor Fabricated by Reduced Graphene Oxide/Polyvinyl Butyral Nanofibers for Detecting Cu (II) in Water

    OpenAIRE

    2015-01-01

    Graphene oxide (GO)/polyvinyl butyral (PVB) nanofibers were prepared by a simple electrospinning technique with PVB as matrix and GO as a functional nanomaterial. GO/PVB nanofibers on glassy carbon electrode (GCE) were reduced through electrochemical method to form reduced graphene oxide (RGO)/PVB nanofibers. The morphology and structure of GO/PVB nanofiber were studied by scanning election microscopy (SEM), transmission electron microscopy (TEM), and Fourier transform infrared (FTIR). RGO/PV...

  4. Antifouling Electrospun Nanofiber Mats Functionalized with Polymer Zwitterions.

    Science.gov (United States)

    Kolewe, Kristopher W; Dobosz, Kerianne M; Rieger, Katrina A; Chang, Chia-Chih; Emrick, Todd; Schiffman, Jessica D

    2016-10-06

    In this study, we exploit the excellent fouling resistance of polymer zwitterions and present electrospun nanofiber mats surface functionalized with poly(2-methacryloyloxyethyl phosphorylcholine) (polyMPC). This zwitterionic polymer coating maximizes the accessibility of the zwitterion to effectively limit biofouling on nanofiber membranes. Two facile, scalable methods yielded a coating on cellulose nanofibers: (i) a two-step sequential deposition featuring dopamine polymerization followed by the physioadsorption of polyMPC, and (ii) a one-step codeposition of polydopamine (PDA) with polyMPC. While the sequential and codeposited nanofiber mat assemblies have an equivalent average fiber diameter, hydrophilic contact angle, surface chemistry, and stability, the topography of nanofibers prepared by codeposition were smoother. Protein and microbial antifouling performance of the zwitterion modified nanofiber mats along with two controls, cellulose (unmodified) and PDA coated nanofiber mats were evaluated by dynamic protein fouling and prolonged bacterial exposure. Following 21 days of exposure to bovine serum albumin, the sequential nanofiber mats significantly resisted protein fouling, as indicated by their 95% flux recovery ratio in a water flux experiment, a 300% improvement over the cellulose nanofiber mats. When challenged with two model microbes Escherichia coli and Staphylococcus aureus for 24 h, both zwitterion modifications demonstrated superior fouling resistance by statistically reducing microbial attachment over the two controls. This study demonstrates that, by decorating the surfaces of chemically and mechanically robust cellulose nanofiber mats with polyMPC, we can generate high performance, free-standing nanofiber mats that hold potential in applications where antifouling materials are imperative, such as tissue engineering scaffolds and water purification technologies.

  5. Layered Perovskite Nanofibers via Electrospinning for Overall Water Splitting.

    Science.gov (United States)

    Hildebrandt, Nils C; Soldat, Julia; Marschall, Roland

    2015-05-06

    The (111)-layered perovskite materials Ba5 Ta4 O15 , Ba5 Ta2 Nb2 O15 and Ba5 Nb4 O15 are prepared with nanofiber morphology via electrospinning for the first time. The nanofibers are built up from small single crystals, with up to several micrometers length even after calcination. The formation mechanism is investigated in detail, revealing an intermediate formation of amorphous barium carbonate strengthening the nanofiber morphology for high temperature treatment. All nanofiber compounds are able to generate hydrogen without any co-catalyst in photocatalytic reformation of methanol. After photodeposition of Rh-Cr2 O3 co-catalysts, the nanofibers show better activity in overall water splitting compared to sol-gel-derived powders.

  6. Study on the Electrospun CNTs/Polyacrylonitrile-Based Nanofiber Composites

    Directory of Open Access Journals (Sweden)

    Bo Qiao

    2011-01-01

    Full Text Available CNTs/PAN nanofibers were electrospun from PAN-based solution for the preparation of carbon nanofiber composites. The as-spun polyacrylonitrile-based nanofibers were hot-stretched by weighing metal in a temperature controlled oven. Scanning electron microscopy (SEM and transmission electron microscopy (TEM were used to characterize the morphology of the nanofibers, which indicated that carbon nanotubes were dispersed well in the composites and were completely wrapped by PAN matrix. Because of the strong interfacial interaction between CNTs and PAN, the CNTs/PAN application performance will be enhanced correspondingly, such as the mechanical properties and the electrical conductivity. It was concluded that the hot-stretched CNTs/PAN nanofibers can be used as a potential precursor to produce high-performance carbon composites.

  7. Imaging, spectroscopy, mechanical, alignment and biocompatibility studies of electrospun medical grade polyurethane (Carbothane™ 3575A) nanofibers and composite nanofibers containing multiwalled carbon nanotubes.

    Science.gov (United States)

    Sheikh, Faheem A; Macossay, Javier; Cantu, Travis; Zhang, Xujun; Shamshi Hassan, M; Esther Salinas, M; Farhangi, Chakavak S; Ahmad, Hassan; Kim, Hern; Bowlin, Gary L

    2015-01-01

    In the present study, we discuss the electrospinning of medical grade polyurethane (Carbothane™ 3575A) nanofibers containing multi-walled-carbon-nanotubes (MWCNTs). A simple method that does not depend on additional foreign chemicals has been employed to disperse MWCNTs through high intensity sonication. Typically, a polymer solution consisting of polymer/MWCNTs has been electrospun to form nanofibers. Physiochemical aspects of prepared nanofibers were evaluated by SEM, TEM, FT-IR and Raman spectroscopy, confirming nanofibers containing MWCNTs. The biocompatibility and cell attachment of the produced nanofiber mats were investigated while culturing them in the presence of NIH 3T3 fibroblasts. The results from these tests indicated non-toxic behavior of the prepared nanofiber mats and had a significant attachment of cells towards nanofibers. The incorporation of MWCNTs into polymeric nanofibers led to an improvement in tensile stress from 11.40 ± 0.9 to 51.25 ± 5.5 MPa. Furthermore, complete alignment of the nanofibers resulted in an enhancement on tensile stress to 72.78 ± 5.5 MPa. Displaying these attributes of high mechanical properties and non-toxic nature of nanofibers are recommended for an ideal candidate for future tendon and ligament grafts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Preparation and Characterization of New Geopolymer-Epoxy Resin Hybrid Mortars

    Directory of Open Access Journals (Sweden)

    Raffaele Cioffi

    2013-07-01

    Full Text Available The preparation and characterization of metakaolin-based geopolymer mortars containing an organic epoxy resin are presented here for the first time. The specimens have been prepared by means of an innovative in situ co-reticulation process, in mild conditions, of commercial epoxy based organic resins and geopolymeric slurry. In this way, geopolymer based hybrid mortars characterized by a different content of normalized sand (up to 66% in weight and by a homogeneous dispersion of the organic resin have been obtained. Once hardened, these new materials show improved compressive strength and toughness in respect to both the neat geopolymer and the hybrid pastes since the organic polymer provides a more cohesive microstructure, with a reduced amount of microcracks. The microstructural characterization allows to point out the presence of an Interfacial Transition Zone similar to that observed in cement based mortars and concretes. A correlation between microstructural features and mechanical properties has been studied too.

  9. Preparation of collagen/hydroxyapatite/alendronate hybrid hydrogels as potential scaffolds for bone regeneration.

    Science.gov (United States)

    Ma, Xin; He, Zhiwei; Han, Fengxuan; Zhong, Zhiyuan; Chen, Liang; Li, Bin

    2016-07-01

    Development of biomimetic scaffolds represents a promising direction in bone tissue engineering. In this study, we designed a two-step process to prepare a type of biomimetic hybrid hydrogels that were composed of collagen, hydroxyapatite (HAP) and alendronate (ALN), an anti-osteoporosis drug. First, water-soluble ALN-conjugated HAP (HAP-ALN) containing 4.0wt.% of ALN was synthesized by treating HAP particles with ALN. Hydrogels were then formed from HAP-ALN conjugate and collagen under physiological conditions using genipin (GNP) as the crosslinker. Depending on the ALN/collagen molar ratio and GNP concentration, the gelation time of hydrogels ranged from 5 to 37min. Notably, these hybrid hydrogels exhibited markedly improved mechanical property (storage modulus G'=38-187kPa), higher gel contents, and lower swelling ratios compared to the hydrogels prepared from collagen alone under similar conditions. Moreover, they showed tunable degradation behaviors against collagenase. The collagen/HAP-ALN hybrid hydrogels supported the adhesion and growth of murine MC3T3-E1 osteoblastic cells well. Such tough yet enzymatically degradable hybrid hydrogels hold potential as scaffolds for bone tissue engineering.

  10. One-step preparation of organometal/Fe{sub 3}O{sub 4} hybrid microspheres and their electromagnetic properties

    Energy Technology Data Exchange (ETDEWEB)

    Wei Junji; Zhan Yingqing; Yang Xulin; Meng Fanbin; Ma Zhen; Zhao Rui; Zhong Jiachun; Zhang Jiandong [Research Branch of Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); Liu Xiaobo, E-mail: liuxb@uestc.edu.cn [Research Branch of Functional Materials, Institute of Microelectronic and Solid State Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2011-12-15

    Novel organometal/Fe{sub 3}O{sub 4} hybrid microspheres were prepared from bisphthalonitrile-benzoxine resin containing ferrocene (FPNBZ) and FeCl{sub 3}.6H{sub 2}O via a one-step solvent-thermal method. The phase structure, composition and morphology of as-prepared hybrid microspheres were characterized by X-ray powder diffraction, Fourier transform infrared spectrophotometer and scanning electron microscopy. The results revealed that crystallinity, dispersity and size of hybrid microspheres can be controlled by altering the reaction parameters. Density measurement showed that the density is decreased with increasing FPNBZ concentration in the hybrid materials. Electromagnetic properties of the FPNBZ/Fe{sub 3}O{sub 4} hybrid microspheres were measured at 2-18 GHz. The electromagnetic measurement indicated that the resonance peaks of complex permittivity, complex permeability, dielectric loss and magnetic loss were shifted to the high frequencies, with the increasing amount of FPNBZ. The as-prepared hybrid materials are believed to have broad applications both in microwave absorption materials in a wide frequency range and in biomedical fields. - Highlights: > The as-prepared hybrid microspheres showed high resistivity, good thermal stability and low density. > Morphology, size, magnetism and electromagnetic properties of hybrid microspheres can illicit by altering the reaction parameters. > Hybrids is alleged to have wide applications both in microwave absorption materials in a wide frequency range and in biomedical fields.

  11. NANOFIBER PRODUCTION [REVIEW

    Directory of Open Access Journals (Sweden)

    KESKIN Reyhan

    2016-05-01

    Full Text Available Nanofibers are very thin fibers having diameters lower than 100 nm and their lengths might be as long as possible within production limits. The large surface area of nanofibers gives opportunity to functionalize them. Nanofibers have several applications including both applications for industrial production in many sectors and for research studies. Nanofibers find applications in energy devices such as solar cells, fuel cells and nanogenarators; in filtration applications (such as water/oil filtration, fine particle filtration, aerosol filtration, air filtration, nanoparticle filtration and in several medical applications including antibacterial efficacy, wound healing, drug delivery and scaffolds for tissue engineering. There are several methods to produce nanofibers: Electrospinning, self assembly, phase separation, bacterial cellulose, templating, drawing, extraction, vapor-phase polymerization, kinetically controlled solution synthesis, conventional chemical polymerization for anyline. Electrospinning is the most widely used method to produce nanofibers.In electrospinning, a high electric field, which is in kilovolts, is applied to a polymer solution. The polymer solution is drawn from a syringe to a collector surface.Electrospinning requires usage of appropriate solvent, removal of evaporating solvent, an adequate power supply to overcome the viscosity and surface tension of the polymer solution; while, jet instability and jet control remain as challenges in electrospinning. Nanofiber production methods possess some disadvantages as: higher cost compared to conventional fiber production methods, health hazards such as inhale risk of nanofibers during production and keeping the environment safe from evaporating solvents used during nanofiber production. Up to date, many researches have been conducted on nanofibers and electrospinning; still, more controllable, more cost effective, more environmentally friendly and safer methods are of

  12. Facile preparation of smooth perovskite films for efficient meso/planar hybrid structured perovskite solar cells.

    Science.gov (United States)

    Zhang, Meng; Yu, Hua; Yun, Jung-Ho; Lyu, Miaoqiang; Wang, Qiong; Wang, Lianzhou

    2015-06-21

    Smooth organolead halide perovskite films for meso/planar hybrid structured perovskite solar cells were prepared by a simple compressed air blow-drying method under ambient conditions. The resultant perovskite films show high surface coverage, leading to a device power conversion efficiency of over 10% with an open circuit voltage up to 1.003 V merely using pristine poly(3-hexylthiophene) (P3HT) as a hole transporter.

  13. Preparation of novel carbon microfiber/carbon nanofiber-dispersed polyvinyl alcohol-based nanocomposite material for lithium-ion electrolyte battery separator.

    Science.gov (United States)

    Sharma, Ajit K; Khare, Prateek; Singh, Jayant K; Verma, Nishith

    2013-04-01

    A novel nanocomposite polyvinyl alcohol precursor-based material dispersed with the web of carbon microfibers and carbon nanofibers is developed as lithium (Li)-ion electrolyte battery separator. The primary synthesis steps of the separator material consist of esterification of polyvinyl acetate to produce polyvinyl alcohol gel, ball-milling of the surfactant dispersed carbon micro-nanofibers, mixing of the milled micron size (~500 nm) fibers to the reactant mixture at the incipience of the polyvinyl alcohol gel formation, and the mixing of hydrophobic reagents along with polyethylene glycol as a plasticizer, to produce a thin film of ~25 μm. The produced film, uniformly dispersed with carbon micro-nanofibers, has dramatically improved performance as a battery separator, with the ion conductivity of the electrolytes (LiPF6) saturated film measured as 0.119 S-cm(-1), approximately two orders of magnitude higher than that of polyvinyl alcohol. The other primary characteristics of the produced film, such as tensile strength, contact angle, and thermal stability, are also found to be superior to the materials made of other precursors, including polypropylene and polyethylene, discussed in the literature. The method of producing the films in this study is novel, simple, environmentally benign, and economically viable.

  14. Highly Aligned Poly(vinylidene fluoride-co-hexafluoro propylene) Nanofibers via Electrospinning Technique.

    Science.gov (United States)

    Han, Tae-Hwan; Nirmala, R; Kim, Tae Woo; Navamathavan, R; Kim, Hak Yong; Park, Soo Jin

    2016-01-01

    We report on the simple way of obtaining aligned poly(vinylidiene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers by electrospinning process. The collector drum rotation speed was adjusted to prepare well aligned PVDF-HFP nanofibers. The degree of alignment and the orientation of PVDF-HFP nanofibers can be significantly altered by varying the speed of collector drum rotation. The resultant PVDF-HFP nanofibers were systematically characterized. From the scanning electron microscopy data, it was found that the electrospun PVDF-HFP nanofibers were formed with well-aligned nature. The X-ray diffraction results revealed that the electrospun PVDF-HFP nanofibers with β-phase can be formed by the increased collector drum rotation speed. Overall, the collector rotation speed during the electrospinning process plays an important role in obtaining well-aligned and improved characteristics of PVDF-HFP nanofibers.

  15. Biofunctionalizing nanofibers with carbohydrate blood group antigens.

    Science.gov (United States)

    Barr, Katie; Kannan, Bhuvaneswari; Korchagina, Elena; Popova, Inna; Ryzhov, Ivan; Henry, Stephen; Bovin, Nicolai

    2016-11-01

    A rapid and simple method of biofunctionalising nylon, cellulose acetate, and polyvinyl butyral electrospun nanofibers with blood group glycans was achieved by preparing function-spacer-lipid constructs and simply contacting them to fibers with a piezo inkjet printer. A series of water dispersible amphipathic glycan-spacer constructs were synthesized representing a range ABO and related blood group antigens. After immediate contact of the amphipathic glycan-spacer constructs with nanofiber surfaces they self-assembled and were detectable by enzyme immunoassays with high sensitivity and specificity.

  16. Preparation of water stable methyl-modified metal-organic framework-5/polyacrylonitrile composite nanofibers via electrospinning and their application for solid-phase extraction of two estrogenic drugs in urine samples.

    Science.gov (United States)

    Asiabi, Mina; Mehdinia, Ali; Jabbari, Ali

    2015-12-24

    The nanofibers of methyl-modified metal-organic framework-5/polyacrylonitrile composite (CH3MOF-5/PAN) were successfully synthesized and used as a solid-phase extraction (SPE) sorbent for pre-concentration of two estrogenic drugs, levonorgestrel and megestrol acetate, in urine samples. A simple, cheap and accessible electrospinning method was employed to prepare a water stable CH3MOF-5/PAN composite. The nanofibers were packed into the mini-disc cartridges to be used as SPE devices. They were also characterized by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffraction and N2 adsorption-desorption experiments. The effects of different parameters influencing the extraction efficiency including the type of eluent and its volume, the amount of the sorbent, pH, the ionic strength, the sample volume and the reusability of the sorbent were investigated and optimized. Under the optimized conditions, the linearity varied in range of 0.05-100μgL(-1) with R(2) values higher than 0.999. The limit of detection for both of the analytes was 0.02μgL(-1). The applicability of the method was examined by analyzing the analytes in the urine samples. The recovery of the analytes varied in the range of 82.8-94.8% which shows capability of the method for the determination of the drugs in the urine samples.

  17. Biodegradable poly (ɛ-caprolactone)/gelatin nanofibers: Effect of tubular halloysite on structure and properties

    Science.gov (United States)

    Švachová, Veronika; Khunová, Viera; Vojtová, Lucy; PavliÅák, David

    2016-05-01

    The work explores preparation of new advanced nanofibers based on biodegradable polymers and biocompatible tubular halloysite (HNT). Electrospun nanofibers comprising 8 wt% gelatin (Gel) and 8 wt% poly (͛-caprolactone) (PCL) have been prepared by using eco-friendly solvent - acetic acid. The content of HNT in PCL/Gel nanofibers was 0.5, 1.0, 3.0, 6.0 and 9.0 wt%. It was found that the addition of HNT significantly affected the polymer mixture spinnability and the fiber diameter. SEM observations revealed that the structure of nanofibers depends on nanofiber composition. Whilst in nanofibers with lower HNT content uniform morphology with HNTs located merely inside the individual nanofibers has been observed, in nanofibers with 6 and 9 wt% HNT individual particles as well as the agglomerates of HNT have been detected in both, the inner part as well as outside part of nanofiber. Important reinforcing effect has been achieved in whole HNT content. The highest improvement has been reached when the HNT content was 0.5 wt%. In this case, multiple enhancements of strength (2x), elongation (4x) and modulus (2x) have been confirmed. ATR-FTIR revealed that improvement of mechanical properties is also due to the increase of interface interaction in between PCL/Gel and HNT. The prepared PCL/Gel/HNT nanofibers can be used for tissue engineering and/or as drug carriers or signal molecules in whole spectrum of medical applications.

  18. Antioxidant activity of polyaniline nanofibers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Well-confined uniform polyaniline (PANT) nanofibers were synthesized by using photo-assisted chemical oxidative polymerization of aniline in the presence of different dopant acids, and the radical scavenging ability of the produced PANI nanofibers was determined by the DPPH assay. It was found that the antioxidant activity of PANI nanofibers was higher than conventional PANI,and increased with decreasing of averaged diameter of the nanofibers. The enhanced antioxidant activity was concerned with increased surface area of PANI nanofibers.

  19. Nanoporous Carbon Nanofibers Decorated with Platinum Nanoparticles for Non-Enzymatic Electrochemical Sensing of H2O2

    Directory of Open Access Journals (Sweden)

    Yang Li

    2015-11-01

    Full Text Available We describe the preparation of nanoporous carbon nanofibers (CNFs decorated with platinum nanoparticles (PtNPs in this work by electrospining polyacrylonitrile (PAN nanofibers and subsequent carbonization and binding of PtNPs. The fabricated nanoporous CNF-PtNP hybrids were further utilized to modify glass carbon electrodes and used for the non-enzymatic amperometric biosensor for the highly sensitive detection of hydrogen peroxide (H2O2. The morphologies of the fabricated nanoporous CNF-PtNP hybrids were observed by scanning electron microscopy, transmission electron microscopy, and their structure was further investigated with Brunauer–Emmett–Teller (BET surface area analysis, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectrum. The cyclic voltammetry experiments indicate that CNF-PtNP modified electrodes have high electrocatalytic activity toward H2O2 and the chronoamperometry measurements illustrate that the fabricated biosensor has a high sensitivity for detecting H2O2. We anticipate that the strategies utilized in this work will not only guide the further design and fabrication of functional nanofiber-based biomaterials and nanodevices, but also extend the potential applications in energy storage, cytology, and tissue engineering.

  20. Preparation of polyaniline/sodium alanate hybrid using a spray-drying process

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, B. R., E-mail: bru-rms@yahoo.com.br, E-mail: fabiopassador@gmail.com, E-mail: pessan@ufscar.br; Passador, F. R., E-mail: bru-rms@yahoo.com.br, E-mail: fabiopassador@gmail.com, E-mail: pessan@ufscar.br; Pessan, L. A., E-mail: bru-rms@yahoo.com.br, E-mail: fabiopassador@gmail.com, E-mail: pessan@ufscar.br [Dep. de Engenharia de Materiais, Federal University of São Carlos (Brazil)

    2014-05-15

    Nowadays, hydrogen is highly interesting as an energy source, in particular in the automotive field. In fact, hydrogen is attractive as a fuel because it prevents air pollution and greenhouse emissions. One of the main problems with the utilization of hydrogen as a fuel is its on-board storage. The purpouse of this work was to develop a new hybrid material consisting of a polyaniline matrix with sodium alanate (NaAlH{sub 4}) using a spray-drying process. The polyaniline used for this experiment was synthesized by following a well-established method for the synthesis of the emeraldine base form of polyaniline using dodecylbenzenesulfonic acid as dopant. Micro particles of polyaniline/sodium alanate hybrids with 30 and 50 wt% of sodium alanate were prepared by using a spray-drying technique. Dilute solutions of polyaniline/sodium alanate were first prepared, 10g of the solid materials were mixed with 350 ml of toluene under stirring at room temperature for 24h and the solutions were dried using spray-dryer (Büchi, Switzerland) with 115°C of an inlet temperature. The hybrids were analyzed by differential scanning calorimetry, FT-IR and scanning electron microscopy (SEM). The addition of sodium alanate decreased the glass transition temperature of the hybrids when compared to neat polyaniline. FT-IR spectrum analysis was performed to identify the bonding environment of the synthesized material and was observed that simply physically mixture occurred between polyaniline and sodium alanate. The SEM images of the hybrids showed the formation of microspheres with sodium alanate dispersed in the polymer matrix.

  1. Surface modification of polyvinyl alcohol/malonic acid nanofibers by gaseous dielectric barrier discharge plasma for glucose oxidase immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Afshari, Esmail, E-mail: e.afshari@mail.sbu.ac.ir [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Mazinani, Saeedeh [Amirkabir Nanotechnology Research Institute (ANTRI), Amirkabir University of Technology, 15875-4413, Tehran (Iran, Islamic Republic of); Ranaei-Siadat, Seyed-Omid [Protein Research Center, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of); Ghomi, Hamid [Laser and Plasma Research Institute, Shahid Beheshti University, Evin, 1983963113 Tehran (Iran, Islamic Republic of)

    2016-11-01

    Highlights: • We fabricated polyvinyl alcohol/malonic acid nanofibers using electrospinning. • The surface nanofibers were modified by gaseous (air, nitrogen, CO{sub 2} and argon) dielectric barrier discharge. • Among them, air plasma had the most significant effect on glucose oxidase immobilization. • Chemical analysis showed that after modification of nanofibers by air plasma, the carboxyl group increased. • After air plasma treatment, reusability and storage stability of glucose oxidase immobilized on nanofibers improved. - Abstract: Polymeric nanofiber prepares a suitable situation for enzyme immobilization for variety of applications. In this research, we have fabricated polyvinyl alcohol (PVA)/malonic acid nanofibers using electrospinning. After fabrication of nanofibers, the effect of air, nitrogen, CO{sub 2}, and argon DBD (dielectric barrier discharge) plasmas on PVA/malonic acid nanofibers were analysed. Among them, air plasma had the most significant effect on glucose oxidase (GOx) immobilization. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectrum analysis and X-ray photoelectron spectroscopy (XPS) results revealed that in case of air plasma modified nanofibers, the carboxyl groups on the surface are increased. The scanning electron microscopy (SEM) images showed that, after GOx immobilization, the modified nanofibers with plasma has retained its nanofiber structure. Finally, we analysed reusability and storage stability of GOx immobilized on plasma modified and unmodified nanofibers. The results were more satisfactory for modified nanofibers with respect to unmodified ones.

  2. Preparation, characterization and electrocatalytic properties of poly(luminol) and polyoxometalate hybrid film modified electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Yu-Tsern; Lin, Kuo-Chiang; Chen, Shen-Ming [National Taipei University of Technology, Taipei 106 (Taiwan). Department of Chemical Engineering

    2005-10-20

    Hybrid films composed of poly(luminol) and nanometer-sized clusters of polyoxometalate, SiMo{sub 12}O{sub 40}{sup 4-} and PMo{sub 12}O{sub 40}{sup 3-} have been prepared in acidic aqueous solutions. These films are stable and electrochemically active, and produced on glassy carbon, platinum, gold and transparent semiconductor tin oxide electrodes. The electrochemical quartz crystal microbalance and cyclic voltammetry were used to study in situ growth of the hybrid poly(luminol)/SiMo{sub 12}O{sub 40}{sup 4-} and poly(luminol)/PMo{sub 12}O{sub 40}{sup 3-}. Both the poly(luminol)/SiMo{sub 12}O{sub 40}{sup 4-} and poly(luminol)/PMo{sub 12}O{sub 40}{sup 3-} hybrid films showed four redox couples and the electrochemical properties were compared to SiMo{sub 12}O{sub 40}{sup 4-} and PMo{sub 12}O{sub 40}{sup 3-}. When transferred to various acidity aqueous solutions, the four redox couples and the formal potentials of two hybride film were observed to be pH-dependent. The electrocatalytic reduction of ClO{sub 3}{sup -}, BrO{sub 3}{sup -}, IO{sub 3}{sup -}, S{sub 2}O{sub 8}{sup 2-} and NO{sub 2}{sup -}by a poly(luminol)/PMo{sub 12}O{sub 40}{sup 3-} hybrid film in an acidic aqueous solution showed an electrocatalytic reduction activity of IO{sub 3}{sup -} > BrO{sub 3}{sup -} and ClO{sub 3}{sup -}. The electrocatalytic oxidation of dopamine and epinephrine by a poly(luminol)/PMo{sub 12}O{sub 40}{sup 3-} hybrid film was also investigated. (author)

  3. Preparation of porous chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles via mineralization

    Institute of Scientific and Technical Information of China (English)

    CHEN ChangJing; DENG Yu; YAN ErYun; HU Yong; JIANG XiQun

    2009-01-01

    In this work,the preparation of chitosan-poly(acrylic acid)-calcium phosphate hybrid nanoparticles (CS-PAA-CaP NP) based on the mineralization of calcium phosphate (CAP) on the surface of chitosan-poly (acrylic acid) nanoparticles (CS-PAA NPs) was reported. CS-PAA-CaP NPs were achieved by directly adding ammonia to the aqueous solution of CS-PAA nanoparticles or by thermal decomposition of urea in the aqueous solution of CS-PAA nanoparticles,resulting in the mineralization of CaP on the surface of CS-PAA NPs. Through these two routes,especially using urea as a pH-regulator,the precipitation of CS-PAA NPs,a common occurrence in basic environment,was avoided. The size,morphology and ingredient of CS-PAA-CaP hybrid nanoparticles were characterized by dynamic light scattering (DLS),transmission electron microscope (TEM),scanning electron microscope (SEM),thermogravimetry analysis (TGA) and X-ray diffractometer (XRD). When urea was used as the pH regulator to facilitate the mineralization during the thermal urea decomposition procedure,regular CS-PAA-CaP hybrid nanoparticles with a porosity-structural CaP shells and 400-600 nm size were obtained. TGA result revealed that the hybrid NPs contained approximately 23% inorganic component,which was consistent with the ratio of starting materials. The XRD spectra of hybrid nanoparticles indicated that dicalcium phosphate (DCP:CaHPO4) crystal was a dominant component of mineralization.The porous structure of the CS-PAA-CaP hybrid NPs might be greatly useful in pharmaceutical and other medical applications.

  4. Surface functionalization of carbon nanofibers by sol-gel coating of zinc oxide

    Energy Technology Data Exchange (ETDEWEB)

    Shao Dongfeng [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China); Changzhou Textile Garment Institute, Changzhou 213164 (China); Wei Qufu [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)], E-mail: qfwei@jiangnan.edu.cn; Zhang Liwei; Cai Yibing; Jiang Shudong [Key Laboratory of Eco-textiles, Ministry of Education, Jiangnan University, Wuxi 214122 (China)

    2008-08-15

    In this paper the functional carbon nanofibers were prepared by the carbonization of ZnO coated PAN nanofibers to expand the potential applications of carbon nanofibers. Polyacrylonitrile (PAN) nanofibers were obtained by electrospinning. The electrospun PAN nanofibers were then used as substrates for depositing the functional layer of zinc oxide (ZnO) on the PAN nanofiber surfaces by sol-gel technique. The effects of coating, pre-oxidation and carbonization on the surface morphology and structures of the nanofibers were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) and Scanning electron microscopy (SEM), respectively. The results of SEM showed a significant increase of the size of ZnO nanograins on the surface of nanofibers after the treatments of coating, pre-oxidation and carbonization. The observations by SEM also revealed that ZnO nanoclusters were firmly and clearly distributed on the surface of the carbon nanofibers. FTIR examination also confirmed the deposition of ZnO on the surface of carbon nanofibers. The XRD analysis indicated that the crystal structure of ZnO nanograins on the surface of carbon nanofibers.

  5. Cyclodextrin-grafted electrospun cellulose acetate nanofibers via “Click” reaction for removal of phenanthrene

    Science.gov (United States)

    Celebioglu, Asli; Demirci, Serkan; Uyar, Tamer

    2014-06-01

    Beta-cyclodextrin (β-CD) functionalized cellulose acetate (CA) nanofibers have been successfully prepared by combining electrospinning and “click” reaction. Initially, β-CD and electrospun CA nanofibers were modified so as to be azide-β-CD and propargyl-terminated CA nanofibers, respectively. Then, “click” reaction was performed between modified CD molecules and CA nanofibers to obtain permanent grafting of CDs onto nanofibers surface. It was observed from the SEM image that, while CA nanofibers have smooth surface, there were some irregularities and roughness at nanofibers morphology after the modification. Yet, the fibrous structure was still protected. ATR-FTIR and XPS revealed that, CD molecules were successfully grafted onto surface of CA nanofibers. The adsorption capacity of β-CD-functionalized CA (CA-CD) nanofibers was also determined by removing phenanthrene (polycyclic aromatic hydrocarbons, PAH) from its aqueous solution. Our results indicate that CA-CD nanofibers have potential to be used as molecular filters for the purpose of water purification and waste water treatment by integrating the high surface area of nanofibers with inclusion complexation property of CD molecules.

  6. Physicochemical properties of hybrid graphene-lead sulfide quantum dots prepared by supercritical ethanol

    Science.gov (United States)

    Tavakoli, Mohammad Mahdi; Tayyebi, Ahmad; Simchi, Abdolreza; Aashuri, Hossein; Outokesh, Mohmmad; Fan, Zhiyong

    2015-01-01

    Recently, hybrid graphene-quantum dot systems have attracted increasing attention for the next-generation optoelectronic devices such as ultrafast photo-detectors and solar energy harvesting. In this paper, a novel, one-step, reproducible, and solution-processed method is introduced to prepare hybrid graphene-PbS colloids by employing supercritical ethanol. In the hybrid nanocomposite, PbS quantum dots ( 3 nm) are decorated on the reduced graphene oxide (rGO) nanosheets ( 1 nm thickness and less than 1 micron lengths). By employing X-ray photoelectron and Raman and infrared spectroscopy techniques, it is shown that the rGO nanosheets are bonded to PbS nanocrystals through carboxylic bonds. Passivation of {111} planes of PbS quantum dots with rGO nanosheets is demonstrated by employing density function theory. Quenching of the photoluminescence emission of PbS nanocrystals through coupling with graphene sheets is also shown. In order to illustrate that the developed preparation method does not impair the quantum efficiency of the PbS nanocrystals, the photovoltaic efficiency of solar cell device is reported and compared with oleic acid-capped PbS colloidal quantum dot solar cells. By employing the "Hall effect" measurement, it is shown that the carrier mobility is significantly increased (by two orders of magnitudes) in the presence of graphene nanosheets.

  7. Nanostructure of PDMS–TEOS–PrZr hybrids prepared by direct deposition of gamma radiation energy

    Energy Technology Data Exchange (ETDEWEB)

    Lancastre, Joana J.H., E-mail: jlancastre@ctn.ist.utl.pt [C2TN, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 (km 139.7), 2695-066 Bobadela, LRS (Portugal); Falcão, António N. [C2TN, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 (km 139.7), 2695-066 Bobadela, LRS (Portugal); Margaça, Fernanda M.A., E-mail: fmargaca@ctn.ist.utl.pt [C2TN, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 (km 139.7), 2695-066 Bobadela, LRS (Portugal); Ferreira, Luís M. [C2TN, Instituto Superior Técnico, Universidade de Lisboa, E.N. 10 (km 139.7), 2695-066 Bobadela, LRS (Portugal); Miranda Salvado, Isabel M. [CICECO & Departamento de Engenharia de Materiais e Cerâmica, Universidade de Aveiro, Campus de Santiago, 3810-193 Aveiro (Portugal); Almásy, László [Wigner Research Centre for Physics, Institute for Solid State Physics and Optics, PO Box 49, 1525 Budapest (Hungary); Casimiro, Maria H. [REQUIMTE/CQFB, Departamento de Química, Faculdade de Ciências e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Meiszterics, Anikó [Gedeon Richter Ltd., PO Box 27, H-1475 Budapest (Hungary)

    2015-10-15

    Highlights: • Hybrid materials were prepared by direct energy deposition. • The influence of the catalyst content (PrZr) was investigated. • The developed oxide network was found to be strongly dependent on the PrZr content. • A model is proposed for the development of the oxide network in these materials. - Abstract: Organic–inorganic materials have been the object of intense research due to their wide range of properties and therefore innumerous applications. We prepared organic–inorganic hybrid materials by direct energy deposition on a mixture of polydimethylsiloxane silanol terminated (33 wt% fixed content), tetraethylorthosilicate and a minor content of zirconium propoxide that varied from 1 to 5 wt% using gamma radiation from a Co-60 source. The samples, dried in air at room temperature, are bulk, flexible and transparent. Their nanostructure was investigated by small angle neutron scattering. It was found that the inorganic oxide network has fractal structure, which becomes denser as the zirconium propoxide content decreases. The results suggest that oxide nanosized regions grow from the OH terminal group of PDMS which are the condensation seeds. Their number and position remains unaltered with the variation of zirconium propoxide content that only affects their microstructure. A model is proposed for the nanostructure of the oxide network that develops in the irradiation processed hybrid materials.

  8. Physicochemical properties of hybrid graphene–lead sulfide quantum dots prepared by supercritical ethanol

    Energy Technology Data Exchange (ETDEWEB)

    Tavakoli, Mohammad Mahdi [Sharif University of Technology, Department of Materials Science and Engineering (Iran, Islamic Republic of); Tayyebi, Ahmad [Sharif University of Technology, Department of Energy (Iran, Islamic Republic of); Simchi, Abdolreza, E-mail: simchi@sharif.edu; Aashuri, Hossein [Sharif University of Technology, Department of Materials Science and Engineering (Iran, Islamic Republic of); Outokesh, Mohmmad [Sharif University of Technology, Department of Energy (Iran, Islamic Republic of); Fan, Zhiyong [Hong Kong University of Science and Technology, Department of Electronic and Computer Engineering (Hong Kong)

    2015-01-15

    Recently, hybrid graphene–quantum dot systems have attracted increasing attention for the next-generation optoelectronic devices such as ultrafast photo-detectors and solar energy harvesting. In this paper, a novel, one-step, reproducible, and solution-processed method is introduced to prepare hybrid graphene–PbS colloids by employing supercritical ethanol. In the hybrid nanocomposite, PbS quantum dots (∼3 nm) are decorated on the reduced graphene oxide (rGO) nanosheets (∼1 nm thickness and less than 1 micron lengths). By employing X-ray photoelectron and Raman and infrared spectroscopy techniques, it is shown that the rGO nanosheets are bonded to PbS nanocrystals through carboxylic bonds. Passivation of {111} planes of PbS quantum dots with rGO nanosheets is demonstrated by employing density function theory. Quenching of the photoluminescence emission of PbS nanocrystals through coupling with graphene sheets is also shown. In order to illustrate that the developed preparation method does not impair the quantum efficiency of the PbS nanocrystals, the photovoltaic efficiency of solar cell device is reported and compared with oleic acid-capped PbS colloidal quantum dot solar cells. By employing the “Hall effect” measurement, it is shown that the carrier mobility is significantly increased (by two orders of magnitudes) in the presence of graphene nanosheets.

  9. Facile aqueous-phase synthesis of copper sulfide nanofibers

    Science.gov (United States)

    Tang, Zengmin; Im, Sang Hyuk; Kim, Woo-Sik; Yu, Taekyung

    2017-07-01

    We report a facile aqueous-phase synthetic route to vine-like copper sulfide (CuS) nanofibers prepared by reacting elemental sulfur with Cu+-branched polyethyleneimine (BPEI) complex obtained by the reaction of Cu2+ with ascorbic acid in the presence of BPEI. By controlling the concentration of BPEI, we could easily control the morphology of CuS from nanofibers to hollow nanoparticles. We also found that concentration of BPEI and the presence of halide anion would play important roles in the formation of vine-like CuS nanofibers.

  10. Preparation and characterization of ZnO/ZnS hybrid photocatalysts via microwave-hydrothermal method

    Institute of Scientific and Technical Information of China (English)

    Jinglian ZHAO; Liang ZHAO; Xinping WANG

    2008-01-01

    The photocatalytic performance of ZnO/ZnS hybrid nanocomposite was largely higher than that of the mere ZnO or ZnS nanoparticles, but the complicated procedure and misdistribution of final products limited its large-scale productions. The exploration of a novel syn-thesis route of ZnO/ZnS hybrid photocatalysts with high catalytic performance is becoming a crucial step for the large-scale application of ZnO/ZnS hybrid photocatalytic technique. Preparation and characterization of nanosized ZnO/ZnS hybrid photocatalysts were studied in this paper. The photocatalysts were obtained via microwave-hydrothermal crystallization with the help of sodium cit-rate. The products were characterized by X-ray diffrac-tion (XRD), transmission electron microscopy (TEM), particle size distribution (PSD), and Fourier transformed infrared spectroscopy (FT-IR). The results indicated that so-synthesized ZnO/ZnS samples consisted of the high pure cubic (sphalerite) ZnS and hexagonal ZnO nanocrys-tallines with a narrow particle size distribution. The pos-sible formation mechanisms of ZnO/ZnS nanocrystallines were mainly attributed to the superficially protective effect of citrate. The photocatalytic experiments demon-strated that the ZnO/ZnS photocatalysts exhibited a higher catalytic activity for the degradation of acid fuchs-ine than other monocomponents.

  11. Preparation of layered double hydroxide/chlorophyll a hybrid nano-antennae: a key step.

    Science.gov (United States)

    Sommer Márquez, Alicia E; Lerner, Dan A; Fetter, Geolar; Bosch, Pedro; Tichit, Didier; Palomares, Eduardo

    2014-07-21

    In the first step to obtain an efficient nano-antenna in a bottom-up approach, new hybrid materials were synthesized using a set of layered double hydroxides (LDHs) with basic properties and pure chlorophyll a (Chl a). The stability of the adsorbed monolayer of Chl a was shown to be dependent on the nature and the ratio of the different metal ions present in the LDHs tested. The hybrid materials turned out to be adequate for stabilizing Chl a on Mg/Al LDHs for more than a month under ambient conditions while a limited catalytic decomposition was observed for the Ni/Al LDHs leading to the formation of pheophytin. These changes were followed by namely XRD, DR-UV-vis and fluorescence spectroscopies of the hybrid antennae and of the solutions obtained from their lixiviation with acetone or diethylether. On Mg/Al hydrotalcites the stability of the adsorbed Chl a was equivalent for values of the metal atom ratio ranging from 2 to 4. The latter hybrids should constitute a good basis to form efficient nanoscale light harvesting units following intercalation of selected dyes. This work describes an efficient preparation of Chl a that allows scale-up as well as the obtention of a stable Chl a monolayer on the surface of various LDHs.

  12. Preparation and antibacterial properties of hybrid-zirconia films with silver nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Azocar, Ignacio, E-mail: manuel.azocar@usach.cl [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Vargas, Esteban [Facultad de Ingenieria, Departamento de Metalurgia, Universidad de Santiago de Chile, USACH (Chile); Duran, Nicole [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Arrieta, Abel [Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH (Chile); Gonzalez, Evelyn [Departamento de Quimica de los Materiales, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH, Avenida Bernardo O' Higgins 3363, Casilla 40, Correo 33, Santiago (Chile); Facultad de Ingenieria, Departamento de Metalurgia, Universidad de Santiago de Chile, USACH (Chile); Departamento de Biologia, Facultad de Quimica y Biologia, Universidad de Santiago de Chile, USACH (Chile); Departamento de Quimica Farmacologica y Toxicologica, Facultad de Ciencias Quimicas, Universidad de Chile, Sergio Livingstone Polhammer 1007, Santiago (Chile); and others

    2012-11-15

    The antimicrobial effect of incorporating silver nanoparticles (AgNps) into zirconia matrix-polyether glycol was studied. AgNps of 4-6 nm in size were synthesized using the inverse micelles method, and different doses of metallic nanoparticles were incorporated into zirconia-polyether glycol mixtures during the ageing procedure. Atomic force microscopy (AFM) of the modified hybrid film showed a homogenous distribution of 20-80 nm diameter AgNps, indicating agglomeration of these structures during film modification; such agglomerations were greater when increasing the dosage of the colloidal system. The AgNps-hybrid films showed higher antimicrobial activity against Gram-positive bacteria than for Gram-negative bacteria. Hybrid films prepared with dioctyl sodium sulfosuccinate (AOT) stabilized AgNps presented enhanced antibacterial activity compared to that obtained through the addition of a high AgNO{sub 3} concentration (0.3 wt%). -- Graphical abstract: Atomic Force Micrographs, top and cross section view, showing silver nanoparticles embedded in a zirconia-polyether glycol hybrid film. Highlights: Black-Right-Pointing-Pointer Antibacterial activity of films (zirconia-polyether glycol) modified with silver nanoparticles. Black-Right-Pointing-Pointer Biofilm formation is prevented. Black-Right-Pointing-Pointer High sensibility against gram positive bacteria.

  13. Sample preparation and in situ hybridization techniques for automated molecular cytogenetic analysis of white blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Rijke, F.M. van de; Vrolijk, H.; Sloos, W. [Leiden Univ. (Netherlands)] [and others

    1996-06-01

    With the advent in situ hybridization techniques for the analysis of chromosome copy number or structure in interphase cells, the diagnostic and prognostic potential of cytogenetics has been augmented considerably. In theory, the strategies for detection of cytogenetically aberrant cells by in situ hybridization are simple and straightforward. In practice, however, they are fallible, because false classification of hybridization spot number or patterns occurs. When a decision has to be made on molecular cytogenetic normalcy or abnormalcy of a cell sample, the problem of false classification becomes particularly prominent if the fraction of aberrant cells is relatively small. In such mosaic situations, often > 200 cells have to be evaluated to reach a statistical sound figure. The manual enumeration of in situ hybridization spots in many cells in many patient samples is tedious. Assistance in the evaluation process by automation of microscope functions and image analysis techniques is, therefore, strongly indicated. Next to research and development of microscope hardware, camera technology, and image analysis, the optimization of the specimen for the (semi)automated microscopic analysis is essential, since factors such as cell density, thickness, and overlap have dramatic influences on the speed and complexity of the analysis process. Here we describe experiments that have led to a protocol for blood cell specimen that results in microscope preparations that are well suited for automated molecular cytogenetic analysis. 13 refs., 4 figs., 1 tab.

  14. Method for isolating chromosomal DNA in preparation for hybridization in suspension

    Science.gov (United States)

    Lucas, Joe N.

    2000-01-01

    A method is provided for detecting nucleic acid sequence aberrations using two immobilization steps. According to the method, a nucleic acid sequence aberration is detected by detecting nucleic acid sequences having both a first nucleic acid sequence type (e.g., from a first chromosome) and a second nucleic acid sequence type (e.g., from a second chromosome), the presence of the first and the second nucleic acid sequence type on the same nucleic acid sequence indicating the presence of a nucleic acid sequence aberration. In the method, immobilization of a first hybridization probe is used to isolate a first set of nucleic acids in the sample which contain the first nucleic acid sequence type. Immobilization of a second hybridization probe is then used to isolate a second set of nucleic acids from within the first set of nucleic acids which contain the second nucleic acid sequence type. The second set of nucleic acids are then detected, their presence indicating the presence of a nucleic acid sequence aberration. Chromosomal DNA in a sample containing cell debris is prepared for hybridization in suspension by treating the mixture with RNase. The treated DNA can also be fixed prior to hybridization.

  15. Preparation and characterization of SiO₂/CMC/Ag hybrids with antibacterial properties.

    Science.gov (United States)

    Rangelova, Nadezhda; Aleksandrov, Lyubomir; Angelova, Tsvetelina; Georgieva, Nelly; Müller, Rudolf

    2014-01-30

    Amorphous hybrids based on sodium salt of carboxymethyl cellulose (CMC) and tetraethoxysilane (TEOS) containing silver nanoparticles were prepared by sol-gel method. The amorphous structure, morphology and antibacterial behavior were clarified. The thermal stability of obtained hybrids decreased with the increase in silver content from 0.5 to 1.5 wt%. Infrared spectra of the material suggest that the main interaction between the cellulose ether and silica network is via hydrogen bonds (bands at approximately 3,540 and 3,625 cm(-1)). According to UV-vis spectra the silver is present in two different states Ag(+) (absorption band at approximately 210 nm) and Ag(0) (band at approximately 300 nm). The different sizes of silver particles are present as clusters. It was demonstrated that these hybrids have a well pronounced antibacterial activity against B. subtilis and E. coli K12. Even the hybrid with 0.5 wt% Ag has efficient antibacterial activity for both Gram-positive and Gram-negative bacteria.

  16. Bioactive thermoresponsive polyblend nanofiber formulations for wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, Mahesh D. [Polymer Science and Engineering, National Chemical Laboratory, Homi Bhabha Road, Pashan, Pune 411008 (India); MAEER' s Maharashtra Institute of Pharmacy S. No. 124, MIT Campus Paud Road, Kothrud, Pune 411 038 (India); Rathna, G.V.N., E-mail: rv.gundloori@ncl.res.in [Polymer Science and Engineering, National Chemical Laboratory, Homi Bhabha Road, Pashan, Pune 411008 (India); Agrawal, Shubhang [Polymer Science and Engineering, National Chemical Laboratory, Homi Bhabha Road, Pashan, Pune 411008 (India); Kuchekar, Bhanudas S. [MAEER' s Maharashtra Institute of Pharmacy S. No. 124, MIT Campus Paud Road, Kothrud, Pune 411 038 (India)

    2015-03-01

    The rationale of this work is to develop new bioactive thermoresponsive polyblend nanofiber formulations for wound healing (topical). Various polymer compositions of thermoresponsive, poly(N-isopropylacrylamide), egg albumen and poly(ε-caprolactone) blend solutions with and without a drug [gatifloxacin hydrochloride, Gati] were prepared. Non-woven nanofibers of various compositions were fabricated using an electrospinning technique. The morphology of the nanofibers was analyzed by an environmental scanning electron microscope. The morphology was influenced by the concentration of polymer, drug, and polymer blend composition. Fourier transform infrared spectroscopy analysis showed the shift in bands due to hydrogen ion interactions between polymers and drug. Thermogram of PNIPAM/PCL/EA with Gati recorded a shift in lower critical solution temperature (LCST) and glass transition temperature (T{sub g}) of PNIPAM. Similarly T{sub g} and melting temperature (T{sub m}) of PCL were shifted. X-ray diffraction patterns recorded a decrease in the crystalline state of PCL nanofibers and transformed crystalline drug to an amorphous state. In vitro release study of nanofibers with Gati showed initial rapid release up to 10 h, followed by slow and controlled release for 696 h (29 days). Nanofiber mats with Gati exhibited antibacterial properties to Staphylococcus aureus, supported suitable controlled drug release with in vitro cell viability and in vivo wound healing. - Highlights: • Thermoresponsive and bioactive nanofiber blends of PNIPAM/EA/PCL were fabricated. • Nanofiber blends favored initial rapid release, followed by controlled release. • In vitro cell viability of pure polymers and nanofiber blends was least toxic. • In vivo studies of drug loaded nanofiber mats recorded faster tissue regeneration.

  17. Electrochemical Preparation of Chiral Polyaniline Nanofibers%手性聚苯胺纳米纤维的电化学制备

    Institute of Scientific and Technical Information of China (English)

    翁少煌; 周剑章; 林仲华; 林新华

    2012-01-01

    Chiral polyaniline ( PANI) nanofibers were synthesized via facilely potentiostatic electropolymeriza-tion method without template in the presence of ( IS) -( +) -camphor-10-sulfonic acid(D-CSA) or ( IR) -( -)-camphor-10-sulfonic acid(L-CSA) as the dopant. The morphology and optical property of chiral PANI nanofibers were characterized with scanning electron microscopy ( SEM ) , transmission electron microscopy ( TEM ) , UV-Vis spectrum(UV-Vis) and circular dichroism(CD) . Combined with the average diameter of micelles and zeta-potential of different deposition solutions, the formation mechanism and the enhanced optical activity of the optical PANI nanofibers were studied. The morphology of PANI nanofibers without the helical structure was consistent with the change of the concentration of aniline in the deposition solution when the concerntion of CSA was 1 mol/L. Furthermore, the chiral PANI nanofibers induced by different chiral CSA exhibited mirror-imaged circular dichroism spectra with high ellipticity, indicating the stereochemical selectivity of the molecular structure of PANI chain in the electrodeposited process. The colors and optical activities of the chiral PANI nanofibers not only can be kept with the chemical dedoping/redoping treatment, but also can reversibly varied with the different oxidized forms which were controlled via electrochemical route.%采用恒电位电聚合法制备了樟脑磺酸(CSA)掺杂的旋光异构性聚苯胺(PANI)纳米纤维.用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、紫外-可见吸收光谱(UV-Vis)和圆二色光谱(CD)对PANI纳米纤维的形貌和光学性质进行表征,结合电聚合溶液胶束平均粒径和ξ电位的测定,研究了具有旋光异构性PANI纳米纤维的形成机理和具有增强旋光异构性的原因.所制备的PANI纳米纤维具有无双螺旋结构,其形貌不随着苯胺浓度的改变而变化.不同手性樟脑磺酸掺杂制备的PANI纳米纤维具有镜像对称

  18. Collection of Electrospun Polymer Nanofibers

    Science.gov (United States)

    Kataphinan, Woraphon; Reneker, Darrell H.

    2000-03-01

    The dry nanofibers produced in a typical electrospinning process are electrically charged. The nanofibers were directed by an electrical field, a tensile force along the axis of the fiber, and by the viscous drag force of moving air. The looping and spiraling path of the nanofibers, which resulted from bending and other kinds of instabilities that occurred as the fiber was formed, also complicated the collection process. Non-woven sheets of nanofibers were made by attracting the nanofibers to a conducting sheet or screen. The sheet or screen was flat and stationary, or wrapped around a rotating drum. Nanofibers were also collected in a liquid. The liquid removed charge or solvent. Nanofibers were collected on the surface of a non-wetting liquid, so that the patterns formed by the arriving nanofibers were observed directly. Streams of air, and air vortices were also used. These methods are being combined with robotic manipulators to collect nanofibers in many useful forms.

  19. Porous polylactic acid-silica hybrids: preparation, characterization, and study of mesenchymal stem cell osteogenic differentiation.

    Science.gov (United States)

    Pandis, Christos; Trujillo, Sara; Matos, Joana; Madeira, Sara; Ródenas-Rochina, Joaquín; Kripotou, Sotiria; Kyritsis, Apostolos; Mano, João F; Gómez Ribelles, José Luis

    2015-02-01

    A novel approach to reinforce polymer porous membranes is presented. In the prepared hybrid materials, the inorganic phase of silica is synthesized in-situ and inside the pores of aminolyzed polylactic acid (PLA) membranes by sol-gel reactions using tetraethylorthosilicate (TEOS) and glycidoxypropyltrimethoxysilane (GPTMS) as precursors. The hybrid materials present a porous structure with a silica layer covering the walls of the pores while GPTMS serves also as coupling agent between the organic and inorganic phase. The adjustment of silica precursors ratio allows the modulation of the thermomechanical properties. Culture of mesenchymal stem cells on these supports in osteogenic medium shows the expression of characteristic osteoblastic markers and the mineralization of the extracellular matrix.

  20. Zirconium oxocluster/polymer hybrid nanoparticles prepared by photoactivated miniemulsion copolymerization

    Science.gov (United States)

    Benedetti, Cesare; Flouda, Paraskevi; Antonello, Alice; Rosenauer, Christine; Pérez-Pla, Francisco F.; Landfester, Katharina; Gross, Silvia; Muñoz-Espí, Rafael

    2017-09-01

    The photoactivated free radical miniemulsion copolymerization of methyl methacrylate (MMA) and the zirconium oxocluster Zr4O2(methacrylate)12 is used as an effective and fast preparation method for polymer/inorganic hybrid nanoparticles. The oxoclusters, covalently anchored to the polymer network, act as metal-organic cross-linkers, thus improving the thermomechanical properties of the resulting hybrid nanoparticles. Benzoin carbonyl organic compounds were used as photoinitiators. The obtained materials are compared in terms of cross-linking, effectiveness of cluster incorporation, and size distribution with the analogous nanoparticles produced by using conventional thermally induced free radical miniemulsion copolymerization. The kinetics of the polymerization process in the absence and in the presence of the oxocluster is also investigated.

  1. Preparation and characterization of gold nanoparticles capped by peptide-biphenyl hybrids.

    Science.gov (United States)

    Pérez, Yolanda; Mann, Enrique; Herradón, Bernardo

    2011-07-15

    Gold nanoparticles were prepared using peptide-biphenyl hybrids (PBHs) as capping agents. AuNPs were characterized by different techniques including UV-Vis, TEM, EDX, FT-IR, elemental analysis, (1)H NMR and (13)C CP/MAS NMR spectroscopy. TEM analysis showed that AuNPs present diameters in the range of 1.8-3.7 nm, depending on the structure and the amount of the capping PBH used. FT-IR spectroscopy and solid-state (13)C NMR revealed that the carboxylic group of PBHs, especially in the case of the acid ligands, interacts with the gold surface (in the form of carboxylate). The results confirm that PBHs are excellent stabilizers of AuNPs, being one of the first examples on the use of peptidomimetics-gold hybrid materials.

  2. Preparation of poly(3,4-ethylenedioxythiophene) nanofibers modified pencil graphite electrode and investigation of over-oxidation conditions for the selective and sensitive determination of uric acid in body fluids

    Energy Technology Data Exchange (ETDEWEB)

    Özcan, Ali, E-mail: aozcan3@anadolu.edu.tr; İlkbaş, Salih

    2015-09-03

    In this study, we have performed the preparation of over-oxidized poly(3,4-ethylenedioxythiophene) nanofibers modified pencil graphite electrode (Ox-PEDOT-nf/PGE) to develop a selective and sensitive voltammetric uric acid (UA) sensor. It was noted that the over-oxidation potential and time had a prominent effect on the UA response of the Ox-PEDOT-nf/PGE. Characterizations of PEDOT-nf/PGE and Ox-PEDOT-nf/PGE have been performed by cyclic voltammetry, electrochemical impedance spectroscopy, scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The highest voltammetric response of UA was obtained at pH 2.0. A linear relationship between the concentration of UA and oxidation peak currents was observed in the concentration range of 0.01–20.0 μM. The detection limit (1.3 nM according to S/N = 3) and reproducibility (RSD: 4.6 % for N:10) have also been determined. The effects of different substances on the determination of UA have been investigated. A very high peak separation value of 423 mV was obtained between UA and ascorbic acid which is the major interfering substance for UA. The use of Ox-PEDOT-nf/PGE has been successfully tested in the determination of UA in human blood serum and urine samples for the first time in the literature. - Highlights: • Modification of pencil graphite with over-oxidized PEDOT nanofibers was performed. • The prepared electrodes were used in the voltammetric determination of uric acid. • The over-oxidation potential and time has a prominent effect on the responses. • A very high peak separation (463 mV) was obtained between ascorbic and uric acids. • Analytical application of the electrodes was successfully tested in real samples.

  3. ACF-Ag-TiO2纳米纤维的制备及其光催化性能%Preparation of ACF-Ag-TiO2 Nanofibers and Their Photocatalytic Properties

    Institute of Scientific and Technical Information of China (English)

    万郁楠; 李巧玲; 李洪刚; 刘晓霞; 武润平; 续丽丽

    2013-01-01

    Activated carbon fiber(ACF)-Ag-TiO2 nanofiber composite materials were prepared using hydrothermal method combining with sol-gel method. The samples were analyzed by SEM, TEM and EDS. Taking methylene orange degradation as a model reaction, the photocatalytic property of the material was investigated. The results indicate that the length of nanofibers is between 4 and 8 μm, and the diameter is between S and 50 nm. As the mass fraction of element Ag doping in the prepared materials is 0.5%, the photocatalysis efficiency was at the maximum. The photocatalysis efficiency on the methylene orange is up to 95 % after lighting for 30 min.%将溶胶-凝胶法与水热法相结合制备活性碳纤维(ACF)-Ag-TiO2纳米纤维复合材料,利用扫描电镜、透射电镜、能量色散型X射线光谱仪对ACF-Ag-TiO2纳米纤维复合物的表面形貌及晶型进行表征,并以甲基橙的脱色降解为模式反应,考察样品的光催化性能.结果表明,ACF-Ag-TiO2纳米纤维长度为4~8 μm,直径约为5~50 nm;制备的材料中Ag元素的质量分数为0.5%时,ACF-Ag-TiO2的催化效果最优,光照30 min后时甲基橙的降解率为95%.

  4. Preparation, characterization and antimicrobial property of ag+- nano Chitosan/ZSM-5: novel Hybrid Biocomposites

    Directory of Open Access Journals (Sweden)

    Maasoumeh Khatamiana

    2016-10-01

    Full Text Available Objective(s: Binary hybrids of chitosan-zeolite have many interesting applications in separation and bacteriostatic activity. Materials and Methods: Template free ZSM-5 zeolite was synthesized by hydrothermal method, physical hydrogels of nano chitosan in the colloidal domain were obtained in the absence of toxic organic solvent and then nano chitosan/ZSM-5 hybrid composites with nano chitosan contents of 0.35%, 3.5%, 35% wt.% were prepared. The as prepared hybrid composites were ion-exchanged with Ag cations. Results: XRD and FT-IR results revealed a good crystalinity of as synthesized template frees ZSM-5 with BET surface area of 307 m2g-1. Presence of chitosan in composites was confirmed by XRD patterns and FT-IR spectroscopic analysis, the chitosan content in composite was obtained with TG analysis. SEM analysis of composites shows that chitosan particles were dispersed within the nanometer scale. The antimicrobial activity of different samples was investigated and the results showed that the Ag+-exchanged samples have the highest antibacterial properties. Cancer cell line A549 cell line were cultured in designated medium treated with Ag+-exchanged samples at the concentration of 0.01 to 0.5 mg/ml. After 24 and 48 hours incubation, the efficacy of Ag+-exchanged samples to treat cancer cell lines were measured by means of cell viability test via MTT assay. Concentrations of 0.05 and 0.1 mg/ml of Ag+-exchanged samples induced a very low toxicity. Conclusion: These hybrid composite materials have potential applications on tissue engineering and antimicrobial food packaging.

  5. Smart nanofibers with a photoresponsive surface for controlled release.

    Science.gov (United States)

    Fu, Guo-Dong; Xu, Li-Qun; Yao, Fang; Li, Guo-Liang; Kang, En-Tang

    2009-11-01

    A novel photocontrolled "ON-OFF" release system for the alpha-cyclodextrin-5-fluorouracial (alpha-CD-5FU) prodrug, based on host-guest interaction on the photoresponsive and cross-linked nanofiber surface, was demonstrated. The nanofibers with a stimuli-responsive surface were electrospun from the block copolymer prepared via controlled radical polymerization, followed by surface modification via "Click Chemistry", and loading of the prodrug via host-guest interaction.

  6. PREPARATION AND PROPERTIES OF SPAES-TiO_2 HYBRID MEMBRANES FOR DIRECT METHANOL FUEL CELL

    Institute of Scientific and Technical Information of China (English)

    Ni Zhang; Hui-ling Liu; Jun-jing Li; Zhi Xia

    2009-01-01

    Sulfonated poly(arylene ether sulfone) (SPAES) copolymer with degree of sulfonation of 1.0 was synthesized and characterized. A series of SPAES-TiO_2 hybrid membranes with various contents of nano-sized TiO_2 particles were prepared and characterized through sol-gel reactions. Scanning electron microscopy (SEM) images indicated the TiO_2 particles were well dispersed within polymer matrix. These composite membranes were evaluated for proton exchange membranes (PEMs) in direct methanol fuel cell (DMFC). These membranes showed good thermal stability and mechanical properties. It was found that the water uptake of these membranes increased with the increase of the TiO_2 contents in the hybrid membranes. Meanwhile, the introduction of inorganic particles increased the proton conductivity and reduced the methanol permeability. The proton conductivities (0.118-0.162 S/cm) of SPAES-TiO_2 hybrid membranes with 8% TiO_2 particles are much higher than those of Nation 117 membrane (0.095-0.117 S/cm) and pure SPAES membrane (0.100-0.124 S/cm) with degree of sulfonation of 1.0 at all temperatures (25-100℃). Especially, the methanol diffusion coefficient (8.4×10~(-7) cm~2/s) of SPAES-TiO_2 hybrid membranes with 8% TiO_2 is much lower than that of Nation 117 membrane (2.1 ×10~(-6) cm~2/s). SPAES-TiO_2 hybrid membranes were therefore proposed as candidates of material for PEM in DMFC.

  7. One-pot preparation of Ni-graphene hybrids with enhanced catalytic performance

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Guiqiang, E-mail: chengphnu@126.com [College of Information Science and Engineering, Hebei North University, Zhangjiakou 075000, Hebei (China); Wang, Fengli [College of Information Science and Engineering, Hebei North University, Zhangjiakou 075000, Hebei (China); Liu, Fei [Department of Electrical Engineering, Zhangjiakou Vocational College of Technology, Zhangjiakou 075000, Hebei (China); Zhang, Xiao, E-mail: Zhangxiao83690@163.com [College of Information Science and Engineering, Hebei North University, Zhangjiakou 075000, Hebei (China)

    2014-10-15

    Highlights: • Ni-rGO hybrids were synthesized by a microwave-assisted method. • NaBH4 was used as a reducing agent to fabricate Ni-rGO hybrids. • Ni-rGO was used as catalyst for the reduction of p-nitrophenol. • Ni-rGO showed higher catalytic ability than pure Ni nanoparticles. • Ni-rGO showed good recyclability and stability. - Abstract: A facile one-pot method was developed to synthesize magnetic nickel nanoparticles (Ni NPs) decorated on reduced graphene oxide (rGO) with NaHB{sub 4} as a reductant under microwave irradiation. The morphologies and structures of the Ni-rGO hybrids were investigated by electron microscopy, thermal gravimetric analysis, X-ray photoelectron spectroscopy, X-ray diffraction, Raman spectroscopy and magnetic measurements. The results showed that Ni-rGO hybrids composed of the well-dispersed Ni NPs with an average diameter of 12 nm were successfully prepared. To demonstrate one potential application, the catalytic ability of Ni-rGO was evaluated and it was found that Ni-rGO showed much enhanced catalytic ability, good recyclability and stability toward the catalytic reduction of p-nitrophenol to p-aminophenol. The excellent catalytic activity of Ni-rGO hybrids was due possibly to the synergistic effect of Ni NPs and rGO, including the uniform distribution of Ni NPs onto rGO, enhanced electrons separation and transport, as well as the fast adsorption of p-nitrophenol by rGO.

  8. Control of mechanical properties of chitin nanofiber film using glycerol without losing its characteristics.

    Science.gov (United States)

    Ifuku, Shinsuke; Ikuta, Akiko; Izawa, Hironori; Morimoto, Minoru; Saimoto, Hiroyuki

    2014-01-30

    Surface-deacetylated chitin nanofiber films plasticized with glycerol were prepared to control mechanical properties. Nanofiber networks were able to retain excessive glycerol content up to 70% to obtain self-standing film. All films were flexible and highly transparent independent of glycerol content. Glycerol significantly decreased the Young's moduli and tensile strengths, and increased the fracture strain due to its plasticizing effect. At the same time, glycerol did not change the high transparency or the low thermal expansion of the nanofiber film.

  9. Carbon-coated Li3 N nanofibers for advanced hydrogen storage.

    Science.gov (United States)

    Xia, Guanglin; Li, Dan; Chen, Xiaowei; Tan, Yingbin; Tang, Ziwei; Guo, Zaiping; Liu, Huakun; Liu, Zongwen; Yu, Xuebin

    2013-11-20

    3D porous carbon-coated Li3 N nanofibers are successfully fabricated via the electrospinning technique. The as-prepared nanofibers exhibit a highly improved hydrogen-sorption performance in terms of both thermodynamics and kinetics. More interestingly, a stable regeneration can be achieved due to the unique structure of the nanofibers, over 10 cycles of H2 sorption at a temperature as low as 250 °C.

  10. Preparation and Characterization of Self-assembly Vesicle of Icariin Nanofiber%淫羊藿苷纳米纤维膜自组装囊泡的制备及表征

    Institute of Scientific and Technical Information of China (English)

    江永南; 莫红缨

    2012-01-01

    OBJECTIVE To improve the compatibility and absorption properties of icariin in vivo by preparing electrospun icariin nanofiber and forming self-assembly nano-vesicles. METHODS Solubility test in solvent was performed to screen suitable solvent system. Icariin nanofibers was prepared by electrospinning. SEM and TEM were used to observe fiber membrane surface and self-assembly vehicle morphology respectively. XRD, DSC and IR were applied to characterize the drug-loaded nanofilber. RESULTS Methanol and dimethylacetamide were selected as the solvent mixture for providing good solubility and formation of drug-loaded fiber. The electron scan microscope showed that diameter of fiber was (400-600 nm) and the fiber surface was smooth without drug absorption. The polymers were well compatible with drug. Hydrogen bonds played a key interaction between drug and polymers. Nano-vehicle was self-assembled by dispersing the drug-loaded nanofiler into water. CONCLUSION Preparation of icariin nanofiber membrane by electrospinning was simple and icariin was highly dispersed in nanofiberse in amorphous form. Nanofibers can be self-assembled in water to form nano-vehicles.%目的 采用静电纺丝制备淫羊藿苷纳米纤维膜,并通过自组装技术形成纳采囊泡,改善淫羊藿苷在体内的相容性及吸收性能.方法 通过溶解度实验筛选合适溶剂,以静电纺丝技术制备淫羊藿苷纳米纤维膜,采用扫描电镜对纤维膜表面形态进行观察,采用X射线晶体衍射(XRD)和差示扫描量热分析(DSC)检测纤维膜中药物的存在状态,通过红外光谱分析药物与纤维材料之间的相互作用.并通过透射电镜观察纳米纤维膜自组装纳采囊泡的性能.结果 甲醇与二甲基乙酰胺混合溶剂的溶解性及纤维成型性较好;载药纤维直径分布均匀(400~600 nm)、表面光滑无药物颗粒,药物与聚合物之间通过氢键作用,具有良好的相容性,水中溶解试验发现纳米纤维膜能

  11. PLGA新型纳米支架的制备及其生物相容性7%Preparation of a novel PLGA nano-fiber scaffold and its biocompatibility

    Institute of Scientific and Technical Information of China (English)

    任谞挺; 刘轶洋; 刘宏伟

    2012-01-01

    目的 探讨和比较应用不同参数静电纺丝技术制备复合型聚乳酸-羟基乙酸[ poly( lactic-co-glycolic acid),PLGA]纳米纤维缓释膜片的可行性,检测其表面特性以及生物相容性.方法 使用不同参数制备纳米纤维膜,扫描电镜观察膜片表面形态;人牙周膜细胞(human periodontal ligament cells,hPLDCs)培养及鉴定后接种于空白膜上,扫描电镜观察细胞与膜的附着情况,以MTT[3-(4,5-dimethylthiaozol-2-yl)-2,5-dip henyltetrazolium bromide]实验检测不同浓度材料浸提液对细胞增殖变化情况的影响.结果 随着PLGA流量增加,纳米纤维直径增加;细胞与PLGA膜复合后粘附良好且增殖状态无明显变化;不同浓度材料浸提液对牙周膜细胞增殖的影响无明显差异.结论 通过不同参数静电纺丝制备的新型纳米纤维膜具有良好的生物相容性,可进一步作为多种药物及细胞因子载体构建缓释型支架,从而用于引导性牙周组织再生(guided tissue regeneration,GTR)或者牙周组织工程.%Objective To prepare a novel poly(lactic-co-glycolic acid) (PLGA) electrospinning nano-fiber membrane and to test its biocompatibility in vitro. Methods Blank nano-fiber membrane was prepared. The morphology and characteristics of membrane surface were observed with electron microscopy. Human periodontal ligament cells ( HPDLCs) were cultured and identified, then inoculated onto the blank membrane. Proliferation of HPDLCs were determined by MTT method and cell adhesion to the membrane was observed by electron microscopy. Results The diameter of nano-fiber was increased with the increasing flow of PLGA. hPDLCs adhered well to PLGA, and the membrane had no effect on cell proliferation. Conclusion The novel PLGA nano-fiber membrane prepared with electrospinning has good biocompatibility in vitro, which may be used as a drug of cytokine carrier for guided tissue regeneration or periodontal tissue engineering.

  12. PREPARATION AND PROPERTIES OF SPAES-TiO_2 HYBRID MEMBRANES FOR DIRECT METHANOL FUEL CELL

    Institute of Scientific and Technical Information of China (English)

    刘惠玲

    2009-01-01

    Sulfonated poly(arylene ether sulfone)(SPAES) copolymer with degree of sulfonation of 1.0 was synthesized and characterized.A series of SPAES-TiO_2 hybrid membranes with various contents of nano-sized TiO_2 particles were prepared and characterized through sol-gel reactions.Scanning electron microscopy(SEM) images indicated the TiO_2 particles were well dispersed within polymer matrix.These composite membranes were evaluated for proton exchange membranes(PEMs) in direct methanol fuel cell(DMFC).These mem...

  13. Hybrid Materials Prepared from Polymers and Self-assembled Systems by Physical Processes

    Institute of Scientific and Technical Information of China (English)

    Jean-Michel; Guenet

    2007-01-01

    1 Results A new type of hybrid materails prepared from ternary systems polymer/bicopper organic complex/solvent is presented.Each binary system displays differing types of behaviour: The polymer solutions produce thermoreversible gels while the bicopper organic complex (designated as CuS8) forms randomly-dispersed,self-assembling threads in organic solvents (See Fig.1(a),(b)).Fig.1 The CuS8 and ips thermoreversible gels Thermoreversible gels possess a fibrillar morphology with a typical mesh size ra...

  14. Influence of Solution Properties and Process Parameters on the Formation and Morphology of YSZ and NiO Ceramic Nanofibers by Electrospinning

    NARCIS (Netherlands)

    Cadafalch Gazquez, G.; Smulders, V.; Veldhuis, S.A.; Wieringa, P.; Moroni, L.; Boukamp, B.A.; Elshof, ten J.E.

    2017-01-01

    The fabrication process of ceramic yttria-stabilized zirconia (YSZ) and nickel oxide nanofibers by electrospinning is reported. The preparation of hollow YSZ nanofibers and aligned nanofiber arrays is also demonstrated. The influence of the process parameters of the electrospinning process, the phys

  15. Preparation and characterization of TiO 2-cationic hybrid nanoparticles as electrophoretic particles

    Science.gov (United States)

    Li, Jingjing; Deng, Liandong; Xing, Jinfeng; Dong, Anjie; Li, Xianggao

    2012-01-01

    The hybrid nanoparticles (TiO2-HNPs) with TiO2 nanoparticles as core and with poly(N,N-dimethylaminoethyl methacrylate-co-methyl methacrylate) by using triallylamine as cross-linking agent as shell were firstly prepared via atom transfer radical polymerization (ATRP) in methanol. Then the hybrid nanoparticles with positive charge were produced by the quaternization with methyl iodide as quaternization reagent so as to endow them with greater electrophoretic mobility. The cationic hybrid nanoparticles (TiO2-CHNPs) were studied by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM), Fourier-transform infrared (FTIR) spectroscopy and dynamic light scattering (DLS) measurements. The results indicate that the cationic polymer is successfully grafted on the surface of the TiO2 nanoparticles. The particle size of TiO2-CHNPs is about 150 nm and the polydispersity index (PDI) is 0.307. The zeta potential, the contrast ratio of white state to dark state and response time of TiO2-CHNPs are +16.8 mV, 30 and 3 s, respectively, which show the potential application prospect in the development of electrophoretic ink.

  16. Preparation, photophysical characterization, and modeling of LDS722/Laponite 2D-ordered hybrid films.

    Science.gov (United States)

    Epelde-Elezcano, Nerea; Duque-Redondo, Eduardo; Martínez-Martínez, Virginia; Manzano, Hegoi; López-Arbeloa, Iñigo

    2014-08-26

    A novel hybrid material with promising optical properties for nonlinear optical applications is presented, as formed by LDS 722 organic dye confined in Laponite clay. Thin films of the hybrid material with different dye loadings have been prepared. The film thickness, the dye and water content, and the clay swelling due to guest molecule incorporation have been characterized. Then, the photophysical properties of the thin films have been studied in detail using experimental methods and molecular simulation. As the dye load increases, the hybrid films present a hypsochromic shift in absorption and a bathochromic shift in emission. The former is attributed to the increasing strength of solvation of the dye donor group, while the latter is ascribed to a switch from an intramolecular to an intermolecular charge-transfer process as the dye load increases. The LDS 722 molecules are preferentially oriented in the host clay almost in parallel to the platelet surfaces, inducing macroscopic order that makes the material responsive to polarized light.

  17. Preparation and gas sensing properties of novel CdS-supramolecular organogel hybrid films

    Energy Technology Data Exchange (ETDEWEB)

    Xia Huiyun; Peng Junxia; Liu Kaiqiang; Li Chen; Fang Yu [Key Laboratory of Applied Surface and Colloid Chemistry of Ministry of Education, School of Chemistry and Materials Science, Shaanxi Normal University, Xi' an 710062 (China)], E-mail: yfang@snnu.edu.cn

    2008-05-21

    A novel CdS-supramolecular organogel hybrid film with unusual morphology has been fabricated by exposing a supramolecular organogel film containing Cd(Ac){sub 2} in an H{sub 2}S atmosphere at room temperature. The organogel film was prepared by spin-coating a LMOG (low-molecular weight organic gelator) gel of dmethyl sulfoxide onto a glass plate substrate. XRD, SEM, EDS, TG-DTA, UV-vis, PL (photoluminescence) spectroscopy and PL lifetime measurements were employed to characterize the film. It was shown that the organogel film had functioned as a template to control the morphology of the final hybrid film. The quantities and sizes of the CdS particles embedded in the organogel films can be easily altered by varying the initial concentration of Cd(Ac){sub 2}. Importantly, the PL of the hybrid film is sensitive to the presence of some volatile organic monoamines and diamines. The selectivity and reversibility of the sensing process were investigated.

  18. Nanocellulose Derivative/Silica Hybrid Core-Shell Chiral Stationary Phase: Preparation and Enantioseparation Performance

    Directory of Open Access Journals (Sweden)

    Xiaoli Zhang

    2016-05-01

    Full Text Available Core-shell silica microspheres with a nanocellulose derivative in the hybrid shell were successfully prepared as a chiral stationary phase by a layer-by-layer self-assembly method. The hybrid shell assembled on the silica core was formed using a surfactant as template by the copolymerization reaction of tetraethyl orthosilicate and the nanocellulose derivative bearing triethoxysilyl and 3,5-dimethylphenyl groups. The resulting nanocellulose hybrid core-shell chiral packing materials (CPMs were characterized and packed into columns, and their enantioseparation performance was evaluated by high performance liquid chromatography. The results showed that CPMs exhibited uniform surface morphology and core-shell structures. Various types of chiral compounds were efficiently separated under normal and reversed phase mode. Moreover, chloroform and tetrahydrofuran as mobile phase additives could obviously improve the resolution during the chiral separation processes. CPMs still have good chiral separation property when eluted with solvent systems with a high content of tetrahydrofuran and chloroform, which proved the high solvent resistance of this new material.

  19. Preparation of Al-Ce hybrid adsorbent and its application for defluoridation of drinking water

    Energy Technology Data Exchange (ETDEWEB)

    Liu Han [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); Deng Shubo, E-mail: dengshubo@tsinghua.edu.cn [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); POPs Research Center, Tsinghua University, Beijing 100084 (China); Li Zhijian; Yu Gang; Huang Jun [Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084 (China); POPs Research Center, Tsinghua University, Beijing 100084 (China)

    2010-07-15

    A novel Al-Ce hybrid adsorbent with high sorption capacity for fluoride was prepared through the coprecipitation method in this study, and its preparation conditions were optimized. X-ray diffraction (XRD) and scanning electron microscope (SEM) results showed that the hybrid adsorbent was of amorphous structure and constituted by some aggregated nanoparticles. As the adsorbent had the zero point of {zeta} potential at pH 9.6, it was very effective in fluoride removal from aqueous solution via electrostatic interaction. The results of sorption experiments including sorption kinetics, isotherms, and the effect of solution pH showed that the sorption of fluoride on the Al-Ce adsorbent was fast and pH-dependent. Especially, the adsorbent had high sorption capacity up to 27.5 mg g{sup -1} for fluoride at the equilibrium fluoride concentration of 1 mg L{sup -1}, much higher than that of the conventional adsorbents. Fourier transform infrared (FTIR) analysis and zeta potential measurement showed that the hydroxyl groups and the protonated hydroxyl groups on the adsorbent surface were involved in the fluoride adsorption.

  20. A Composite of Electrospun Nylon-6 Nanofibers and in-situ Polymerized Polypyrrole as an NH3 Gas Sensor

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1 Results Electrospinning provides a simple and versatile method for preparing nanofibers with different morphology, such as porous fibers and nanotubes. It has been widely used for preparing nanomaterials with unique properties and potential applications in medicine, catalyst, photonics and sensors[1, 2]. In this study, uniform Nylon-6 nanofibers with diameter of ≈300 nm by electrospun from formic acid solution containing 15%wt Nylon-6. Polypyrrole (PPy) was then deposited on the nanofibers by in-situ ...

  1. Fabrication of electrospun nanofibers bundles

    Science.gov (United States)

    Ye, Junjun; Sun, Daoheng

    2007-12-01

    Aligned nanofibers, filament bundle composed of large number of nanofibers have potential applications such as bio-material, composite material etc. A series of electrospinning experiments have been conducted to investigate the electrospinning process,in which some parameters such as polymer solution concentration, bias voltage, distance between spinneret and collector, solution flow rate etc have been setup to do the experiment of nanofibers bundles construction. This work firstly reports electrospun nanofiber bundle through non-uniform electrical field, and nanofibers distributed in different density on electrodes from that between them. Thinner nanofibers bundle with a few numbers of nanofiber is collected for 3 seconds; therefore it's also possible that the addressable single nanofiber could be collected to bridge two electrodes.

  2. Preparation of asymmetrically distributed bimetal ceria (CeO₂) and copper (Cu) nanoparticles in nitrogen-doped activated carbon micro/nanofibers for the removal of nitric oxide (NO) by reduction.

    Science.gov (United States)

    Bhaduri, Bhaskar; Verma, Nishith

    2014-12-15

    A novel multi-scale web of carbon micro/nanofibers (ACF/CNF) was prepared by the catalytic chemical vapor deposition (CCVD), in which CeO2 and Cu nanoparticles (NPs) were in-situ incorporated during a synthesis step. The CVD temperature was adjusted such that the prepared material had asymmetric distribution of the bimetals, with the Cu NPs located at the tips of the CNFs and the CeO2 particles adhered to the surface of the ACF substrate. The prepared bimetals-dispersed web of ACF/CNF was treated with pyridine and the surface functionalized material was applied for the removal of NO by reduction. The complete reduction of NO was achieved at 500°C and for 400ppm NO concentration. Whereas the Cu NPs acted as the catalyst for the reduction, CeO2 facilitated the incorporation of nitrogen from the pyridine source into the ACF/CNF surface. The produced nitrogen containing surface functional groups enhanced the reactivity of the material toward the NO. The bimetals CeO2 and Cu nanoparticles (NPs)-dispersed ACF/CNF produced in this study is a potential candidate for effectively removing NO by reduction, without requiring urea or ammonia used in conventional abatement methods. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Organic/hybrid nanoparticles and single-walled carbon nanotubes: preparation methods and chiral applications.

    Science.gov (United States)

    Alhassen, Haysem; Antony, Vijy; Ghanem, Ashraf; Yajadda, Mir Massoud Aghili; Han, Zhao Jun; Ostrikov, Kostya Ken

    2014-11-01

    Nanoparticles are molecular-sized solids with at least one dimension measuring between 1-100 nm or 10-1000 nm depending on the individual discipline's perspective. They are aggregates of anywhere from a few hundreds to tens of thousands of atoms which render them larger than molecules but smaller than bulk solids. Consequently, they frequently exhibit physical and chemical properties somewhere between. On the other hand, nanocrystals are a special class of nanoparticles which have started gaining attention recently owing to their unique crystalline structures which provide a larger surface area and promising applications including chiral separations. Hybrid nanoparticles are supported by the growing interest of chemists, physicists, and biologists, who are researching to fully exploit them. These materials can be defined as molecular or nano-composites with mixed (organic or bio) and inorganic components, where at least one of the component domain has a dimension ranging from a few Å to several nanometers. Similarly, and due to their extraordinary physical, chemical, and electrical properties, single-walled carbon nanotubes have been the subject of intense research. In this short review, the focus is mainly on the current well-established simple preparation techniques of chiral organic and hybrid nanoparticles as well as single-walled carbon nanotubes and their applications in separation science. Of particular interest, cinchonidine, chitosan, and β-CD-modified gold nanoparticles (GNPs) are discussed as model examples for organic and hybrid nanoparticles. Likewise, the chemical vapor deposition method, used in the preparation of single-walled carbon nanotubes, is discussed. The enantioseparation applications of these model nanomaterials is also presented.

  4. Novel dental composites reinforced with zirconia-silica ceramic nanofibers.

    Science.gov (United States)

    Guo, Guangqing; Fan, Yuwei; Zhang, Jian-Feng; Hagan, Joseph L; Xu, Xiaoming

    2012-04-01

    To fabricate and characterize dental composites reinforced with various amounts of zirconia-silica (ZS) or zirconia-yttria-silica (ZYS) ceramic nanofibers. Control composites (70 wt% glass particle filler, no nanofibers) and experimental composites (2.5, 5.0, and 7.5 wt% ZS or ZYS nanofibers replacing glass particle filler) were prepared by blending 29 wt% dental resin monomers, 70 wt% filler, and 1.0 wt% initiator, and polymerized by either heat or dental curing light. Flexural strength (FS), flexural modulus (FM), energy at break (EAB), and fracture toughness (FT) were tested after the specimens were stored in 37°C deionized water for 24h, 3 months, or 6 months. Degree of conversion (DC) of monomers in composites was measured using Fourier transformed near-infrared (FT-NIR) spectroscopy. Fractured surfaces were observed by field-emission scanning electron microscope (FE-SEM). The data were analyzed using ANOVA with Tukey's Honestly Significant Differences test used for post hoc analysis. Reinforcement of dental composites with ZS or ZYS nanofibers (2.5% or 5.0%) can significantly increase the FS, FM and EAB of dental composites over the control. Further increase the content of ZS nanofiber (7.5%), however, decreases these properties (although they are still higher than those of the control). Addition of nanofibers did not decrease the long-term mechanical properties of these composites. All ZS reinforced composites (containing 2.5%, 5.0% and 7.5% ZS nanofibers) exhibit significantly higher fracture toughness than the control. The DC of the composites decreases with ZS nanofiber content. Incorporation of ceramic nanofibers in dental composites can significantly improve their mechanical properties and fracture toughness and thus may extend their service life. Copyright © 2011 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Porous block nanofiber composite filters

    Energy Technology Data Exchange (ETDEWEB)

    Ginley, David S.; Curtis, Calvin J.; Miedaner, Alexander; Weiss, Alan J.; Paddock, Arnold

    2016-08-09

    Porous block nano-fiber composite (110), a filtration system (10) and methods of using the same are disclosed. An exemplary porous block nano-fiber composite (110) includes a porous block (100) having one or more pores (200). The porous block nano-fiber composite (110) also includes a plurality of inorganic nano-fibers (211) formed within at least one of the pores (200).

  6. Precisely Assembled Nanofiber Arrays as a Platform to Engineer Aligned Cell Sheets for Biofabrication

    Directory of Open Access Journals (Sweden)

    Vince Beachley

    2014-08-01

    Full Text Available A hybrid cell sheet engineering approach was developed using ultra-thin nanofiber arrays to host the formation of composite nanofiber/cell sheets. It was found that confluent aligned cell sheets could grow on uniaxially-aligned and crisscrossed nanofiber arrays with extremely low fiber densities. The porosity of the nanofiber sheets was sufficient to allow aligned linear myotube formation from differentiated myoblasts on both sides of the nanofiber sheets, in spite of single-side cell seeding. The nanofiber content of the composite cell sheets is minimized to reduce the hindrance to cell migration, cell-cell contacts, mass transport, as well as the foreign body response or inflammatory response associated with the biomaterial. Even at extremely low densities, the nanofiber component significantly enhanced the stability and mechanical properties of the composite cell sheets. In addition, the aligned nanofiber arrays imparted excellent handling properties to the composite cell sheets, which allowed easy processing into more complex, thick 3D structures of higher hierarchy. Aligned nanofiber array-based composite cell sheet engineering combines several advantages of material-free cell sheet engineering and polymer scaffold-based cell sheet engineering; and it represents a new direction in aligned cell sheet engineering for a multitude of tissue engineering applications.

  7. Influence of TiO2 nanofiber additives for high efficient dye-sensitized solar cells.

    Science.gov (United States)

    Hwang, Kyung-Jun; Lee, Jae-Wook; Park, Ju-Young; Kim, Sun-Il

    2011-02-01

    TiO2 nanofibers were prepared from a mixture of titanium-tetra-isopropoxide and poly vinyl pyrrolidone by applying the electrospinning method. The samples were characterized by XRD, FE-SEM, TEM and BET analyses. The diameter of electrospun TiO2 nanofibers is in the range of 70 approximately 160 nm. To improve the short-circuit photocurrent, we added the TiO2 nanofibers in the TiO2 electrode of dye-sensitized solar cells (DSSCs). TiO2 nanofibers added in DSSCs can make up to 20% more conversion energy than the conventional DSSC with only TiO2 films only.

  8. Highly Sensitive Local Surface Plasmon Resonance in Anisotropic Au Nanoparticles Deposited on Nanofibers

    Directory of Open Access Journals (Sweden)

    Masanari Saigusa

    2015-01-01

    Full Text Available This paper reports the facile and high-throughput fabrication method of anisotropic Au nanoparticles with a highly sensitive local surface plasmon resonance (LPR using cylindrical nanofibers as substrates. The substrates consisting of nanofibers were prepared by the electrospinning of poly(vinylidene fluoride (PVDF. The Au nanoparticles were deposited on the surface of electrospun nanofibers by vacuum evaporation. Scanning electron microscopy revealed the formation of a curved Au island structure on the surface of cylindrical nanofibers. Polarized UV-visible extinction spectroscopy showed anisotropy in their LPR arising from the high surface curvature of the nanofiber. The LPR of the Au nanoparticles on the thinnest nanofiber with a diameter of ~100 nm showed maximum refractive index (RI sensitivity over 500 nm/RI unit (RIU. The close correlation between the fiber diameter dependence of the RI sensitivity and polarization dependence of the LPR suggests that anisotropic Au nanoparticles improve RI sensitivity.

  9. Electrospun nanofibers composed of poly({epsilon}-caprolactone) and polyethylenimine for tissue engineering applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jang Ho [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Choung, Pill-Hoon [Department of Oral and Maxillofacial Surgery, Tooth Bioengineering National Research Lab, School of Dentistry, Seoul National University, Seoul 110-744 (Korea, Republic of); Kim, In Yong [Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Lim, Ki Taek; Son, Hyun Mok [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Choung, Yun-Hoon [Department of Otolaryngology, Ajou University School of Medicine, Suwon, 443-721 (Korea, Republic of); Cho, Chong-Su, E-mail: chocs@plaza.snu.ac.kr [Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921 (Korea, Republic of); Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of); Chung, Jong Hoon, E-mail: jchung@snu.ac.kr [Department of Biosystems and Biomaterials Science and Engineering, Seoul National University, Seoul 151-921 (Korea, Republic of); Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921 (Korea, Republic of)

    2009-06-01

    Poly({epsilon}-caprolactone) (PCL) electrospun nanofibers have been reported as a scaffold for tissue engineering application. However, high hydrophobicity of PCL limits use of functional scaffold. In this study, PCL/polyethylenimine (PEI) blend electrospun nanofibers were prepared to overcome the limitation of PCL ones because the PEI as a cationic polymer can increase cell adhesion and can improve the electrospinnability of PCL. The structure, mechanical properties and biological activity of the PCL/PEI electrospun nanofibers were studied. The diameters of the PCL/PEI nanofibers ranged from 150.4 {+-} 33 to 220.4 {+-} 32 nm. The PCL/PEI nanofibers showed suitable mechanical properties with adequate porosity and increased hydrophilic behavior. The cell adhesion and cell proliferation of PCL nanofibers were increased by blending with PEI due to the hydrophilic properties of PEI.

  10. Antibacterial polylactic acid/chitosan nanofibers decorated with bioactive glass

    Energy Technology Data Exchange (ETDEWEB)

    Goh, Yi-fan; Akram, Muhammad; Alshemary, Ammarz [Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 Johor Bahru, Johor (Malaysia); Hussain, Rafaqat, E-mail: rafaqat@comsats.edu.pk [Department of Physics, COMSATS Institute of Information Technology, Islamabad (Pakistan)

    2016-11-30

    Highlights: • PLA/Chitosan nanofibers were coated with functional bioglass. • Polymer/ceramic composite fibers exhibited good in-vitro bioactivity. • Nanofibers coated with Ag doped bioglass exhibited good antibacterial activity. - Abstract: In this study, we have presented the structural and in vitro characterization of electrospun polylactic acid (PLA)/Chitosan nanofibers coated with cerium, copper or silver doped bioactive glasses (CeBG/CuBG/AgBG). Bead-free, smooth surfaced nanofibers were successfully prepared by using electrospinning technique. The nanocomposite fibers were obtained using a facile dip-coating method, their antibacterial activities against E. coliE. coli (ATCC 25922 strains) were measured by the disk diffusion method after 24 h of incubation at 37 °C. CeBG and CuBG decorated PLA/Chitosan nanofibers did not develop an inhibition zone against the bacteria. On the other hand, nanofibers coated with AgBG developed an inhibition zone against the bacteria. The as-prepared nanocomposite fibers were immersed in SBF for 1, 3 and 7 days in Simulated Body Fluid (SBF) for evaluation of in vitro bioactivity. All samples induced the formation of crystallites with roughly ruffled morphology and the pores of fibers were covered with the extensive growth of crystallites. Energy Dispersive X-ray (EDX) composition analysis showed that the crystallites possessed Ca/P ratio close to 1.67, confirming the good in-vitro bioactivity of the fibers.

  11. Fabrication of Poly(vinylidene fluoride) (PVDF) Nanofibers Containing Nickel Nanoparticles as Future Energy Server Materials.

    Science.gov (United States)

    Sheikh, Faheem A; Cantu, Travis; Macossay, Javier; Kim, Hern

    2011-04-01

    In the present study, we introduce Poly(vinylidene fluoride) (PVDF) nanofibers containing nickel (Ni) nanoparticles (NPs) as a result of an electrospinning. Typically, a colloidal solution consisting of PVDF/Ni NPs was prepared to produce nanofibers embedded with solid NPs by electrospinning process. The resultant nanostructures were studied by SEM analyses, which confirmed well oriented nanofibers and good dispersion of Ni NPs over them. The XRD results demonstrated well crystalline feature of PVDF and Ni in the obtained nanostructures. Physiochemical aspects of prepared nano-structures were characterized for TEM which confirmed nanofibers were well-oriented and had good dispersion of Ni NPs. Furthermore, the prepared nano-structures were studied for hydrogen production applications. Due to high surface to volume ratio of nanofibers form than the thin film ones, there was tremendous increase in the rate of hydrogen production. Overall, results satisfactorily confirmed the use of these materials in hydrogen production.

  12. Development and characterization of the cisplatin loaded nanofibers for the treatment of cervical cancer.

    Science.gov (United States)

    Aggarwal, Urvashi; Goyal, Amit Kumar; Rath, Goutam

    2017-06-01

    A small scale study was carried out to investigate the therapeutic efficacy cisplatin loaded poly-caprolactone/chitosan composite electrospun nanofibers for local chemotherapy of cervical cancers in mice. The prepared nanofibers had shown the sustained release pattern up to one month. Prepared nanofibers were found to have greater mucoadhesive strength. An orthotopic cervical cancer model was established by inducing the EAC cell lines in the vaginal mucosa at cervix region of the mice. Intravaginal administration of the cisplatin loaded nanofibers showed lesser % cell viability as compared to the plain drug. In vivo studies showed a better anti-tumour efficacy of prepared nanofibers in animals at 14th and 21st after the beginning of treatment. Therefore the technique of electrospinning provides a favourable approach for the targeted delivery of the anti-cancer drug via vaginal route against cervical cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Recent trends in preparation and application of carbon nanotube-graphene hybrid thin films

    Science.gov (United States)

    Thanh Dang, Van; Dung Nguyen, Duc; Thanh Cao, Thi; Le, Phuoc Huu; Tran, Dai Lam; Phan, Ngoc Minh; Chuc Nguyen, Van

    2016-09-01

    The combination of one-dimensional (1D) carbon nanotubes (CNTs) and two-dimensional (2D) graphene materials to generate three-dimensional (3D) carbon nanotube-graphene hybrid thin films (CNGHTFs) has attracted great attention owing to their intriguing properties via the synergistic effects of these two materials on their electrical, optical, and electrochemical properties in comparison with their individual components. This review aims to provide a brief introduction of recent trends in preparation methodologies and some outstanding applications of CNGHTFs. It contains two main scientific subjects. The first of these is the research on preparation techniques of CNGHTFs, including reduction agent-assisted mechanical blending of reduced graphene oxide (rGO) and CNTs, hybridization methods for layer-by-layer (LBL) assembly of CNTs and rGO sheets, multi-step methods using combinations of a solution and chemical vapor deposition (CVD) processing, one-step growth of CNGHTFs by the CVD method, and modified CVD methods via thermal deposition of carbon source on catalyst surfaces. The advantages and disadvantages of the preparation methods of CNGHTFs are presented and discussed in detail. The second scientific subject of the review is the research on some outstanding applications of CNGHTFs in various research fields, including transparent conductors, electron field emitters, field-effect transistors, biosensors and supercapacitors. In most cases, the CNGHTFs showed superior performances than those of the pristine GO/graphene or CNT materials. Therefore, the CNGHTFs exhibit as high-potential materials for various practical applications. Opportunites and challenges in the fields are also presented.

  14. Field Emission Properties of the Graphene Double-Walled Carbon Nanotube Hybrid Films Prepared by Vacuum Filtration and Screen Printing

    OpenAIRE

    Jinzhuo Xu; Tao Feng; Yiwei Chen; Zhuo Sun

    2013-01-01

    The graphene double-walled carbon nanotube (DWCNT) hybrid films were prepared by vacuum filtration and screen printing. Their electron field emission properties have been studied systematically. The electron emission properties of the hybrid films are much better than those of pure DWCNT films and pure graphene films. Comparing with the screen printed films, the vacuum filtered films have many advantages, such as lower turn-on field, higher emission current density, better uniformity, better ...

  15. Controlled Morphology of Porous Polyvinyl Butyral Nanofibers

    Directory of Open Access Journals (Sweden)

    Daniela Lubasova

    2011-01-01

    Full Text Available A simple and effective method for the fabrication of porous nanofibers based on the solvent evaporation methods in one-step electrospinning process from the commercial polyvinyl butyral (PVB is presented. The obtained nanofibers are prevalently amorphous with diameters ranging from 150 to 4350 nm and specific surface area of approximately 2–20 m2/g. Pore size with irregular shape of the porous PVB fibers ranged approximately from 50 to 200 nm. The effects of polymer solution concentration, composition of the solvents mixture, and applied voltage on fiber diameter and morphology were investigated. The theoretical approach for the choice of poor and good solvents for PVB was explained by the application Hansen solubility parameter (HSP and two-dimensional graph. Three basic conditions for the production of porous PVB nanofibers were defined: (i application of good/poor solvent mixture for spinning solution, (ii differences of the evaporation rate between good/poor solvent, and (iii correct ratios of good/poor solvent (v/v. The diameter of prepared porous PVB fibers decreased as the polymer concentration was lowered and with higher applied voltage. These nanofiber sheets with porous PVB fibers could be a good candidate for high-efficiency filter materials in comparison to smooth fibers without pores.

  16. Novel electrospun gelatin/oxycellulose nanofibers as a suitable platform for lung disease modeling

    Energy Technology Data Exchange (ETDEWEB)

    Švachová, Veronika, E-mail: xcsvachova@fch.vutbr.cz [Institute of Materials Chemistry, Brno University of Technology (Czech Republic); Vojtová, Lucy [CEITEC – Central European Institute of Technology, Brno University of Technology (Czech Republic); SCITEG, a.s., Brno (Czech Republic); Pavliňák, David [Department of Physical Electronics, Masaryk University (Czech Republic); Vojtek, Libor [Institute of Experimental Biology, Masaryk University (Czech Republic); Sedláková, Veronika [Department of Histology and Embryology, Masaryk University (Czech Republic); International Clinical Research, St. Anne' s University Hospital, Brno (Czech Republic); Hyršl, Pavel [Institute of Experimental Biology, Masaryk University (Czech Republic); Alberti, Milan [Department of Physical Electronics, Masaryk University (Czech Republic); Jaroš, Josef; Hampl, Aleš [Department of Histology and Embryology, Masaryk University (Czech Republic); International Clinical Research, St. Anne' s University Hospital, Brno (Czech Republic); Jančář, Josef [Institute of Materials Chemistry, Brno University of Technology (Czech Republic); CEITEC – Central European Institute of Technology, Brno University of Technology (Czech Republic); SCITEG, a.s., Brno (Czech Republic)

    2016-10-01

    Novel hydrolytically stable gelatin nanofibers modified with sodium or calcium salt of oxycellulose were prepared by electrospinning method. The unique inhibitory effect of these nanofibers against Escherichia coli bacteria was examined by luminometric method. Biocompatibility of these gelatin/oxycellulose nanofibers with eukaryotic cells was tested using human lung adenocarcinoma cell line NCI-H441. Cells firmly adhered to nanofiber surface, as determined by scanning electron microscopy, and no signs of cell dying were detected by fluorescent live/dead assay. We propose that the newly developed gelatin/oxycellulose nanofibers could be used as promising scaffold for lung disease modeling and anti-cancer drug testing. - Highlights: • Novel hydrolytically stable gelatin nanofibers modified with oxycellulose were prepared by electrospinning. • ATR–FTIR spectroscopy and EDX confirmed the presence of oxycellulose in the nanofibers. • Nanofibers modified with calcium salt of oxycellulose exhibited significant antibacterial properties. • Nanofibers modified with sodium salt of oxycellulose revealed excellent biocompatibility with cell line NCI-H441.

  17. Preparation of AgBr@SiO{sub 2} core@shell hybrid nanoparticles and their bactericidal activity

    Energy Technology Data Exchange (ETDEWEB)

    Li, Yuanyuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Yang, Lisu [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Henna Sports School, Zhengzhou 450045 (China); Zhao, Yanbao, E-mail: yanbaozhao@126.com [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China); Li, Binjie; Sun, Lei; Luo, Huajuan [Key Laboratory for Special Functional Materials of Ministry of Education, Henan University, Kaifeng 475004 (China)

    2013-04-01

    AgBr@SiO{sub 2} core@shell hybrid nanoparticles (NPs) were successfully prepared by sol-gel method. Their morphology and structure were characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The hybrid NPs are predominantly spherical in shape, with an average diameter of 180–200 nm, and each NP contains one inorganic core. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the hybrid NPs were examined against Staphylococcus aureus (S. aureus), Pseudomonas aeruginosa (P. aeruginosa) and Escherichia coli (E. coli), respectively. Results indicated that the AgBr@SiO{sub 2} NPs had excellent antibacterial activity. - Highlights: ► Presents a novel antibacterial agent “AgBr@ SiO{sub 2} NPs”. ► AgBr@SiO{sub 2} hybrid NPs could provide long-term antimicrobial effect. ► AgBr@SiO{sub 2} hybrid NPs have excellent antibacterial activity.

  18. Photovoltaic and thermal properties of electrolytes based on electrospun poly(vinylidene fluoride-hexafluoro propylene)/poly(methyl methacrylate) nanofibers for dye-sensitized solar cells.

    Science.gov (United States)

    Jang, Young-Wook; Won, Du-Hyun; Kim, Young-Keun; Hwang, Won-Pill; Jang, Sung-Il; Jeong, Sung-Hoon; Kim, Mi-Ra; Lee, Jin-Kook

    2014-08-01

    We prepared electrospun polymer nanofibers by electrospnning method and investigated about their applications to dye-sensitized solar cells (DSSCs). Electrospun polymer nanofibers applied to the polymer matrix in electrolyte for DSSCs. To improve the stiffness of polymer nanofiber, poly(vinylidene fluoride-hexafluoro propylene)/Poly(methyl methacrylate) (PVDF-HFP/PMMA) blend nanofibers were prepared and examined. In the electrospun PVDF-HFP/PMMA (1:1) blend nanofibers, the best results of VOC, JSC, FF, and efficiency of the DSSC devices showed 0.71 V, 12.8 mA/cm2, 0.61, and 5.56% under AM 1.5 illumination.

  19. Soft Graphene Nanofibers Designed for the Acceleration of Nerve Growth and Development.

    Science.gov (United States)

    Feng, Zhang-Qi; Wang, Ting; Zhao, Bin; Li, Jiacheng; Jin, Lin

    2015-11-01

    Soft graphene nanofibers with recoverable electrical conductivity and excellent physicochemical stability are prepared by a controlled assembly technique. By using the soft graphene nanofibers for cellular electrical stimulation, the common inhibitory effect of long-term electrical stimulation on nerve growth and development is avoided, which usually happens with traditional 2D conductive materials.

  20. Preparation and characterization of inorganic-organic trilayer core-shell polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles

    Science.gov (United States)

    Bai, Ruiqin; Qiu, Teng; Han, Feng; He, Lifan; Li, Xiaoyu

    2012-07-01

    The inorganic-organic trilayer core-shell polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles have been successfully prepared via seeded emulsion polymerization of acrylate monomers and octamethylcyclotetrasiloxane (D4) gradually, using functional polymethacryloxypropylsilsesquioxane (PSQ) latex particles with reactive methacryloxypropyl groups synthesized by the hydrolysis and polycondensation of (3-methacryloxypropyl)trimethoxysilane in the presence of mixed emulsifiers as seeds. The FTIR spectra show that acrylate monomers and D4 are effectively involved in the emulsion copolymerization and formed the polydimethylsiloxane-containing hybrid latex particles. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirm that the resultant hybrid latex particles have evident trilayer core-shell structure and a narrow size distribution. XPS analysis also indicates that polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles have been successfully prepared and PDMS is rich in the surface of the hybrid latex film. Additionally, compared with the hybrid latex film without PDMS, the hybrid latex film containing PDMS shows higher hydrophobicity (water contact angle) and lower water absorption.

  1. Preparation and characterization of inorganic-organic trilayer core-shell polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles

    Energy Technology Data Exchange (ETDEWEB)

    Bai Ruiqin [College of Materials Science and Engineering, State Key Laboratory of Organic-Inorganic Composite, Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qiu Teng, E-mail: qiuteng@mail.buct.edu.cn [College of Materials Science and Engineering, State Key Laboratory of Organic-Inorganic Composite, Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Han Feng; He Lifan [College of Materials Science and Engineering, State Key Laboratory of Organic-Inorganic Composite, Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Li Xiaoyu, E-mail: lixy@mail.buct.edu.cn [College of Materials Science and Engineering, State Key Laboratory of Organic-Inorganic Composite, Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)

    2012-07-15

    The inorganic-organic trilayer core-shell polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles have been successfully prepared via seeded emulsion polymerization of acrylate monomers and octamethylcyclotetrasiloxane (D{sub 4}) gradually, using functional polymethacryloxypropylsilsesquioxane (PSQ) latex particles with reactive methacryloxypropyl groups synthesized by the hydrolysis and polycondensation of (3-methacryloxypropyl)trimethoxysilane in the presence of mixed emulsifiers as seeds. The FTIR spectra show that acrylate monomers and D{sub 4} are effectively involved in the emulsion copolymerization and formed the polydimethylsiloxane-containing hybrid latex particles. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) confirm that the resultant hybrid latex particles have evident trilayer core-shell structure and a narrow size distribution. XPS analysis also indicates that polysilsesquioxane/polyacrylate/polydimethylsiloxane hybrid latex particles have been successfully prepared and PDMS is rich in the surface of the hybrid latex film. Additionally, compared with the hybrid latex film without PDMS, the hybrid latex film containing PDMS shows higher hydrophobicity (water contact angle) and lower water absorption.

  2. Preparation and characterization of phosphorylated Zr-doped hybrid silica/PSF composite membrane.

    Science.gov (United States)

    Zhang, Yuqing; Jin, Zhenhua; Shan, Xing; Sunarso, Jaka; Cui, Ping

    2011-02-15

    Polysulfone (PSF) membranes are broadly applied in many fields owing to good physicochemical stability, resistance to oxidation and chlorine. But when treated with wastewater containing oil, PSF membranes are easy to be contaminated for its hydrophobicity, which can result in the declining of flux and lifespan of the membrane and limit their application in large scale. To enhance the capability of PSF membrane in the above circumstances, phosphorylated Zr-doped hybrid silica particles (SZP particles) were firstly prepared. SZP particles have various point defects inside their structure and lots of hydroxide radicals on their surface. SZP particles were added to the porous matrix of PSF to prepare a novel composite membrane (SZP/PSF) through a phase inversion process. Finally, the optimum preparation conditions of SZP/PSF composite membranes were determined. The optimum conditions are: the mass ratio of PSF, PEG400 and SZP is 12:10:10; ultrasound 10 min inside each 30 min; the pre-evaporating time is 10s. Optimized SZP/PSF composite membrane was characterized by scanning electron microscope (SEM) and ultrafiltration experiment. The results indicate that SZP particles can be uniformly dispersed in SZP/PSF composite membranes with excellent hydrophilic property, antifouling capability and tensile strength. Therefore, it can be concluded that the optimized SZP/PSF composite membrane is desirable in the treatment of wastewater containing oil and wastewater.

  3. Engineering hybrid between nickel oxide and nickel cobaltate to achieve exceptionally high activity for oxygen reduction reaction

    Science.gov (United States)

    Cui, Zhentao; Wang, Shuguang; Zhang, Yihe; Cao, Minhua

    2014-12-01

    The porous NiO/NiCo2O4 nanotubes are prepared via a coaxial electrospinning technique followed by an annealing treatment. The resultant NiO/NiCo2O4 hybrid is developed as a highly efficient electrocatalyst, which exhibits significantly enhanced electrocatalytic activity, long-term operation stability, and tolerance to crossover effect compared to NiO nanofibers, NiCo2O4 nanofibers and commercial Pt(20%)/C for oxygen reduction reactions (ORR) in alkaline environment. The excellent electrocatalytic performance may be attributed to the unique microstructures of the porous NiO/NiCo2O4 nanotubes, such as heterogeneous hybrid structure, open porous tubular structure, and the well dispersity of the two components. Moreover, the promising and straightforward coaxial electrospinning proves itself to be an efficient pathway for the preparation of nanomaterials with tubular architectures and it can be used for large-scale production of catalysts in fuel cells.

  4. Preparation and Properties of Composite Filtration Membranes Containing Energy-storage Nanofibers%纳米储能纤维复合过滤膜的制备及性能

    Institute of Scientific and Technical Information of China (English)

    王海霞; 刘明巧; 崔建平; 石海峰; 齐鲁; 王笃金

    2014-01-01

    以静电纺丝技术制备的同轴聚甲基丙烯酸十八烷基酯( PSMA)/聚对苯二甲酸乙二酯( PET)纳米储能纤维为支撑层,经聚偏氟乙烯( PVDF)涂覆成膜和溶剂化处理,制备了一种低压高水通量的纳米储能纤维复合过滤膜( NFCM),其中以水或乙醇为凝固溶液的复合过滤膜分别记为NFCM@H2 O或NFCM@EtOH.分析并讨论了不同溶剂处理方式对NFCM力学性能和表面形貌的影响,表征了膜的纯水通量和抗污性能,用扫描电子显微镜( SEM)观察了膜的横断面形貌.结果表明, PSMA/PET纳米储能纤维具有明显的吸放热行为,熔融温度和热焓值分别为36.5℃和10.7 J/g, NFCM的熔融温度和热焓值分别为36℃和2.7 J/g. NFCM的形貌结构、纯水通量和截留率与溶剂处理方式相关, NFCM@EtOH膜的水通量介于100~1400 L/( m2·h)之间,而NFCM@H2 O膜的水通量仅在40~220 L/( m2·h)之间. NFCM的拉伸强度由初始0.925 MPa( PVDF)提高到4.28 MPa以上. NFCM中的相变材料对膜过滤性能有重要影响,并在过滤温度低于50℃时具有减缓作用.%Two type of composite membranes ( NFCM ) containing poly ( stearyl methacrylate ) ( PSMA )/poly( ethylene terephthalate) ( PET) nanofiber supporting layer, prepared by coaxial electrospinning technolo-gy, and poly( vinylidene fluoride) ( PVDF) substrate, were prepared using water or ethanol as the coagulation solution. NFCM has the low pressure and high water flux against the bulk PVDF membrane at the same condition. The morphological structure, the pure water flux and the rejection of NFCM show the strong dependence upon the solvent-treated process. The water flux of NFCM@EtOH is in the range from 100 to 1400 L/( m2 ·h);while for NFCM@H2 O, its water flux only is between 40 and 220 L/( m2 ·h) , indicating that EtOH shows the greatly influence on the surface porosity of membrane. The tensile strength of membrane changes from 0. 925 MPa of the original PVDF to 4. 28 MPa of NFCM

  5. Preparation of Cu2ZnSnS4 thin films by hybrid sputtering

    Science.gov (United States)

    Tanaka, Tooru; Nagatomo, Takeshi; Kawasaki, Daisuke; Nishio, Mitsuhiro; Guo, Qixin; Wakahara, Akihiro; Yoshida, Akira; Ogawa, Hiroshi

    2005-11-01

    In order to fabricate Cu2ZnSnS4 thin films, hybrid sputtering system with two sputter sources and two effusion cells is used. The Cu2ZnSnS4 films are fabricated by the sequential deposition of metal elements and annealing in S flux, varying the substrate temperature. The Cu2ZnSnS4 films with stoichiometric composition are obtained at the substrate temperature up to 400 °C, whereas the film composition becomes quite Zn-pool at the substrate temperature above 450 °C. The Cu2ZnSnS4 film shows p-type conductivity, and the optical absorption coefficient and the band gap of the Cu2ZnSnS4 film prepared in this experiment are suitable for fabricating a thin film solar cell.

  6. Preparation of P(DVB-co-MPS) inorganic-organic hybrid polymer microspheres

    Science.gov (United States)

    Wu, Chunrong; Zhang, Jimei; Dai, Zhao; Chen, Xiaoyu

    2010-07-01

    A novel inorganic-organic hybrid polymer microspheres were facilely synthesised by distillation-precipitation polymerization in absence of any stabilizer or surfcant. The process were conducted with [3-(Methacryloyloxy) propyl] trimethoxysilan (MPS) as monomer, divinyl benzene (DVB) as cross linking agent and azobisisobutyronitrile (AIBN) as initator in acetonitrile. A series of silica nanoparticles were prepared in accordance with the volume ratio of MPS, which was varied in the range of 10% to 50%. However, there is no microspheres obtained while the ratio up to 50%. Products were charactered by transmission electron micrograph (TEM) and fourier transform infrared spectroscopy (FTIR). We may infer it from the constructional formular and FTIR graph that there were silicon hydroxyl remained in the microsphere surface.

  7. [Preparation, characterization and surface-enhanced Raman properties of agarose gel/gold nanoparticles hybrid].

    Science.gov (United States)

    Ma, Xiao-yuan; Liu, Ying; Wang, Zhou-ping

    2014-08-01

    Agarose gel/gold nanoparticles hybrid was prepared by adding gold nanoparticles to preformed agarose gel. Naniocomposite structures and properties were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and UV-Vis-NIR absorption spectroscopy. Experimental data indicated a uniform distribution of gold nanoparticles adsorbed on agarose gel network And the excellent optical absorption properties were shown. Based on the swelling-contraction characteristics of agarose gel and the adjustable localized surface plasmon resonance (LSPR) of the gold nanoparticles, the nano-composites were used as surface enhanced Raman scattering (SERS) substrate to detect the Raman signal molecules Nile blue A. Results revealed that the porous structure of the agarose gel provided a good carrier for the enrichment of the gold nanoparticles. The gold nanoparticles dynamic hot-spot effect arising from the agarose gel contraction loss of water in the air greatly enhanced the Raman signal.

  8. Preparation of fluorescent-dye-labeled cDNA from RNA for microarray hybridization.

    Science.gov (United States)

    Ares, Manuel

    2014-01-01

    This protocol describes how to prepare fluorescently labeled cDNA for hybridization to microarrays. It consists of two steps: first, a mixture of anchored oligo(dT) and random hexamers is used to prime amine-modified cDNA synthesis by reverse transcriptase using a modified deoxynucleotide with a reactive amine group (aminoallyl-dUTP) and an RNA sample as a template. Second, the cDNA is purified and exchanged into bicarbonate buffer so that the amine groups in the cDNA react with the dye N-hydroxysuccinimide (NHS) esters, covalently joining the dye to the cDNA. The dye-coupled cDNA is purified again, and the amount of dye incorporated per microgram of cDNA is determined.

  9. Nanostructure of PDMS-TEOS-PrZr hybrids prepared by direct deposition of gamma radiation energy

    Science.gov (United States)

    Lancastre, Joana J. H.; Falcão, António N.; Margaça, Fernanda M. A.; Ferreira, Luís M.; Miranda Salvado, Isabel M.; Almásy, László; Casimiro, Maria H.; Meiszterics, Anikó

    2015-10-01

    Organic-inorganic materials have been the object of intense research due to their wide range of properties and therefore innumerous applications. We prepared organic-inorganic hybrid materials by direct energy deposition on a mixture of polydimethylsiloxane silanol terminated (33 wt% fixed content), tetraethylorthosilicate and a minor content of zirconium propoxide that varied from 1 to 5 wt% using gamma radiation from a Co-60 source. The samples, dried in air at room temperature, are bulk, flexible and transparent. Their nanostructure was investigated by small angle neutron scattering. It was found that the inorganic oxide network has fractal structure, which becomes denser as the zirconium propoxide content decreases. The results suggest that oxide nanosized regions grow from the OH terminal group of PDMS which are the condensation seeds. Their number and position remains unaltered with the variation of zirconium propoxide content that only affects their microstructure. A model is proposed for the nanostructure of the oxide network that develops in the irradiation processed hybrid materials.

  10. New Inorganic-organic Hybrid Tetravanadate:Preparation, Characterization and Application in Chemically Modified Electrode

    Institute of Scientific and Technical Information of China (English)

    SUN Ying-hua; LI Xiao-ping; MEI Ze-min; ZHU Yu; NIU Li

    2011-01-01

    A new inorganic-organic hybrid tetravanadate [Co(2,2'-bpy)3]2V4O12.llH2O(l) has been prepared and characterized. X-Ray diffraction study reveals that compound 1 contains classical cluster anions [V4O12]4-, coordi nated cations [Co(2,2'-bpy)3]2+ and eleven water molecules, in which an interesting decamer water cluster is formed.The hybrid nanoparticles were firstly used as a bulk-modifier to fabricate a chemically modified paste electrode (1-CPE). The electrochemical behavior and electrocatalysis of 1-CPE have been studied in detail. The results indicate that 1-CPE has a good electrocatalytic activity toward the reduction of bromate in a 0.5 mol/L H2SO4 aqueous solu tion. I-CPE shows remarkable stability that be ascribed to the hydrogen bonding interactions between V4O12 cluster and water cluster, which are very important for practical application in electrode modification.

  11. PA6/PVA复合纳米纤维的制备及性能研究%Research of preparation and property of PA6/PVA composite nanofibers

    Institute of Scientific and Technical Information of China (English)

    丁玲; 侯大寅; 凤权

    2011-01-01

    Electrospinning method was used to fabricate PA6 and PVA composite nanofibers.The viscosity,conductivity and surface tension of PA6/PVA blended electrospun solutions with different concentration ratio were analyzed,and their influences on the electrospinning was investigated.The morphology of the nanofiber mats,the compatibility and hydrophilic of composition were characteristiced by scanning electron microscopy,Infrared Spectroscopy and the determination of surface tension.The results show that well-shaped fibers were obtained when the concentration ratio of PA6/PVA was 12%∶4%,the spinning voltage was 19 KV,the collecting distance was 16 cm and the extruding speed was 0.2 mL/h.PA6/PVA prossessed perfect nanofibrous morphology and eliminated the excess swelling in aqueous solution effectively.%采用静电纺丝法制备了PA6/PVA复合纳米纤维.分析了不同质量比的PA6/PVA共混纺丝溶液的粘度、电导率、表面张力,并探讨其静电纺丝效果.采用扫描电镜、红外光谱、表面张力仪等对纳米纤维膜的形貌结构、成分相容性及亲水性能进行表征.结果表明,在纺丝电压为19kV、纺丝距离为20cm、丝液流量为0.2mL/h的条件下,共混溶液质量比为12%∶4%时的静电纺丝所得纤维具有良好的形貌,复合纳米纤维中PA6与PVA具有良好的相容性,并有效地克服了纯纺PVA纳米纤维在水溶液中出现的过度溶胀问题.

  12. Preparation and Characterization of Poly(L-lactic acid)/Rapeseed Protein Blend Nanofiber%聚L-乳酸/菜籽蛋白共混纳米纤维毡的制备与表征

    Institute of Scientific and Technical Information of China (English)

    姜绍通; 刘涛涛; 姜苏薇; 江勤; 王华林

    2011-01-01

    以聚L-乳酸、菜籽蛋白为原料,高压静电纺丝制备聚L-乳酸(PLLA)/菜籽蛋白共混复合纳米纤维毡,考察了不同电压、极距和三氟乙酸添加量对纳米纤维形态及直径的影响,采用傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)和X-射线衍射(XRD)对相关产物进行结构表征.结果表明:复合纤维中PLLA与菜籽蛋白之间以氢键结合,PLLA的结晶性能降低;PLLA纺丝溶液中,菜籽蛋白的三氟乙酸溶液的适量引入可显著提高纺丝速率.在PLLA质量浓度为24%的氯仿溶液中,6.5%菜籽蛋白的三氟乙酸溶液加入量为0.25 mL,电压16 kV,极距10 cm的条件下,可快速制备平均直径622 am的PLLA/菜籽蛋白复合纳米纤维毡,纺丝速率达到5.2 mg/min.%The rapeseed protein/PLLA composite nanofiber felt was prepared via electrospinning. The effects of voltages, tip to collector distance and trifluoroaeetic acid on the morphology and structure of the nanofibers were investigated by scanning electron microscopy (SEM), Fourier transform infrared (FT-IR),X-ray diffraction(XRD). Results indicated that there were hydrogen bonds between rapeseed protein and PLLA in the composite fibers, and the crystal structure of PLLA was destroyed seriously. The addition of rapeseed protein/trifluoroaeetie acid solution results in a higher spinning speed, and the finer fibers would be also obtained. The rapeseed protein/PLLA composite fiber felt (about 5.2 mg/min) with average diameter of 622 nm could be prepared quickly at the following optimal process parameters: the concentration of PLLA was 24 %(contained 1 g PLLA), the volume of rapeseed protein/trifluoroacetic acid solution was 0.25 mL, the applied voltage was 16 kV, and the tip-to-collector distance was 10 cm.

  13. 静电纺丝法制备金纳米粒子/PVP复合纳米纤维%The Preparation of Gold Nanoparticles/PVP Composites Nanofibers by Electrospinning Technique

    Institute of Scientific and Technical Information of China (English)

    白杰

    2011-01-01

    The paper dealing with the preparation of gold nanoparticles by chemical reducing from relativety with a solution of HAuCl4 with N2H4· H2O as reduction reagent and polyvinylpyrrolidone (PVP) as dispersion and stabilizer,the smaller gold nanoparticles were obtained, the optical property of gold nanoparticles in PVP aqueous solution was observed by UV-visible absorption spectra. Gold nanoparticles/PVP composite fibers were prepared by electrospinning technique. The composite nanofibers were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). Field-emission scanning electron microscopy (FESEM) showed the morphology of fibers,and the diameters of composite nanofibers obviously decreased with the increasing concentration of gold nanoparticles in the solution. The existence of the gold nanoparticles was approved by XRD patterns.%采用水合肼还原一定浓度氯金酸溶液的方法,在聚乙烯吡咯烷酮(PVP)作保护剂的乙醇/水溶液中,成功制备出粒度较小,且高度分散的金溶胶,紫外吸收光谱证实了溶液中金纳米粒子的存在.采用静电纺丝技术制备了AuNs/PVP复合纳米纤维.采用扫描电镜(SEM)和X射线衍射(XRD)等分析手段对纤维的表面形貌等进行了表征.由扫描电镜照片可以看出所制得的纤维的尺寸较为均匀,随着纺前溶液内金纳米粒子含量的增加,获得的复合纤维的直径随之减小;XRD测试显示出样品内含有立方面心结构的金纳米粒子.

  14. High-Temperature Stable Anatase Titanium Oxide Nanofibers for Lithium-Ion Battery Anodes.

    Science.gov (United States)

    Lee, Sangkyu; Eom, Wonsik; Park, Hun; Han, Tae Hee

    2017-08-02

    Control of the crystal structure of electrochemically active materials is an important approach to fabricating high-performance electrodes for lithium-ion batteries (LIBs). Here, we report a methodology for controlling the crystal structure of TiO2 nanofibers by adding aluminum isopropoxide to a common sol-gel precursor solution utilized to create TiO2 nanofibers. The introduction of aluminum cations impedes the phase transformation of electrospun TiO2 nanofibers from the anatase to the rutile phase, which inevitably occurs in the typical annealing process utilized for the formation of TiO2 crystals. As a result, high-temperature stable anatase TiO2 nanofibers were created in which the crystal structure was well-maintained even at high annealing temperatures of up to 700 °C. Finally, the resulting anatase TiO2 nanofibers were utilized to prepare LIB anodes, and their electrochemical performance was compared to pristine TiO2 nanofibers that contain both anatase and rutile phases. Compared to the electrode prepared with pristine TiO2 nanofibers, the electrode prepared with anatase TiO2 nanofibers exhibited excellent electrochemical performances such as an initial Coulombic efficiency of 83.9%, a capacity retention of 89.5% after 100 cycles, and a rate capability of 48.5% at a current density of 10 C (1 C = 200 mA g(-1)).

  15. An optical nanofiber-based interface for single molecules

    CERN Document Server

    Skoff, Sarah M; Schauffert, Hardy; Rauschenbeutel, Arno

    2016-01-01

    Optical interfaces for quantum emitters are a prerequisite for implementing quantum networks. Here, we couple single molecules to the guided modes of an optical nanofiber. The molecules are embedded within a crystal that provides photostability and due to its inhomogeneous environment, a means to spectrally address single molecules. Single molecules are excited and detected solely via the nanofiber interface without the requirement of additional optical access. In this way, we realize a fully fiber-integrated system that is scalable and may become a versatile constituent for quantum hybrid systems.

  16. Field-enhanced nonlinear optical properties of organic nanofibers

    DEFF Research Database (Denmark)

    Kostiučenko, Oksana; Fiutowski, Jacek; Brewer, Jonathan R.;

    Second harmonic generation in nonlinearly optically active organic nanofibers, generated via self-assembled surface growth from nonsymmetrically functionalized para-quarterphenylene (CNHP4) molecules, has been investigated. After the growth on mica templates, nanofibers have been transferred onto...... lithographically defined regular arrays of metal and dielectric nanostructures. Such hybrid systems were employed to correlate the second harmonic response to both morphology of the fibers i.e. local field enhancement due to local changes in the fiber’s morphology and field enhancement effects appearing...

  17. Field-enhanced nonlinear optical properties of organic nanofibers

    DEFF Research Database (Denmark)

    Kostiučenko, Oksana; Fiutowski, Jacek; Brewer, Jonathan R.;

    2014-01-01

    Second harmonic generation in nonlinearly optically active organic nanofibers, generated via self-assembled surface growth from nonsymmetrically functionalized para-quarterphenylene (CNHP4) molecules, has been investigated. After the growth on mica templates, nanofibers have been transferred onto...... lithographically defined regular arrays of metal and dielectric nanostructures. Such hybrid systems were employed to correlate the second harmonic response to both morphology of the fibers i.e. local field enhancement due to local changes in the fiber’s morphology and field enhancement effects appearing...

  18. Local field enhanced second-harmonic response of organic nanofibers

    DEFF Research Database (Denmark)

    Leißner, Till; Kostiučenko, Oksana; Fiutowski, Jacek

    Organic CNHP4 nanofibers showing a strong second-harmonic (SH) response have been successfully implemented as active components in a metal-organic hybrid system. Using nondestructive roll-on transfer technique nanofibers were transferred from the growing mica substrates onto electron......-beam lithography-defined regular arrays of gold, titanium and silicon oxide. As shown in a femtosecond laser scanning microscopy study the fiber-substrate interplay leads (only) on gold to a significantly enhanced SH signal. We suggest that this effect is driven by the local field enhancement i.e. the excitation...

  19. Optics of Nanofibers

    DEFF Research Database (Denmark)

    Bordo, Vladimir

    During the last decade, fabrication and investigation of submicron-sized optical fibers have been received growing attention. Such nanofibers or nanowires can be grown from both inorganic and organic semiconductor materials being arranged in mutually parallel nanoaggregates. Also, selected...... nanofibers can be placed on a substrate or immersed in a liquid that allows one to study them individually. It has been demonstated that such structures possess promising waveguiding and photoluminescence properties. Under pumping conditions, they operate as a nanolaser. This remarkable progress dictates...

  20. Facile preparation of organic-silica hybrid monolith for capillary hydrophilic liquid chromatography based on "thiol-ene" click chemistry.

    Science.gov (United States)

    Chen, Ming-Luan; Zhang, Jun; Zhang, Zheng; Yuan, Bi-Feng; Yu, Qiong-Wei; Feng, Yu-Qi

    2013-04-05

    In this work, a one-step approach to facile preparation of organic-inorganic hybrid monoliths was successfully developed. After vinyl-end organic monomers and azobisisobutyronitrile (AIBN) were mixed with hydrolyzed tetramethoxysilane (TMOS) and 3-mercaptopropyltrimethoxysilane (MPTMS), the homogeneous mixture was introduced into a fused-silica capillary for simultaneous polycondensation and "thiol-ene" click reaction to form the organic-silica hybrid monoliths. By employing this strategy, two types of organic-silica hybrid monoliths with positively charged quaternary ammonium and amide groups were prepared, respectively. The functional groups were successfully introduced onto the monoliths during the sol-gel process with "thiol-ene" click reaction, which was demonstrated by ζ-potential assessment, energy dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FT-IR) spectroscopy. The porous structure of the prepared monolithic columns was examined by scanning electron microscopy (SEM), nitrogen adsorption-desorption measurement, and mercury intrusion porosimetry. These results indicate the prepared organic-silica hybrid monoliths possess homogeneous column bed, large specific surface area, good mechanical stability, and excellent permeability. The prepared monolithic columns were then applied for anion-exchange/hydrophilic interaction liquid chromatography. Different types of analytes, including benzoic acids, inorganic ions, nucleosides, and nucleotides, were well separated with high column efficiency around 80,000-130,000 plates/m. Taken together, we present a facile and universal strategy to prepare organic-silica hybrid monoliths with a variety of organic monomers using one-step approach. Copyright © 2013 Elsevier B.V. All rights reserved.

  1. Enhanced photocatalytic activity in electrospun bismuth vanadate nanofibers with phase junction.

    Science.gov (United States)

    Cheng, Jing; Feng, Jing; Pan, Wei

    2015-05-13

    BiVO4 nanofibers were successfully prepared by electrospinning and precisely controlled heat treatment. The obtained BiVO4 nanofibers showed an enhanced photocatalytic activity in the degradation of rhodamine-B under visible light irradiation. The as-prepared nanofibers were characterized by means of numerous techniques. The enhanced photocatalyst activity is attributed to the formation of a phase junction of tetragonal sheelite (s-t) and monoclinic sheelite (s-m) phases in the electrospun BiVO4 nanofibers. We have also investigated the band structure of BiVO4 using first principle calculation. The main photon transition mechanism of the photocatalyst should be from the O 2p to V 3d state of s-m/t BiVO4 nanofibers.

  2. Preparing Teachers to Use GIS: The Impact of a Hybrid Professional Development Program on Teachers' Use of GIS

    Science.gov (United States)

    Moore, Steven; Haviland, Don; Moore, William; Tran, Michael

    2016-08-01

    This article reports the findings of a 3-year study of a hybrid professional development program designed to prepare science and mathematics teachers to implement GIS in their classrooms. The study was conducted as part of the CoastLines Innovative Technology Experiences for Students and Teachers project funded by the National Science Foundation. Three cohorts of teachers participated in the program, with each participant receiving 40 h of synchronous online instruction and 80 h of in-person instruction and support over an 8-month period. Data from surveys of participants both before and after the program were analyzed using correlation, ordinary least squares, and ordered logit regression analyses. The analyses revealed increases in the self-reported frequency of GIS use and enhanced feelings of preparation, competence, community, and comfort with respect to using GIS for instruction. A composite index of all impact variables was positively influenced as well. The statistical analyses found a strong relationship between self-reported feelings of preparation and use of GIS. Some support was found for the idea that feelings of competence, community, and comfort were related to the teachers' sense of preparation. The findings suggest that a robust hybrid model of teacher professional development can prepare teachers to use GIS in their classrooms. More research is needed to understand how hybrid models influence the sociopsychological and other dimensions that support teachers' feelings of preparation to implement GIS.

  3. Preparing Teachers to Use GIS: The Impact of a Hybrid Professional Development Program on Teachers' Use of GIS

    Science.gov (United States)

    Moore, Steven; Haviland, Don; Moore, William; Tran, Michael

    2016-12-01

    This article reports the findings of a 3-year study of a hybrid professional development program designed to prepare science and mathematics teachers to implement GIS in their classrooms. The study was conducted as part of the CoastLines Innovative Technology Experiences for Students and Teachers project funded by the National Science Foundation. Three cohorts of teachers participated in the program, with each participant receiving 40 h of synchronous online instruction and 80 h of in-person instruction and support over an 8-month period. Data from surveys of participants both before and after the program were analyzed using correlation, ordinary least squares, and ordered logit regression analyses. The analyses revealed increases in the self-reported frequency of GIS use and enhanced feelings of preparation, competence, community, and comfort with respect to using GIS for instruction. A composite index of all impact variables was positively influenced as well. The statistical analyses found a strong relationship between self-reported feelings of preparation and use of GIS. Some support was found for the idea that feelings of competence, community, and comfort were related to the teachers' sense of preparation. The findings suggest that a robust hybrid model of teacher professional development can prepare teachers to use GIS in their classrooms. More research is needed to understand how hybrid models influence the sociopsychological and other dimensions that support teachers' feelings of preparation to implement GIS.

  4. Electrospun ZnO/SiO2 hybrid nanofibrous mat for flexible ultraviolet sensor

    Science.gov (United States)

    Xi, Min; Wang, Xiaoxu; Zhao, Yong; Zhu, Zhengtao; Fong, Hao

    2014-03-01

    A freestanding/flexible hybrid mat consisting of crystalline ZnO nanofibers (˜75 wt. %) and amorphous SiO2 nanofibers (˜25 wt. %) was prepared by the technique of electrospinning followed by the pyrolysis in air at 650 °C. The electrospun ZnO/SiO2 hybrid mat was then studied to fabricate a flexible ultraviolet (UV) sensor, and the photo-response of this sensor was characterized under varied UV light intensities; additionally, the sensor performance under the bending condition was also evaluated. The results indicated that the flexible UV sensor had excellent sensitivity and reproducibility/reversibility, and it also exhibited high performance under the bending condition.

  5. Titanium Carbide Nanofibers-Reinforced Aluminum Compacts, a New Strategy to Enhance Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Khalil Abdelrazek Khalil

    2016-05-01

    Full Text Available TiC nanofibers reinforced Al matrix composites were produced by High Frequency Induction Heat Sintering (HFIHS.The titanium carbide nanofibers with an average diameter of 90 nm are first prepared by electrospinning technique and high temperature calcination process. A composite solution containing polyacrylonitrile and titanium isopropoxide is first electrospun into the nanofibers, which are subsequently stabilized and then calcined to produce the desired TiC nanofibers. The X-ray diffraction pattern and transmission electron microscopy results show that the main phase of the as-synthesized nanofibers is titanium carbide. The TiC nanofibers is then mixed with the aluminum powders and introduced into high frequency induction heat sintering (HFIHS to produce composites of TiC nanofibers reinforced aluminum matrix. The potential application of the TiC nanofibers reinforced aluminum matrix composites was systematically investigated. 99.5% relative density and around 85 HV (833 MPa Vickers hardness of the Al reinforced with 5 wt % TiC nanofiber has been obtained. Furthermore, the sample of Al contains 5 wt % TiC, has the highest value of compression and yield strength of about 415 and 350 MPa, respectively. The ductility of the Al/5 wt % TiC showed increasing with increasing the TiC contents.

  6. CONFORMATION AND MICROSTRUCTURE OF CARBON NANOFIBERS DEPOSITED ON FOAM Ni

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Bundles of pure carbon nanofibers were prepared by catalytic decomposition of acetylene on foam Ni. The morphological and structural characteristics of the carbon nanostructures, in the as-prepared state, were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high resolution transmission electron microscopy (HTEM). A special conformation of carbon nanofibers composed of segmented structures was found among the products by both SEM and TEM observations. Further HTEM ex amination indicated that the segments were stacked with well ordered graphite platelets arranged perpendicular to the axis of the filaments.

  7. Hybrid nanocellulose/nanoclay composites for food packaging applications

    DEFF Research Database (Denmark)

    Trifol Guzman, Jon

    to larger spherulite sizes, which had a more significant impacton water diffusion and transparency reduction but also showed an increased water sorption. Finally, it was found that cellulose nanofibers reduced water diffusion to an extent similar to C30B (21% vs.27%), while hybrid composites showed 49......% decrease, albeit CNF based composites showed increased water sorption (7% for PLA/CNF 1% composite and 9% for PLA/CNF 1%/C30B 1% when compared with neat PLA).The reduced diffusivity of the hybrid nanocomposites suggested that the material was promising for active packaging, since low diffusivity leads....../gCNF and hybrid PLA/CNF/C30B composites were prepared and evaluated on controlled release applications. It was established that the surface modification of CNF greatly enhanced the dispersion of the gCNF and that carvacrolloaded hybrid composites showed a decreased release rate, high ductility and a reduced WVTR...

  8. Retrospective study of trisomy 18 in chorionic villi with fluorescent in situ hybridization on archival direct preparations

    NARCIS (Netherlands)

    A.R.M. van Opstal (Diane); C.D.F. van den Berg (Cardi); M.G. Jahoda (M.); H. Brandenburg (Helen); F.J. Los; P.A. In't Veld (Peter)

    1995-01-01

    textabstractTrisomy 18 in direct chorionic villus preparations needs further investigation since the chromosome abnormality may be confined to the placenta and may not represent the actual fetal karyotype. We performed, retrospectively, fluorescent in situ hybridization (FISH) with the chromosome 18

  9. Dispersion of cellulose nanofibers in biopolymer based nanocomposites

    Science.gov (United States)

    Wang, Bei

    The focus of this work was to understand the fundamental dispersion mechanism of cellulose based nanofibers in bionanocomposites. The cellulose nanofibers were extracted from soybean pod and hemp fibers by chemo-mechanical treatments. These are bundles of cellulose nanofibers with a diameter ranging between 50 to 100 nm and lengths of thousands of nanometers which results in very high aspect ratio. In combination with a suitable matrix polymer, cellulose nanofiber networks show considerable potential as an effective reinforcement for high quality specialty applications of bio-based nanocomposites. Cellulose fibrils have a high density of --OH groups on the surface, which have a tendency to form hydrogen bonds with adjacent fibrils, reducing interaction with the surrounding matrix. The use of nanofibers has been mostly restricted to water soluble polymers. This thesis is focused on synthesizing the nanocomposite using a solid phase matrix polypropylene (PP) or polyethylene (PE) by hot compression and poly (vinyl alcohol) (PVA) in an aqueous phase by film casting. The mechanical properties of nanofiber reinforced PVA film demonstrated a 4-5 fold increase in tensile strength, as compared to the untreated fiber-blend-PVA film. It is necessary to reduce the entanglement of the fibrils and improve their dispersion in the matrix by surface modification of fibers without deteriorating their reinforcing capability. Inverse gas chromatography (IGC) was used to explore how various surface treatments would change the dispersion component of surface energy and acid-base character of cellulose nanofibers and the effect of the incorporation of these modified nanofibers into a biopolymer matrix on the properties of their nano-composites. Poly (lactic acid) (PLA) and polyhydroxybutyrate (PHB) based nanocomposites using cellulose nanofibers were prepared by extrusion, injection molding and hot compression. The IGC results indicated that styrene maleic anhydride coated and ethylene

  10. Synthesis of NiO Nanofibers Composed of Hollow Nanospheres with Controlled Sizes by the Nanoscale Kirkendall Diffusion Process and Their Electrochemical Properties.

    Science.gov (United States)

    Cho, Jung Sang; Lee, Seung Yeon; Ju, Hyeon Seok; Kang, Yun Chan

    2015-11-25

    NiO nanofibers composed of hollow NiO nanospheres with different sizes were prepared by electrospinning method. The mean size of the hollow NiO nanospheres was determined by the mean size of the Ni nanocrystals of the Ni-C composite nanofibers formed as an intermediate product. Porous-structured NiO nanofibers were also prepared as a comparison sample by direct oxidation of the electrospun nanofibers. The discharge capacities of the nanofibers composed of hollow nanospheres reduced at 300, 500, and 700 °C for the 250th cycle were 707, 655, and 261 mA h g(-1), respectively. However, the discharge capacity of the porous-structured NiO nanofibers for the 250th cycle was low as 206 mA h g(-1). The nanofibers composed of hollow nanospheres had good structural stability during cycling.

  11. Adsorption of Th{sup 4+}, U{sup 6+}, Cd{sup 2+}, and Ni{sup 2+} from aqueous solution by a novel modified polyacrylonitrile composite nanofiber adsorbent prepared by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Dastbaz, Abolfazl [Department of Chemical engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Keshtkar, Ali Reza, E-mail: akeshtkar@aeoi.org.ir [Nuclear Fuel Cycle Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2014-02-28

    In this study, SiO{sub 2} nanoparticles were modified by 3-aminopropyltriethoxysilane (APTES) and then applied to prepare a novel polyacrylonitrile (PAN) composite nanofiber adsorbent by the electrospinning method. In addition, the adsorbent was characterized by SEM, BET, and FTIR analyses. Then the effects of pH, SiO{sub 2} and APTES content, adsorbent dosage, contact time and temperature were investigated. Moreover, adsorption experiments were carried out with initial concentrations in the range of 30–500 mg L{sup −1} and the adsorbent affinity for metal ions was in order of Th{sup 4+} > U{sup 6+} > Cd{sup 2+} > Ni{sup 2+}. Furthermore, it was observed that the optimum pH for adsorption was different for each metal. Some isotherm and kinetic models were applied to analyze the experimental data, among which the Langmuir and pseudo-second order models were better than the others. The regeneration study showed that the adsorbent could be used for industrial processes repeatedly without any significant reduction in its adsorption capacity. Based on the Langmuir model, the maximum adsorption capacity of Th{sup 4+}, U{sup 6+}, Cd{sup 2+}, and Ni{sup 2+} at 45 °C was 249.4, 193.1, 69.5 and 138.7 mg g{sup −1}, respectively. Besides, the calculated thermodynamic parameters showed an endothermic as well as chemical nature through the adsorption process.

  12. Temperature responsive hydrogel nanofibers and nanoparticles

    Science.gov (United States)

    Ruokolainen, Janne

    2011-03-01

    Poly(N-isopropylacrylamide) (PNIPAM) is one of the most extensively investigated synthetic temperature-responsive polymers. In this work temperature-responsive PNIPAM based triblock copolymer hydrogels, their self-assembly and phase behavior in bulk, are described. Additionally, recent results from responsive hydrogel nanofibers and hydrogel nanoparticles are shown. It is known that block copolymers form well-organized nano structures in bulk or thin films when annealed thermally or in solvent vapours. However, in the case of nanofibers or nanoparticles, the annealing leads in most cases to aggregation and particle sintering. This work utilizes aerosol-based gas phase method where the preparation and annealing of hydrogel nanoparticles with well-organized, hierarchical inner structures are performed without any particle coagulation or sintering. In the method, the block copolymers assemble within aerosol nanoparticles to form, for instance, lamellar onion-like or gyroid inner structures.

  13. Process Dependence of Cellulose Nanofiber Fabrication

    Science.gov (United States)

    Henderson, Doug; Zhang, Xin; Mao, Yimin; Jang, Soo-Hwan; Hu, Liangbing; Briber, Robert; Wang, Howard

    Cellulose nanofibers (CNF) are the most abundant natural nanomaterial on earth with potential applications in renewable energy, polymer nanocomposites and flexible electronics. CNF can be produced through TEMPO oxidation which separates the hierarchical structure of cellulose fibers into smaller micro- and nanofibers by altering their surface chemistry, inducing a repulsive electrostatic charge on the fibers. This work will examine the structural evolution of CNF during production. Samples were prepared by removing and quenching aliquots during the TEMPO reaction. The fibers were washed, filtered and re-dispersed into D2O for small angle neutron scattering (SANS) measurements. The SANS data was analyzed to track the changes in the CNF structure as a function of reaction time.

  14. General strategy for fabricating thoroughly mesoporous nanofibers

    KAUST Repository

    Hou, Huilin

    2014-12-03

    Recently, preparation of mesoporous fibers has attracted extensive attentions because of their unique and broad applications in photocatalysis, optoelectronics, and biomaterials. However, it remains a great challenge to fabricate thoroughly mesoporous nanofibers with high purity and uniformity. Here, we report a general, simple and cost-effective strategy, namely, foaming-assisted electrospinning, for producing mesoporous nanofibers with high purity and enhanced specific surface areas. As a proof of concept, the as-fabricated mesoporous TiO2 fibers exhibit much higher photocatalytic activity and stability than both the conventional solid counterparts and the commercially available P25. The abundant vapors released from the introduced foaming agents are responsible for the creation of pores with uniform spatial distribution in the spun precursor fibers. The present work represents a critically important step in advancing the electrospinning technique for generating mesoporous fibers in a facile and universal manner.

  15. Study on preparation of hollow α-Fe2 O3 magnetic nanofibers%α-Fe2O3中空磁性纳米纤维的制备研究

    Institute of Scientific and Technical Information of China (English)

    王新月; 高强; 高春霞; 葛明桥; 冯古雨

    2015-01-01

    磁性铁氧化物纳米材料是近几十年发展起来的一种具有磁靶向性的纳米材料。其中磁性纳米纤维由于具有独特的形状各向异性和磁晶各向异性,可以突破各向同性的磁性粉体材料对电磁性能的限制而引起研究者的广泛关注。通过静电纺丝、水热合成以及高温煅烧相结合的方法成功制备了新型 Fe2 O 3中空磁性纳米纤维。采用扫描电子显微镜(SEM)、红外光谱分析仪(FT-IR)、差热扫描量热仪(DSC)、热重分析仪(TG)及 X 射线衍射仪(XRD)对煅烧产物进行测试表征,结果表明煅烧产生的磁性纳米纤维非织造布具有新颖的中空结构,对甲基橙有快速吸附。%In recent decades,magnetic iron oxide material has developed into a kind of nanomaterial with the property of magnetic targeting.Magnetic nanoscale fibers have aroused extensive concern of researchers because of the unique shape anisotropy and magnetocrystalline anisotropy which can break through the isotropic magnet-ic powder materials on the properties of electromagnetic limit.Electrospinning,hydrothermal synthesis and high-temperature calcination were combined successfully to prepare novel magnetic nanofibers.Scanning elec-tron microscopy (SEM),fourier transform infrared spectroscopy (FT-IR),thermal gravimetric analysis (TG) and X-ray diffraction (XRD)were employed to test and represent the calcination.The results indicated that the magnetic nanofiber after calcination has a novel structure of the hollow porous microstructure which shows quick and effective adsorption of methyl orange.

  16. Daidzein-loaded nanostructured lipid carriers-PLGA nanofibers for transdermal delivery.

    Science.gov (United States)

    Song, Jia; Fan, Xiucong; Shen, Qi

    2016-03-30

    Daidzein is one of the most effective candidates for treating cardiovascular and cerebrovascular disease. However, considering its poor oral absorption and limited bioavailability, daidzein-loaded nanostructured lipid carriers-PLGA nanofibers were designed to handle the drawbacks. Daidzein-NLCs were successfully prepared by an emulsification and low-temperature solidification method. The physicochemical characteristics of NLCs were evaluated afterwards. Based on the preparation of daidzein-loaded NLCs, Daidzein-NLCs-nanofibers were optimized by electrospinning and were observed under Scanning Electron Microscope to capture the appearance. The sustained release profile of daidzein from Daidzein-NLCs-nanofibers in vivo was best fitted to the Kormeyer-Peppas equation. The in vitro skin permeable behavior showed the cumulative amount of daidzein from Daidzein-NLCs-nanofibers reached 21.71 μg cm(-2) at 60 h, which was 3.78 times higher than pure daidzein solution. It demonstrated that the Daidzein-NLCs-nanofibers could significantly enhance the transported amount of drug. Confocal Laser Scanning Microscopy resulting images revealed a more effective content accumulation of Daidzein-NLCs-nanofibers than Daidzein-NLCs in epidermis. In vivo study indicated that Daidzein-NLCs-nanofibers had better skin retention than Daidzein-NLCs in the long term. The skin irritation experiment showed a positive result with no obvious stimulus observed. These results suggested that Daidzein-NLCs-nanofibers could be a potential candidate for transdermal delivery. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Stable and Continuous Long-term Enzymatic Reaction using an Enzyme-Nanofiber Composite

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jin Hyung; Hwang, Ee Taek; Kim, Byoung Chan; Lee, Sun Mi; Sang, Byoung-In; Choi, Yong Su; Kim, Jungbae; Gu, Man Bock

    2007-07-01

    This study shows the preparation and application of enzyme-nanofiber composites for long-term stable operation. The enzyme-nanofiber composite was prepared by coating an enzyme-aggregate, the esterase from Rhizopus oryzae, on the surface of the nanofibers. The activity and stability of the esterase-nanofiber composite was evaluated by measuring the production of p-nitrophenol from the hydrolysis of p-nitrophenyl butyrate. It was found that enzyme-nanofiber was very stable, even when the fibers were shaken in glasses, preserving 80 % of the initial activity for 100 days. In addition, the enzyme nanofiber composite was repeatedly used in 30 cycles of substrate hydrolysis and still remained active. Consequently, the esterase-nanofiber composite was finally employed to find its feasibility of long-term and stable continuous substrate hydrolysis reaction. In the sample reactor, the production of p-nitrophenol was consistent for 400 hr. Additionally, it was found that the production of p-nitrophenol proportionally decreased as the dilution rate was increased, showing the relationship between the efficiency of hydrolysis and the retention time within the reactor. This study demonstrates that the enzyme-nanofiber composite can be used in both repeated-batch and continuous modes for long-term stable operation.

  18. Properties of Electrospun TiO2 Nanofibers

    Directory of Open Access Journals (Sweden)

    Bianca Caratão

    2014-01-01

    Full Text Available Titanium oxide filled polyvinylpyrrolidone (PVP composite nanofibers have been prepared via a simple electrospinning technique. The combination of good TiO2 properties with its high surface area leads these nanofibers into having a vast applicability such as cosmetics, scaffolds for tissue engineering, catalytic devices, sensors, solar cells, and optoelectronic devices. The structural and chemical properties of the prepared samples have been studied. The presence of the TiO2 phase on the nanofibers was confirmed. An anatase to rutile transformation was observed at 600°C. Regarding the thermogravimetric and differential thermal analysis (TGA/DTA, the TIP decomposition and the PVP evaporation at 225°C were verified.

  19. Preparing of TiO2 Nanofibers Using Electrospinning and Its Application to Photo-degradation of Organic Compound%静电纺丝法制备纳米二氧化钛纤维及其光降解有机物的性能研究

    Institute of Scientific and Technical Information of China (English)

    李美杰; 陆军建

    2015-01-01

    The titania precursor solution is prepared through sol-gel process, and the PVP/TiO2 composite nanofibers are prepared using electrospinning technique. The titanium dioxide precursor fibers are calcinated at 450 ° C for TiO2 nanofibers. Good-shaped, equal-sized TiO2 nanofibers of 300-500 nm can be generated when a voltage of 18 kv, a collecting distance of 20 cm, and a needle speed of 0. 002 mm/s is applied. Fluorescence spectrum analysis shows that TiO2 nanofibers have remarkable catalytic effect on the photo-degradation of the organic light yellow compound.%采用溶胶-凝胶法制备二氧化钛前驱体溶液,借助静电纺丝技术纺丝出PVP/TiO2前驱体复合纤维,将前驱体复合纤维在450 o C煅烧后得到TiO2纳米纤维。当纺丝电压为18 kv,接受距离为20 cm,注射器推进速度为0.002 mm/s时,所制备的TiO2纤维尺寸均一且表面形貌佳,纤维的尺寸在300-500 nm。借助荧光光谱分析法,初步证明了TiO2纳米纤维对有机染料耐晒黄的光降解具有显著的催化作用。

  20. Hybrid micro-/nano-structures derived from metal-organic frameworks: preparation and applications in energy storage and conversion.

    Science.gov (United States)

    Cao, Xiehong; Tan, Chaoliang; Sindoro, Melinda; Zhang, Hua

    2017-05-22

    Metal-organic frameworks (MOFs), an important class of inorganic-organic hybrid crystals with intrinsic porous structures, can be used as versatile precursors or sacrificial templates for preparation of numerous functional nanomaterials for various applications. Recent developments of MOF-derived hybrid micro-/nano-structures, constructed by more than two components with varied functionalities, have revealed their extensive capabilities to overcome the weaknesses of the individual counterparts and thus give enhanced performance for energy storage and conversion. In this tutorial review, we summarize the recent advances in MOF-derived hybrid micro-/nano-structures. The synthetic strategies for preparing MOF-derived hybrid micro-/nano-structures are first introduced. Focusing on energy storage and conversion, we then discuss their potential applications in lithium-ion batteries, lithium-sulfur batteries, supercapacitors, lithium-oxygen batteries and fuel cells. Finally, we give our personal insights into the challenges and opportunities for the future research of MOF-derived hybrid micro-/nano-structures.

  1. Nanobiotechnology approach to fabricate polycaprolactone nanofibers containing solid titanium nanoparticles as future implant materials

    DEFF Research Database (Denmark)

    Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Cha, Jaegwan

    2011-01-01

    are exploited to form nanofibers by the simple electrospinning process. The prepared colloidal solutions were characterized using dynamic light scattering and electrophoratic light scattering which indicated unimodal size distribution and negative zeta potential. To investigate the bioactivity of the resultant...

  2. Chemical isolation and characterization of different cellulose nanofibers from cotton stalks

    Science.gov (United States)

    Recently, cellulose nanofibers (CNFs) have received wide attention in green nanomaterial technologies. Production of CNFs from agricultural residues has many economic and environmental advantages. In this study, four different CNFs were prepared from cotton stalks by different chemical treatments fo...

  3. Nanofibers and nanoplatelets of MoO3 via an electrospinning technique

    Science.gov (United States)

    Li, Shouzhu; Shao, Changlu; Liu, Yichun; Tang, Shanshan; Mu, Rixiang

    2006-08-01

    Polyvinyl alcohol (PVA)/ammonium molybdate composite fibers were prepared by using sol gel processing and electrospinning technique. After calcinations of the above precursor fibers at 500 °C, MoO3 nanofibers with a diameter of 100 150 nm were successfully obtained. MoO3 nanoplatelets and submicron platelets were prepared by further calcinations of the MoO3 nanofibers at 600 and 700 °C. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT IR) and scanning electron microscopy (SEM). A possible growth mechanism for the MoO3 nanofibers and nanoplatelets was suggested.

  4. A facile method for electrospinning of Ag nanoparticles/poly (vinyl alcohol)/carboxymethyl-chitosan nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Yinghui; Zhou, Ying [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Wu, Xiaomian [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Orthodontics College of Stomatology, Chongqing Medical University, Chongqing 401147 (China); Wang, Lu [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Xu, Ling, E-mail: lingxu@pku.edu.cn [Beijing Key Laboratory for Solid Waste Utilization and Management, College of Engineering, Peking University, Beijing 100871 (China); Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); PKU-HKUST ShenZhen-HongKong Institution, Shenzhen 518057 (China); Wei, Shicheng, E-mail: sc-wei@pku.edu.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871 (China); Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2012-09-01

    Highlights: Black-Right-Pointing-Pointer AgNPs/PVA/CM-chitosan nanofibers were prepared via electrospinning method. Black-Right-Pointing-Pointer AgNPs were in situ synthesized in electrospinning solution via a facile method. Black-Right-Pointing-Pointer AgNPs distributed homogeneously on the surface of nanofibers. Black-Right-Pointing-Pointer The prepared nanofibers possessed certain antibacterial ability against Escherichia coli. Black-Right-Pointing-Pointer The AgNPs containing nanofibers had potential as antibacterial biomaterial. - Abstract: A facile method to prepare silver nanoparticles (AgNPs) containing nanofibers via electrospinning has been demonstrated. AgNPs were in situ synthesized in poly (vinyl alcohol) (PVA)/carboxymethyl-chitosan (CM-chitosan) blend aqueous solution before electrospinning. UV-vis spectra, viscosity and conductivity of the electrospinning solution were measured to investigate their effects on the electrospinning procedure. The morphology of AgNPs/PVA/CM-chitosan nanofibers was observed by Field Emission Scanning Electron Microscopy. The formation and morphology of AgNPs were investigated by Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy. The resulted nanofibers have smooth surface and uniform diameters ranging from 295 to 343 nm. The diameters of AgNPs mainly distributed in the range of 4-14 nm, and the electrostatic interaction between AgNPs and fibers was observed. Finally, in vitro Ag release from the nanofibers was measured and the antibacterial behavior of the nanofibers against Escherichia coli was studied by bacterial growth inhibition halos and bactericidal kinetic testing. The AgNPs/PVA/CM-chitosan nanofibers possessed certain antibacterial ability, which makes them capable for antibacterial biomaterials.

  5. A novel fixed-bed reactor design incorporating an electrospun PVA/chitosan nanofiber membrane

    Energy Technology Data Exchange (ETDEWEB)

    Esmaeili, Akbar, E-mail: akbaresmaeili@yahoo.com; Beni, Ali Aghababai

    2014-09-15

    Graphical abstract: PVA/Cs nanofiber membrane was prepared by the electrospinning technique. The membrane was installed in a new fixed-bed reactor. The test results showed heavy metals absorbed by the PVA/Cs nanofiber membrane. - Highlights: • PVA/Cs nano-fiber membrane was produced using electrospinning technique. • The prepared nanofiber membrane was mesoporous. • Thermal crosslinking was successful to improve the stability of PVA/Cs nano-fiber membrane. • Experimental data were studied by adsorption isotherm models and thermodynamic relationships. - Abstract: In this research, a novel fixed-bed reactor was designed with a nanofiber membrane composed of a polyvinyl alcohol (PVA)/chitosan nanofiber blend prepared using an electrospinning technique. The applied voltage, tip-collector distance, and solution flow rate of the electrospinning process were 18 kV, 14.5 cm, and 0.5 mL h{sup −1}, respectively. Brunauer–Emmett–Teller (BET) theory, scanning electron microscope (SEM), and Fourier transform infrared spectroscopy (FT-IR) were employed to characterize and analyze the nanofiber membranes. Homogeneous electrospun nanofibers with an average diameter of 99.47 nm and surface area of 214.12 m{sup 2} g{sup −1} were obtained. Adsorption experiments were carried out in a batch system to investigate the effect of different adsorption parameters such as pH, adsorbent dose, biomass dose, contact time, and temperature. The kinetic data, obtained at the optimal pH of 6, were analyzed by pseudo first-order and pseudo second-order kinetic models. Three isotherm models and thermodynamic parameters (ΔG°, ΔH°, and ΔS°) were applied to describe the equilibrium data of the metal ions adsorbed onto the PVA/chitosan nanofiber membrane.

  6. Syringeless Electrospinning toward Versatile Fabrication of Nanofiber Web

    Science.gov (United States)

    Moon, Seongjun; Gil, Manjae; Lee, Kyung Jin

    2017-01-01

    Although electrospinning is considered a powerful and generic tool for the preparation of nanofiber webs, several issues still need to be overcome for real-world applications. Most of these issues stem from the use of a syringe-based system, where the key factor influencing successful electrospinning is the maintenance of several subtle balances such as those of between the mass and the electrical state. It is extremely difficult to maintain these balances throughout the spinning process until all the polymeric solution in the syringe has been consumed. To overcome these limitations, we have developed a syringeless electrospinning technique as an alternative and efficient means of preparing a nanofiber web. This new technique uses a helically probed rotating cylinder. This technique can not only cover conventional methods, but also provides several advantages over syringe-based and needless electrospinning in terms of productivity (6 times higher) and processibility. For example, we can produce nanofibers with highly crystalline polymers and nanofiber-webs comprising networks of several different polymers, which is sometimes difficult in conventional electrospinning. In addition, this method provides several benefits for colloidal electrospinning as well. This method should help expand the range of applications for electrospun nanofiber webs in the near future.

  7. Syringeless Electrospinning toward Versatile Fabrication of Nanofiber Web

    Science.gov (United States)

    Moon, Seongjun; Gil, Manjae; Lee, Kyung Jin

    2017-01-01

    Although electrospinning is considered a powerful and generic tool for the preparation of nanofiber webs, several issues still need to be overcome for real-world applications. Most of these issues stem from the use of a syringe-based system, where the key factor influencing successful electrospinning is the maintenance of several subtle balances such as those of between the mass and the electrical state. It is extremely difficult to maintain these balances throughout the spinning process until all the polymeric solution in the syringe has been consumed. To overcome these limitations, we have developed a syringeless electrospinning technique as an alternative and efficient means of preparing a nanofiber web. This new technique uses a helically probed rotating cylinder. This technique can not only cover conventional methods, but also provides several advantages over syringe-based and needless electrospinning in terms of productivity (6 times higher) and processibility. For example, we can produce nanofibers with highly crystalline polymers and nanofiber-webs comprising networks of several different polymers, which is sometimes difficult in conventional electrospinning. In addition, this method provides several benefits for colloidal electrospinning as well. This method should help expand the range of applications for electrospun nanofiber webs in the near future. PMID:28120916

  8. Tin Oxide-Carbon-Coated Sepiolite Nanofibers with Enhanced Lithium-Ion Storage Property.

    Science.gov (United States)

    Hou, Kai; Wen, Xin; Yan, Peng; Tang, Aidong; Yang, Huaming

    2017-12-01

    Natural sepiolite (Sep) nanofibers were coated with carbon and nanoscale SnO2 to prepare an emerging nanocomposite (SnO2-C@Sep), which exhibited enhanced electrochemical performance. Sepiolite could act as a steady skeleton, carbon coating principally led sepiolite from an isolated to an electric state, and decoration of nanoscale SnO2 was beneficial to the functionization of sepiolite. Cycling performances indicated that SnO2-C@Sep showed higher discharge capacities than commercial SnO2 after 50 cycles. The nanocomposite SnO2-C@Sep possessed enhanced lithium storage properties with stable capacity retention and low cost, which could open up a new strategy to synthesize a variety of functional hybrid materials based on the cheap and abundant clay and commercialization of lithium-metal oxide batteries.

  9. Preparation of alpha-bisabolol and phenylethyl resorcinol/TiO2 hybrid composites for potential applications in cosmetics.

    Science.gov (United States)

    Leong, H J; Jang, I; Hyun, K-S; Jung, S-K; Hong, G-H; Jeong, H-A; Oh, S-G

    2016-10-01

    Bifunctional alpha-bisabolol and phenylethyl resorcinol/TiO2 hybrids were prepared to apply in cosmetic fields, particularly in anti-ageing and hyperpigmentation treatment. The synergistic effect of combined antioxidant and UV filtering properties was achieved through functionalization of TiO2 particles with skin-lightening materials such as alpha-bisabolol and phenylethyl resorcinol. TiO2 microspheres with a diameter of about 1 μm were synthesized through surfactant-assisted sol-gel method for use as supporting materials in the formation of hybrid composites. Carboxylation treatment was performed for surface modification of the TiO2 surface with carboxyl groups as chemical binders. Esterification reaction between carboxyl groups of carboxylated TiO2 and hydroxyl groups of alpha-bisabolol or phenylethyl resorcinol was performed. The hybrids were characterized using various techniques such as FE-SEM, DLS, EDS, ATR-FTIR, XPS and TGA. For application of prepared TiO2 composites in the field of cosmetics, the anti-radicular antioxidant abilities were evaluated using ABTS and DPPH colorimetric antioxidant assay. Organic/inorganic hybrid composites were successfully formed using esterification reaction between the carboxyl groups at TiO2 surface and the hydroxyl groups of the skin-lightening materials. The results demonstrate that both functionalized microspheres show scavenging ability towards the ABTS(•) and DPPH(•) radicals. Specifically, the phenylethyl resorcinol/TiO2 composites exhibited the highest antioxidant ability among the prepared samples owing to the presence of phenolic groups to scavenge free radicals. Using this strategy, it could be possible to prepare not only inorganic UV filter but also hybrid organic/inorganic materials with multifunctions and advantages which would be in a great demand for cosmetic applications. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  10. Optimization of blend parameters for the fabrication of polycaprolactone-silicon based ormoglass nanofibers by electrospinning.

    Science.gov (United States)

    Sachot, Nadège; Castano, Oscar; Planell, Josep A; Engel, Elisabeth

    2015-08-01

    Electrospinning is a method that can be used to efficiently produce scaffolds that mimic the fibrous structure of natural tissue, such as muscle structures or the extracellular matrix of bone. The technique is often used as a way of depositing composites (organic/inorganic materials) to obtain bioactive nanofibers which have the requisite mechanical properties for use in tissue engineering. However, many factors can influence the formation and collection of fibers, including experimental variables such as the parameters of the solution of the electrospun slurry. In this study, we assessed the influence of the polymer concentration, glass content and glass hydrolysis level on the morphology and thickness of fibers produced by electrospinning for a PCL-(Si-Ca-P2 ) bioactive ormoglass-organically modified glass-blend. Based on previous assays, this combination of materials shows good angiogenic and osteogenic properties, which gives it great potential for use in tissue engineering. The results of our study showed that blend preparation directly affected the features of the resulting fibers, and when the parameters of the blend are precisely controlled, fibers with a regular diameter could be produced fairly easily when 2,2,2-trifluoroethanol was used as a solvent instead of tetrahydrofuran. The diameter of the homogeneous fibers ranged from 360 to 620 nm depending on the experimental conditions used. This demonstrates that experimental optimization of the electrospinning process is crucial in order to obtain a deposit of hybrid nanofibers with a regular shape.

  11. Fabrication of NiCo 2O 4 nanofibers by electrospinning

    Science.gov (United States)

    Guan, Hongyu; Shao, Changlu; Liu, Yichun; Yu, Na; Yang, Xinghua

    2004-07-01

    The spinel NiCo 2O 4 nanofibers with diameters of 50-100 nm were prepared by high temperature calcinations of a simple inorganic-polymer composite fibers, which were obtained by electrospinning of the PVA/cobalt acetate/nickel acetate composite precursor. The crystallinity, purity, and surface morphology of the as-prepared NiCo 2O 4 nanofibers were investigated by XRD, FT-IR, SEM, respectively.

  12. Preparation,performance and comparison of co-electrospun and coaxial-electrospun drug-loaded PVA-SbQ/Zein composite nanofibers%共混与同轴静电纺载药纳米纤维的制备、表征及比较

    Institute of Scientific and Technical Information of China (English)

    崔静; 邱玉宇; 卢杭诣; 聂清欣; 魏取福

    2016-01-01

    采用共混和同轴静电纺制备了负载盐酸四环素药物的聚乙烯醇-苯乙烯吡啶盐(PVA-SbQ)/玉米醇溶蛋白(Zein)复合纳米纤维,在紫外光照射下得到光交联载药 PVA-SbQ/Zein 复合纳米纤维。利用扫描电镜(SEM)对不同纤维的形貌和直径分布进行了分析;采用透射电镜(TEM)对不同静电纺丝法制备的纳米纤维结构进行了观察和比较;强力测试表明同轴静电纺丝制备的纳米纤维力学性能更强;傅里叶变换红外光谱(FT-IR)曲线表明载药PVA-SbQ/Zein复合纳米纤维保持了原有的化学功能基团;最后比较了两种方法制备的载药纳米纤维膜的药物释放行为。%Drug tetracycline hydrochloride (TCH)-loaded PVA-SbQ/Zein composite nanofibers were fabricated by co-electrospinning and coaxial-electrospinning,respectively.Then the nanofibers were irradiated under UV light to get the cross-linked ones.The morphologies and diameter distributions of drug-loaded PVA-SbQ/Zein composite nanofibers were observed by SEM.TEM was used to compare the structure of the two kind of nanofi-bers.The strength test showed that the tensile strength of coaxial-electrospun nanofibers was better than the co-electrospun ones.The spectra of FT-IR indicated that composite nanofibers maintained their own original functional groups.Finally,the drug release behavior of drug-loaded nanofibers prepared with two methods was compared.

  13. Antimicrobial filtration with electrospun poly(vinyl alcohol) nanofibers containing benzyl triethylammonium chloride: Immersion, leaching, toxicity, and filtration tests.

    Science.gov (United States)

    Park, Jeong-Ann; Kim, Song-Bae

    2017-01-01

    Antimicrobial electrospun poly(vinyl alcohol) (PVA) nanofibers were synthesized by impregnating benzyl triethylammonium chloride (BTEAC) as an antimicrobial agent into PVA nanofibers. The BTEAC-PVA nanofibers were heat-methanol treated during the preparation for various tests. The BTEAC-PVA nanofibers became more hydrophilic than the PVA nanofibers due to incorporation of BTEAC. Through heat-methanol treatment, thermal property, crystallinity, and water stability of BTEAC-PVA nanofibers were improved considerably. The immersion test shows that heat-methanol treatment has an advantage over heat treatment to maintain BTEAC content in BTEAC-PVA nanofibers. The acute toxicity test demonstrates that the 24-h EC50 and 48-h EC50 values (EC50 = median effective concentration) of BTEAC to Daphnia magna were 113 and 90 mg/L, respectively. The leaching test indicates that the BTEAC concentration leached from BTEAC-PVA nanofibers was far below the concentration affecting the immobilization of D. magna. For antimicrobial filtration tests, the BTEAC-PVA nanofibers were deposited onto glass fiber filter. The antimicrobial filtration test was conducted against bacteria (Escherichia coli, Staphylococcus aureus) and bacteriophages (MS2, PhiX174), demonstrating that the BTEAC-PVA nanofibers could enhance the removal of E. coli and S. aureus considerably but not the removal of MS2 and PhiX174 under dynamic flow conditions.

  14. Facile preparation of TiO{sub 2}–polyvinyl alcohol hybrid nanoparticles with improved visible light photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Filippo, Emanuela [Department of Innovation Engineering, University of Salento, Monteroni Street, 73100, Lecce (Italy); Carlucci, Claudia; Capodilupo, Agostina Lina [National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy); Perulli, Patrizia [Department of Innovation Engineering, University of Salento, Monteroni Street, 73100, Lecce (Italy); Conciauro, Francesca [National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy); Corrente, Giuseppina Anna [University of Calabria, Pietro Bucci Street, 87036 Arcavacata di Rende, Cosenza (Italy); Gigli, Giuseppe [National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy); Center for Biomolecular Nanotechnologies (CBN) of Italian Institute of Technology (IIT), Barsanti Street 1, 73010 Arnesano (Italy); Department of Physics, University of Salento, Monteroni Street, 73100, Lecce (Italy); Ciccarella, Giuseppe, E-mail: giuseppe.ciccarella@unisalento.it [Department of Innovation Engineering, University of Salento, Monteroni Street, 73100, Lecce (Italy); National Nanotechnology Laboratory (NNL), Nanoscience Institure – CNR, Arnesano Street, 73100 Lecce (Italy)

    2015-03-15

    Graphical abstract: - Highlights: • Hybrid TiO{sub 2}/PVA core/shell nanoparticles were prepared through a two step procedure. • TiO{sub 2}–PVA samples were prepared based on different TiO{sub 2}–PVA weight ratios. • All samples were characterized using XRD, TEM, FT-IR and BET analysis. • The photocatalytic performance was evaluated. - Abstract: Hybrid inorganic/organic core/shell nanoparticles were prepared through a two step synthesis procedure. In the first step, pure anatase TiO{sub 2} nanoparticles were synthesized though a rapid microwave assisted non-aqueous route. Then, the obtained titania nanoparticles were coated with polyvinyl alcohol (PVA) using a simple solution method followed by relatively low temperature treatment. The PVA-coated titania nanoparticles samples were prepared at different TiO{sub 2}–PVA weight ratio and they were characterized using X-Ray diffraction, transmission electron microscopy, infrared spectroscopy and Brunauer–Emmett–Teller (BET) analysis. Photocatalytic performance was also evaluated for all samples and the results indicated that TiO{sub 2}:PVA weight ratio was a key factor to obtain an improvement of the photocatalytic activity with respect to bare TiO{sub 2} nanoparticles, since PVA concentration influenced the surface area and the aggregation of nanoparticles and the thickness of the coating layer. This inexpensive system provides a simple, quick and effective approach which allows to obtain core/shell hybrid nanostructures.

  15. Large 2D-arrays of size-controllable silver nanoparticles prepared by hybrid deposition

    Science.gov (United States)

    Dieu Thuy Ung, Thi; Hoa Nguyen, Thi; Liem Nguyen, Quang

    2016-09-01

    Two main results are presented in this paper. (i) Silver nanoparticles (AgNPs) with uniform size-distribution and controllability in the range of 20-50 nm were synthesized by seeding and growing at ambient conditions. The single-crystal Ag nano-seeds were created by reduction of AgNO3 in presence of citrate surfactant at 70 °C. Then, importantly, the fresh AgCl precursor was used in the presence of polyvinylpyrrolidone to adjust the reaction rate with ascorbic acid to generate Ag for growing on the surface of single-crystal Ag nano-seeds. The AgNPs size could be well-controlled by varying the amount of Ag nano-seeds while keeping the AgCl precursor concentration to be constant. (ii) The large 2D-arrays with homogeneous and dense monolayers of AgNPs were prepared on ITO substrates by hybrid method, in which the key technological point is the surface functionalization of AgNPs using mixed alkanethiols (dodecanethiol:octadecanethiol = 6:1). We have used the fabricated 2D-arrays from the 50 nm AgNPs as a surface enhanced Raman scattering substrate to take the Raman scattering spectra of rhodamine B (RhB), glucose and viral pathogen (H5N1) at very low concentrations of 10-10 M, 10-12 M and 4 ng μl-1, respectively.

  16. Synthesis, characterization, and mercury adsorption properties of hybrid mesoporous aluminosilicate sieve prepared with fly ash.

    Science.gov (United States)

    Liu, Minmin; Hou, Li-An; Xi, Beidou; Zhao, Ying; Xia, Xunfeng

    2013-05-15

    A novel hybrid mesoporous aluminosilicate sieve (HMAS) was prepared with fly ash and impregnated with zeolite A precursors. This improved the mercury adsorption of HMAS compared to original MCM-41. The HMAS was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM) images and (29)Si and (27)Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra. These showed that the HMAS structure was still retained after impregnated with zeolite A. But the surface area and pore diameter of HMAS decreased due to pore blockage. Adsorption of mercury from aqueous solution was studied on untreated MCM-41and HMAS. The mercury adsorption rate of HMAS was higher than that of origin MCM-41. The adsorption of mercury was investigated on HMAS regarding the pH of mercury solution, initial mercury concentration, and the reaction temperature. The experimental data fit well to Langmuir and Freundlich isotherm models. The Dublin-Radushkevich isotherm and the characterization show that the mercury adsorption on HMAS involved the ion-exchange mechanisms. In addition, the thermodynamic parameters suggest that the adsorption process was endothermic in nature. The adsorption of mercury on HMAS followed the first order kinetics.

  17. Synthesis, characterization, and mercury adsorption properties of hybrid mesoporous aluminosilicate sieve prepared with fly ash

    Science.gov (United States)

    Liu, Minmin; Hou, Li-an; Xi, Beidou; Zhao, Ying; Xia, Xunfeng

    2013-05-01

    A novel hybrid mesoporous aluminosilicate sieve (HMAS) was prepared with fly ash and impregnated with zeolite A precursors. This improved the mercury adsorption of HMAS compared to original MCM-41. The HMAS was characterized by X-ray diffraction (XRD), nitrogen adsorption-desorption, Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM) images and 29Si and 27Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra. These showed that the HMAS structure was still retained after impregnated with zeolite A. But the surface area and pore diameter of HMAS decreased due to pore blockage. Adsorption of mercury from aqueous solution was studied on untreated MCM-41and HMAS. The mercury adsorption rate of HMAS was higher than that of origin MCM-41. The adsorption of mercury was investigated on HMAS regarding the pH of mercury solution, initial mercury concentration, and the reaction temperature. The experimental data fit well to Langmuir and Freundlich isotherm models. The Dublin-Radushkevich isotherm and the characterization show that the mercury adsorption on HMAS involved the ion-exchange mechanisms. In addition, the thermodynamic parameters suggest that the adsorption process was endothermic in nature. The adsorption of mercury on HMAS followed the first order kinetics.

  18. Synthesis, characterization, and mercury adsorption properties of hybrid mesoporous aluminosilicate sieve prepared with fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Minmin [School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Hou, Li-an, E-mail: 11liuminmin@tongji.edu.cn [School of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092 (China); Xi, Beidou; Zhao, Ying; Xia, Xunfeng [China Research Academy of Environmental Science, Beijing 200012 (China)

    2013-05-15

    A novel hybrid mesoporous aluminosilicate sieve (HMAS) was prepared with fly ash and impregnated with zeolite A precursors. This improved the mercury adsorption of HMAS compared to original MCM-41. The HMAS was characterized by X-ray diffraction (XRD), nitrogen adsorption–desorption, Fourier transform infrared (FTIR) analysis, transmission electron microscopy (TEM) images and {sup 29}Si and {sup 27}Al magic angle spinning nuclear magnetic resonance (MAS NMR) spectra. These showed that the HMAS structure was still retained after impregnated with zeolite A. But the surface area and pore diameter of HMAS decreased due to pore blockage. Adsorption of mercury from aqueous solution was studied on untreated MCM-41and HMAS. The mercury adsorption rate of HMAS was higher than that of origin MCM-41. The adsorption of mercury was investigated on HMAS regarding the pH of mercury solution, initial mercury concentration, and the reaction temperature. The experimental data fit well to Langmuir and Freundlich isotherm models. The Dublin–Radushkevich isotherm and the characterization show that the mercury adsorption on HMAS involved the ion-exchange mechanisms. In addition, the thermodynamic parameters suggest that the adsorption process was endothermic in nature. The adsorption of mercury on HMAS followed the first order kinetics.

  19. Optically active substituted polyacetylene@carbon nanotube hybrids: Preparation, characterization and infrared emissivity property study

    Energy Technology Data Exchange (ETDEWEB)

    Bu, Xiaohai; Zhou, Yuming, E-mail: ymzhou@seu.edu.cn; Zhang, Tao; Wang, Yongjuan; Zhang, Zewu; He, Man

    2014-08-15

    Optically active substituted polyacetylene@multiwalled carbon nanotubes (SPA@MWCNTs) nanohybrids were fabricated by wrapping helical SPA copolymers onto the surface of modified nanotubes through ester bonding linkage. SPA copolymer based on chiral phenylalanine and serine was pre-polymerized by a rhodium zwitterion catalyst in THF, and evidently proved to possess strong optical activity and adopt a predominately one-handed helical conformation. Various characterizations including Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM) demonstrated that the SPA had been covalently grafted onto the nanotubes without destroying their original graphite structure. The wrapped SPA was found to exhibit an enhancement in thermal stability and still maintained considerable optical activity after grafting. The infrared emissivity property of the nanohybrids at 8–14 μm was investigated in addition. The results indicated that the SPA@MWCNTs hybrid matrix could possess a much lower infrared emissivity value (ε=0.707) than raw MWCNTs, which might be due to synergistic effect of the unique helical conformation of optically active SPA and strengthened interfacial interaction between the organic polymers and inorganic nanoparticles. - Graphical abstract: Optically active SPA@MWCNTs nanohybrids with low infrared emissivity. - Highlights: • Synthesis of optically active SPA copolymer derived from serine and phenylalanine. • Preparation and characterization of optically active SPA@MWCNTs nanohybrids. • Application study of the SPA@MWCNTs nanohybrids (ε=0.707) in lowering the infrared emissivity.

  20. AC-driven light emission from in situ grown organic nanofibers

    Science.gov (United States)

    Liu, Xuhai; Kjelstrup-Hansen, Jakob; de Oliveira Hansen, Roana Melina; Madsen, Morten; Rubahn, Horst-Günter

    2012-06-01

    In-situ grown organic nanofibers have been prepared on metal electrodes patterned by electron beam lithography. A systematic investigation shows that the light emission from these nanofibers driven by an AC gate voltage depends nonlinearly on the amplitude of the AC gate voltage and linearly on the frequency of the gate voltage, which indicates that a model involving thermally assisted charge-carrier tunneling can be applied. The photoluminescence spectra of parahexaphenylene (p6P) and α-sexithiophene (6T) nanofibers illustrate that the emission color of the in-situ grown nanofibers can be tuned by depositing two types of discontinuous organic layers on the same platform. Electroluminescence from two nanofiber thin films suggests that the relative light emission contribution from the two organic molecules can be varied by changing, e.g., the nominal thickness of the two materials.

  1. Influence of carbon nanofiber properties as electrocatalyst support on the electrochemical performance for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, D.; Suelves, I.; Moliner, R.; Lazaro, M.J. [Instituto de Carboquimica (CSIC), Energy and Environment, C/Miguel Luesma Castan 4, 50018 Zaragoza (Spain); Calderon, J.C.; Gonzalez-Exposito, J.A.; Pastor, E. [Universidad de La Laguna, Dpto de Quimica-Fisica, Avda. Astrofisico Francisco Sanchez s/n, 38071 La Laguna, Tenerife (Spain); Martinez-Huerta, M.V. [Instituto de Catalisis y Petroleoquimica (CSIC), C/Marie Curie 2, 28049 Madrid (Spain)

    2010-09-15

    Novel carbonaceous supports for electrocatalysts are being investigated to improve the performance of polymer electrolyte fuel cells. Within several supports, carbon nanofibers blend two properties that rarely coexist in a material: a high mesoporosity and a high electrical conductivity, due to their particular structure. Carbon nanofibers have been obtained by catalytic decomposition of methane, optimizing growth conditions to obtain carbon supports with different properties. Subsequently, the surface chemistry has been modified by an oxidation treatment, in order to create oxygen surface groups of different nature that have been observed to be necessary to obtain a higher performance of the electrocatalyst. Platinum has then been supported on the as-prepared carbon nanofibers by different deposition methods and the obtained catalysts have been studied by different electrochemical techniques. The influence of carbon nanofibers properties and functionalization on the electrochemical behavior of the electrocatalysts has been studied and discussed, obtaining higher performances than commercial electrocatalysts with the highest electrical conductive carbon nanofibers as support. (author)

  2. Structural characteristics and biological performance of silk fibroin nanofiber containing microalgae Spirulina extract.

    Science.gov (United States)

    Cha, Bum-Gyu; Kwak, Hyo Won; Park, A Reum; Kim, Shin Hwan; Park, Sook-Young; Kim, Hyun-Jeong; Kim, Ick-Soo; Lee, Ki Hoon; Park, Young Hwan

    2014-04-01

    Silk fibroin (SF) nanofiber scaffold containing microalgae Spirulina extract were prepared by electrospinning and the performance and functionality of the scaffold were evaluated. The viscosity and conductivity of the dope solution of Spirulina containing SF were examined for electrospinability and we found that the morphological structure of SF nanofiber is affected by the concentration of Spirulina extract added. The platelet adhesion and coagulation time test confirmed that the Spirulina containing SF nanofiber scaffold had excellent ability to prevent blood clotting or antithrombogenicity that is comparable to heparin. Low cytotoxicity and excellent cell adhesion and proliferation were also observed for Sprulina containing SF nanofiber scaffold by methylthiazolyldiphenyl-tetrazolium bromide assay and confocal fluorescence microscope using fibroblast and human umbilical vein endothelial cells. Based on these results, we believe SF nanofiber scaffold containing Spirulina extract has the potential to be used as tissue engineering scaffold that requires high hemocompatibility. Copyright © 2013 Wiley Periodicals, Inc.

  3. Development, optimization and evaluation of polymeric electrospun nanofiber: A tool for local delivery of fluconazole for management of vaginal candidiasis.

    Science.gov (United States)

    Sharma, Rahul; Garg, Tarun; Goyal, Amit K; Rath, Goutam

    2016-01-01

    The present study is designed to explore the localized delivery of fluconazole using mucoadhesive polymeric nanofibers. Drug-loaded polymeric nanofibers were fabricated by the electrospinning method using polyvinyl alcohol (PVA) as the polymeric constituent. The prepared nanofibers were found to be uniform, non-beaded and non-woven, with the diameter of the fibers ranging from 150 to 180 nm. Further drug release studies indicate a sustained release of fluconazole over a period of 6 h. The results of studies on anti-microbial activity indicated that drug-loaded polymeric nanofibers exhibit superior anti-microbial activity against Candida albicans, when compared to the plain drug.

  4. Influences of Silver-Doping on the Crystal Structure, Morphology and Photocatalytic Activity of TiO2 Nanofibers

    DEFF Research Database (Denmark)

    Barakat, Nasser A. M.; Kanjwal, Muzafar Ahmed; Al-Deyab, Salem S.

    2011-01-01

    activity of titanium oxide nanofibers has been studied. Sil-ver-doped TiO2 nanofibers having different silver contents were prepared by calcination of electrospun nanofiber mats consisting of silver nitrate, titanium isopropoxide and poly(vinyl acetate) at 600°C. The results affirmed formation of silver......-doped TiO2 nanofibers composed of anatase and rutile when the silver nitrate content in the original electrospun solution was more than 3 wt%. The rutile phase content was directly proportional with the AgNO3 concentration in the electrospun solution. Negative impact of the silver-doping on the nanofibrous...

  5. Nanofibers for drug delivery - incorporation and release of model molecules, influence of molecular weight and polymer structure.

    Science.gov (United States)

    Hrib, Jakub; Sirc, Jakub; Hobzova, Radka; Hampejsova, Zuzana; Bosakova, Zuzana; Munzarova, Marcela; Michalek, Jiri

    2015-01-01

    Nanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using Nanospider(TM) technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influences of the molecular length and chemical composition of the nanofibers on the release rate and the amount of released polyethylene glycols were evaluated. Longer molecules released faster, as evidenced by a significantly higher amount of released molecules after 72 hours. However, the influence of the chemical composition of nanofibers was even more distinct - the highest amount of polyethylene glycol molecules released from polyvinyl alcohol nanofibers, the lowest amount from polylactide nanofibers.

  6. Nanofibers for drug delivery – incorporation and release of model molecules, influence of molecular weight and polymer structure

    Directory of Open Access Journals (Sweden)

    Jakub Hrib

    2015-09-01

    Full Text Available Nanofibers were prepared from polycaprolactone, polylactide and polyvinyl alcohol using NanospiderTM technology. Polyethylene glycols with molecular weights of 2 000, 6 000, 10 000 and 20 000 g/mol, which can be used to moderate the release profile of incorporated pharmacologically active compounds, served as model molecules. They were terminated by aromatic isocyanate and incorporated into the nanofibers. The release of these molecules into an aqueous environment was investigated. The influences of the molecular length and chemical composition of the nanofibers on the release rate and the amount of released polyethylene glycols were evaluated. Longer molecules released faster, as evidenced by a significantly higher amount of released molecules after 72 hours. However, the influence of the chemical composition of nanofibers was even more distinct – the highest amount of polyethylene glycol molecules released from polyvinyl alcohol nanofibers, the lowest amount from polylactide nanofibers.

  7. Capture of toxic radioactive and heavy metal ions from water by using titanate nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jiasheng, E-mail: jiashengxu@bhu.edu.cn [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Zhang, He; Zhang, Jie [Liaoning Province Key Laboratory for Synthesis and Application of Functional Compounds, College of Chemistry, Chemical Engineering and Food Safety, Center of Science and Technology Experiment, Bohai University, 19 Sci-tech Road, Jinzhou 121013 (China); Kim, Eui Jung [School of Chemical Engineering and Bioengineering, University of Ulsan, Ulsan 680-749 (Korea, Republic of)

    2014-11-25

    Highlights: • Three types of titanate nanofibers were prepared via a hydrothermal porcess. • These nanofibers show availability for removal of the toxic ions from water. • The equilibrium data were fitted well with the Langmuir model. - Abstract: Three types of titanate nanofibers (sodium titanate nanofibers (TNF-A), potassium/sodium titanate nanofibers (TNF-B), potassium titanate nanofibers (TNF-C)) were prepared via a hydrothermal treatment of anatase powders in different alkali solutions at 170 °C for 96 h, respectively. The as-prepared nanofibers have large specific surface area and show availability for the removal of radioactive and heavy metal ions from water system, such as Ba{sup 2+} (as substitute of {sup 226}Ra{sup 2+}) and Pb{sup 2+} ions. The TNF-A shows a better capacity in the removal of Ba{sup 2+} and Pb{sup 2+} than TNF-B and TNF-C. Structural characterization of the materials was performed with powder X-ray diffraction (XRD), scanning electron microscopy (SEM) equipped with energy dispersive spectrometer (EDS) and with inductively coupled plasma optical emission spectrometry (ICP-OES). It is found that the equilibrium data fit well with the Langmuir model. This study highlights that nanoparticles of inorganic ion exchangers with layered structure are potential materials for efficient removal of the toxic ions from contaminated water.

  8. Preparation of a Hybrid Zirconium Phytate and Its Application for the Removal of Fluorine in Metal-Precoating Effluent

    Directory of Open Access Journals (Sweden)

    Cheng Wenkai

    2016-01-01

    Full Text Available A hybrid zirconium phytate (ZrxIP6 with porous surface was synthesized via the direct precipitation method. The as-prepared ZrxIP6 was characterized by SEM, EDS, FT-IR. The sample obtained from P/Zr = 3:1(mol/mol indicated that a hybrid material might be formed through coordination of the zirconium ions with the –COPO3 groups in phytic acid molecules. An attempt to employ the hybrid ZrxIP6 as a sorbent in the removal of fluoride ions in metal-precoating wastewater was performed. The adsorption capacity qe and the residual F- ions concentration Ce using the ZrxIP6 (P/Zr = 3:1 as an adsorbent, were 1.21 mg.g-1 and 1.47 mg.L-1, respectively.

  9. High Refractive Organic–Inorganic Hybrid Films Prepared by Low Water Sol-Gel and UV-Irradiation Processes

    Directory of Open Access Journals (Sweden)

    Hsiao-Yuan Ma

    2016-03-01

    Full Text Available Organic-inorganic hybrid sols (Ti–O–Si precursor were first synthesized by the sol-gel method at low addition of water, and were then employed to prepare a highly refractive hybrid optical film. This film was obtained by blending the Ti–O–Si precursor with 2-phenylphenoxyethyl acrylate (OPPEA to perform photo-polymerization by ultraviolet (UV irradiation. Results show that the film transparency of poly(Ti–O–Si precursor-co-OPPEA film is higher than that of a pure poly(Ti–O–Si precursor film, and that this poly(Ti–O–Si precursor-co-OPPEA hybrid film exhibits a high transparency of ~93.7% coupled with a high refractive index (n of 1.83 corresponding to a thickness of 2.59 μm.

  10. Field Emission Properties of the Graphene Double-Walled Carbon Nanotube Hybrid Films Prepared by Vacuum Filtration and Screen Printing

    Directory of Open Access Journals (Sweden)

    Jinzhuo Xu

    2013-01-01

    Full Text Available The graphene double-walled carbon nanotube (DWCNT hybrid films were prepared by vacuum filtration and screen printing. Their electron field emission properties have been studied systematically. The electron emission properties of the hybrid films are much better than those of pure DWCNT films and pure graphene films. Comparing with the screen printed films, the vacuum filtered films have many advantages, such as lower turn-on field, higher emission current density, better uniformity, better long-term stability, and stronger adhesive strength with conductive substrates. The optimized hybrid films with 20% weight ratio of graphene, which were fabricated by vacuum filtration, show the best electron emission performances with a low turn-on field of 0.50 Vμm−1 (at 1 μAcm−2 and a high field enhancement factor β of 27000.

  11. PREPARATION OF POLYIMIDE-BaTiO3 HYBRID FILMS BY A DISPERSION PROCESS AND THEIR MICROSTRUCTURE

    Institute of Scientific and Technical Information of China (English)

    Yue-sheng Li; Yue-jin Tong; Kai Jing; Meng-xian Ding

    2001-01-01

    Barium titanate (BaTiO3) powders with particle sizes of 30~50 nm were prepared from barium stearate, titanium alkoxides and stearic acid by stearic acid-gel method. Dispersing the agglomerate of BaTiO3 nanoparticles into poly(amic acid) solution followed by curing led to the formation of polyimide hybrid films. The hybrid films were transparent and well distributed with BaTiO3 nanoparticles when the BaTiO3 content was less than 1 wt%. Highly loaded hybrid film containing 30 wt % BaTiO3 was tough, had a smooth surface and possessed much higher dielectric and piezoelectric constants than the parent polyimide.

  12. Investigation of electrochemical actuation by polyaniline nanofibers

    Science.gov (United States)

    Mehraeen, Shayan; Alkan Gürsel, Selmiye; Papila, Melih; Çakmak Cebeci, Fevzi

    2017-09-01

    Polyaniline nanofibers have shown promising electrical and electrochemical properties which make them prominent candidates in the development of smart systems employing sensors and actuators. Their electrochemical actuation potential is demonstrated in this study. A trilayer composite actuator based on polyaniline nanofibers was designed and fabricated. Cross-linked polyvinyl alcohol was sandwiched between two polyaniline nanofibrous electrodes as ion-containing electrolyte gel. First, electrochemical behavior of a single electrode was studied, showing reversible redox peak pairs in 1 M HCl using a cyclic voltammetry technique. High aspect ratio polyaniline nanofibers create a porous network which facilitates ion diffusion and thus accelerates redox reactions. Bending displacement of the prepared trilayer actuator was then tested and reported under an AC potential stimulation as low as 0.5 V in a variety of frequencies from 50 to 1000 mHz, both inside 1 M HCl solution and in air. Decay of performance of the composite actuator in air is investigated and it is reported that tip displacement in a solution was stable and repeatable for 1000 s in all selected frequencies.

  13. Silver-functionalized carbon nanofiber composite electrodes for ibuprofen detection

    NARCIS (Netherlands)

    Manea, F.; Motoc, S.; Pop, A.; Remes, A.; Schoonman, J.

    2012-01-01

    The aim of this study is to prepare and characterize two types of silver-functionalized carbon nanofiber (CNF) composite electrodes, i.e., silver-decorated CNF-epoxy and silver-modified natural zeolite-CNF-epoxy composite electrodes suitable for ibuprofen detection in aqueous solution. Ag carbon nan

  14. Dexamethasone loaded core-shell SF/PEO nanofibers via green electrospinning reduced endothelial cells inflammatory damage.

    Science.gov (United States)

    Chen, Weiming; Li, Dawei; Ei-Shanshory, Ahmed; El-Newehy, Mohamed; Ei-Hamshary, Hany A; Al-Deyab, Salem S; He, Chuanglong; Mo, Xiumei

    2015-02-01

    Silk fibroin (SF)/PEO nanofibers prepared by green electrospinning is safe, non-toxic and environment friendly, it is a potential drug delivery carrier for tissue engineering. In this study, a core-shell nanofibers named as Dex@SF/PEO were obtained by green electrospinning with SF/PEO as the shell and dexamethasone (Dex) in the core. The nanofiber morphology and core-shell structure were studied by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). The Dex release behavior from the nanofibers was tested by High Performance liquid (HPLC) method. The protective effect of drug loaded nanofibers mats on Porcine hip artery endothelial cells (PIECs) against LPS-induced inflammatory damage were determined by MTT assay. TEM result showed the distinct core-shell structure of nanofibers. In vitro drug release studies demonstrated that dexamethasone can sustain release over 192 h and core-shell nanofibers showed more slow release of Dex compared with the blending electrospinning nanofibers. Anti-inflammatory activity in vitro showed that released Dex can reduce the PIECs inflammatory damage and apoptosis which induced by lipopolysaccharide (LPS). Dex@SF/PEO nanofibers are safe and non-toxic because of no harmful organic solvents used in the preparation, it is a promising environment friendly drug carrier for tissue engineering.

  15. Function of NaOH hydrolysis in electrospinning ZnO nanofibers via using polylactide as templates

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Mengzhu, E-mail: liumengzhu125@163.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Wang, Yongpeng, E-mail: wyp4889@gmail.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Cheng, Zhiqiang, E-mail: czq5974@163.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); College of Resources and Environment, Jilin Agriculture University, Changchun, Jilin Province 130118 (China); Song, Lihua, E-mail: 120836684@qq.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Shenyang Institute of Geology and Mineral Resources, CGS, Shenyang, Liaoning Province 110034 (China); Zhang, Mingyue, E-mail: zhangmingyue8803@163.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Hu, Meijuan, E-mail: 442675083@qq.com [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China); Li, Junfeng, E-mail: jfli@jlu.edu.cn [College of Chemistry, Jilin University, Changchun, Jilin Province 130012 (China)

    2014-09-15

    Graphical abstract: - Highlights: • PLA was used as templates to electrospin ZnO nanofibers for the first time. • Without NaOH hydrolysis, only ZnO film was prepared. • Under function of NaOH, ZnO nanofibers were obtained. • The function of NaOH was discussed. • ZnO nanofibers showed much higher photocatalytical efficiency than ZnO film. - Abstract: Mixture of polylactide (8 wt%), zinc acetate (6 wt%) and hexafluoroisopropanol was first used as electrospinning solution to fabricate ZnO nanofibers. Unfortunately, after direct calcination of the precursor polylactide/zinc acetate nanofibers, only ZnO film was prepared. Surprisingly, when the precursor fibers were pre-hydrolyzed with NaOH, ZnO nanofibers with diameter of 678 nm were obtained. The mechanism analysis showed that the preserve of fiber structure was attributed to the formation of zinc polylactic acid in the process of hydrolyzation. After characterized by scanning electron microscope and transmission electron microscope, the ZnO film was found to be an aggregation of irregular nanoparticles and the ZnO nanofiber was a necklace-like arrangement of cylindrical grains. X-ray diffraction and photoluminescence measurements indicated that the crystalline quality of the ZnO nanofibers was higher than the film. Furthermore, photocatalytic performance of the ZnO samples was investigated. Comparing with ZnO film, ZnO nanofibers exhibited much higher activity.

  16. Preparation of poly(ethylene glycol/polylactide hybrid fibrous scaffolds for bone tissue engineering

    Directory of Open Access Journals (Sweden)

    Ni P

    2011-11-01

    Full Text Available PeiYan Ni, ShaoZhi Fu, Min Fan, Gang Guo, Shuai Shi, JinRong Peng, Feng Luo, ZhiYong QianState Key Laboratory of Biotherapy and Cancer Center, West China Hospital, West China Medical School, Sichuan University, Chengdu, Sichuan, People's Republic of ChinaAbstract: Polylactide (PLA electrospun fibers have been reported as a scaffold for bone tissue engineering application, however, the great hydrophobicity limits its broad application. In this study, the hybrid amphiphilic poly(ethylene glycol (PEG/hydrophobic PLA fibrous scaffolds exhibited improved morphology with regular and continuous fibers compared to corresponding blank PLA fiber mats. The prepared PEG/PLA fibrous scaffolds favored mesenchymal stem cell (MSC attachment and proliferation by providing an interconnected porous extracellular environment. Meanwhile, MSCs can penetrate into the fibrous scaffold through the interstitial pores and integrate well with the surrounding fibers, which is very important for favorable application in tissue engineering. More importantly, the electrospun hybrid PEG/PLA fibrous scaffolds can enhance MSCs to differentiate into bone-associated cells by comprehensively evaluating the representative markers of the osteogenic procedure with messenger ribonucleic acid quantitation and protein analysis. MSCs on the PEG/PLA fibrous scaffolds presented better differentiation potential with higher messenger ribonucleic acid expression of the earliest osteogenic marker Cbfa-1 and mid-stage osteogenic marker Col I. The significantly higher alkaline phosphatase activity of the PEG/PLA fibrous scaffolds indicated that these can enhance the differentiation of MSCs into osteoblast-like cells. Furthermore, the higher messenger ribonucleic acid level of the late osteogenic differentiation markers OCN (osteocalcin and OPN (osteopontin, accompanied by the positive Alizarin red S staining, showed better maturation of osteogenic induction on the PEG/PLA fibrous scaffolds at the

  17. Fluorescent carbon nanowires made by pyrolysis of DNA nanofibers and plasmon-assisted emission enhancement of their fluorescence.

    Science.gov (United States)

    Nakao, Hidenobu; Tokonami, Shiho; Yamamoto, Yojiro; Shiigi, Hiroshi; Takeda, Yoshihiko

    2014-10-14

    We report on a facile method for preparing fluorescent carbon nanowires (CNWs) with pyrolysis of highly aligned DNA nanofibers as carbon sources. Silver nanoparticle (AgNP)-doped CNWs were also produced using pyrolysis of DNA nanofibers with well-attached AgNPs, indicating emission enhancement assisted by localized plasmon resonances.

  18. Lecithin blended polyamide-6 high aspect ratio nanofiber scaffolds via electrospinning for human osteoblast cell culture

    Energy Technology Data Exchange (ETDEWEB)

    Nirmala, R. [Bio-nano System Engineering, College of Engineering, Chonbuk National University, Jeonju, 561 756 (Korea, Republic of); Park, Hye-Min [Department of Pharmacology and Toxicology, College of Veterinary Medicine, Chonbuk National University, Jeonju 561 756 (Korea, Republic of); Navamathavan, R. [School of Advanced Materials Engineering, Chonbuk National University, Jeonju 561 756 (Korea, Republic of); Kang, Hyung-Sub [Department of Pharmacology and Toxicology, College of Veterinary Medicine, Chonbuk National University, Jeonju 561 756 (Korea, Republic of); El-Newehy, Mohamed H. [Petrochemical Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Kim, Hak Yong, E-mail: khy@jbnu.ac.kr [Petrochemical Research Chair, Department of Chemistry, College of Science, King Saud University, Riyadh 11451 (Saudi Arabia); Center for Healthcare Technology and Development, Chonbuk National University, Jeonju, 561 756 (Korea, Republic of)

    2011-03-12

    In this study, we focused on the preparation and characterization of lecithin blended polyamide-6 nanofibers via an electrospinning process for human osteoblastic (HOB) cell culture applications. The morphological, structural characterizations and thermal properties of polyamide-6/lecithin nanofibers were determined by using scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and thermogravimetry (TGA). SEM images revealed that the nanofibers were well-oriented with good incorporation of lecithin. FT-IR results indicated the presence of amino groups of lecithin in the blended nanofibers. TGA analysis revealed that the onset degradation temperature decreased with increasing lecithin content in the blended nanofibers. The morphological features of cells attached on polyamide-6/lecithin nanofibers were confirmed by SEM. The adhesion, viability and proliferation properties of osteoblast cells on the polyamide-6/lecithin blended nanofibers were analyzed by in vitro cell compatibility test. This study demonstrated the non-cytotoxic behavior of electrospun polyamide-6/lecithin nanofibers for the osteoblast cell culture.

  19. Synthesis and Characterization of Electrospun Nanocomposite TiO Nanofibers with Ag Nanoparticles for Photocatalysis Applications

    Directory of Open Access Journals (Sweden)

    Srujan Mishra

    2012-01-01

    Full Text Available Polycrystalline mixed-phase TiO2 nanofibers embedded with 2.0% w/v Ag nanoparticles was prepared by the electrospinning technique. Calcination of dry Ag nanoparticles-titanium (IV isopropoxide/PVP electrospun nanofiber mats in air at 510∘C for 24 h yielded polycrystalline TiO2/Ag nanofibers. The morphology and distribution of silver nanoparticles were observed by transmission electron microscopy (TEM, scanning TEM (STEM, and high-angle annular dark-field (HAADF imaging. Mixed-phase anatase and rutile TiO2 nanofibers were produced with Ag nanoparticles. High-resolution TEM lattice-fringe measurements showed good agreement with Ag (111, anatase (101, and rutile (110 phases. The photocatalytic activity of TiO2/Ag nanofibers was compared to the photocatalytic activity of pure TiO2 nanofibers by studying the photodegradation of methyl red dye under UV light irradiation, in a photoreactor. UV-visible absorbance spectra showed that the rate of decay of the dye in case of photodegradation by TiO2/Ag nanofibers was 10.3 times higher than that by pure TiO2 nanofibers. The retaining of the fiber morphology along with the increased surface area due to the addition of Ag nanoparticles can be believed to enhance the photocatalytic oxidation of methyl red dye.

  20. Electrospun polyacrylonitrile nanofibers loaded with silver nanoparticles by silver mirror reaction

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Yongzheng; Li, Yajing; Zhang, Jianfeng; Yu, Zhongzhen; Yang, Dongzhi, E-mail: yangdz@mail.buct.edu.cn

    2015-06-01

    The silver mirror reaction (SMR) method was selected in this paper to modify electrospun polyacrylonitrile (PAN) nanofibers, and these nanofibers loaded with silver nanoparticles showed excellent antibacterial properties. PAN nanofibers were first pretreated in AgNO{sub 3} aqueous solution before the SMR process so that the silver nanoparticles were distributed evenly on the outer surface of the nanofibers. The final PAN nanofibers were characterized by scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), transmission electron microscopy (TEM), TEM-selected area electron diffraction (SAED), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). SEM, TEM micrographs and SAED patterns confirmed homogeneous dispersion of the silver nanoparticles which were composed of monocrystals with diameters 20–30 nm. EDS and XRD results showed that these monocrystals tended to form face-centered cubic single silver. TGA test indicated that the nanoparticles loaded on the nanofibers reached above 50 wt.%. This material was also evaluated by the viable cell-counting method. The results indicated that PAN nanofibers loaded with silver nanoparticles exhibited excellent antimicrobial activities against gram-negative Escherichia coli (E. coli), gram-positive Staphylococcus aureus (S. aureus) and the fungus Monilia albicans. Thus, this material had many potential applications in biomedical fields. - Highlights: • Silver mirror reaction was used to prepare nanofibers loaded with silver nanoparticles. • The SAED patterns demonstrated the monocrystallinity of silver nanocrystals. • The XRD results showed nanoparticles tended to be face-centered cubic single silver. • The material showed excellent antimicrobial activities against bacteria and fungi.

  1. Enhancement of photoresponse and UV-assisted gas sensing with Au decorated ZnO nanofibers

    Energy Technology Data Exchange (ETDEWEB)

    Li Yinhua [School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620 (United States); State Key Laboratory of Fine Chemicals, R and D Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Gong Jian [School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620 (United States); He Gaohong [State Key Laboratory of Fine Chemicals, R and D Center of Membrane Science and Technology, School of Chemical Engineering, Dalian University of Technology, Dalian 116024 (China); Deng Yulin, E-mail: yulin.deng@chbe.gatech.edu [School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0620 (United States)

    2012-06-15

    To increase the photoresponsive and gas sensing properties of ZnO nanofibers under UV illumination, Au nanoparticles were introduced to the ZnO nanofibers (Au/ZnO) using electrospinning technique. It is found that adding Au nanoparticles into the ZnO nanofibers enhances significantly the photoresponse and makes the nanofibers also respond to visible light. The gas sensing performance with the assist of UV irradiation at room temperature was also improved greatly, e.g., the sensor response (SR) for 5 ppm ethanol increases from 0.12 to 0.31 by introducing 0.20 mol% of Au in ZnO nanofibers. The improvement of gas sensing performance is attributed to the enhanced photocatalytic reactions of organic gases on the Au/ZnO nanofibers surface. In addition, the sensitive behaviors of the nanofibers to ethanol, benzene, toluene and acetone under UV irradiation with different wavelengths were investigated and compared as well. Highlights: Black-Right-Pointing-Pointer Au/ZnO nanofiber sensors were successfully prepared using electrospinning. Black-Right-Pointing-Pointer The Au/ZnO sensors respond not only to UV light but also to visible light. Black-Right-Pointing-Pointer The response to organic analyte at room temperature is also greatly improved. Black-Right-Pointing-Pointer Schottky junction between Au and ZnO is one key for the improvement of sensing.

  2. Aptamer-based organic-silica hybrid affinity monolith prepared via "thiol-ene" click reaction for extraction of thrombin.

    Science.gov (United States)

    Wang, Zheng; Zhao, Jin-cheng; Lian, Hong-zhen; Chen, Hong-yuan

    2015-06-01

    A novel strategy for preparing aptamer-based organic-silica hybrid monolithic column was developed via "thiol-ene" click chemistry. Due to the large specific surface area of the hybrid matrix and the simplicity, rapidness and high efficiency of "thiol-ene" click reaction, the average coverage density of aptamer on the organic-silica hybrid monolith reached 420 pmol μL(-1). Human α-thrombin can be captured on the prepared affinity monolithic column with high specificity and eluted by NaClO4 solution. N-p-tosyl-Gly-Pro-Arg p-nitroanilide acetate was used as the sensitive chromogenic substrate of thrombin. The thrombin enriched by this affinity column was detected with a detection of limit of 0.01 μM by spectrophotometry. Furthermore, the extraction recovery of thrombin at 0.15 μM in human serum was 91.8% with a relative standard deviation of 4.0%. These results indicated that "thiol-ene" click chemistry provided a promising technique to immobilize aptamer on organic-inorganic hybrid monolith and the easily-assembled affinity monolithic material could be used to realize highly selective recognition of trace proteins.

  3. Nanofibers Offer Alternative Ways to the Treatment of Skin Infections

    Directory of Open Access Journals (Sweden)

    T. D. J. Heunis

    2010-01-01

    Full Text Available Injury to the skin causes a breach in the protective layer surrounding the body. Many pathogens are resistant to antibiotics, rendering conventional treatment less effective. This led to the use of alternative antimicrobial compounds, such as silver ions, in skin treatment. In this review nanofibers, and the incorporation of natural antimicrobial compounds in these scaffolds, are discussed as an alternative way to control skin infections. Electrospinning as a technique to prepare nanofibers is discussed. The possibility of using these structures as drug delivery systems is investigated.

  4. Electrospun anatase-phase TiO2 nanofibers with different morphological structures and specific surface areas.

    Science.gov (United States)

    He, Guangfei; Cai, Yibing; Zhao, Yong; Wang, Xiaoxu; Lai, Chuilin; Xi, Min; Zhu, Zhengtao; Fong, Hao

    2013-05-15

    Electrospun anatase-phase TiO2 nanofibers with desired morphological structure and relatively high specific surface area are expected to outperform other nanostructures (e.g., powder and film) of TiO2 for various applications (particularly dye-sensitized solar cell and photo-catalysis). In this study, systematic investigations were carried out to prepare and characterize electrospun anatase-phase TiO2 nanofibers with different morphological structures (e.g., solid, hollow/tubular, and porous) and specific surface areas. The TiO2 nanofibers were generally prepared via electrospinning of precursor nanofibers followed by pyrolysis at 500°C. For making hollow/tubular TiO2 nanofibers, the technique of co-axial electrospinning was utilized; while for making porous TiO2 nanofibers, the etching treatment in NaOH aqueous solution was adopted. The results indicated that the hollow/tubular TiO2 nanofibers (with diameters of ~300-500 nm and wall-thickness in the range from tens of nanometers to ~200 nm) had the BET specific surface area of ~27.3 m(2)/g, which was approximately twice as that of the solid TiO2 nanofibers (~15.2 m(2)/g) with diameters of ~200-300 nm and lengths of at least tens of microns. Porous TiO2 nanofibers made from the precursor of Al2O3/TiO2 composite nanofibers had the BET specific surface area of ~106.5 m(2)/g, whereas porous TiO2 nanofibers made from the precursor of ZnO/TiO2 composite nanofibers had the highest BET specific surface area of ~148.6 m(2)/g.

  5. Retrospective study of trisomy 18 in chorionic villi with fluorescent in situ hybridization on archival direct preparations

    OpenAIRE

    Van Opstal, Diane; Berg, Cardi; Jahoda, M.; Brandenburg, Helen; Los, F.J.; in 't Veld, Peter

    1995-01-01

    textabstractTrisomy 18 in direct chorionic villus preparations needs further investigation since the chromosome abnormality may be confined to the placenta and may not represent th