WorldWideScience

Sample records for hybrid carbon material

  1. Carbon nanotubes/carbon fiber hybrid material: a super support material for sludge biofilms.

    Science.gov (United States)

    Liu, Qijie; Dai, Guangze; Bao, Yanling

    2017-07-16

    Carbon fiber (CF) is widely used as a sludge biofilm support material for wastewater treatment. Carbon nanotubes/carbon fiber (CNTs/CF) hybrid material was prepared by ultrasonically assisted electrophoretic deposition (EPD). CF supports (CF without handling, CF oxidized by nitric acid, CNTs/CF hybrid material) were evaluated by sludge immobilization tests, bacterial cell adsorption tests and Derjaguin -Landau -Verwey -Overbeek (DLVO) theory. We found that the CNTs/CF hybrid material has a high capacity for adsorbing activated sludge, nitrifying bacterial sludge and pure strains (Escherichia coli and Staphylococcus aureus). CNTs deposited on CF surface easily wound around the curved surface of bacterial cell which resulted in capturing more bacterial cells. DLVO theory indicated the lowest total interaction energy of CNTs/CF hybrid material, which resulted in the highest bacteria cell adsorption velocity. Experiments and DLVO theory results proved that CNTs/CF hybrid material is a super support material for sludge biofilms.

  2. Graphene-carbon nanotube hybrid materials and use as electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Tour, James M.; Zhu, Yu; Li, Lei; Yan, Zheng; Lin, Jian

    2016-09-27

    Provided are methods of making graphene-carbon nanotube hybrid materials. Such methods generally include: (1) associating a graphene film with a substrate; (2) applying a catalyst and a carbon source to the graphene film; and (3) growing carbon nanotubes on the graphene film. The grown carbon nanotubes become covalently linked to the graphene film through carbon-carbon bonds that are located at one or more junctions between the carbon nanotubes and the graphene film. In addition, the grown carbon nanotubes are in ohmic contact with the graphene film through the carbon-carbon bonds at the one or more junctions. The one or more junctions may include seven-membered carbon rings. Also provided are the formed graphene-carbon nanotube hybrid materials.

  3. Graphene-carbon nanotube hybrid materials and use as electrodes

    Science.gov (United States)

    Tour, James M.; Zhu, Yu; Li, Lei; Yan, Zheng; Lin, Jian

    2016-09-27

    Provided are methods of making graphene-carbon nanotube hybrid materials. Such methods generally include: (1) associating a graphene film with a substrate; (2) applying a catalyst and a carbon source to the graphene film; and (3) growing carbon nanotubes on the graphene film. The grown carbon nanotubes become covalently linked to the graphene film through carbon-carbon bonds that are located at one or more junctions between the carbon nanotubes and the graphene film. In addition, the grown carbon nanotubes are in ohmic contact with the graphene film through the carbon-carbon bonds at the one or more junctions. The one or more junctions may include seven-membered carbon rings. Also provided are the formed graphene-carbon nanotube hybrid materials.

  4. Modification of the Interfacial Interaction between Carbon Fiber and Epoxy with Carbon Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Kejing Yu

    2016-05-01

    Full Text Available The mechanical properties of the hybrid materials and epoxy and carbon fiber (CF composites were improved significantly as compared to the CF composites made from unmodified epoxy. The reasons could be attributed to the strong interfacial interaction between the CF and the epoxy composites for the existence of carbon nanomaterials. The microstructure and dispersion of carbon nanomaterials were characterized by transmission electron microscopy (TEM and optical microscopy (OM. The results showed that the dispersion of the hybrid materials in the polymer was superior to other carbon nanomaterials. The high viscosity and shear stress characterized by a rheometer and the high interfacial friction and damping behavior characterized by dynamic mechanical analysis (DMA indicated that the strong interfacial interaction was greatly improved between fibers and epoxy composites. Remarkably, the tensile tests presented that the CF composites with hybrid materials and epoxy composites have a better reinforcing and toughening effect on CF, which further verified the strong interfacial interaction between epoxy and CF for special structural hybrid materials.

  5. Strongly coupled inorganic-nano-carbon hybrid materials for energy storage.

    Science.gov (United States)

    Wang, Hailiang; Dai, Hongjie

    2013-04-07

    The global shift of energy production from fossil fuels to renewable energy sources requires more efficient and reliable electrochemical energy storage devices. In particular, the development of electric or hydrogen powered vehicles calls for much-higher-performance batteries, supercapacitors and fuel cells than are currently available. In this review, we present an approach to synthesize electrochemical energy storage materials to form strongly coupled hybrids (SC-hybrids) of inorganic nanomaterials and novel graphitic nano-carbon materials such as carbon nanotubes and graphene, through nucleation and growth of nanoparticles at the functional groups of oxidized graphitic nano-carbon. We show that the inorganic-nano-carbon hybrid materials represent a new approach to synthesize electrode materials with higher electrochemical performance than traditional counterparts made by simple physical mixtures of electrochemically active inorganic particles and conducting carbon materials. The inorganic-nano-carbon hybrid materials are novel due to possible chemical bonding between inorganic nanoparticles and oxidized carbon, affording enhanced charge transport and increased rate capability of electrochemical materials without sacrificing specific capacity. Nano-carbon with various degrees of oxidation provides a novel substrate for nanoparticle nucleation and growth. The interactions between inorganic precursors and oxidized-carbon substrates provide a degree of control over the morphology, size and structure of the resulting inorganic nanoparticles. This paper reviews the recent development of inorganic-nano-carbon hybrid materials for electrochemical energy storage and conversion, including the preparation and functionalization of graphene sheets and carbon nanotubes to impart oxygen containing groups and defects, and methods of synthesis of nanoparticles of various morphologies on oxidized graphene and carbon nanotubes. We then review the applications of the SC-hybrid

  6. Glassy Carbon Coating Deposited on Hybrid Structure of Composite Materials

    Directory of Open Access Journals (Sweden)

    Posmyk A.

    2016-06-01

    Full Text Available This paper presents a method of production metal matrix composites with aluminum oxide foam covered by glassy carbon layer used as reinforcement. The glassy carbon coating was formed for decreasing of friction coefficient and reducing the wear. In first step of technology liquid glassy carbon precursor is on ceramic foam deposited, subsequently cured and carbonated at elevated temperature. In this way ceramic foam is covered with glassy carbon coating with thickness of 2-8 μm. It provides desirable amount of glassy carbon in the structure of the material. In the next step, porous spheres with carbon coating are infiltrated by liquid matrix of Al-Cu-Mg alloy. Thereby, equable distribution of glassy carbon in composite volume is achieved. Moreover, typical problems for composites reinforced by particles like sedimentation, agglomeration and clustering of particles are avoided. Tribological characteristics during friction in air versus cast iron as a counterpart were made. Produced composites with glassy carbon layer are characterised by friction coefficient between 0.08-0.20, thus meeting the typical conditions for solid lubricants.

  7. Hybrid Aluminum Composite Materials Based on Carbon Nanostructures

    Directory of Open Access Journals (Sweden)

    Tatiana S. Koltsova

    2015-09-01

    Full Text Available We investigated formation of carbon nanofibers grown by chemical deposition (CVD method using an acetylene-hydrogen mixture on the surface of micron-sized aluminum powder particles. To obtain uniform distribution of the carbon nanostructures on the particles we deposited nickel catalyst on the surface by spraying from the aqueous solution of nickel nitrate. It was found that increasing the time of the synthesis lowers the rate of growth of carbon nanostructures due to the deactivation of the catalyst. The Raman spectroscopy measurements confirm the presence of disordered carbon corresponding to CNFs in the specimen. X-ray photoelectron spectroscopy showed the presence of aluminum carbide in the hot pressed samples. An aluminum composite material prepared using 1 wt.% CNFs obtained by uniaxial cold pressing and sintering showed 30% increase in the hardness compared to pure aluminum, whereas the composites prepared by hot pressing showed 80% increase in the hardness. Composite materials have satisfactory ductility. Thus, the aluminum based material reinforced with carbon nanostructures should be appropriate for creating high-strength and light compacts for aerospace and automotive applications and power engineering.DOI: http://dx.doi.org/10.5755/j01.ms.21.3.7355

  8. Carbon nanotubes, phthalocyanines and porphyrins: attractive hybrid materials for electrocatalysis and electroanalysis.

    Science.gov (United States)

    Zagal, José H; Griveau, Sophie; Ozoemena, Kenneth I; Nyokong, Tebello; Bedioui, Fethi

    2009-04-01

    The manuscript discusses different ways of forming hybrid materials between single (SWCNT) or multi (MWCNT) walled carbon nanotubes and biomimetic compounds such as metalloporphyrins, metallophthalocyanines and other MN4 complexes. The hybrid materials are employed for electrocatalysis of reactions such as oxygen and hydrogen peroxide reduction, nitric oxide oxidation, oxidation of thiols and other pollutants. Methods of characterizing the hybrid materials such as cyclic voltammetry (CV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and scanning electrochemical microscopy (SECM) are discussed.

  9. Hybrid Direct Carbon Fuel Cell Performance with Anode Current Collector Material

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2015-01-01

    The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate-carbon slurry in contact with the anode, has been investigated using current-voltage curves. Four different anode current...... collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector...

  10. Fabrication of nanoscale to macroscale nickel-multiwall carbon nanotube hybrid materials with tunable material properties

    Science.gov (United States)

    Abdalla, Ahmed M.; Majdi, Tahereh; Ghosh, Suvojit; Puri, Ishwar K.

    2016-12-01

    To utilize their superior properties, multiwall carbon nanotubes (MWNTs) must be manipulated and aligned end-to-end. We describe a nondestructive method to magnetize MWNTs and provide a means to remotely manipulate them through the electroless deposition of magnetic nickel nanoparticles on their surfaces. The noncovalent bonds between Ni nanoparticles and MWNTs produce a Ni-MWNT hybrid material (NiCH) that is electrically conductive and has an enhanced magnetic susceptibility and elastic modulus. Our experiments show that MWNTs can be plated with Ni for Ni:MWNT weight ratios of γ = 1, 7, 14 and 30, to control the material properties. The phase, atom-level, and morphological information from x-ray diffraction, energy dispersive x-ray spectroscopy, scanning electron microscopy, transmission electron microscopy, dark field STEM, and atomic force microscopy clarify the plating process and reveal the mechanical properties of the synthesized material. Ni metalizes at the surface of the Pd catalyst, forming a continuous wavy layer that encapsulates the MWNT surfaces. Subsequently, Ni acts as an autocatalyst, allowing the plating to continue even after the original Pd catalyst has been completely covered. Raising γ increases the coating layer thickness from 10 to 150 nm, which influences the NiCH magnetic properties and tunes its elastic modulus from 12.5 to 58.7 GPa. The NiCH was used to fabricate Ni-MWNT macrostructures and tune their morphologies by changing the direction of an applied magnetic field. Leveraging the hydrophilic Ni-MWNT outer surface, a water-based conductive ink was created and used to print a conductive path that had an electrical resistivity of 5.9 Ω m, illustrating the potential of this material for printing electronic circuits.

  11. Hydrothermal Treatment of Tannin: A Route to Porous Metal Oxides and Metal/Carbon Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Flavia L. Braghiroli

    2017-01-01

    Full Text Available In the present paper, porous materials were prepared from the hydrothermal treatment of aqueous solutions of tannin, a renewable phenolic resource extracted from tree barks, containing dissolved salts of transition metals: V, Cr, Ni and Fe. Hydrothermal treatment produced carbonaceous particles doped with the aforementioned metals, and such materials were treated according to two different routes: (i calcination in air in order to burn the carbon and to recover porous oxides; (ii pyrolysis in inert atmosphere so as to recover porous metal/carbon hybrid materials. The nature of the metal salt was found to have a dramatic impact on the structure of the materials recovered by the first route, leading either to nano-powders (V, Cr or to hollow microspheres (Ni, Fe. The second route was only investigated with iron, leading to magnetic Fe-loaded micro/mesoporous carbons whose texture, pore volumes and surface areas gradually changed with the iron content.

  12. Gas-Transport-Property Performance of Hybrid Carbon Molecular Sieve−Polymer Materials

    KAUST Repository

    Das, Mita

    2010-10-06

    High-performance hybrid materials using carbon molecular sieve materials and 6FDA-6FpDA were produced. A detailed analysis of the effects of casting processes and the annealing temperature is reported. Two existing major obstacles, sieve agglomeration and residual stress, were addressed in this work, and subsequently a new membrane formation technique was developed to produce high-performing membranes. The successfully improved interfacial region of the hybrid membranes allows the sieves to increase the selectivity of the membranes above the neat polymer properties. Furthermore, an additional performance enhancement was seen with increased sieve loading in the hybrid membranes, leading to an actual performance above the upper bound for pure polymer membranes. The membranes were also tested under a mixed-gas environment, which further demonstrated promising results. © 2010 American Chemical Society.

  13. A bolometer based on single-walled carbon nanotubes and hybrid materials

    Science.gov (United States)

    Kopylova, D. S.; Boldyrev, N. Yu.; Iakovlev, V. Ya.; Gladush, Yu. G.; Nasibulin, A. G.

    2016-12-01

    We have designed a bolometric IR detector based on freestanding aerosol synthesised carbon nanotubes and hybrid graphene materials deposited on a film suspended over a hole in the substrate. In this case, graphene serves as an absorber. The effect of the amount of the deposited absorber on the spectral characteristics, voltage sensitivity, response time and noise of the bolometer is investigated. The best response time is observed for the samples of pristine carbon nanotubes, whereas the hybrid sample with the largest amount of graphene demonstrates the highest sensitivity to radiation. Moreover, we have measured and analysed the bolometer parameters as functions of the ambient pressure and temperature, which has allowed us to determine the optimum operating conditions for the device.

  14. Superstructured Carbon Nanotube/Porous Silicon Hybrid Materials for Lithium-Ion Battery Anodes

    Science.gov (United States)

    Lee, Jun-Ki; Kang, Shin-Hyun; Choi, Sung-Min

    2015-03-01

    High energy Li-ion batteries (LIBs) are in great demand for electronics, electric-vehicles, and grid-scale energy storage. To further increase the energy and power densities of LIBs, Si anodes have been intensively explored due to their high capacity, and high abundance compared with traditional carbon anodes. However, the poor cycle-life caused by large volume expansion during charge/discharge process has been an impediment to its applications. Recently, superstructured Si materials were received attentions to solve above mentioned problem in excellent mechanical properties, large surface area, and fast Li and electron transportation aspects, but applying superstructures to anode is in early stage yet. Here, we synthesized superstructured carbon nanotubes (CNTs)/porous Si hybrid materials and its particular electrochemical properties will be presented. Department of Nuclear and Quantum Engineering

  15. Anisotropic Thermal Properties of Nanostructured Magnetic, Carbon and Hybrid Magnetic - Carbon Materials

    Science.gov (United States)

    Ramirez, Sylvester

    In this dissertation research we investigated thermal properties of three groups of nanostructured materials: (i) magnetic; (ii) reduced graphene oxide films; and (iii) hybrid magnetic -- graphite -- graphene composites. The thermal measurements were conducted using the transient "hot disk" and "laser flash" techniques. The rare-earth free nanostructured SrFe12O19 permanent magnets were produced by the current activated pressure assisted densification technique. The thermal conductivity of the nanostructured bulk magnets was found to range from 3.8 to 5.6 W/mK for the in-plane and 2.36 W/mk to 2.65 W/mK for the cross-plane directions, respectively. The heat conduction was dominated by phonons near the room temperature. The anisotropy of heat conduction was explained by the brick-like alignment of crystalline grains with the longer grain size in-plane direction. The thermal conductivity scales up with the average grain size and mass density of the material revealing weak temperature dependence. Using the nanostructured ferromagnetic Fe3O4 composites as an example system, we incorporated graphene and graphite fillers into magnetic material without changing their morphology. It was demonstrated that addition of 5 wt. % of equal mixture of graphene and graphite flakes to the composite results in a factor of x2.6 enhancement of the thermal conductivity without significant degradation of the saturation magnetization. We investigated thermal conductivity of free-standing reduced graphene oxide films subjected to a high-temperature treatment of up to 1000°C. It was found that the high-temperature annealing dramatically increased the in-plane thermal conductivity, K, of the films from ˜3 W/mK to ˜61 W/mK at room temperature. The cross-plane thermal conductivity, K⊥, revealed an interesting opposite trend of decreasing to a very small value of ˜0.09 W/mK in the reduced graphene oxide films annealed at 1000°C. The obtained films demonstrated an exceptionally strong

  16. Carbon-Based Materials for Lithium-Ion Batteries, Electrochemical Capacitors, and Their Hybrid Devices.

    Science.gov (United States)

    Yao, Fei; Pham, Duy Tho; Lee, Young Hee

    2015-07-20

    A rapidly developing market for portable electronic devices and hybrid electrical vehicles requires an urgent supply of mature energy-storage systems. As a result, lithium-ion batteries and electrochemical capacitors have lately attracted broad attention. Nevertheless, it is well known that both devices have their own drawbacks. With the fast development of nanoscience and nanotechnology, various structures and materials have been proposed to overcome the deficiencies of both devices to improve their electrochemical performance further. In this Review, electrochemical storage mechanisms based on carbon materials for both lithium-ion batteries and electrochemical capacitors are introduced. Non-faradic processes (electric double-layer capacitance) and faradic reactions (pseudocapacitance and intercalation) are generally explained. Electrochemical performance based on different types of electrolytes is briefly reviewed. Furthermore, impedance behavior based on Nyquist plots is discussed. We demonstrate the influence of cell conductivity, electrode/electrolyte interface, and ion diffusion on impedance performance. We illustrate that relaxation time, which is closely related to ion diffusion, can be extracted from Nyquist plots and compared between lithium-ion batteries and electrochemical capacitors. Finally, recent progress in the design of anodes for lithium-ion batteries, electrochemical capacitors, and their hybrid devices based on carbonaceous materials are reviewed. Challenges and future perspectives are further discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Novel Hybrid Nanoparticles of Vanadium Nitride/Porous Carbon as an Anode Material for Symmetrical Supercapacitor

    Institute of Scientific and Technical Information of China (English)

    Yunlong Yang; Kuiwen Shen; Ying Liu; Yongtao Tan; Xiaoning Zhao; Jiayu Wu; Xiaoqin Niu; Fen Ran

    2017-01-01

    Hybrid materials of vanadium nitride and porous carbon nanoparticles (VN/PCNPs) were fabricated by a facile pyrolysis process of vanadium pentoxide (V2O5) xerogel and melamine at relatively low temperature of 800 ?C for supercapacitor application. The effects of the feed ratio of V2O5 to melamine (r), and nitrogen flow rate on the microstructure and electrochemical performance were also investigated. It was found that the size of the as-synthesized nanoparticles is about 20 nm. Both r value and N2 flow rate have enormous impacts on morphology and microstructure of the nanoparticle, which correspondingly determined the electrochemical performance of the material. The VN/C hybrid nanoparticles exhibited high capacitive properties, and a maximum specific capacitance of 255.0 F g-1 was achieved at a current density of 1.0 A g-1 in 2 M KOH aqueous electrolyte and the potential range from 0 to -1.15 V. In addition, symmetrical supercapacitor fabricated with the as-synthesized VN/PCNPs presents a high specific capacitance of 43.5 F g-1 at 0.5 A g-1 based on the entire cell, and an energy density of 8.0 Wh kg-1 when the power density was 575 W kg-1. Even when the power density increased to 2831.5 W kg-1, the energy density still remained 6.1 Wh kg-1.

  18. Hybrid nanostructured microporous carbon-mesoporous carbon doped titanium dioxide/sulfur composite positive electrode materials for rechargeable lithium-sulfur batteries

    Science.gov (United States)

    Zegeye, Tilahun Awoke; Kuo, Chung-Feng Jeffrey; Wotango, Aselefech Sorsa; Pan, Chun-Jern; Chen, Hung-Ming; Haregewoin, Atetegeb Meazah; Cheng, Ju-Hsiang; Su, Wei-Nien; Hwang, Bing-Joe

    2016-08-01

    Herein, we design hybrid nanostructured microporous carbon-mesoporous carbon doped titanium dioxide/sulfur composite (MC-Meso C-doped TiO2/S) as a positive electrode material for lithium-sulfur batteries. The hybrid MC-Meso C-doped TiO2 host material is produced by a low-cost, hydrothermal and annealing process. The resulting conductive material shows dual microporous and mesoporous behavior which enhances the effective trapping of sulfur and polysulfides. The hybrid MC-Meso C-doped TiO2/S composite material possesses rutile TiO2 nanotube structure with successful carbon doping while sulfur is uniformly distributed in the hybrid MC-Meso C-doped TiO2 composite materials after the melt-infusion process. The electrochemical measurement of the hybrid material also shows improved cycle stability and rate performance with high sulfur loading (61.04%). The material delivers an initial discharge capacity of 802 mAh g-1 and maintains it at 578 mAh g-1 with a columbic efficiency greater than 97.1% after 140 cycles at 0.1 C. This improvement is thought to be attributed to the unique hybrid nanostructure of the MC-Meso C-doped TiO2 host and the good dispersion of sulfur in the narrow pores of the MC spheres and the mesoporous C-doped TiO2 support.

  19. Immobilization of carbon nanotubes on functionalized graphene film grown by chemical vapor deposition and characterization of the hybrid material

    Directory of Open Access Journals (Sweden)

    Prashanta Dhoj Adhikari

    2014-01-01

    Full Text Available We report the surface functionalization of graphene films grown by chemical vapor deposition and fabrication of a hybrid material combining multi-walled carbon nanotubes and graphene (CNT–G. Amine-terminated self-assembled monolayers were prepared on graphene by the UV-modification of oxidized groups introduced onto the film surface. Amine-termination led to effective interaction with functionalized CNTs to assemble a CNT–G hybrid through covalent bonding. Characterization clearly showed no defects of the graphene film after the immobilization reaction with CNT. In addition, the hybrid graphene material revealed a distinctive CNT–G structure and p–n type electrical properties. The introduction of functional groups on the graphene film surface and fabrication of CNT–G hybrids with the present technique could provide an efficient, novel route to device fabrication.

  20. Hierarchically porous silicon-carbon-nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes.

    Science.gov (United States)

    Meng, Lala; Zhang, Xiaofei; Tang, Yusheng; Su, Kehe; Kong, Jie

    2015-01-21

    The hierarchically macro/micro-porous silicon-carbon-nitrogen (Si-C-N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg·g(-1) and 1084.5 mg·g(-1) for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

  1. Hierarchically porous silicon-carbon-nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes

    Science.gov (United States)

    Meng, Lala; Zhang, Xiaofei; Tang, Yusheng; Su, Kehe; Kong, Jie

    2015-01-01

    The hierarchically macro/micro-porous silicon-carbon-nitrogen (Si-C-N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg.g-1 and 1084.5 mg.g-1 for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si-C-N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants.

  2. Hybrid Composite of Polyaniline Containing Carbon Nanotube

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Carbon nanotube-polyaniline hybrid material was synthesized by emulsion polymerization in-situ. The morphology of hybrid material was studied by TEM and X-ray diffraction. The conductivity of nanocomposite increases with the increasing of carbon nanotube content because of the new conductivity passageways formed by carbon nanotubes.

  3. Design of antimicrobial membrane based on polymer colloids/multiwall carbon nanotubes hybrid material with silver nanoparticles.

    Science.gov (United States)

    Rusen, Edina; Mocanu, Alexandra; Nistor, Leona Cristina; Dinescu, Adrian; Călinescu, Ioan; Mustăţea, Gabriel; Voicu, Ştefan Ioan; Andronescu, Corina; Diacon, Aurel

    2014-10-22

    The aim of this study was to obtain membranes with antimicrobial activity presenting a complex sandwich-type structure. The outer layers are comprised of poly(methyl methacrylate) membranes, whereas the inner active layer consists of a modified commercial membrane to achieve antimicrobial properties. This activity arises due to the presence of silver nanoparticles in a material with a hybrid composition deposited on a commercial membrane. This hybrid material consists of polymer colloids and multiwall carbon nanotubes used for both the stabilization of the active layer by the interconnections of the polymer particles and as active component. The filtration tests revealed a good stability of the materials and an increased hydrophilicity of the hybrid membranes. The antimicrobial properties have been evaluated using Staphylococcus aureus and Escherichia coli, and have been correlated with the content and migration rate of silver ions.

  4. Encapsulated Vanadium-Based Hybrids in Amorphous N-Doped Carbon Matrix as Anode Materials for Lithium-Ion Batteries.

    Science.gov (United States)

    Long, Bei; Balogun, Muhammad-Sadeeq; Luo, Lei; Luo, Yang; Qiu, Weitao; Song, Shuqin; Zhang, Lei; Tong, Yexiang

    2017-09-12

    Recently, researchers have made significant advancement in employing transition metal compound hybrids as anode material for lithium-ion batteries and developing simple preparation of these hybrids. To this end, this study reports a facile and scalable method for fabricating a vanadium oxide-nitride composite encapsulated in amorphous carbon matrix by simply mixing ammonium metavanadate and melamine as anode materials for lithium-ion batteries. By tuning the annealing temperature of the mixture, different hybrids of vanadium oxide-nitride compounds are synthesized. The electrode material prepared at 700 °C, i.e., VM-700, exhibits excellent cyclic stability retaining 92% of its reversible capacity after 200 cycles at a current density of 0.5 A g(-1) and attractive rate performance (220 mAh g(-1) ) under the current density of up to 2 A g(-1) . The outstanding electrochemical properties can be attributed to the synergistic effect from heterojunction form by the vanadium compound hybrids, the improved ability of the excellent conductive carbon for electron transfer, and restraining the expansion and aggregation of vanadium oxide-nitride in cycling. These interesting findings will provide a reference for the preparation of transition metal oxide and nitride composites as well. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Sustainable hybrid photocatalysts: titania immobilized on carbon materials derived from renewable and biodegradable resources

    Science.gov (United States)

    This review comprises the preparation, properties and heterogeneous photocatalytic applications of TiO2 immobilized on carbon materials derived from earth-abundant, renewable and biodegradable agricultural residues and sea food waste resources. The overview provides key scientifi...

  6. Sustainable hybrid photocatalysts: titania immobilized on carbon materials derived from renewable and biodegradable resources

    Science.gov (United States)

    This review comprises the preparation, properties and heterogeneous photocatalytic applications of TiO2 immobilized on carbon materials derived from earth-abundant, renewable and biodegradable agricultural residues and sea food waste resources. The overview provides key scientifi...

  7. Evaluating biomass-derived hierarchically porous carbon as the positive electrode material for hybrid Na-ion capacitors

    Science.gov (United States)

    Chen, Jizhang; Zhou, Xiaoyan; Mei, Changtong; Xu, Junling; Zhou, Shuang; Wong, Ching-Ping

    2017-02-01

    As a promising renewable resource, biomass has several advantages such as wide availability, low cost, and versatility. In this study, we use peanut shell, wheat straw, rice straw, corn stalk, cotton stalk, and soybean stalk as the precursors to synthesize hierarchically porous carbon as the positive electrode material for hybrid Na-ion capacitors, aiming to establish a criterion of choosing suitable biomass precursors. The carbon derived from wood-like cotton stalk has abundant interconnected macropores, high surface area of 1994 m2 g-1, and large pore volume of 1.107 cm3 g-1, thanks to which it exhibits high reversible capacitance of 160.5 F g-1 at 0.2 A g-1 and great rate capability, along with excellent cyclability. The carbonaceous positive electrode material is combined with a Na2Ti2.97Nb0.03O7 negative electrode material to assemble a hybrid Na-ion capacitor, which delivers a high specific energy of 169.4 Wh kg-1 at 120.5 W kg-1, ranking among the best-performed hybrid ion capacitors.

  8. Preparation and characterization of humic acid-carbon hybrid materials as adsorbents for organic micro-pollutants.

    Science.gov (United States)

    Radwan, Emad K; Abdel Ghafar, Hany H; Moursy, Ahmed S; Langford, Cooper H; Bedair, Ahmed H; Achari, Gopal

    2015-08-01

    The present work involves the preparation of novel adsorbent materials by the insolubilization and hybridization of humic acid (HA) with carbon. The prepared materials were characterized by N2 adsorption, elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, solid-state (13)C cross polarization magic angle spinning nuclear magnetic resonance, and low-field nuclear magnetic resonance (NMR) relaxometry on wetted samples. The water solubility of these materials and the lack of effect of oxidants were also confirmed. With this background, the adsorption capacities toward phenol, 2,4,6-tricholrophenol, and atrazine were evaluated, using these as model compounds for organic micropollutants of concern in water. Experimental results show that the prepared materials are mesoporous and have a higher surface area than humic acid and even than the porous carbon in the case of carbon coating. They retain the basic features of the starting materials with lowered functional group content. Moreover, there are interesting new features. NMR relaxometry shows that equilibration of water uptake is very fast, making use in water simple. They have higher adsorption capacities than the pure materials, and they can be applied under a wide range of environmental conditions.

  9. Nitrogen-doped carbon/graphene hybrid anode material for sodium-ion batteries with excellent rate capability

    Science.gov (United States)

    Liu, Huan; Jia, Mengqiu; Cao, Bin; Chen, Renjie; Lv, Xinying; Tang, Renjie; Wu, Feng; Xu, Bin

    2016-07-01

    Nitrogen-doped carbon/graphene (NCG) hybrid materials were prepared by an in-situ polymerization and followed pyrolysis for sodium-ion batteries. The NCG has a large interlayer distance (0.360 nm) and a high nitrogen content of 7.54 at%, resulting in a high reversible sodium storage capacity of 336 mAh g-1 at 30 mA g-1. The NCG shows a sandwich-like structure, i.e. nitrogen-doped carbon nanosheets closely coated on both sides of graphene. The carbon nanosheets shorten the ion diffusion distance, while the sandwiched graphene with high electronic conductivity guarantees fast electron transport, making the NCG exhibit excellent rate capability (94 mAh g-1 at 5 A g-1). It also exhibits good cycle stability with a capacity retention of 89% after 200 cycles at 50 mA g-1.

  10. Nanostructured TiO2-coated activated carbon composite as an electrode material for asymmetric hybrid capacitors.

    Science.gov (United States)

    Kim, Sang-Ok; Lee, Joong Kee

    2012-02-01

    A nanostructured TiO2-coated activated carbon (TAC) composite was synthesized by a modified sol-gel reaction and employed it as a negative electrode active material for an asymmetric hybrid capacitor. The structural characterization showed that the TiO2 nano-layer was deposited on the surface of the activated carbon and the TAC composite has a highly mesoporous structure. The evaluation of electrochemical characteristics of the TAC electrode was carried out by galvanostatic charge/discharge cycling tests and electrochemical impedance spectroscopy. The obtained specific capacitance of the TAC composite was 42.87 F/g, which showed by 27.1% higher than that of the activated carbon (AC). The TAC composite also exhibited an excellent cycle performance and kept 95% of initial capacitance over 500 cycles.

  11. Hybrid Multi-Walled Carbon Nanotube TiO2 Electrode Material for Next Generation Energy Storage Devices

    CERN Document Server

    Marler, Sydney

    2016-01-01

    Current supercapacitors present several distinct limitations that severely inhibit the efficiency, power, and electrical capacitance of energy storage devices. Supercapacitors present an exciting prospect that has countless applications in renewable energy storage and modern day electronic devices. In recent years the exciting development of carbon nanotubes (CNTs) has presented an advantage in electrode development. CNTs, however beneficial for their increased electrode surface area, have severe limitations regarding conductivity and electrode density. Creating a nanocomposite hybrid out of a transition metal-oxide and carbon nanotube array would help the current limitations of the modern supercapacitor. TiO2 was chosen for its common occurrence in everyday materials and promising capacitance levels. A multi-walled carbon nanotube array was grown on a SiO2 precursor via CCVD. The transition metal oxide was then deposited via RF Sputtering methods to a MWCNT array. Recharge tests and characterization were con...

  12. Simultaneous Electrochemical Determination of Hydroquinone, Catechol and Resorcinol at Nitrogen Doped Porous Carbon Nanopolyhedrons-multiwall Carbon Nanotubes Hybrid Materials Modified Glassy Carbon Electrode

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Wei; Wu, Liang; Zhang, Xiaohua; Chen, Jinhua [Hunan Univ., Changsha (China)

    2014-01-15

    The nitrogen doped porous carbon nanopolyhedrons (N-PCNPs)-multi-walled carbon nanotubes (MWCNTs) hybrid materials were prepared for the first time. Combining the excellent catalytic activities, good electrical conductivities and high surface areas of N-PCNPs and MWCNTs, the simultaneous determination of hydroquinone (HQ), catechol (CC) and resorcinol (RE) with good analytical performance was achieved at the N-PCNPs-MWCNTs modified electrode. The linear response ranges for HQ, CC and RE are 0.2-455 μM, 0.7-440 μM and 3.0-365 μM, respectively, and the detection limits (S/N = 3) are 0.03 μM, 0.11 μM and 0.38 μM, respectively. These results are much better than that obtained on some graphene or CNTs-based materials modified electrodes. Furthermore, the developed sensor was successfully applied to simultaneously detect HQ, CC and RE in the local river water samples.

  13. Carbon Nanotube Enhanced Aerospace Composite Materials A New Generation of Multifunctional Hybrid Structural Composites

    CERN Document Server

    Kostopoulos, V

    2013-01-01

    The well documented increase in the use of high performance composites as structural materials in aerospace components is continuously raising the demands in terms of dynamic performance, structural integrity, reliable life monitoring systems and adaptive actuating abilities. Current technologies address the above issues separately; material property tailoring and custom design practices aim to the enhancement of dynamic and damage tolerance characteristics, whereas life monitoring and actuation is performed with embedded sensors that may be detrimental to the structural integrity of the component. This publication explores the unique properties of carbon nanotubes (CNT) as an additive in the matrix of Fibre Reinforced Plastics (FRP), for producing structural composites with improved mechanical performance as well as sensing/actuating capabilities. The successful combination of the CNT properties and existing sensing actuating technologies leads to the realization of a multifunctional FRP structure. The curre...

  14. THERMALLY CLEAVABLE HYBRID MATERIALS

    Directory of Open Access Journals (Sweden)

    Constantin Gaina

    2011-12-01

    Full Text Available Thermally cleavable hybrid materials were prepared by the Diels-Alder cycloaddition reaction of poly(vinyl furfural to N phenylmaleimido-N’-(triethoxysilylpropylurea followed by the sol-gel condensation reaction of trietoxysilyl groups with water and acetic acid. Thermal and dynamic mechanical analysis, dielectric and FTIR spectroscopy were used to characterize the structure and properties of the composites. The size of the inorganic silica particles in the hybrid material varied dependent on the silica content. The DSC study of the prepared materials revealed that the cleavage process of the formed cycloadducts takes place at temperatures varying between 143-165°C and is an endothermic process.

  15. Porosity in hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, D.W.; Beaucage, G.; Loy, D. [Sandia National Labs., Albuquerque, NM (United States)

    1995-12-31

    Multicomponent, or hybrid composites are emerging as precursors to porous materials. Sacrifice of an ephemeral phase can be used to generate porosity, the nature of which depends on precursor structure. Retention of an organic constituent, on the other hand, can add desirable toughness to an otherwise brittle ceramic. We use small-angle x-ray and neutron scattering to examine porosity in both simple and hybrid materials. We find that microphase separation controls porosity in almost all systems studied. Pore distributions are controlled by the detailed bonding within and between phases as well as the flexibility of polymeric constituents. Thus hybridization opens new regions of pore distributions not available in simple systems. We look at several sacrificial concepts and show that it is possible to generate multimodal pore size distributions due to the complicated phase structure in the precursor.

  16. Single step hydrothermal synthesis of carbon nanodot decorated V2O5 nanobelts as hybrid conducting material for supercapacitor application

    Science.gov (United States)

    Narayanan, Remya

    2017-09-01

    Carbon nanodot (C-dot) decorated V2O5 (C-dot@V2O5) nanobelts are synthesized by single step, low cost hydrothermal route at low temperature by using V2O5 and glucose as precursors. We have not added any extra organic solvents or surfactants which are commonly used for the preparation of different nanostructures of V2O5. Electron microscopy analyses demonstrate that C-dot is entrapped inside V2O5 nanobelts which in turn enhance the conductivity and ion propagation property of this composite material. The C-dot@V2O5 nanobelts exhibit an excellent three electrode electrochemical performance in 1 M Na2SO4 and which showed a specific capacitance of 270 F g-1 at 1 A g-1, which is 4.5 times higher than the pristine V2O5 electrode. The electrochemical energy storage capacity of this hybrid is investigated towards solid state supercapacitor application also for the first time by employing electrophoretically deposited C-dot as the counter electrode and Li based gel as the electrolyte. The hybrid material delivers an energy density of 60 W h kg-1 and a reasonably high power density of 4.1 kW kg-1 at 5 A g-1 and good cycling stability and capacitance retention of about 87% was observed even after 5000 cycles. Above mentioned results clearly show that C-dot embedded hybrid, nanostructured transition metal oxides has great potential towards fabrication of electrodes for energy storage devices.

  17. Controlled growth of carbon nanotube-graphene hybrid materials for flexible and transparent conductors and electron field emitters.

    Science.gov (United States)

    Nguyen, Duc Dung; Tai, Nyan-Hwa; Chen, Szu-Ying; Chueh, Yu-Lun

    2012-01-21

    We report a versatile synthetic process based on rapid heating and cooling chemical vapor deposition for the growth of carbon nanotube (CNT)-graphene hybrid materials where the thickness of graphene and density of CNTs are properly controlled. Graphene films are demonstrated as an efficient barrier layer for preventing poisoning of iron nanoparticles, which catalyze the growth of CNTs on copper substrates. Based on this method, the opto-electronic and field emission properties of graphene integrated with CNTs can be remarkably tailored. A graphene film exhibits a sheet resistance of 2.15 kΩ sq(-1) with a transmittance of 85.6% (at 550 nm), while a CNT-graphene hybrid film shows an improved sheet resistance of 420 Ω sq(-1) with an optical transmittance of 72.9%. Moreover, CNT-graphene films are demonstrated as effective electron field emitters with low turn-on and threshold electric fields of 2.9 and 3.3 V μm(-1), respectively. The development of CNT-graphene films with a wide range of tunable properties presented in this study shows promising applications in flexible opto-electronic, energy, and sensor devices.

  18. Graphene Hybrid Materials in Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Usman Latif

    2015-12-01

    Full Text Available Graphene, a two dimensional structure of carbon atoms, has been widely used as a material for gas sensing applications because of its large surface area, excellent conductivity, and ease of functionalization. This article reviews the most recent advances in graphene hybrid materials developed for gas sensing applications. In this review, synthetic approaches to fabricate graphene sensors, the nano structures of hybrid materials, and their sensing mechanism are presented. Future perspectives of this rapidly growing field are also discussed.

  19. Facile synthesis of a Cu-based MOF confined in macroporous carbon hybrid material with enhanced electrocatalytic ability.

    Science.gov (United States)

    Zhang, Yufan; Bo, Xiangjie; Luhana, Charles; Wang, Huan; Li, Mian; Guo, Liping

    2013-08-07

    The Cu-based MOF loaded on macroporous carbon (MPC) creates novel Cu-MOF-MPC hybrids for the first time. The obtained Cu-MOF-MPC composites are used as electrocatalysts for the oxidation of NADH and reduction of H2O2 in neutral solution.

  20. Elucidating How Surface Functionalization of Multiwalled Carbon Nanotube Affects Nanostructured MWCNT/Titania Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Cheng-Fu Yang

    2015-01-01

    Full Text Available The new class of multiwalled carbon nanotube (MWCNT/titania nanocomposites was prepared using a sol-gel technique. The addition of titania to MWCNTs has the potential to provide new capability for the development of electrical devices by taking advantage of the favorable electric characteristics of MWCNTs. MWCNTs were first functionalized with carboxyl, acyl chloride, amine, and hydroxyl groups and were then dispersed in a tetraisopropyl titanate (TIPT solution via ultrasonic processing. After gelation, well-dispersed titania in the MWCNT/titania nanocomposites was obtained. Functionalized MWCNTs with varied functional groups were proved by Fourier transform infrared spectroscopy (FT-IR. For the nanocomposites, the degree of the sol-gel process were proved by Raman spectroscopy and wide-angle X-ray diffraction (WAXD. Furthermore, the morphology of the MWCNT/titania nanocomposites was observed using transmission electron microscopy (TEM. In the sol-gel process, the functionalized MWCNTs with carboxyl, acyl chloride, amine, and hydroxyl groups have resulted in the carbon nanotube-graft-titania nanocomposites with a network structure of titania between the carbon nanotubes.

  1. 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.

  2. Structural and Optical Properties of Spray Coated Carbon Hybrid Materials Applied to Transparent and Flexible Electrodes

    Directory of Open Access Journals (Sweden)

    Grzegorz Wroblewski

    2017-01-01

    Full Text Available Transparent and flexible electrodes were fabricated with cost-effective spray coating technique on polyethylene terephthalate foil substrates. Particularly designed paint compositions contained mixtures of multiwalled carbon nanotubes and graphene platelets to achieve their desired rheology and electrooptical layers parameters. Electrodes were prepared in standard technological conditions without the need of clean rooms or high temperature processing. The sheet resistance and optical transmittance of fabricated layers were tuned with the number of coatings; then the most suitable relation of these parameters was designated through the figure of merit. Optical measurements were performed in the range of wavelengths from 250 to 2500 nm with a spectrophotometer with the integration sphere. Spectral dependence of total and diffusive optical transmission for thin films with graphene platelet covered by multiwalled carbon nanotubes was designated which allowed determining the relative absorbance. Layer parameters such as thickness, refractive index, energy gap, and effective reflectance coefficient show the correlation of electrooptical properties with the technological conditions. Moreover the structural properties of fabricated layers were examined by means of the X-ray diffraction.

  3. Facile scalable synthesis of Co{sub 3}O{sub 4}/carbon nanotube hybrids as superior anode materials for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhiguo; Xu, Weiwei [Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, and the College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Huang, Tao [Department of Chemistry, Fudan University, Shanghai 210024 (China); Li, Maolin; Wang, Wanren; Liu, Yanping; Mao, Chaochao; Meng, Fanli; Wang, Mengjiao [Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, and the College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China); Cheng, Minghai [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (China); Yu, Aishui [Department of Chemistry, Fudan University, Shanghai 210024 (China); Guo, Xiaohui, E-mail: guoxh2009@nwu.edu.cn [Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, and the College of Chemistry and Materials Science, Northwest University, Xi’an 710069 (China)

    2013-10-15

    Graphical abstract: Co{sub 3}O{sub 4}/MWCNT hybrids were synthesized via strong ultra-sonication assisted shaking processes. The resultant samples as anode electrode display enhanced cycling performance and rate capability compared with pure Co{sub 3}O{sub 4} particle. - Highlights: • Co{sub 3}O{sub 4}/MWCNT hybrids were synthesized via ultra-sonication assisted shaking process. • The resulting Co{sub 3}O{sub 4} nanoparticles are highly dispersed onto MWCNT network backbone. • Co{sub 3}O{sub 4}/MWCNT hybrid displays highly enhanced lithium storage properties. • The present synthetic approach is facile, controllable, and scalable. - Abstract: In this report, Co{sub 3}O{sub 4}/multiple-wall carbon nanotube (MWCNT) hybrid materials were synthesized via strong ultrasonication-assisted shaking and magnetic stirring processes. The prepared samples were well characterized by utilizing powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy techniques. Results indicated that the resulting Co{sub 3}O{sub 4} nanoparticles were highly dispersed in the MWCNT network backbone and further form Co{sub 3}O{sub 4}/MWCNT hybrid materials. The obtained Co{sub 3}O{sub 4}/MWCNT hybrids can be employed as anode electrode in Lithium-ion batteries and deliver as high as discharge capacity of 1250 mA h g{sup −1} at a current density of 0.2 C, additionally, 81% of the discharge capacity for sample 2 with 20 wt.% MWCNT loading could be retained after 70 cycles, which could be associated with the specific hybrid structure of the electrode as well as the addition of MWCNT. Most importantly, the present synthetic approach is facile, controllable, and scalable, which allowing it more easily adapted to prepare other hybrid materials with specific architectures.

  4. MoO2-ordered mesoporous carbon hybrids as anode materials with highly improved rate capability and reversible capacity for lithium-ion battery.

    Science.gov (United States)

    Chen, Ailian; Li, Caixia; Tang, Rui; Yin, Longwei; Qi, Yongxin

    2013-08-28

    A novel hybrid of MoO2-ordered mesoporous carbon (MoO2-OMC) was prepared through a two-step solvothermal chemical reaction route. The electrochemical performances of the mesoporous MoO2-OMC hybrids were examined using galvanostatical charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) techniques. The MoO2-OMC hybrid exhibits significantly improved electrochemical performance of high reversible capacity, high-rate capability, and excellent cycling performance as an anode electrode material for Li ion batteries. It is revealed that the MoO2-OMC hybrid could deliver the first discharge capacity of 1641.8 mA h g(-1) with an initial Coulombic efficiency of 63.6%, and a reversible capacity as high as 1049.1 mA h g(-1) even after 50 cycles at a current density of 100 mA g(-1), much higher than the theoretical capacity of MoO2 (838 mA h g(-1)) and OMC materials. The MoO2-OMC hybrid demonstrates an excellent high rate capability with capacity of ∼600 mA h g(-1) even at a charge current density of 1600 mA g(-1) after 50 cycles, which is approximately 11.1 times higher than that of the OMC (54 mA h g(-1)) materials. The improved rate capability and reversible capacity of the MoO2-OMC hybrid are attributed to a synergistic reaction between the MoO2 nanoparticles and mesoporous OMC matrices. It is noted that the electrochemical performance of the MoO2-OMC hybrid is evidently much better than the previous MoO2-based hybrids.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-10

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

  6. Development of carbon nanotubes/CoFe{sub 2}O{sub 4} magnetic hybrid material for removal of tetrabromobisphenol A and Pb(II)

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Lincheng, E-mail: zhoulc@lzu.edu.cn [State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China); Ji, Liqin [State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China); Ma, Peng-Cheng [The Xinjiang Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Urumqi 830011 (China); Shao, Yanming; Zhang, He; Gao, Weijie; Li, Yanfeng [State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Institute of Biochemical Engineering and Environmental Technology, Lanzhou University, Lanzhou 730000 (China)

    2014-01-30

    Highlights: • Amino-functionalized CoFe{sub 2}O{sub 4} nanoparticles were deposited on MWCNTs in one-pot. • Novel chitosan modified MWCNTs/CoFe{sub 2}O{sub 4} hybrid material were successfully synthesized. • The hybrid material had high specific surface area and abundant functional groups. • The hybrid material exhibited high adsorption properties for TBBPA and Pb(II). • The hybrid material was an efficient, eco-friendly and reusable adsorbent. -- Abstract: Multi-walled carbon nanotubes (MWCNTs) coated with magnetic amino-modified CoFe{sub 2}O{sub 4} (CoFe{sub 2}O{sub 4}–NH{sub 2}) nanoparticles (denoted as MNP) were prepared via a simple one-pot polyol method. The MNP composite was further modified with chitosan (CTS) to obtain a chitosan-functionalized MWCNT/CoFe{sub 2}O{sub 4}–NH{sub 2} hybrid material (MNP–CTS). The obtained hybrid materials were characterized by Transmission Electron Microscopy (TEM), Fourier Transform Infrared Spectrogram (FT-IR) Analysis and X-ray Photoelectron Spectroscopy (XPS) Analysis, Vibrating Sample Magnetometer (VSM) Analysis and the Brunauer–Emmett–Teller (BET) surface area method, respectively. The composites were tested as adsorbents for tetrabromobisphenol A (TBBPA) and Pb(II), and were investigated using a pseudo-second-order model. The adsorption of TBBPA was well represented by the Freundlich isotherm; the Langmuir model better described Pb(II) absorption. MNP–CTS adsorbed both TBBPA and Pb(II) (maximum adsorption capacities of 42.48 and 140.1 mg g{sup −1}, respectively) better than did MNP without CTS. Magnetic composite particles with adsorbed TBBPA and Pb(II) could be regenerated using 0.2 M NaOH solution and were separable from liquid media using a magnetic field.

  7. Inexpensive sol-gel synthesis of multiwalled carbon nanotube-TiO2 hybrids for high performance antibacterial materials.

    Science.gov (United States)

    Abbas, Nadir; Shao, Godlisten N; Haider, M Salman; Imran, Syed Muhammad; Park, Sung Soo; Jeon, Sun-Jeong; Kim, Hee Taik

    2016-11-01

    This study reports an inexpensive sol-gel method to synthesize TiO2-CNT hybrid materials. Synthesized TiO2-CNT materials show strong antibacterial activity in the absence of light. Cheap TiO2 source TiOCl2 is used during synthesis in the absence of high temperatures, high pressures and organic solvents. TiO2-CNT materials with 0, 2, 5, 10, 15 and 20wt% of CNT were synthesized and compared for antibacterial activity, surface area, porosity, crystalline structure, chemical state, and HaCaT cell proliferation. The antibacterial strength of hybrid materials increased significantly with the increase in CNT loading amount, and the TiO2-CNT samples with a CNT loading of 10wt% or more nearly removed all of the E.coli bacteria. HaCaT cell proliferation studies of synthesized hybrid materials illustrated that prepared TiO2-CNT systems exhibit minimum cytotoxicity. The characteristics of prepared materials were analyzed by means of XRD, FTIR, Raman spectroscopy, XPS, TEM, and nitrogen gas physisorption studies, compared and discussed. Copyright © 2016. Published by Elsevier B.V.

  8. Materials for carbon dioxide separation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Qingqing

    2014-10-01

    The CO{sub 2} adsorption capacities at room temperature have been investigated by comparing carbon nanotubes, fullerene, graphenes, graphite and granular activated carbons. It turned out that the amount of the micropore surface area was dominating the CO{sub 2} adsorption ability. Another promising class of materials for CO{sub 2} capture and separation are CaO derived from the eggshells. Two aspects were studied in present work: a new hybrid materials synthesized by doping the CaTiO{sub 3} and the relationship between physisorption and chemisorption properties of CaO-based materials.

  9. Study on the application of reduced graphene oxide and multiwall carbon nanotubes hybrid materials for simultaneous determination of catechol, hydroquinone, p-cresol and nitrite

    Energy Technology Data Exchange (ETDEWEB)

    Hu Fangxin [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Chen Shihong, E-mail: cshong@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Wang Chengyan [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Ruo, E-mail: yuanruo@swu.edu.cn [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); Yuan Dehua; Wang Cun [Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-04-29

    Graphical abstract: In this paper, the reduced graphene oxide and multiwall carbon nanotubes hybrid materials (RGO-MWNTs) were prepared and a novel strategy for the simultaneous determination of multiple environmental contaminations has been proposed on the basis of RGO-MWNTs hybrid materials modified electrode. The hybrid materials were characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and N{sub 2} sorption-desorption isotherms. Due to the excellent catalytic activity, enhanced electrical conductivity, high surface area and porous structure of the RGO-MWNTs, the RGO-MWNTs/GCE achieved the simultaneous measurement of hydroquinone (HQ), catechol (CC), p-cresol (PC) and nitrite (NO{sub 2}{sup -}) with well-separate four peaks. Scheme 1a illuminated the preparation process of the RGO-MWNTs hybrid materials. Scheme 1b explains the electron mediating properties of RGO-MWNTs/GCE towards the oxidation of HQ, CC, PC and NO{sub 2}{sup -}. Scheme 1c presented the SEM image of RGO-MWNTs hybrid materials. Scheme 1d and e showed the 2D and 3D AFM images of RGO-MWNTs films, respectively. Highlights: Black-Right-Pointing-Pointer The novel RGO-MWNTs hybrid materials were synthesized. Black-Right-Pointing-Pointer The simultaneous detection of four environmental contaminations was achieved. Black-Right-Pointing-Pointer SEM, AFM, XPS was employed to characterize the RGO-MWNTs hybrid materials. - Abstract: In this paper, the reduced graphene oxide and multiwall carbon nanotubes hybrid materials (RGO-MWNTs) were prepared and a strategy for detecting environmental contaminations was proposed on the basis of RGO-MWNTs modified electrode. The hybrid materials were characterized by the scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and N{sub 2} sorption-desorption isotherms. Due to the excellent catalytic activity, enhanced electrical conductivity and high

  10. Carbon Nanotubes Hybrid Hydrogels in Drug Delivery: A Perspective Review

    OpenAIRE

    Giuseppe Cirillo; Silke Hampel; Umile Gianfranco Spizzirri; Ortensia Ilaria Parisi; Nevio Picci; Francesca Iemma

    2014-01-01

    The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability) with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior). The applicability of polymer-carbon nanotubes composites i...

  11. Continuous Carbon Nanotube-Ultrathin Graphite Hybrid Foams for Increased Thermal Conductivity and Suppressed Subcooling in Composite Phase Change Materials.

    Science.gov (United States)

    Kholmanov, Iskandar; Kim, Jaehyun; Ou, Eric; Ruoff, Rodney S; Shi, Li

    2015-12-22

    Continuous ultrathin graphite foams (UGFs) have been actively researched recently to obtain composite materials with increased thermal conductivities. However, the large pore size of these graphitic foams has resulted in large thermal resistance values for heat conduction from inside the pore to the high thermal conductivity graphitic struts. Here, we demonstrate that the effective thermal conductivity of these UGF composites can be increased further by growing long CNT networks directly from the graphite struts of UGFs into the pore space. When erythritol, a phase change material for thermal energy storage, is used to fill the pores of UGF-CNT hybrids, the thermal conductivity of the UGF-CNT/erythritol composite was found to increase by as much as a factor of 1.8 compared to that of a UGF/erythritol composite, whereas breaking the UGF-CNT bonding in the hybrid composite resulted in a drop in the effective room-temperature thermal conductivity from about 4.1 ± 0.3 W m(-1) K(-1) to about 2.9 ± 0.2 W m(-1) K(-1) for the same UGF and CNT loadings of about 1.8 and 0.8 wt %, respectively. Moreover, we discovered that the hybrid structure strongly suppresses subcooling of erythritol due to the heterogeneous nucleation of erythritol at interfaces with the graphitic structures.

  12. Functional hybrid materials

    National Research Council Canada - National Science Library

    Fahmi, Amir; Pietsch, Torsten; Mendoza, Cesar; Cheval, Nicolas

    2009-01-01

    .... This paper describes our group's achievements towards the development of multifunctional nanostructures via self-assembly of hybrid systems based on the block copolymer PS-b-P4VP and inorganic nanoparticles (NPs...

  13. Carbon nanotube composite materials

    Energy Technology Data Exchange (ETDEWEB)

    O' Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  14. Carbon nanotube composite materials

    Science.gov (United States)

    O'Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  15. Solid phase extraction-capillary electrophoresis determination of sulphonamide residues in milk samples by use of C18-carbon nanotubes as hybrid sorbent materials.

    Science.gov (United States)

    Polo-Luque, M L; Simonet, B M; Valcárcel, M

    2013-07-07

    The exceptional sorption capabilities of carbon nanotubes were used to preconcentrate trace sulphonamides from milk samples. To this end, single walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs) dispersed in the ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate were retained on a C18 stationary phase to obtain a hybrid material in a simple manner. In this approach ionic liquids are an excellent alternative to improve the dispersion of CNTs, without chemical modification or the use of solid substances or organic solvents. MWNTs provided better results than SWNTs. Carbon nanotubes retained in the C18 sorbent matrix were found to confer aromatic character, increasing its preconcentration capacity as a result. The conventional C18 stationary phase played a two-fold role: as a support to retain carbon nanotubes in the cartridge and as a medium to prevent their aggregation. The modified MWNT/C18 and SWNT/C18 materials were used to preconcentrate residual sulphonamides (SAs) in milk samples for their determination at concentrations as low as 0.03-0.069 mg L(-1) by capillary electrophoresis. Analyte recoveries from spiked samples ranged from 103.2 to 98.8% and precision, as RSD, from 8.2 to 5.4%.

  16. 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.

  17. On the isolation of elemental carbon for micro-molar 14C accelerator mass spectrometry; evaluation of alternative isolation procedures, and accuracy assurance using a hybrid isotopic particulate carbon reference material

    OpenAIRE

    Currie, L A; Kessler,J.D.

    2005-01-01

    International audience; The primary objective of the research reported here has been the development of an hybrid reference material (RM) to serve as a test of accuracy for elemental carbon (EC) isotopic (14C) speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of ''soot'' (EC), the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement qual...

  18. Metallic carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, M.L.; Crespi, V.H.; Louie, S.G.S.; Zettl, A.K.

    1999-11-30

    Novel metallic forms of planar carbon are described, as well as methods of designing and making them. Nonhexagonal arrangements of carbon are introduced into a graphite carbon network essentially without destroying the planar structure. Specifically a form of carbon comprising primarily pentagons and heptagons, and having a large density of states at the Fermi level is described. Other arrangements of pentagons and heptagons that include some hexagons, and structures incorporating squares and octagons are additionally disclosed. Reducing the bond angle symmetry associated with a hexagonal arrangement of carbons increases the likelihood that the carbon material will have a metallic electron structure.

  19. Hybrid and hierarchical composite materials

    CERN Document Server

    Kim, Chang-Soo; Sano, Tomoko

    2015-01-01

    This book addresses a broad spectrum of areas in both hybrid materials and hierarchical composites, including recent development of processing technologies, structural designs, modern computer simulation techniques, and the relationships between the processing-structure-property-performance. Each topic is introduced at length with numerous  and detailed examples and over 150 illustrations.   In addition, the authors present a method of categorizing these materials, so that representative examples of all material classes are discussed.

  20. Boron-Filled Hybrid Carbon Nanotubes

    Science.gov (United States)

    Patel, Rajen B.; Chou, Tsengming; Kanwal, Alokik; Apigo, David J.; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-07-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs.

  1. Boron-Filled Hybrid Carbon Nanotubes

    Science.gov (United States)

    Patel, Rajen B.; Chou, Tsengming; Kanwal, Alokik; Apigo, David J.; Lefebvre, Joseph; Owens, Frank; Iqbal, Zafar

    2016-01-01

    A unique nanoheterostructure, a boron-filled hybrid carbon nanotube (BHCNT), has been synthesized using a one-step chemical vapor deposition process. The BHCNTs can be considered to be a novel form of boron carbide consisting of boron doped, distorted multiwalled carbon nanotubes (MWCNTs) encapsulating boron nanowires. These MWCNTs were found to be insulating in spite of their graphitic layered outer structures. While conventional MWCNTs have great axial strength, they have weak radial compressive strength, and do not bond well to one another or to other materials. In contrast, BHCNTs are shown to be up to 31% stiffer and 233% stronger than conventional MWCNTs in radial compression and have excellent mechanical properties at elevated temperatures. The corrugated surface of BHCNTs enables them to bond easily to themselves and other materials, in contrast to carbon nanotubes (CNTs). BHCNTs can, therefore, be used to make nanocomposites, nanopaper sheets, and bundles that are stronger than those made with CNTs. PMID:27460526

  2. Three-dimensional interconnected cobalt oxide-carbon hollow spheres arrays as cathode materials for hybrid batteries

    Institute of Scientific and Technical Information of China (English)

    Jiye Zhan; Xinhui Xia n; Yu Zhong; Xiuli Wang; Jiangping Tu n

    2016-01-01

    Hierarchical porous metal oxides arrays is critical for development of advanced energy storage devices. Herein, we report a facile template-assisted electro-deposition plus glucose decomposition method for synthesis of multilayer CoO/C hollow spheres arrays. The CoO/C arrays consist of multilayer inter-connected hollow composite spheres with diameters of ∼350 nm as well as thin walls of ∼20 nm. Hierarchical hollow spheres architecture with 3D porous networks are achieved. As cathode of high-rate hybrid batteries, the multilayer CoO/C hollow sphere arrays exhibit impressive enhanced performances with a high capacity (73.5 mAh g?1 at 2 A g?1), and stable high-rate cycling life (70 mAh g?1 after 12,500 cycles at 2 A g?1). The improved electrochemical performance is owing to the composite hollow-sphere architecture with high contact area between the active materials and electrolyte as well as fast ion/electron transportation path.

  3. Multi-walled carbon nanotube-based ternary rare earth (Eu3+, Tb3+) hybrid materials with organically modified silica-oxygen bridge.

    Science.gov (United States)

    Li, Qiu-Ping; Yan, Bing

    2012-08-15

    A series of ternary rare earth (Eu(3+), Tb(3+)) complexes are covalently coated to the 3-aminopropyltriethoxysilane functionalized multi-walled carbon nanotube (MWCNT) by a simple in situ sol-gel method by the bifunctional silylated monomer TTA-Si and TAA-Si (TTA-Si and TAA-Si are 3-(triethoxysilyl)propylisocyanate (TEPIC) modified thenoyltrifluoroacetone (TTA) and trifluoroacetylacetone (TAA), respectively). The resulting materials are characterized by Fourier transform infrared spectra, scanning electronic microscope, transmission electron microscope, thermogravimetric analysis, ultraviolet visible diffused reflection measure, photoluminescence spectra, and X-ray diffraction. The photoluminesce measurements indicated that these hybrids exhibit characteristic red and green luminescence originating from the corresponding ternary rare earth ion (Eu(3+), Tb(3+)). The luminescence quenching effect of MWCNT networks have been successfully restrained by coating a relatively thicker silica-oxygen-based organic-inorganic complex. Furthermore, the fluorescence lifetimes and emission quantum efficiencies of Eu(3+) hybrid materials are also determined. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Dry Process for Manufacturing Hybridized Boron Fiber/Carbon Fiber Thermoplastic Composite Materials from a Solution Coated Precursor

    Science.gov (United States)

    Belvin, Harry L. (Inventor); Cano, Roberto J. (Inventor)

    2003-01-01

    An apparatus for producing a hybrid boron reinforced polymer matrix composite from precursor tape and a linear array of boron fibers. The boron fibers are applied onto the precursor tapes and the precursor tape processed within a processing component having an impregnation bar assembly. After passing through variable-dimension forming nip-rollers, the precursor tape with the boron fibers becomes a hybrid boron reinforced polymer matrix composite. A driving mechanism is used to pulled the precursor tape through the method and a take-up spool is used to collect the formed hybrid boron reinforced polymer matrix composite.

  5. Graphene Hybrid Materials in Gas Sensing Applications †

    Science.gov (United States)

    Latif, Usman; Dickert, Franz L.

    2015-01-01

    Graphene, a two dimensional structure of carbon atoms, has been widely used as a material for gas sensing applications because of its large surface area, excellent conductivity, and ease of functionalization. This article reviews the most recent advances in graphene hybrid materials developed for gas sensing applications. In this review, synthetic approaches to fabricate graphene sensors, the nano structures of hybrid materials, and their sensing mechanism are presented. Future perspectives of this rapidly growing field are also discussed. PMID:26690156

  6. Carbon nanotubes hybrid hydrogels in drug delivery: a perspective review.

    Science.gov (United States)

    Cirillo, Giuseppe; Hampel, Silke; Spizzirri, Umile Gianfranco; Parisi, Ortensia Ilaria; Picci, Nevio; Iemma, Francesca

    2014-01-01

    The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability) with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior). The applicability of polymer-carbon nanotubes composites in drug delivery, with particular attention to the controlled release by composites hydrogel, is being extensively investigated in the present review.

  7. Carbon Nanotubes Hybrid Hydrogels in Drug Delivery: A Perspective Review

    Directory of Open Access Journals (Sweden)

    Giuseppe Cirillo

    2014-01-01

    Full Text Available The use of biologics, polymers, silicon materials, carbon materials, and metals has been proposed for the preparation of innovative drug delivery devices. One of the most promising materials in this field are the carbon-nanotubes composites and hybrid materials coupling the advantages of polymers (biocompatibility and biodegradability with those of carbon nanotubes (cellular uptake, stability, electromagnatic, and magnetic behavior. The applicability of polymer-carbon nanotubes composites in drug delivery, with particular attention to the controlled release by composites hydrogel, is being extensively investigated in the present review.

  8. On the isolation of elemental carbon for micro-molar 14C accelerator mass spectrometry; evaluation of alternative isolation procedures, and accuracy assurance using a hybrid isotopic particulate carbon reference material

    Directory of Open Access Journals (Sweden)

    L. A. Currie

    2005-05-01

    Full Text Available The primary objective of the research reported here has been the development of an hybrid reference material (RM to serve as a test of accuracy for elemental carbon (EC isotopic (14C speciation measurements. Such measurements are critically important for the quantitative apportionment of fossil and biomass sources of ''soot'' (EC, the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust, showed a range of results, but since the ''truth'' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC of measurement validity (Currie et al., 2002. Components of the new Hybrid RM (DiesApple, however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically. NIST SRM 2975 (Forklift Diesel Soot has little or no 14C, and its major compositional component is EC. SRM 1515 (Apple Leaves has the 14C content of biomass-C, and it has little or no EC. Thus, the hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C from SRM 1515 in the EC isolate of the hybrid RM, together with testing for conservation of its dominant soot fraction through the isolation procedure.

  9. Carbon materials for supercapacitors

    Science.gov (United States)

    Gao, Yang

    As an important energy storage device, electrochemical supercapacitors or ultracapacitors fill the gap between conventional dielectric capacitors and batteries in terms of specific energy and power. Although supercapacitors have been used in electric vehicles, digital communication instruments, and pulsed lasers, further improvement of supercapacitor performance is highly needed to enhance the energy density without significantly losing the power density. Additionally, the conventional supercapacitors use rigid packages and liquid electrolytes, which limit applications in transparent and flexible electronics. To address these challenges, the research efforts in this dissertation mainly focused on: 1) improvement of the energy density of carbon nanoonions by chemical activation; 2) laser-assisted activation of carbon nanotubes for improved energy density; 3) fabrication of flexible solid-state supercapacitors based on nanocarbon and manganese dioxide (MnO2) hybrid electrodes; and 4) investigation of the electrochemical performance of graphene as transparent and flexible supercapacitor electrodes.

  10. Novel hybrid polymeric materials for barrier coatings

    Science.gov (United States)

    Pavlacky, Erin Christine

    . The novel preparation of hybrid films coupling the advantageous properties of organic-inorganic hybrids formed through sol-gel chemistry with polymer-clay nanocomposite technology was also explored. Alkoxysilane-functional copolymer-clay nanocomposites were first synthesized, followed by crosslinking via simultaneous hydrolysis and condensation reactions to create the novel hybrid barrier films. By dispersing organomodified clay throughout the hybrid network, dramatic improvements in several film properties were observed, particularly regarding the viscoelastic properties. Additional studies with the same organic-inorganic preparation technique were performed to incorporate amine-functionality into the hybrid film for potential applications as protective membranes in carbon dioxide capture and separation technologies. Finally, controlled free-radical polymerization techniques were combined with the preparation of the organic-inorganic hybrids.

  11. Amorphous Carbon-Boron Nitride Nanotube Hybrids

    Science.gov (United States)

    Kim, Jae Woo (Inventor); Siochi, Emilie J. (Inventor); Wise, Kristopher E. (Inventor); Lin, Yi (Inventor); Connell, John (Inventor)

    2016-01-01

    A method for joining or repairing boron nitride nanotubes (BNNTs). In joining BNNTs, the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures. In repairing BNNTs, the damaged site of the nanotube structure is modified with amorphous carbon deposited by controlled electron beam irradiation to form well bonded hybrid a-C/BNNT structures at the damage site.

  12. Photochromic organic-inorganic hybrid materials.

    Science.gov (United States)

    Pardo, Rosario; Zayat, Marcos; Levy, David

    2011-02-01

    Photochromic organic-inorganic hybrid materials have attracted considerable attention owing to their potential application in photoactive devices, such as optical memories, windows, photochromic decorations, optical switches, filters or non-linear optics materials. The growing interest in this field has largely expanded the use of photochromic materials for the purpose of improving existing materials and exploring new photochromic hybrid systems. This tutorial review summarizes the design and preparation of photochromic hybrid materials, and particularly those based on the incorporation of organic molecules in organic-inorganic matrices by the sol-gel method. This is the most commonly used method for the preparation of these materials as it allows vitreous hybrid materials to be obtained at low temperatures, and controls the interaction between the organic molecule and its embedding matrix, and hence allows tailoring of the performance of the resulting devices.

  13. 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

  14. Mesoporous carbon materials

    Science.gov (United States)

    Dai, Sheng; Fulvio, Pasquale Fernando; Mayes, Richard T.; Wang, Xiqing; Sun, Xiao-Guang; Guo, Bingkun

    2014-09-09

    A conductive mesoporous carbon composite comprising conductive carbon nanoparticles contained within a mesoporous carbon matrix, wherein the conductive mesoporous carbon composite possesses at least a portion of mesopores having a pore size of at least 10 nm and up to 50 nm, and wherein the mesopores are either within the mesoporous carbon matrix, or are spacings delineated by surfaces of said conductive carbon nanoparticles when said conductive carbon nanoparticles are fused with each other, or both. Methods for producing the above-described composite, devices incorporating them (e.g., lithium batteries), and methods of using them, are also described.

  15. Engineering carbon materials from the hydrothermal carbonization process of biomass.

    Science.gov (United States)

    Hu, Bo; Wang, Kan; Wu, Liheng; Yu, Shu-Hong; Antonietti, Markus; Titirici, Maria-Magdalena

    2010-02-16

    Energy shortage, environmental crisis, and developing customer demands have driven people to find facile, low-cost, environmentally friendly, and nontoxic routes to produce novel functional materials that can be commercialized in the near future. Amongst various techniques, the hydrothermal carbonization (HTC) process of biomass (either of isolated carbohydrates or crude plants) is a promising candidate for the synthesis of novel carbon-based materials with a wide variety of potential applications. In this Review, we will discuss various synthetic routes towards such novel carbon-based materials or composites via the HTC process of biomass. Furthermore, factors that influence the carbonization process will be analyzed and the special chemical/physical properties of the final products will be discussed. Despite the lack of a clear mechanism, these novel carbonaceous materials have already shown promising applications in many fields such as carbon fixation, water purification, fuel cell catalysis, energy storage, CO(2) sequestration, bioimaging, drug delivery, and gas sensors. Some of the most promising examples will also be discussed here, demonstrating that the HTC process can rationally design a rich family of carbonaceous and hybrid functional carbon materials with important applications in a sustainable fashion.

  16. Euro hybrid materials and structures. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Hausmann, Joachim M.; Siebert, Marc (eds.)

    2016-08-01

    In order to use the materials as best as possible, several different materials are usually mixed in one component, especially in the field of lightweight design. If these combinations of materials are joined inherently, they are called multi material design products or hybrid structures. These place special requirements on joining technology, design methods and manufacturing and are challenging in other aspects, too. The eight chapters with manuscripts of the presentations are: Chapter 1- Interface: What happens in the interface between the two materials? Chapter 2 - Corrosion and Residual Stresses: How about galvanic corrosion and thermal residual stresses in the contact zone of different materials? Chapter 3 - Characterization: How to characterize and test hybrid materials? Chapter 4 - Design: What is a suitable design and dimensioning method for hybrid structures? Chapter 5 - Machining and Processing: How to machine and process hybrid structures and materials? Chapter 6 - Component Manufacturing: What is a suitable manufacturing route for hybrid structures? Chapter 7 - Non-Destructive Testing and Quality Assurance: How to assure the quality of material and structures? Chapter 8 - Joining: How to join components of different materials?.

  17. Recent progress in hybrid materials science.

    Science.gov (United States)

    Sanchez, Clément; Shea, Kenneth J; Kitagawa, Susumu

    2011-02-01

    This themed issue of Chemical Society Reviews reviews recent progress made in hybrid materials science. Guest editors Clément Sanchez, Susumu Kitagawa and Ken Shea introduce the issue and the academic and industrial importance of the field.

  18. 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.

  19. Building complex hybrid carbon architectures by covalent interconnections: graphene-nanotube hybrids and more.

    Science.gov (United States)

    Lv, Ruitao; Cruz-Silva, Eduardo; Terrones, Mauricio

    2014-05-27

    Graphene is theoretically a robust two-dimensional (2D) sp(2)-hybridized carbon material with high electrical conductivity and optical transparency. However, due to the existence of grain boundaries and defects, experimentally synthesized large-area polycrystalline graphene sheets are easily broken and can exhibit high sheet resistances; thus, they are not suitable as flexible transparent conductors. As described in this issue of ACS Nano, Tour et al. circumvented this problem by proposing and synthesizing a novel hybrid structure that they have named "rebar graphene", which is composed of covalently interconnected carbon nanotubes (CNTs) with graphene sheets. In this particular configuration, CNTs act as "reinforcing bars" that not only improve the mechanical strength of polycrystalline graphene sheets but also bridge different crystalline domains so as to enhance the electrical conductivity. This report seems to be only the tip of the iceberg since it is also possible to construct novel and unprecedented hybrid carbon architectures by establishing covalent interconnections between CNTs with graphene, thus yielding graphene-CNT hybrids, three-dimensional (3D) covalent CNT networks, 3D graphene networks, etc. In this Perspective, we review the progress of these carbon hybrid systems and describe the challenges that need to be overcome in the near future.

  20. Fabrication of free-standing pure carbon-based composite material with the combination of sp{sup 2}–sp{sup 3} hybridizations

    Energy Technology Data Exchange (ETDEWEB)

    Varga, M., E-mail: varga@fzu.cz [Institute of Physics of the ASCR, v.v.i., Cukrovarnicka 10, Prague 6 16253 (Czech Republic); Institute of Electronics and Photonics, FEI STU, Ilkovicova 3, 812 19 Bratislava (Slovakia); Vretenar, V. [Danubia NanoTech, s.r.o., Ilkovicova 3, 841 04 Bratislava (Slovakia); Institute of Physics of the SAS, Dubravska cesta 9, 845 11 Bratislava (Slovakia); Kotlar, M. [Institute of Electronics and Photonics, FEI STU, Ilkovicova 3, 812 19 Bratislava (Slovakia); Skakalova, V. [Danubia NanoTech, s.r.o., Ilkovicova 3, 841 04 Bratislava (Slovakia); Physics of Nanostructured Materials, University of Vienna, Boltzmanngasse 5, 1090 Vienna (Austria); Kromka, A. [Institute of Physics of the ASCR, v.v.i., Cukrovarnicka 10, Prague 6 16253 (Czech Republic)

    2014-07-01

    Composite structures have been in a center of interest for many decades. Carbon–carbon composites combine different carbon-based allotropes. Combining different carbon structures each with its unique property results in a new composite material with designed properties. In this contribution we present a technological procedure for preparation of a new flexible material consisting of single-wall carbon nanotubes (SWNTs) and nanocrystalline diamond (NCD). The fabrication process starts from the preparation of a paper made of SWNTs bundles followed by the CVD-growth of NCD in the interior of the SWNT paper. Keeping balance between the two competing processes during the CVD, i.e. growth of diamond particles versus etching SWNTs, is found as a key factor for the formation of a compact SWNT/NCD composite material. From a technological point of view, both processes are influenced mainly by the CVD conditions (temperature, gas composition, etc.) and/or substrate pretreatment. The essential idea of the diamond integration into the SWNT paper is demonstrated and discussed in more details. The morphology and structural aspects of the prepared composite material are further characterized by scanning electron microscopy and Raman spectroscopy.

  1. Coaxial MoS2@Carbon Hybrid Fibers: A Low-Cost Anode Material for High-Performance Li-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Rui Zhou

    2017-02-01

    Full Text Available A low-cost bio-mass-derived carbon substrate has been employed to synthesize MoS2@carbon composites through a hydrothermal method. Carbon fibers derived from natural cotton provide a three-dimensional and open framework for the uniform growth of MoS2 nanosheets, thus hierarchically constructing coaxial architecture. The unique structure could synergistically benefit fast Li-ion and electron transport from the conductive carbon scaffold and porous MoS2 nanostructures. As a result, the MoS2@carbon composites—when serving as anodes for Li-ion batteries—exhibit a high reversible specific capacity of 820 mAh·g−1, high-rate capability (457 mAh·g−1 at 2 A·g−1, and excellent cycling stability. The use of bio-mass-derived carbon makes the MoS2@carbon composites low-cost and promising anode materials for high-performance Li-ion batteries.

  2. 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.

  3. Hybrid carbon nanomaterials for electrochemical detection of biomolecules

    Science.gov (United States)

    Laurila, Tomi

    2015-09-01

    Electrochemical detection of different biomolecules in vivo is a promising path towards in situ monitoring of human body and its functions. However, there are several major obstacles, such as sensitivity, selectivity and biocompatiblity, which must be tackled in order to achieve reliably and safely operating sensor devices. Here we show that by utilizing hybrid carbon materials as electrodes to detect two types of neurotransmitters, dopamine and glutamate, several advantages over commonly used electrode materials can be achieved. In particular, we will demonstrate here that it is possible to combine the properties of different carbon allotropes to obtain hybrid materials with greatly improved electrochemical performance. Three following examples of the approach are given: (i) diamond-like carbon (DLC) thin film electrodes with different layer thicknesses, (ii) multi-walled carbon nanotubes grown directly on top of DLC and (iii) carbon nanofibres synthesized on top of DLC thin films. Detailed structural and electrochemical characterization is carried out to rationalize the reasons behind the observed behvior. In addition, results from the atomistic simulations are utilized to obtain more information about the properties of the amorphous carbon thin films.

  4. Hybrid nanostructured materials for high-performance electrochemical capacitors

    KAUST Repository

    Yu, Guihua

    2013-03-01

    The exciting development of advanced nanostructured materials has driven the rapid growth of research in the field of electrochemical energy storage (EES) systems which are critical to a variety of applications ranging from portable consumer electronics, hybrid electric vehicles, to large industrial scale power and energy management. Owing to their capability to deliver high power performance and extremely long cycle life, electrochemical capacitors (ECs), one of the key EES systems, have attracted increasing attention in the recent years since they can complement or even replace batteries in the energy storage field, especially when high power delivery or uptake is needed. This review article describes the most recent progress in the development of nanostructured electrode materials for EC technology, with a particular focus on hybrid nanostructured materials that combine carbon based materials with pseudocapacitive metal oxides or conducting polymers for achieving high-performance ECs. This review starts with an overview of EES technologies and the comparison between various EES systems, followed by a brief description of energy storage mechanisms for different types of EC materials. This review emphasizes the exciting development of both hybrid nanomaterials and novel support structures for effective electrochemical utilization and high mass loading of active electrode materials, both of which have brought the energy density of ECs closer to that of batteries while still maintaining their characteristic high power density. Last, future research directions and the remaining challenges toward the rational design and synthesis of hybrid nanostructured electrode materials for next-generation ECs are discussed. © 2012 Elsevier Ltd.

  5. Branch Content in Hybrid Materials using Small-Angle Scattering

    Science.gov (United States)

    Beaucage, Greg

    2005-03-01

    Inorganic/organic hybrid materials often display ramified mass- fractal structures characterized by primary particle size, aggregate size, and mass-fractal dimension. Physical properties, such as mechanical and dynamic mechanical properties and electrical conductivity (in carbon composites for instance), can not be predicted using only these structural features since such properties are intimately tied to the degree and type of branching as shown by Witten [1]. Witten suggested the use of the minimum dimension, or the related connectivity dimension, to calculate mechanical response in these hybrid systems. A viable technique to quantify the minimum dimension and connectivity dimension in hybrid materials has, until recently, been absent from the literature. This presentation will discuss the use of small-angle x-ray and neutron scattering to describe branch content in hybrid materials [2] and will outline an approach to use the minimum dimension and connectivity dimension to predict static and dynamic mechanical properties for hybrid materials based on structure [1, 3]. 1. Witten TA, Rubinstein M, Colby RH Reinforcement of Rubber by Fractal Aggregates J Phys II 3 (3): 367-383 (1993). 2. Beaucage G Determination of branch fraction and minimum dimension of mass-fractal aggregates Phys Rev E 70 (3): art. no. 031401 Part 1 (2004). 3. Kohls DJ, Beaucage G Rational design of reinforced rubber Curr Opin Solid St M 6 (3): 183-194 (2002).

  6. Material Flows and Carbon Cycles

    Science.gov (United States)

    Worrell, E.

    2003-12-01

    The industrial sector emits almost 43 percent of the global anthropogenic carbon dioxide emissions to produce materials and products. Furthermore, energy is used to move materials and products and process the waste. Hence, a large amount of energy is consumed and CO2 is emitted to sustain our materials system. Until recently, studies investigating mitigation options focused on changes in the energy system. For industrial processes most studies evaluate how the current materials system can be maintained producing fewer greenhouse gas emissions. Three elements of a strategy to improve the long-term materials productivity are the reduction of dissipative uses of non-biodegradable materials, secondly, the re-design of products to use less material or design for re-use or recycling, and thirdly, develop more efficient technologies for material conversion and recycling. This will reduce or eliminate the need to extract virgin materials from the environment, and reduce CO2 emissions from the energy-intensive production processes. To assess measures to reduce materials consumption, fossil fuels consumption and CO2 emissions, detailed understanding of the material system is needed. The lifecycle of materials has to be investigated including all branches of industry with all the inputs and outputs. We start with a discussion of materials and the carbon cycle focusing on the contribution of materials to anthropogenic carbon flows. We discuss CO2 emissions from energy use in materials extraction and production, fossil (e.g. plastics) and biomass carbon (e.g. lumber, paper) used as feedstock of materials, and mineral sources (e.g. cement). We discuss opportunities to reduce CO2 emissions by improving the efficiency with which society uses materials through product design, material substitution, product reuse and material recycling.

  7. Luminescent hybrid materials based on laponite clay.

    Science.gov (United States)

    Li, Huanrong; Li, Man; Wang, Yu; Zhang, Wenjun

    2014-08-11

    The spectroscopic behavior of ionic Eu(3+) or Tb(3+) complexes of an aromatic carboxyl-functionalized organic salt as well as those of the hybrid materials derived from adsorption of the ionic complexes on Laponite clay are reported. X-ray diffraction (XRD) patterns suggest that the complexes are mainly adsorbed on the outer surfaces of the Laponite disks rather than intercalated within the interlayer spaces. Photophysical data showed that the energy-transfer efficiency from the ligand to Eu(3+) ions in the hybrid material is increased remarkably with respect to the corresponding ionic complex. The hybrid material containing the Eu(3+) complex shows bright red emission from the prominent (5) D0 →(7) F2 transition of Eu(3+) ions, and that containing the Tb(3+) complex exhibits bright green emission due to the dominant (5) D4 →(7) F5 transition of Tb(3+) ions.

  8. Hybrid materials for optics and photonics.

    Science.gov (United States)

    Lebeau, Benedicte; Innocenzi, Plinio

    2011-02-01

    The interest in organic-inorganic hybrids as materials for optics and photonics started more than 25 years ago and since then has known a continuous and strong growth. The high versatility of sol-gel processing offers a wide range of possibilities to design tailor-made materials in terms of structure, texture, functionality, properties and shape modelling. From the first hybrid material with optical functional properties that has been obtained by incorporation of an organic dye in a silica matrix, the research in the field has quickly evolved towards more sophisticated systems, such as multifunctional and/or multicomponent materials, nanoscale and self-assembled hybrids and devices for integrated optics. In the present critical review, we have focused our attention on three main research areas: passive and active optical hybrid sol-gel materials, and integrated optics. This is far from exhaustive but enough to give an overview of the huge potential of these materials in photonics and optics (254 references).

  9. Calcium phosphate polymer hybrid materials

    OpenAIRE

    2011-01-01

    Calcium phosphate (CaP) is of strong interest to the medical field because of its potential for bone repair, gene transfection, etc.1-3 Nowadays, the majority of the commercially available materials are fabricated via “classical” materials science approaches, i.e. via high temperature or high pressure approaches, from rather poorly defined slurries, or from organic solvents.3,4 Precipitation of inorganics with (polymeric) additives from aqueous solution on the other hand enables the synthesis...

  10. Thermal Properties of Hybrid Carbon Nanotube/Carbon Fiber Polymer

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Luong, Hoa; Ratcliffe, James G.; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    Carbon fiber reinforced polymer (CFRP) composites possess many advantages for aircraft structures over conventional aluminum alloys: light weight, higher strength- and stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low thermal and electrical conductivities of CFRP composites are deficient in providing structural safety under certain operational conditions such as lightning strikes. One possible solution to these issues is to interleave carbon nanotube (CNT) sheets between conventional carbon fiber (CF) composite layers. However, the thermal and electrical properties of the orthotropic hybrid CNT/CF composites have not been fully understood. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel (Registered Trademark) IM7/8852 prepreg. The CNT sheets were infused with a 5% solution of a compatible epoxy resin prior to composite fabrication. Orthotropic thermal and electrical conductivities of the hybrid polymer composites were evaluated. The interleaved CNT sheets improved the in-plane thermal conductivity of the hybrid composite laminates by about 400% and the electrical conductivity by about 3 orders of magnitude.

  11. Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Composites

    Science.gov (United States)

    Kang, Jin Ho; Cano, Roberto J.; Ratcliffe, James G.; Luong, Hoa; Grimsley, Brian W.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strengthand stiffness-to-weight ratio, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Despite several attempts to solve these issues with the addition of carbon nanotubes (CNT) into polymer matrices, and/or by interleaving CNT sheets between conventional carbon fiber (CF) composite layers, there are still interfacial problems that exist between CNTs (or CF) and the resin. In this study, hybrid CNT/CF polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing (double cantilever beam and end-notched flexure test). Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated. Interleaving CNT sheets significantly improved the in-plane (axial and perpendicular direction of CF alignment) thermal conductivity of the hybrid composite laminates by 50 - 400%.

  12. Bio-inspired Hybrid Carbon Nanotube Muscles

    Science.gov (United States)

    Kim, Tae Hyeob; Kwon, Cheong Hoon; Lee, Changsun; An, Jieun; Phuong, Tam Thi Thanh; Park, Sun Hwa; Lima, Márcio D.; Baughman, Ray H.; Kang, Tong Mook; Kim, Seon Jeong

    2016-05-01

    There has been continuous progress in the development for biomedical engineering systems of hybrid muscle generated by combining skeletal muscle and artificial structure. The main factor affecting the actuation performance of hybrid muscle relies on the compatibility between living cells and their muscle scaffolds during cell culture. Here, we developed a hybrid muscle powered by C2C12 skeletal muscle cells based on the functionalized multi-walled carbon nanotubes (MWCNT) sheets coated with poly(3,4-ethylenedioxythiophene) (PEDOT) to achieve biomimetic actuation. This hydrophilic hybrid muscle is physically durable in solution and responds to electric field stimulation with flexible movement. Furthermore, the biomimetic actuation when controlled by electric field stimulation results in movement similar to that of the hornworm by patterned cell culture method. The contraction and relaxation behavior of the PEDOT/MWCNT-based hybrid muscle is similar to that of the single myotube movement, but has faster relaxation kinetics because of the shape-maintenance properties of the freestanding PEDOT/MWCNT sheets in solution. Our development provides the potential possibility for substantial innovation in the next generation of cell-based biohybrid microsystems.

  13. Carbon Materials Research

    Science.gov (United States)

    2006-08-01

    electrodes, high temperature molds, rocket nozzles and exit cones, tires , ink, nuclear reactors and fuel particles, filters, prosthetics, batteries and...carbon would be highly oriented pyrolytic graphite (HOPG), which is formed by depositing one atom at a time on a surface utilizing the pyrolysis of a...Moreover, it is well known that during pyrolysis , mesophase converts into a matrix that is very anisotropic. The formation of onion-like “sheaths

  14. Improving rate performance of LiFePO{sub 4} cathode materials by hybrid coating of nano-Li{sub 3}PO{sub 4} and carbon

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Shi-Xi, E-mail: zhaosx@sz.tsinghua.edu.cn [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Ding, Hao; Wang, Yan-Chao [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Li, Bao-Hua [Graduate School at Shenzhen, Tsinghua University, Shenzhen 518055 (China); Nan, Ce-Wen [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)

    2013-07-25

    Highlights: •This paper reports an improved solid-state method which leads to a uniform coating. The influence of Li{sub 3}PO{sub 4} and carbon coating on the electrochemical performance of LiFePO{sub 4} was studied. •LiFePO{sub 4} coating with Li{sub 3}PO{sub 4} and carbon shows a higher capacity than pure carbon coating sample. •Results indicate that the surface structure has an important influence on the electrochemical performance of LiFePO{sub 4}. The addition of Li{sub 3}PO{sub 4} can decrease the interfacial resistance of Li FePO{sub 4}. -- Abstract: Li{sub 3}PO{sub 4} coating on the surface of LiFePO{sub 4} particles was prepared by direct dispersing LiFePO{sub 4} precursor in starch slurry with nano-Li{sub 3}PO{sub 4}. The existence of nano-Li{sub 3}PO{sub 4} was confirmed with X-ray powder diffraction (XRD). And the particle size and morphology were observed by scanning electron microscope (SEM) and transmission electron microscope analysis (TEM). The effects of the mixture coating on rate performance of LiFePO{sub 4} cathode vs Li anode at 25 °C was investigated. Li{sub 3}PO{sub 4} and carbon mixing coated LiFePO{sub 4} cathode materials exhibited markedly improved rate capability relative to bare carbon-coated LiFePO{sub 4}. Analyses on cell impedance showed that the Li{sub 3}PO{sub 4} coating decreased the interfacial impedance. Transmission electron microscope analysis, electrochemical impedance spectroscopy (EIS) and cyclic voltammograms (CV) were carried out to explain the reason of better rate performance by Li{sub 3}PO{sub 4} coating.

  15. Hybrid materials offer new perspectives.

    Science.gov (United States)

    Arnetzl, G; Arnetzl, G V

    2015-01-01

    Dental materials, especially in restorative dentistry, must not only be cost-effective, they must also meet many other requirements: biocompatibility, durability, excellent shade and light effects, abrasion resistance, hardness, mechanical strength under pressure, chemical resistance, surface density, ease of manufacture, and easy intraoral maintenance.

  16. 碳纳米管/石墨烯杂化材料改性环氧树脂研究%Study on Epoxy Resin Composites Modiifed with Carbon Nanotubes/Graphene Hybrid Materials

    Institute of Scientific and Technical Information of China (English)

    吴俊青; 俞科静; 钱坤

    2015-01-01

    采用物理法和化学多步法合成了碳纳米管/石墨烯杂化材料,通过红外光谱表征证明杂化材料的成功合成,通过沉淀实验表明化学多步法合成的碳杂化材料具有良好的分散性和分散稳定性。将碳纳米杂化材料按照质量分数0.3%添加到环氧树脂(EP)中制备复合材料,对复合材料的拉伸强度和断裂韧性进行表征,并通过扫描电子显微镜对复合材料的断面进行表征。结果表明,碳纳米管/石墨烯杂化材料对EP的增强增韧效果较好,尤其是化学多步法合成的杂化材料改性EP复合材料,其拉伸强度最大,曲线积分面积最大,弹性模量最小,韧性最好。这可能要归因于化学多步法合成的杂化材料具有更为稳定的三维结构,可以更好地承担和转移外部载荷。%The successful preparation of hybrid materials through physical and multi-step methods were characterized by FTIR. The sedimentation tests proved that the hybrid materials(multi-step) had excellent dispersion and dispersion stability. The epoxy resin(EP) composites were prepared by adding 0.3%content of carbon nanomaterials into EP. The tensile strength and tensile toughness were tested by tensile experiment. And then the micromorphology of fracture surface of EP composites was characterized by scanning electron microscope. The results indicate that both hybrid materials have strengthening and toughness effect,especially EP composites with multi-step hybrid materials have the biggest tensile strength and tensile toughness with big integral area and smallest elasticity modulus. The reasons may be attributed to that the multi-step hybrid materials have more stable nanostructure to help EP to undertake and transfer more external load.

  17. Influence of Carbon & Glass Fiber Reinforcements on Flexural Strength of Epoxy Matrix Polymer Hybrid Composites

    Directory of Open Access Journals (Sweden)

    T.D. Jagannatha

    2015-04-01

    Full Text Available Hybrid composite materials are more attracted by the engineers because of their properties like stiffness and high specific strength which leads to the potential application in the area of aerospace, marine and automobile sectors. In the present investigation, the flexural strength and flexural modulus of carbon and glass fibers reinforced epoxy hybrid composites were studied. The vacuum bagging technique was adopted for the fabrication of polymer hybrid composite materials. The hardness, flexural strength and flexural modulus of the hybrid composites were determined as per ASTM standards. The hardness, flexural strength and flexural modulus were improved as the fiber reinforcement contents increased in the epoxy matrix material.

  18. Hybrid solar cell on a carbon fiber

    Science.gov (United States)

    Grynko, Dmytro A.; Fedoryak, Alexander N.; Smertenko, Petro S.; Dimitriev, Oleg P.; Ogurtsov, Nikolay A.; Pud, Alexander A.

    2016-05-01

    In this work, a method to assemble nanoscale hybrid solar cells in the form of a brush of radially oriented CdS nanowire crystals around a single carbon fiber is demonstrated for the first time. A solar cell was assembled on a carbon fiber with a diameter of ~5-10 μm which served as a core electrode; inorganic CdS nanowire crystals and organic dye or polymer layers were successively deposited on the carbon fiber as active components resulting in a core-shell photovoltaic structure. Polymer, dye-sensitized, and inverted solar cells have been prepared and compared with their analogues made on the flat indium-tin oxide electrode.

  19. Natural materials for carbon capture.

    Energy Technology Data Exchange (ETDEWEB)

    Myshakin, Evgeniy M. (National Energy Technology Laboratory, Pittsburgh, PA); Romanov, Vyacheslav N. (National Energy Technology Laboratory, Pittsburgh, PA); Cygan, Randall Timothy

    2010-11-01

    Naturally occurring clay minerals provide a distinctive material for carbon capture and carbon dioxide sequestration. Swelling clay minerals, such as the smectite variety, possess an aluminosilicate structure that is controlled by low-charge layers that readily expand to accommodate water molecules and, potentially, carbon dioxide. Recent experimental studies have demonstrated the efficacy of intercalating carbon dioxide in the interlayer of layered clays but little is known about the molecular mechanisms of the process and the extent of carbon capture as a function of clay charge and structure. A series of molecular dynamics simulations and vibrational analyses have been completed to assess the molecular interactions associated with incorporation of CO2 in the interlayer of montmorillonite clay and to help validate the models with experimental observation.

  20. Structural and Morphological Investigation for Water-Processed Graphene Oxide/Single-Walled Carbon Nanotubes Hybrids

    Science.gov (United States)

    Muda, M. R.; Ramli, M. M.; Mat Isa, S. S.; Halin, D. S. C.; Talip, L. F. A.; Mazelan, N. S.; Anhar, N. A. M.; Danial, N. A.

    2017-06-01

    New group of materials derived from hybridization of single walled carbon nanotubes (SWCNTs) and graphene oxide (GO) which resulting novel three dimensional (3D) materials generates an outstanding properties compared to corresponding SWCNTs and GO/Graphene. In this paper, we describe a simple approach using water processing method to develop integrated rGO/GO-SWCNT hybrids with different hybrid ratios. The hybrid ratios were varied into three divided ratio and the results were compared between pristine SWCNTs and GO in order to investigate the structural density and morphology of these carbonaceous materials. With an optimized ratio of rGO/GO-SWCNT, the hybrid shows a well-organized hybrid film structures with less defects density sites. The optimized mixture ratio emphasized the important of both rGO and SWCNTs in the hybrid structures. Morphological structural and defects density degrees were examined by Field Emission Scanning Electron Microscopy (FESEM) and Raman spectroscopy.

  1. Novel hybrid sol-gel materials for smart sensor windows

    Science.gov (United States)

    Wencel, Dorota; Higgins, Clare; Guckian, Adrian; McDonagh, Colette; MacCraith, Brian D.

    2005-06-01

    Current sensor trends, such as multianalyte capability, miniaturisation and patternability are important drivers for materials requirements in optical chemical sensors. In particular, issues such as enhanced sensitivity and printablity are key in developing optimised sensor materials for smart windows for bioprocessing applications. This study focuses on combining novel sol-gel-based hybrid matrices with engineered luminescent complexes to produce stable luminescence-based optical sensors with enhanced sensitivity for a range of analytes including oxygen, pH and carbon dioxide. As well as optimising sensor performance, issues such as surface modification of the plastic substrate and compatibility with different deposition techniques were addressed. Hybrid sol-gel matrices were developed using a range of precursors including tetraethoxysilane (TEOS), methyltriethoxysilane (MTEOS), ethyltriethoxysilane (ETEOS), n-propyltriethoxysilane (PTEOS), phenyltriethoxysilane (PhTEOS), and n-octyltriethoxysilane (C8TEOS). Oxygen sensing, based on luminescence quenching of ruthenium phenanthroline complexes, has been realised with each of these hybrid materials. Furthermore, the possibility of immobilising pH-indicators for pH and carbon dioxide sensing has been investigated with some success. In the context of in-situ monitoring of bioprocesses, issues such as humidity interference as well as the chemical robustness of the multianalyte platform, were addressed.

  2. MOF-derived crumpled-sheet-assembled perforated carbon cuboids as highly effective cathode active materials for ultra-high energy density Li-ion hybrid electrochemical capacitors (Li-HECs)

    Science.gov (United States)

    Banerjee, Abhik; Upadhyay, Kush Kumar; Puthusseri, Dhanya; Aravindan, Vanchiappan; Madhavi, Srinivasan; Ogale, Satishchandra

    2014-03-01

    Lithium ion hybrid capacitors (Li-HECs) have attracted significant attention for use in next generation advanced energy storage technologies to satisfy the demand of both high power density as well as energy density. Herein we demonstrate the use of very high surface area 3D carbon cuboids synthesized from a metal-organic framework (MOF) as a cathode material with Li4Ti5O12 as the anode for high performance Li-HECs. The energy density of the cell is ~65 W h kg-1 which is significantly higher than that achievable with commercially available activated carbon (~36 W h kg-1) and a symmetric supercapacitor based on the same MOF-derived carbon (MOF-DC ~20 W h kg-1). The MOF-DC/Li4Ti5O12 Li-HEC assembly also shows good cyclic performance with ~82% of the initial value (~25 W h kg-1) retained after 10 000 galvanostatic cycles under high rate cyclic conditions. This result clearly indicates that MOF-DC is a very promising candidate for future P-HEVs in a Li-HEC configuration.Lithium ion hybrid capacitors (Li-HECs) have attracted significant attention for use in next generation advanced energy storage technologies to satisfy the demand of both high power density as well as energy density. Herein we demonstrate the use of very high surface area 3D carbon cuboids synthesized from a metal-organic framework (MOF) as a cathode material with Li4Ti5O12 as the anode for high performance Li-HECs. The energy density of the cell is ~65 W h kg-1 which is significantly higher than that achievable with commercially available activated carbon (~36 W h kg-1) and a symmetric supercapacitor based on the same MOF-derived carbon (MOF-DC ~20 W h kg-1). The MOF-DC/Li4Ti5O12 Li-HEC assembly also shows good cyclic performance with ~82% of the initial value (~25 W h kg-1) retained after 10 000 galvanostatic cycles under high rate cyclic conditions. This result clearly indicates that MOF-DC is a very promising candidate for future P-HEVs in a Li-HEC configuration. Electronic supplementary information

  3. Amine-oxide hybrid materials for acid gas separations

    KAUST Repository

    Bollini, Praveen

    2011-01-01

    Organic-inorganic hybrid materials based on porous silica materials functionalized with amine-containing organic species are emerging as an important class of materials for the adsorptive separation of acid gases from dilute gas streams. In particular, these materials are being extensively studied for the adsorption of CO 2 from simulated flue gas streams, with an eye towards utilizing these materials as part of a post-combustion carbon capture process at large flue gas producing installations, such as coal-fired electricity-generating power plants. In this Application Article, the utilization of amine-modified organic-inorganic hybrid materials is discussed, focusing on important attributes of the materials, such as (i) CO 2 adsorption capacities, (ii) adsorption and desorption kinetics, and (iii) material stability, that will determine if these materials may one day be useful adsorbents in practical CO 2 capture applications. Specific research needs and limitations associated with the current body of work are identified. © 2011 The Royal Society of Chemistry.

  4. Hybrid sol-gel optical materials

    Science.gov (United States)

    Zeigler, John M.

    1992-01-01

    Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

  5. Template-free electrochemical nanofabrication of polyaniline nanobrush and hybrid polyaniline with carbon nanohorns for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Wei Di; Andrew, Piers; Ryhaenen, Tapani [Nokia Research Centre Cambridge, Broers Building, 21 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Wang, Haolan; Hiralal, Pritesh; Amaratunga, Gehan A J [Electrical Engineering Division, Department of Engineering, University of Cambridge, 9 J J Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Hayashi, Yasuhiko, E-mail: di.wei@nokia.com, E-mail: gaja1@cam.ac.uk [Department of Materials Science, Nagoya Institute of Technology, Nagoya 466-8555 (Japan)

    2010-10-29

    Polyaniline (PANI) nanobrushes were synthesized by template-free electrochemical galvanostatic methods. When the same method was applied to the carbon nanohorn (CNH) solution containing aniline monomers, a hybrid nanostructure containing PANI and CNHs was enabled after electropolymerization. This is the first report on the template-free method to make PANI nanobrushes and homogeneous hybrid soft matter (PANI) with carbon nanoparticles. Raman spectroscopy was used to analyze the interaction between CNH and PANI. Electrochemical nanofabrication offers simplicity and good control when used to make electronic devices. Both of these materials were applied in supercapacitors and an improvement capacitive current by using the hybrid material was observed.

  6. Design and Fabrication of E-Glass /carbon/graphite epoxy hybrid composite leaf spring

    Science.gov (United States)

    Gopalakrishnan, T.; Raja, M.; Jothi Prakash, V. M.; Gnanavel, C.

    2017-03-01

    The Automobile Industry has shown increase interest for replacement of steel leaf spring with that of composite leaf spring. Substituting composite materials for conventional metallic materials has many advantages because of higher specific stiffness, strength and fatigue resistance etc. This work deals with the replacement of conventional steel leaf spring with a hybrid Composite leaf spring using E -Glass/Carbon/Graphite/Epoxy. The hybrid composite is obtained by introducing more than one fiber in the reinforcement phase. The hybrid composite is fabricated by the vacuum bag technique. The result shows that introduction of carbon and graphite fiber in the reinforcement phase increases the stiffness of the composite.

  7. Effect of water on the physical properties and carbon dioxide capture capacities of liquid-like Nanoparticle Organic Hybrid Materials and their corresponding polymers

    KAUST Repository

    Petit, Camille

    2013-10-01

    Binary systems composed of liquid-like Nanoparticle Organic Hybrid Materials (NOHMs) and the secondary fluid (i.e., water) were prepared, and their thermal stabilities, densities, viscosities, and CO2 absorption capacities were investigated. Recent work has suggested NOHMs as an alternative CO2 capture media with interesting chemical and physical tunability. Anhydrous CO2 capture solvents often degrade when they are exposed to water, while flue gas generally contains about 8-16% water. Thus, this study was conducted to investigate the effect of water on the NOHMs\\' properties relevant to CO2 capture as well as the chemical and thermal stabilities of H2O-loaded NOHMs. It was found that water acted as an antisolvent of NOHMs, and therefore, caused a decreased CO2 capture capacity. On the other hand, the results indicated that while water did not affect the NOHMs\\' thermal stability, it significantly helped lowering their density and viscosity. In order to investigate the effect of intermolecular interactions among two fluids on the density and viscosity, the excess volumes and viscosity deviations were calculated and correlated with Redlich-Kister equations. The trends revealed the existence of strong intermolecular interactions between water molecules and the poly(ethlyne glycol) component of NOHMs, which may have caused the drastic decrease in the NOHMs\\' viscosity with the addition of water. © 2013 Elsevier Inc.

  8. Hybrid Composites Based on Carbon Fiber/Carbon Nanofilament Reinforcement

    Directory of Open Access Journals (Sweden)

    Mehran Tehrani

    2014-05-01

    Full Text Available Carbon nanofilament and nanotubes (CNTs have shown promise for enhancing the mechanical properties of fiber-reinforced composites (FRPs and imparting multi-functionalities to them. While direct mixing of carbon nanofilaments with the polymer matrix in FRPs has several drawbacks, a high volume of uniform nanofilaments can be directly grown on fiber surfaces prior to composite fabrication. This study demonstrates the ability to create carbon nanofilaments on the surface of carbon fibers employing a synthesis method, graphitic structures by design (GSD, in which carbon structures are grown from fuel mixtures using nickel particles as the catalyst. The synthesis technique is proven feasible to grow nanofilament structures—from ethylene mixtures at 550 °C—on commercial polyacrylonitrile (PAN-based carbon fibers. Raman spectroscopy and electron microscopy were employed to characterize the surface-grown carbon species. For comparison purposes, a catalytic chemical vapor deposition (CCVD technique was also utilized to grow multiwall CNTs (MWCNTs on carbon fiber yarns. The mechanical characterization showed that composites using the GSD-grown carbon nanofilaments outperform those using the CCVD-grown CNTs in terms of stiffness and tensile strength. The results suggest that further optimization of the GSD growth time, patterning and thermal shield coating of the carbon fibers is required to fully materialize the potential benefits of the GSD technique.

  9. Roles of metal/activated carbon hybridization on elemental mercury adsorption.

    Science.gov (United States)

    Bae, Kyong-Min; Kim, Byung-Joo; Rhee, Kyong Yop; Park, Soo-Jin

    2014-08-01

    In this study, the elemental mercury removal behavior of metal (copper or nickel)/activated carbon hybrid materials were investigated. The pore structures and total pore volumes of the hybrid materials were analyzed using the N2/77 K adsorption isotherms. The microstructure and surface morphologies of the hybrid materials were characterized by X-ray diffraction and scanning electron microscopy, respectively. In the experimental results, the elemental mercury adsorption capacities of all copper/activated carbon hybrid materials were higher than that of the as-received material despite the decrease in specific surface areas and total pore volumes after the metal loading. All the samples containing the metal particles showed excellent elemental mercury adsorption. The Ni/ACs exhibited superior elemental mercury adsorption to those of Cu/ACs. This suggests that Ni/ACs have better elemental mercury adsorption due to the higher activity of nickel.

  10. Application of poly 1,8-diaminonaphthalene/multiwalled carbon nanotubes-COOH hybrid material as an efficient sorbent for trace determination of cadmium and lead ions in water samples.

    Science.gov (United States)

    Nabid, Mohammad Reza; Sedghi, Roya; Behbahani, Mohammad; Arvan, Behnoush; Heravi, Majid M; Oskooie, Hossein Abdi

    2014-07-01

    Poly 1,8-diaminonaphthalene/multiwalled carbon nanotubes-COOH hybrid material as an effective sorbents in solid phase extraction has been developed for the separation and preconcentration of Cd(II) and Pb(II) at trace levels in environmental water samples. The results indicate that the novel nanocomposite show a high affinity for these heavy metals due to the presence of several good extractive sites, which are introduced to the synthesized nanocomposite The maximum adsorption capacity of the synthesized sorbent for cadmium and lead ions was found to be 101.2 and 175.2 mg g(-1) , respectively. The detection limits of this method were 0.09 and 0.7 ng ml(-1) for Cd(II) and Pb(II), respectively.

  11. MOF-derived crumpled-sheet-assembled perforated carbon cuboids as highly effective cathode active materials for ultra-high energy density Li-ion hybrid electrochemical capacitors (Li-HECs).

    Science.gov (United States)

    Banerjee, Abhik; Upadhyay, Kush Kumar; Puthusseri, Dhanya; Aravindan, Vanchiappan; Madhavi, Srinivasan; Ogale, Satishchandra

    2014-04-21

    Lithium ion hybrid capacitors (Li-HECs) have attracted significant attention for use in next generation advanced energy storage technologies to satisfy the demand of both high power density as well as energy density. Herein we demonstrate the use of very high surface area 3D carbon cuboids synthesized from a metal-organic framework (MOF) as a cathode material with Li₄Ti₅O₁₂ as the anode for high performance Li-HECs. The energy density of the cell is ∼65 W h kg(-1) which is significantly higher than that achievable with commercially available activated carbon (∼36 W h kg(-1)) and a symmetric supercapacitor based on the same MOF-derived carbon (MOF-DC ∼20 W h kg(-1)). The MOF-DC/Li₄Ti₅O₁₂ Li-HEC assembly also shows good cyclic performance with ∼82% of the initial value (∼25 W h kg(-1)) retained after 10,000 galvanostatic cycles under high rate cyclic conditions. This result clearly indicates that MOF-DC is a very promising candidate for future P-HEVs in a Li-HEC configuration.

  12. Carbon material for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Bourlinos, Athanasios; Steriotis, Theodore; Stubos, Athanasios; Miller, Michael A

    2016-09-13

    The present invention relates to carbon based materials that are employed for hydrogen storage applications. The material may be described as the pyrolysis product of a molecular precursor such as a cyclic quinone compound. The pyrolysis product may then be combined with selected transition metal atoms which may be in nanoparticulate form, where the metals may be dispersed on the material surface. Such product may then provide for the reversible storage of hydrogen. The metallic nanoparticles may also be combined with a second metal as an alloy to further improve hydrogen storage performance.

  13. Biomineralization-inspired synthesis of functional organic/inorganic hybrid materials: organic molecular control of self-organization of hybrids.

    Science.gov (United States)

    Arakaki, Atsushi; Shimizu, Katsuhiko; Oda, Mayumi; Sakamoto, Takeshi; Nishimura, Tatsuya; Kato, Takashi

    2015-01-28

    Organisms produce various organic/inorganic hybrid materials, which are called biominerals. They form through the self-organization of organic molecules and inorganic elements under ambient conditions. Biominerals often have highly organized and hierarchical structures from nanometer to macroscopic length scales, resulting in their remarkable physical and chemical properties that cannot be obtained by simple accumulation of their organic and inorganic constituents. These observations motivate us to create novel functional materials exhibiting properties superior to conventional materials--both synthetic and natural. Herein, we introduce recent progress in understanding biomineralization processes at the molecular level and the development of organic/inorganic hybrid materials by these processes. We specifically outline fundamental molecular studies on silica, iron oxide, and calcium carbonate biomineralization and describe material synthesis based on these mechanisms. These approaches allow us to design a variety of advanced hybrid materials with desired morphologies, sizes, compositions, and structures through environmentally friendly synthetic routes using functions of organic molecules.

  14. In Situ Formation of Carbon Nanomaterials on Bulk Metallic Materials

    Directory of Open Access Journals (Sweden)

    J. Y. Xu

    2014-01-01

    Full Text Available Carbon nanomaterials were synthesized in situ on bulk 316L stainless steel, pure cobalt, and pure nickel by hybrid surface mechanical attrition treatment (SMAT. The microstructures of the treated samples and the resulted carbon nanomaterials were investigated by SEM and TEM characterizations. Different substrates resulted in different morphologies of products. The diameter of carbon nanomaterials is related to the size of the nanograins on the surface layer of substrates. The possible growth mechanism was discussed. Effects of the main parameters of the synthesis, including the carbon source and gas reactant composition, hydrogen, and the reaction temperature, were studied. Using hybrid SMAT is proved to be an effective way to synthesize carbon nanomaterials in situ on surfaces of metallic materials.

  15. INVESTIGATION OF NON ERODING NOZZLE MATERIALS FOR OPTIMIZED COATED HYBRID LEADING EDGE DESIGNS FOR REUSABLE LAUNCH VEHICALS WITH LEADING EDGE RADII OF 0.03? TO 1? AND TEMPERATURES NEAR 4000?F Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Effort explores using innovative hybrid reinforced carbon-carbon, refractory ceramics, super alloys and composite materials as thermal protection system specifically...

  16. Organic/inorganic hybrid materials: challenges for ab initio methodology.

    Science.gov (United States)

    Draxl, Claudia; Nabok, Dmitrii; Hannewald, Karsten

    2014-11-18

    terms of interfacial electronic structure. We face the problem of a so far hidden variable, namely, electron-vibrational coupling, regarding level alignment at interfaces between organic and inorganic semiconductors. Poly(para-phenylene) adsorbed on graphene and encapsulated in carbon nanotubes represent case studies to demonstrate the impact of polarization effects and exciton delocalization in optoelectronic excitations, respectively. Polaron-induced band narrowing and its consequences for charge transport in organic crystals is exemplified for the HOMO bandwidth in naphthalene crystals. On the basis of these prototypical systems, we discuss what is missing to reach predictive power on a quantitative level for organic/inorganic hybrid materials and, thus, open a perspective toward the computational discovery of new materials for optoelectronic applications.

  17. Tough, bio-inspired hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Munch, Etienne; Launey, Maximimilan E.; Alsem, Daan H.; Saiz, Eduardo; Tomsia, Antoni P.; Ritchie, Robert O.

    2008-10-06

    The notion of mimicking natural structures in the synthesis of new structural materials has generated enormous interest but has yielded few practical advances. Natural composites achieve strength and toughness through complex hierarchical designs extremely difficult to replicate synthetically. Here we emulate Nature's toughening mechanisms through the combination of two ordinary compounds, aluminum oxide and polymethylmethacrylate, into ice-templated structures whose toughness can be over 300 times (in energy terms) that of their constituents. The final product is a bulk hybrid ceramic material whose high yield strength and fracture toughness ({approx}200 MPa and {approx}30 MPa{radical}m) provide specific properties comparable to aluminum alloys. These model materials can be used to identify the key microstructural features that should guide the synthesis of bio-inspired ceramic-based composites with unique strength and toughness.

  18. Sustainable carbon materials from hydrothermal processes

    CERN Document Server

    Titirici, Maria-Magdalena

    2013-01-01

    The production of low cost and environmentally friendly high performing carbon materials is crucial for a sustainable future. Sustainable Carbon Materials from Hydrothermal Processes describes a sustainable and alternative technique to produce carbon from biomass in water at low temperatures, a process known as Hydrothermal Carbonization (HTC). Sustainable Carbon Materials from Hydrothermal Processes presents an overview of this new and rapidly developing field, discussing various synthetic approaches, characterization of the final products, and modern fields of application fo

  19. A Magnesium-Activated Carbon Hybrid Capacitor

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, HD; Shterenberg, I; Gofer, Y; Doe, RE; Fischer, CC; Ceder, G; Aurbach, D

    2013-12-11

    Prototype cells of hybrid capacitor were developed, comprising activated carbon (AC) cloth and magnesium (Mg) foil as the positive and negative electrodes, respectively. The electrolyte solution included ether solvent (TBF) and a magnesium organo-halo-aluminate complex 0.25 M Mg2Cl3+-Ph2AlCl2-. In this solution Mg can be deposited/dissolved reversibly for thousands of cycles with high reversibility (100% cycling efficiency). The main barrier for integrating porous AC electrodes with this electrolyte solution was the saturation of the pores with the large ions in the AC prior to reaching the potential limit. This is due to the existence of bulky Mg and Al based ionic complexes consisting Cl, alkyl or aryl (R), and THF ligands. This problem was resolved by adding 0.5 M of lithium chloride (LiCl), thus introducing smaller ionic species to the solution. This Mg hybrid capacitor system demonstrated a stable cycle performance for many thousands of cycles with a specific capacitance of 90 Fg(-1) for the AC positive electrodes along a potential range of 2.4 V. (C) 2014 The Electrochemical Society. All rights reserved.

  20. Strongly coupled inorganic/nanocarbon hybrid materials for advanced electrocatalysis.

    Science.gov (United States)

    Liang, Yongye; Li, Yanguang; Wang, Hailiang; Dai, Hongjie

    2013-02-13

    Electrochemical systems, such as fuel cell and water splitting devices, represent some of the most efficient and environmentally friendly technologies for energy conversion and storage. Electrocatalysts play key roles in the chemical processes but often limit the performance of the entire systems due to insufficient activity, lifetime, or high cost. It has been a long-standing challenge to develop efficient and durable electrocatalysts at low cost. In this Perspective, we present our recent efforts in developing strongly coupled inorganic/nanocarbon hybrid materials to improve the electrocatalytic activities and stability of inorganic metal oxides, hydroxides, sulfides, and metal-nitrogen complexes. The hybrid materials are synthesized by direct nucleation, growth, and anchoring of inorganic nanomaterials on the functional groups of oxidized nanocarbon substrates including graphene and carbon nanotubes. This approach affords strong chemical attachment and electrical coupling between the electrocatalytic nanoparticles and nanocarbon, leading to nonprecious metal-based electrocatalysts with improved activity and durability for the oxygen reduction reaction for fuel cells and chlor-alkali catalysis, oxygen evolution reaction, and hydrogen evolution reaction. X-ray absorption near-edge structure and scanning transmission electron microscopy are employed to characterize the hybrids materials and reveal the coupling effects between inorganic nanomaterials and nanocarbon substrates. Z-contrast imaging and electron energy loss spectroscopy at single atom level are performed to investigate the nature of catalytic sites on ultrathin graphene sheets. Nanocarbon-based hybrid materials may present new opportunities for the development of electrocatalysts meeting the requirements of activity, durability, and cost for large-scale electrochemical applications.

  1. Molecular Design of Low-Density Multifunctional Hybrid Materials

    Science.gov (United States)

    2016-01-01

    Structure -Property Relationships of Hybrid Mixed Oxide Organic - Inorganic Films for Multilayer Adhesive Bonding”, MRS 2012 Spring Meeting, San Francisco...AVAILABILITY STATEMENT No distribution limitation. 13. SUPPLEMENTARY NOTES 14. ABSTRACT Low-density hybrid materials, which contain organic and... hybrid materials, which contain organic and inorganic molecular components, can be engineered over a wide range of length scales to exhibit unique

  2. The devil and holy water: protein and carbon nanotube hybrids.

    Science.gov (United States)

    Calvaresi, Matteo; Zerbetto, Francesco

    2013-11-19

    Integrating carbon nanotubes (CNTs) with biological systems to form hybrid functional assemblies is an innovative research area with great promise for medical, nanotechnology, and materials science applications. The specifics of molecular recognition and catalytic activity of proteins combined with the mechanical and electronic properties of CNTs provides opportunities for physicists, chemists, biologists, and materials scientists to understand and develop new nanomachines, sensors, or any of a number of other molecular assemblies. Researchers know relatively little about the structure, function, and spatial orientation of proteins noncovalently adsorbed on CNTs, yet because the interaction of CNTs with proteins depends strongly on the tridimensional structure of the proteins, many of these questions can be answered in simple terms. In this Account, we describe recent research investigating the properties of CNT/protein hybrids. Proteins act to solvate CNTs and may sort them according to diameter or chirality. In turn, CNTs can support and immobilize enzymes, creating functional materials. Additional applications include proteins that assemble ordered hierarchical objects containing CNTs, and CNTs that act as protein carriers for vaccines, for example. Protein/CNT hybrids can form bioscaffolds and can serve as therapeutic and imaging materials. Proteins can detect CNTs or coat them to make them biocompatible. One of the more challenging applications for protein/CNT hybrids is to make CNT substrates for cell growth and neural interfacing applications. The challenge arises from the structures' interactions with living cells, which poses questions surrounding the (nano)toxicology of CNTs and whether and how CNTs can detect biological processes or sense them as they occur. The surface chemistry of CNTs and proteins, including interactions such as π-π stacking interactions, hydrophobic interactions, surfactant-like interactions, and charge-π interactions, governs the

  3. 3D hybrid-porous carbon derived from carbonization of metal organic frameworks for high performance supercapacitors

    Science.gov (United States)

    Bao, Weizhai; Mondal, Anjon Kumar; Xu, Jing; Wang, Chengyin; Su, Dawei; Wang, Guoxiu

    2016-09-01

    We report a rational design and synthesis of 3D hybrid-porous carbon with a hierarchical pore architecture for high performance supercapacitors. It contains micropores (<2 nm diameter) and mesopores (2-4 nm), derived from carbonization of unique porous metal organic frameworks (MOFs). Owning to the synergistic effect of micropores and mesopores, the hybrid-porous carbon has exceptionally high ion-accessible surface area and low ion diffusion resistance, which is desired for supercapacitor applications. When applied as electrode materials in supercapacitors, 3D hybrid-porous carbon demonstrates a specific capacitance of 332 F g-1 at a constant charge/discharge current of 500 mA g-1. The supercapacitors can endure more than 10,000 cycles without degradation of capacitance.

  4. Carbon nanotube based hybrid nanocarbon foam

    Science.gov (United States)

    Shahrizan Jamal, M.; Zhang, Mei

    2017-03-01

    Carbon nanotube (CNT) based nanocarbon foams (NFs) and the hybrid nanocarbon foams (HNFs) are fabricated in this work. The NFs are formed by using poly(methyl methacrylate) microspheres as a template to create micro-scaled pores. The cell walls are made of CNT networks with nano-scaled pores. The interconnections among CNTs are secured using graphene and nanographite generated via carbonization of polyacrylonitrile. The resulting NFs are ultra-lightweight, highly elastic, electrically and thermally conductive, and robust in structure. The HNFs are made by infiltrating thermoplastic polymer into the NFs in a controllable procedure. Compared to NFs, the HNFs have much higher strength, same electrical conductivity, and limited increase in density. The compressive strength of the HNF increased more than 50 times while the density was changed less than 10 times due to the polymer infiltration. It is found that the deformed HNFs can recover in both structure and property when they are heated over the glass transition temperature of the infiltrated polymer. Such remarkable healing capability could broaden the applications of the HNFs.

  5. Polymer hybrid materials for planar optronic systems

    Science.gov (United States)

    Körner, Martin; Prucker, Oswald; Rühe, Jürgen

    2015-09-01

    Planar optronic systems made entirely from polymeric functional materials on polymeric foils are interesting architectures for monitoring and sensing applications. Key components in this regard are polymer hybrid materials with adjustable optical properties. These materials can then be processed into optical components such as waveguides for example by using embossing techniques. However, the resulting microstructures have often low mechanical or thermal stability which quickly leads to a degradation of the microstructures accompanied often by a complete loss of function. A simple and versatile way to increase the thermal and mechanical stability of polymers is to connect the individual chains to a polymer network by using thermally or photochemically reactive groups. Upon excitation, these groups form reactive intermediates such as radicals or nitrenes which then crosslink with adjacent C-H-groups through a C,H insertion reaction (CHic = C,H insertion based crosslinking). To generate waveguide structures a PDMS stamp is filled with the waveguide core material e.g. poly(methylmethacrylate) (PMMA), which is modified with a few mol% of the thermal crosslinker and hot embossed onto a foil substrate e.g. PMMA. In this one-step hot embossing process polymer ridge waveguides are formed and simultaneously the polymer becomes crosslinked. Due to the reaction across the boundary between waveguide and substrate it is also possible to combine initially incompatible polymers for the waveguide and the substrate foil. The thermomechanical properties of the obtained materials are studied.

  6. Diversity in carbon materials; Tanso zairyo no tayosei

    Energy Technology Data Exchange (ETDEWEB)

    Inagaki, M. [Hokkaido Univ., Sapporo (Japan). Faculty of Engineering

    1995-12-01

    Recently, fullerene of which C60 is representative being discovered, it is bringing new development in the carbon material field. And besides, quite recently some reports concerning carbyne which belongs to another carbon material region have begun to be submitted. Carbon atoms being able to adopt three kinds of sp hybrid orbitals, combination of these orbitals is ground of diversity which can produce many inorganic and organic compounds. Diamond is representative of materials having sp{sup 3} hybrid orbitals, and graphite is representative of materials having sp{sup 2} ones. Atoms of fullerene have hybrid orbitals which are very close to sp{sup 2}, and one C60 molecule is a hollow sphere assorted with 20 six-membered carbon rings and 12 five-membered ones. C60 molecules crystallize into cubic close-packed structure, and this structure can become intercalation by accepting another atoms just like the case of graphite intercalations. Some of fullerene intercalations which are also called doping compounds, exhibiting superconductivity, are being watched with keenest interest. 2 refs., 3 figs.

  7. Status of Biomass Derived Carbon Materials for Supercapacitor Application

    Directory of Open Access Journals (Sweden)

    Talam Kibona Enock

    2017-01-01

    Full Text Available Environmental concerns and energy security uncertainties associated with fossil fuels have driven the world to shift to renewable energy sources. However, most renewable energy sources with exception of hydropower are intermittent in nature and thus need storage systems. Amongst various storage systems, supercapacitors are the promising candidates for energy storage not only in renewable energies but also in hybrid vehicles and portable devices due to their high power density. Supercapacitor electrodes are almost invariably made of carbon derived from biomass. Several reviews had been focused on general carbon materials for supercapacitor electrode. This review is focused on understanding the extent to which different types of biomasses have been used as porous carbon materials for supercapacitor electrodes. It also details hydrothermal microwave assisted, ionothermal, and molten salts carbonization as techniques of synthesizing activated carbon from biomasses as well as their characteristics and their impacts on electrochemical performance.

  8. Carbon nanotube reinforced hybrid composites: Computational modeling of environmental fatigue and usability for wind blades

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon

    2015-01-01

    The potential of advanced carbon/glass hybrid reinforced composites with secondary carbon nanotube reinforcement for wind energy applications is investigated here with the use of computational experiments. Fatigue behavior of hybrid as well as glass and carbon fiber reinforced composites...... with the secondary CNT reinforcements (especially, aligned tubes) present superior fatigue performances than those without reinforcements, also under combined environmental and cyclic mechanical loading. This effect is stronger for carbon composites, than for hybrid and glass composites....... automatically using the Python based code. 3D computational studies of environment and fatigue analyses of multiscale composites with secondary nano-scale reinforcement in different material phases and different CNTs arrangements are carried out systematically in this paper. It was demonstrated that composites...

  9. Carbon nanotube reinforced hybrid composites: Computational modeling of environmental fatigue and usability for wind blades

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon

    2015-01-01

    The potential of advanced carbon/glass hybrid reinforced composites with secondary carbon nanotube reinforcement for wind energy applications is investigated here with the use of computational experiments. Fatigue behavior of hybrid as well as glass and carbon fiber reinforced composites...... with and without secondary CNT reinforcement is simulated using multiscale 3D unit cells. The materials behavior under both mechanical cyclic loading and combined mechanical and environmental loading (with phase properties degraded due to the moisture effects) is studied. The multiscale unit cells are generated...... with the secondary CNT reinforcements (especially, aligned tubes) present superior fatigue performances than those without reinforcements, also under combined environmental and cyclic mechanical loading. This effect is stronger for carbon composites, than for hybrid and glass composites....

  10. Catalytic Enhancement of Carbon Black and Coal-Fueled Hybrid Direct Carbon Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Ippolito, Davide; Kammer Hansen, Kent

    2015-01-01

    Hybrid direct carbon fuel cells (HDCFCs) consisting of a solid carbon (carbon black)-molten carbonate ((62–38 wt% Li-K)2CO3) mixtures in the anode chamber of an anode-supported solid oxide fuel cell type full-cell are tested for their electrochemical performance between 700 and 800°C. Performance...

  11. Adaptive, Active and Multifunctional Composite and Hybrid Materials Program: Composite and Hybrid Materials ERA

    Science.gov (United States)

    2014-04-01

    16 4.2.4.3 Fabrication and Modeling of Rubber Muscle Actuators ..........17 4.2.4.4 Modeling of Power Response of SMP/SMA...Processing of BMI/Preceramic Polymer Blends .................................28 4.9 Task 9.0 Hybrid Material Processing and Fabrication...electrical stimulus, similar in action to the natural response of the conformation of a bird wing during flight vs. takeoff or landing, a muscle pair

  12. In Situ Carbonized Cellulose-Based Hybrid Film as Flexible Paper Anode for Lithium-Ion Batteries.

    Science.gov (United States)

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

    2016-01-20

    Flexible free-standing carbonized cellulose-based hybrid film is integrately designed and served both as paper anode and as lightweight current collector for lithium-ion batteries. The well-supported heterogeneous nanoarchitecture is constructed from Li4Ti5O12 (LTO), carbonized cellulose nanofiber (C-CNF) and carbon nanotubes (CNTs) using by a pressured extrusion papermaking method followed by in situ carbonization under argon atmospheres. The in situ carbonization of CNF/CNT hybrid film immobilized with uniform-dispersed LTO results in a dramatic improvement in the electrical conductivity and specific surface area, so that the carbonized paper anode exhibits extraordinary rate and cycling performance compared to the paper anode without carbonization. The flexible, lightweight, single-layer cellulose-based hybrid films after carbonization can be utilized as promising electrode materials for high-performance, low-cost, and environmentally friendly lithium-ion batteries.

  13. Cathode-supported hybrid direct carbon fuel cells

    DEFF Research Database (Denmark)

    Gil, Vanesa; Gurauskis, Jonas; Deleebeeck, Lisa

    2017-01-01

    The direct conversion of coal to heat and electricity by a hybrid direct carbon fuel cell (HDCFC) is a highly efficient and cleaner technology than the conventional combustion power plants. HDCFC is defined as a combination of solid oxide fuel cell and molten carbonate fuel cell. This work...

  14. Lignin-Derived Advanced Carbon Materials.

    Science.gov (United States)

    Chatterjee, Sabornie; Saito, Tomonori

    2015-12-07

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure-property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templated carbon, are discussed. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Surface modification of microfibrous materials with nanostructured carbon

    Energy Technology Data Exchange (ETDEWEB)

    Krasnikova, Irina V., E-mail: tokareva@catalysis.ru [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Mishakov, Ilya V.; Vedyagin, Aleksey A. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk 630090 (Russian Federation); National Research Tomsk Polytechnic University, Lenin av., 30, Tomsk 634050 (Russian Federation); Bauman, Yury I. [Boreskov Institute of Catalysis SB RAS, pr. Ac. Lavrentieva, 5, Novosibirsk 630090 (Russian Federation); Korneev, Denis V. [State Research Center of Virology and Biotechnology VECTOR, Koltsovo, Novosibirsk Region 630559 (Russian Federation)

    2017-01-15

    The surface of fiberglass cloth, carbon and basalt microfibers was modified with carbon nanostructured coating via catalytic chemical vapor deposition (CCVD) of 1,2-dichloroethane. Incipient wetness impregnation and solution combustion synthesis (SCS) methods were used to deposit nickel catalyst on the surface of microfibrous support. Prepared NiO/support samples were characterized by X-ray diffraction analysis and temperature-programmed reduction. The samples of resulted hybrid materials were studied by means of scanning and transmission electron microscopies as well as by low-temperature nitrogen adsorption. The nature of the support was found to have considerable effect on the CCVD process peculiarities. High yield of nanostructured carbon with largest average diameter of nanofibers within the studied series was observed when carbon microfibers were used as a support. This sample characterized with moderate surface area (about 80 m{sup 2}/g after 2 h of CCVD) shows the best anchorage effect. Among the mineral supports, fiberglass tissue was found to provide highest carbon yield (up to 3.07 g/g{sub FG}) and surface area (up to 344 m{sup 2}/g) due to applicability of SCS method for Ni deposition. - Highlights: • The microfibers of different nature were coated with nanostructured carbon layer. • Features of CNF growth and characteristics of hybrid materials were studied. • Appropriate anchorage of CNF layer on microfiber’s surface was demonstrated.

  16. Lignin Based Carbon Materials for Energy Storage Applications

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Sabornie [ORNL; Saito, Tomonori [ORNL; Rios, Orlando [ORNL; Johs, Alexander [ORNL

    2014-01-01

    The implementation of Li-ion battery technology into electric and hybrid electric vehicles and portable electronic devices such as smart phones, laptops and tablets, creates a demand for efficient, economic and sustainable materials for energy storage. However, the high cost and long processing time associated with manufacturing battery-grade anode and cathode materials are two big constraints for lowering the total cost of batteries and environmentally friendly electric vehicles. Lignin, a byproduct of the pulp and paper industry and biorefinery, is one of the most abundant and inexpensive natural biopolymers. It can be efficiently converted to low cost carbon fibers with optimal properties for use as anode materials. Recent developments in the preparation of lignin precursors and conversion to carbon fiber-based anode materials have created a new class of anode materials with excellent electrochemical characteristics suitable for immediate use in existing Li- or Na-ion battery technologies.

  17. Processing, structure and flexural strength of CNT and carbon fibre reinforced, epoxy-matrix hybrid composite

    Indian Academy of Sciences (India)

    K Chandra Shekar; M Sai Priya; P K Subramanian; Anil Kumar; B Anjaneya Prasad; N Eswara Prasad

    2014-05-01

    Advanced materials such as continuous fibre-reinforced polymer matrix composites offer significant enhancements in variety of properties, as compared to their bulk, monolithic counterparts. These properties include primarily the tensile stress, flexural stress and fracture parameters. However, till date, there are hardly any scientific studies reported on carbon fibre (Cf) and carbon nanotube (CNT) reinforced hybrid epoxy matrix composites (unidirectional). The present work is an attempt to bring out the flexural strength properties along with a detailed investigation in the synthesis of reinforced hybrid composite. In this present study, the importance of alignment of fibre is comprehensively evaluated and reported. The results obtained are discussed in terms of material characteristics, microstructure and mode of failure under flexural (3-point bend) loading. The study reveals the material exhibiting exceptionally high strength values and declaring itself as a material with high strength to weight ratio when compared to other competing polymer matrix composites (PMCs); as a novel structural material for aeronautical and aerospace applications.

  18. Synergetic Hybrid Aerogels of Vanadia and Graphene as Electrode Materials of Supercapacitors

    Directory of Open Access Journals (Sweden)

    Xuewei Fu

    2016-08-01

    Full Text Available The performance of synergetic hybrid aerogel materials of vanadia and graphene as electrode materials in supercapacitors was evaluated. The hybrid materials were synthesized by two methods. In Method I, premade graphene oxide (GO hydrogel was first chemically reduced by L-ascorbic acid and then soaked in vanadium triisopropoxide solution to obtain V2O5 gel in the pores of the reduced graphene oxide (rGO hydrogel. The gel was supercritically dried to obtain the hybrid aerogel. In Method II, vanadium triisopropoxide was hydrolyzed from a solution in water with GO particles uniformly dispersed to obtain the hybrid gel. The hybrid aerogel was obtained by supercritical drying of the gel followed by thermal reduction of GO. The electrode materials were prepared by mixing 80 wt % hybrid aerogel with 10 wt % carbon black and 10 wt % polyvinylidene fluoride. The hybrid materials in Method II showed higher capacitance due to better interactions between vanadia and graphene oxide particles and more uniform vanadia particle distribution.

  19. Hybrid gate dielectric materials for unconventional electronic circuitry.

    Science.gov (United States)

    Ha, Young-Geun; Everaerts, Ken; Hersam, Mark C; Marks, Tobin J

    2014-04-15

    Recent advances in semiconductor performance made possible by organic π-electron molecules, carbon-based nanomaterials, and metal oxides have been a central scientific and technological research focus over the past decade in the quest for flexible and transparent electronic products. However, advances in semiconductor materials require corresponding advances in compatible gate dielectric materials, which must exhibit excellent electrical properties such as large capacitance, high breakdown strength, low leakage current density, and mechanical flexibility on arbitrary substrates. Historically, conventional silicon dioxide (SiO2) has dominated electronics as the preferred gate dielectric material in complementary metal oxide semiconductor (CMOS) integrated transistor circuitry. However, it does not satisfy many of the performance requirements for the aforementioned semiconductors due to its relatively low dielectric constant and intransigent processability. High-k inorganics such as hafnium dioxide (HfO2) or zirconium dioxide (ZrO2) offer some increases in performance, but scientists have great difficulty depositing these materials as smooth films at temperatures compatible with flexible plastic substrates. While various organic polymers are accessible via chemical synthesis and readily form films from solution, they typically exhibit low capacitances, and the corresponding transistors operate at unacceptably high voltages. More recently, researchers have combined the favorable properties of high-k metal oxides and π-electron organics to form processable, structurally well-defined, and robust self-assembled multilayer nanodielectrics, which enable high-performance transistors with a wide variety of unconventional semiconductors. In this Account, we review recent advances in organic-inorganic hybrid gate dielectrics, fabricated by multilayer self-assembly, and their remarkable synergy with unconventional semiconductors. We first discuss the principals and functional

  20. THE SYNERGISTIC EFFECT OF HYBRID FLAME RETARDANTS ON PYROLYSIS BEHAVIOUR OF HYBRID COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    M. T. ALBDIRY

    2012-06-01

    Full Text Available The aim of this investigation is to comprehensively understand the polymeric composite behavior under direct fire sources. The synergistic effects of hybrid flame retardant material on inhabiting the pyrolysis of hybrid reinforced fibers, woven roving (0°- 45° carbon and kevlar (50/50 wt/wt, and an araldite resin composites were studied. The composites were synthesised and coated primarily by zinc borate (2ZnO.3B2O3.3.5H2O and modified by antimony trioxide (Sb2O3 with different amounts (10-30 wt% of flame retardant materials. In the experiments, the composite samples were exposed to a direct flame source generated by oxyacetylene flame (~3000ºC at variable exposure distances of 10-20 mm. The synergic flame retardants role of antimony trioxide and zinc borate on the composite surface noticeably improves the flame resistance of the composite which is attributed to forming a protective mass and heat barrier on the composite surface and increasing the melt viscosity.

  1. Hydrogenation of carbon dioxide by hybrid catalysts, direct synthesis of aromatic from carbon dioxide and hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kuei Chikung; Lee Mindar (National Taiwan Univ., Taipei (Taiwan))

    1991-02-01

    To improve climatic conditions and to solve the carbon resource problem, it is desirable to develop techniques whereby carbon dioxide can be converted to valuable liquid hydrocarbons which can be used either as fuels or industrial raw materials. Direct synthesis of aromatics from carbon dioxide hydrogenation was investigated in a single stage reactor using hybrid catalysts composed of iron catalysts and HZSM-5 zeolite. Carbon dioxide was first converted to CO by the reverse water gas shift reaction, followed by the hydrogenation of CO to hydrocarbons on iron catalyst, and finally the hydrocarbons were converted to aromatics in HZSM-5. Under the operating conditions of 350{degree}C, 2100 kilopascals and CO{sub 2}/H{sub 2}={1/2} the maximum aromatic selectivity obtained was 22% with a CO{sub 2} conversion of 38% using fused iron catalyst combined with the zeolite. Together with the kinetic studies, thermodynamic analysis of the CO{sub 2} hydrogenation was also conducted. It was found that unlike Fischer Tropsch synthesis, the formation of hydrocarbons from CO{sub 2} may not be thermodynamically favored at higher temperature. However, the sufficiently high yields of aromatics possible with this process provides a route for the direct synthesis of high-octane gasoline from carbon dioxide. 24 refs., 9 figs., 5 tabs.

  2. Electrochemical synthesis and characterisation of hybrid materials polypyrrole/dodecatungstophosphate as protective agents against steel corrosion

    Science.gov (United States)

    Bonastre Cano, Jose Antonio

    The losses caused by the effect of the corrosion are of the order of 2-3,5% of the GDP of the developed countries or developing only in direct costs, losses in structures or products. This figure doubles by the indirect costs, losses of productivity or demands for delays. Beside the possible losses of human lives, any intent leaded to the decrease of the corrosion in rusty metals is a commendable objective from the point of view of the protection of the environment. Building industry employing reinforced concrete is able to project some structural elements (pillars, wrought, beam, etc.) in principle free of corrosion, assuring during many years the useful life of the work in service. However, the reinforced concrete would be' a perfect solution if the indefinite permanency of the passive state of the steel could be guaranteed. Indeed, although the steel is protected against corrosion due to basic pH which provides the cement, the severe action of saline media or the effect of CO2 can diminish this protection conditions beginning the corrosion in steel elements. Type-p doped conducting polymers, as polypyrrole, are firm candidates to protect carbon steel providing galvanic protection by stabilising the passive layer of Fe oxides initially grown. Doping the polymeric matrix with polioxometalates, concretely phosphotungstate PW12O403-, is a very interesting hypothesis due to their oxidising effect, improving the anodic protection by the hybrid material electrosynthesised on carbon steel substrate. First in the present work, a new method was developed by cyclic voltammetry in LiClO4 + acetonitrile medium in order to diminish the unavoidable oxidation of carbon steel when the electrosyntesis of the hybrid material polypyrrole/PW12O403- is carrying out. The beginning potential of polypyrrole polymerisation is about 0.8 V (vs. Ag/AgCl), a positive potential where oxidation of Fe substrate is high, not allowing the electrodeposition of the hybrid material. On the other

  3. First-Principles Study of Electronic Structure of Type I Hybrid Carbon-Silicon Clathrates

    Science.gov (United States)

    Chan, Kwai S.; Peng, Xihong

    2016-08-01

    A new class of type I hybrid carbon-silicon clathrates has been designed using computational methods by substituting some of the Si atoms in the silicon clathrate framework with carbon atoms. In this work, the electronic structure of hybrid carbon-silicon clathrates with and without alkaline or alkaline-earth metal guest atoms has been computed within the density functional theory framework. The theoretical calculations indicate that a small number of carbon substitutions in the Si46 framework slightly reduces the density of states (DOS) near the band edge and narrows the bandgap of carbon-silicon clathrates. Weak hybridization of the conduction band occurs when alkaline metal (Li, Na, K) atoms are inserted into the structure, while strong hybridization of the conduction band occurs when alkaline-earth metal (Mg, Ca, Ba) atoms are inserted into the hybrid structure. Empty C y Si46- y clathrates within the composition range of 2 ≤ y ≤ 15 can be tuned to exhibit indirect bandgaps of 1.5 eV or less, and may be considered as potential electronic materials.

  4. Fatigue of hybrid glass/carbon composites: 3D computational studies

    DEFF Research Database (Denmark)

    Dai, Gaoming; Mishnaevsky, Leon

    2014-01-01

    3D computational simulations of fatigue of hybrid carbon/glass fiber reinforced composites is carried out using X-FEM and multifiber unit cell models. A new software code for the automatic generation of unit cell multifiber models of composites with randomly misaligned fibers of various properties...... and geometrical parameters is developed. With the use of this program code and the X-FEM method, systematic investigations of the effect of microstructure of hybrid composites (fraction of carbon versus glass fibers, misalignment, and interface strength) and the loading conditions (tensile versus compression...... cyclic loading effects) on fatigue behavior of the materials are carried out. It was demonstrated that the higher fraction of carbon fibers in hybrid composites is beneficial for the fatigue lifetime of the composites under tension-tension cyclic loading, but might have negative effect on the lifetime...

  5. Free-standing carbon nanotube/graphene hybrid papers as next generation adsorbents.

    Science.gov (United States)

    Dichiara, Anthony B; Sherwood, Tyler J; Benton-Smith, Jared; Wilson, Jonathan C; Weinstein, Steven J; Rogers, Reginald E

    2014-06-21

    The adsorption of a series of aromatic compounds from aqueous solution onto purified, free-standing single-walled carbon nanotube/graphene nanoplatelet hybrid papers is studied both experimentally and theoretically. Experimental data is obtained via changes in optical absorption spectra of the aqueous solutions and is used to extract all parameters required to implement a semi-empirical mass-transfer model. Agreement between experiment and theory is excellent and data from all compounds can be cast on a universal adsorption curve. Results indicate that the rate of adsorption and long-time capacity of many aromatic compounds on hybrid paper adsorbent significantly exceeds that of activated carbon by at least an order of magnitude. The combination of carbon nanotubes and graphene also promotes on the order of a 25% improvement in adsorption rates and capacities than either component alone. Hybrid nanocomposites show significant promise as adsorption materials used for environmental remediation efforts.

  6. Gyroidal mesoporous carbon materials and methods thereof

    Energy Technology Data Exchange (ETDEWEB)

    Wiesner, Ulrich B.; Werner, Joerg G.

    2017-07-25

    The present invention relates to, inter alia, gyroidal mesoporous carbon materials and methods of use and manufacture thereof. In one embodiment, the present invention relates to a mesoporous carbon composition comprising a gyroidal mesoporous carbon having an ordered gyroidal structure and mesopores having a pore size of greater than 2 nanometers (nm) in diameter, and more particularly greater than 11 nm in diameter.

  7. Mechanical Properties of Graphene Nanoplatelet/Carbon Fiber/Epoxy Hybrid Composites: Multiscale Modeling and Experiments

    Science.gov (United States)

    Hadden, C. M.; Klimek-McDonald, D. R.; Pineda, E. J.; King, J. A.; Reichanadter, A. M.; Miskioglu, I.; Gowtham, S.; Odegard, G. M.

    2015-01-01

    Because of the relatively high specific mechanical properties of carbon fiber/epoxy composite materials, they are often used as structural components in aerospace applications. Graphene nanoplatelets (GNPs) can be added to the epoxy matrix to improve the overall mechanical properties of the composite. The resulting GNP/carbon fiber/epoxy hybrid composites have been studied using multiscale modeling to determine the influence of GNP volume fraction, epoxy crosslink density, and GNP dispersion on the mechanical performance. The hierarchical multiscale modeling approach developed herein includes Molecular Dynamics (MD) and micromechanical modeling, and it is validated with experimental testing of the same hybrid composite material system. The results indicate that the multiscale modeling approach is accurate and provides physical insight into the composite mechanical behavior. Also, the results quantify the substantial impact of GNP volume fraction and dispersion on the transverse mechanical properties of the hybrid composite, while the effect on the axial properties is shown to be insignificant.

  8. Mechanical Properties of Graphene Nanoplatelet Carbon Fiber Epoxy Hybrid Composites: Multiscale Modeling and Experiments

    Science.gov (United States)

    Hadden, Cameron M.; Klimek-McDonald, Danielle R.; Pineda, Evan J.; King, Julie A.; Reichanadter, Alex M.; Miskioglu, Ibrahim; Gowtham, S.; Odegard, Gregory M.

    2015-01-01

    Because of the relatively high specific mechanical properties of carbon fiber/epoxy composite materials, they are often used as structural components in aerospace applications. Graphene nanoplatelets (GNPs) can be added to the epoxy matrix to improve the overall mechanical properties of the composite. The resulting GNP/carbon fiber/epoxy hybrid composites have been studied using multiscale modeling to determine the influence of GNP volume fraction, epoxy crosslink density, and GNP dispersion on the mechanical performance. The hierarchical multiscale modeling approach developed herein includes Molecular Dynamics (MD) and micromechanical modeling, and it is validated with experimental testing of the same hybrid composite material system. The results indicate that the multiscale modeling approach is accurate and provides physical insight into the composite mechanical behavior. Also, the results quantify the substantial impact of GNP volume fraction and dispersion on the transverse mechanical properties of the hybrid composite, while the effect on the axial properties is shown to be insignificant.

  9. Effect of Hybrid Surface Modifications on Tensile Properties of Polyacrylonitrile- and Pitch-Based Carbon Fibers

    Science.gov (United States)

    Naito, Kimiyoshi

    2016-05-01

    Recent interest has emerged in techniques that modify the surfaces of carbon fibers, such as carbon nanotube (CNT) grafting or polymer coating. Hybridization of these surface modifications has the potential to generate highly tunable, high-performance materials. In this study, the mechanical properties of surface-modified polyacrylonitrile (PAN)-based and pitch-based carbon fibers were investigated. Single-filament tensile tests were performed for fibers modified by CNT grafting, dipped polyimide coating, high-temperature vapor deposition polymerized polyimide coating, grafting-dipping hybridization, and grafting-vapor deposition hybridization. The Weibull statistical distributions of the tensile strengths of the surface-modified PAN- and pitch-based carbon fibers were examined. All surface modifications, especially hybrid modifications, improved the tensile strengths and Weibull moduli of the carbon fibers. The results exhibited a linear relationship between the Weibull modulus and average tensile strength on a log-log scale for all surface-modified PAN- and pitch-based carbon fibers.

  10. IF-WS2/Nanostructured Carbon Hybrids Generation and Their Characterization

    Directory of Open Access Journals (Sweden)

    Claudia C. Luhrs

    2014-05-01

    Full Text Available With the aim to develop a new generation of materials that combine either the known energy absorbing properties of carbon nanofibers (CNF, or the carbon-carbon bond strength of graphene sheets (G, with the shock resistance properties reported for Inorganic Fullerene type WS2 structures (IF-WS2, hybrid CNF/IF-WS2 and G/IF-WS2 were generated, characterized and tested. Experimentation revealed that in situ growth of carbon nanostructures with inorganic fullerene tungsten disulfide particulates had to be performed from particular precursors and fabrication conditions to avoid undesirable byproducts that hinder fiber growth or deter graphene generation. The novel protocols that allowed us to integrate the IF-WS2 with the carbon nanostructures, producing dispersions at the nanoscale, are reported. Resulting hybrid CNF/IF-WS2 and G/IF-WS2 products were analyzed by X-ray Diffraction (XRD, Scanning Electron Microscope (SEM and TEM (Transmission Electron Microscopy. The thermal stability of samples in air was evaluated by Thermogravimetric Analysis (TGA. CNF/IF-WS2 and G/IF-WS2 hybrids were introduced into epoxy matrices, and the mechanical properties of the resulting composites were analyzed using nanoindentation. Epoxy composite samples showed drastic improvements in the Young’s modulus and hardness values by the use of only 1% hybrid weight loadings. The carbon nanofiber inclusions seem to have a much greater impact on the mechanical properties of the composite than the graphene based counterparts.

  11. Poly(3-hexylthiophene)/multiwalled carbon hybrid coaxial nanotubes: nanoscale rectification and photovoltaic characteristics.

    Science.gov (United States)

    Kim, Kihyun; Shin, Ji Won; Lee, Yong Baek; Cho, Mi Yeon; Lee, Suk Ho; Park, Dong Hyuk; Jang, Dong Kyu; Lee, Cheol Jin; Joo, Jinsoo

    2010-07-27

    We fabricate hybrid coaxial nanotubes (NTs) of multiwalled carbon nanotubes (MWCNTs) coated with light-emitting poly(3-hexylthiophene) (P3HT). The p-type P3HT material with a thickness of approximately 20 nm is electrochemically deposited onto the surface of the MWCNT. The formation of hybrid coaxial NTs of the P3HT/MWCNT is confirmed by a transmission electron microscope, FT-IR, and Raman spectra. The optical and structural properties of the hybrid NTs are characterized using ultraviolet and visible absorption, Raman, and photoluminescence (PL) spectra where, it is shown that the PL intensity of the P3HT materials decreases after the hybridization with the MWCNTs. The current-voltage (I-V) characteristics of the outer P3HT single NT show the semiconducting behavior, while ohmic behavior is observed for the inner single MWCNT. The I-V characteristics of the hybrid junction between the outer P3HT NT and the inner MWCNT, for the hybrid single NT, exhibit the characteristics of a diode (i.e., rectification), whose efficiency is clearly enhanced with light irradiation. The rectification effect of the hybrid single NT has been analyzed in terms of charge tunneling models. The quasi-photovoltaic effect is also observed at low bias for the P3HT/MWCNT hybrid single NT.

  12. Csub60/Collapsed Carbon Nanotube Hybrids: A Variant of Peapods (Open Access)

    Science.gov (United States)

    2015-01-02

    fullerenes, collapsed carbon nanotubes, silocrystals Hybrid nanostructures are of great interest due to thepotential for engineering new materials with...the duct size. A related observation is that insertion of C60 in large diameter uncollapsed SWCNT is exothermic, 2 while it is strongly endothermic ...supported in part by the Director, Office of Basic Energy Sciences, Materials Sciences and Engineering Division, of the U.S. Department of Energy

  13. Properties of glass/carbon fiber reinforced epoxy hybrid polymer composites

    Science.gov (United States)

    Patel, R. H.; Sevkani, V. R.; Patel, B. R.; Patel, V. B.

    2016-05-01

    Composite Materials are well known for their tailor-made properties. For the fabrication of composites different types of reinforcements are used for different applications. Sometimes for a particular application, one type of reinforcement may not fulfill the requirements. Therefore, more than one type of reinforcements may be used. Thus, the idea of hybrid composites arises. Hybrid composites are made by joining two or more different reinforcements with suitable matrix system. It helps to improve the properties of composite materials. In the present work glass/carbon fiber reinforcement have been used with a matrix triglycidyl ether of tris(m-hydroxy phenyl) phosphate epoxy resin using amine curing agent. Different physical and mechanical properties of the glass, carbon and glass/carbon fiber reinforced polymeric systems have been found out.

  14. Hydrogen adsorption in new carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Zubizarreta, L.; Arenillas, A.; Rubiera, F.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

    2006-07-01

    Hydrogen physi-sorption on porous carbon materials is one among the different technologies which could be used for hydrogen storage. In addition hydrogen spillover on a carbon supports can enhance the hydrogen adsorption capacities obtained by physi-sorption. In this study two different carbon supports were synthesised: carbon gels and carbon microspheres. Carbon microspheres were doped with Ni(NO{sub 3}){sub 2} to study the hydrogen spillover on carbon support. The texture of the materials was characterised by CO{sub 2} adsorption at 0 C and their hydrogen storage capacity was evaluated at -196 and 10 C with a Micromeritics Tristar 3000, and at room temperature with a high pressure gravimetric analyser. (authors)

  15. Tensile properties of a boron/nitrogen-doped carbon nanotube–graphene hybrid structure

    Directory of Open Access Journals (Sweden)

    Kang Xia

    2014-03-01

    Full Text Available Doping is an effective approach that allows for the intrinsic modification of the electrical and chemical properties of nanomaterials. Recently, a graphene and carbon nanotube hybrid structure (GNHS has been reported, which extends the excellent properties of carbon-based materials to three dimensions. In this paper, we carried out a first-time investigation on the tensile properties of the hybrid structures with different dopants. It is found that with the presence of dopants, the hybrid structures usually exhibit lower yield strength, Young’s modulus, and earlier yielding compared to that of a pristine hybrid structure. For dopant concentrations below 2.5% no significant reduction of Young’s modulus or yield strength could be observed. For all considered samples, the failure is found to initiate at the region where the nanotubes and graphene sheets are connected. After failure, monatomic chains are normally observed around the failure region. Dangling graphene layers without the separation of a residual CNT wall are found to adhere to each other after failure with a distance of about 3.4 Å. This study provides a fundamental understanding of the tensile properties of the doped graphene–nanotube hybrid structures, which will benefit the design and also the applications of graphene-based hybrid materials.

  16. Enhanced Electrical Conductivity of Aluminum by Carbon Nanotube Hybrid Dilution

    Science.gov (United States)

    Stigers, Shelby; Savadelis, Alexader; Carruba, Kathryn; Johns, Kiley; Adu, Kofi

    2015-03-01

    Carbon nanotubes (CNTs) have been recognized as potential candidate for reinforcements in lightweight metals. A composite consisting of CNTs embedded in an Al-matrix might work as an ultra-low-resistive material with the potential of having a room-temperature resistivity far below Al, Cu and Ag. While several advances have been made in developing Al-CNT composites, three major challenges: (1) interfacial bond strength between CNT and the Al matrix, (2) homogeneous dispersion of the CNTs in the Al matrix and impurity (CNTs) scattering centers, continue to limit progress in Al-CNT composites. Several conventional methods including powder metallurgy, melting and solidification, thermal spray and electrochemical deposition have been used to process Al and CNT to form composites. We present preliminary results that address these challenges and demonstrate the fabrication of easily drawable Al-CNT composites into wires of diameter <= 1.0mm with ~ 18% +/- 2% reduction in the electrical resistivity of Al-CNT composite using CNT-hybrid as reinforcement and an inductive melting technique that takes advantage of the induced eddy current in the melt to provide in-situ stirring. This Work is Supported by Penn State Altoona Undergraduate Research Sponsored Program and Penn State Materials Research Institute, University Park.

  17. Enhanced electrochemical performance of carbon quantum dots-polyaniline hybrid

    Science.gov (United States)

    Zhao, Zhichao; Xie, Yibing

    2017-01-01

    Carbon quantum dots-polyaniline (CQDs-PANI) hybrid was developed as supercapacitor electorde material by incorporating CQDs into PANI. PANI nanowires were grown vertically on carbon fiber substrate to form an interconnected network structure. Meanwhile, CQDs were uniformly distributed in the interior and on the surface of well-established net-like PANI nanowires. High specific capacitance of 738.3 F g-1 at 1.0 A g-1 was obtained for CQDs-PANI compared to that of 432.5 F g-1 for pure PANI. The capacitance retention after 1000 cycles of CQDs-PANI and PANI is 78.0% and 68.0% at 5.0 A g-1, respectively. The high capacitance and reasonable cycle stability were ascribed to the incorporation of CQDs into PANI, which improved the conductivity and alleviated the volume change of the CQDs-PANI electrode during the charge/discharge process. In addition, a flexible solid-state CQDs-PANI supercapacitor was constructed using carbon paper as current collector and polyvinyl alcohol gel electrolyte, exhibiting the stable capacitive performance at planar and bending state. The specific capacitance, energy and power density were determined to be 169.2 mF cm-2, 33.8 μWh cm-2 and 0.3 mW cm-2 at a potential window of 1.2 V and a current density of 1.0 mA cm-2. CQDs-PANI presented the promising application in flexible energy-related device.

  18. High-energy X-ray powder diffraction and atomic-pair distribution-function studies of charged/discharged structures in carbon-hybridized Li2MnSiO4 nanoparticles as a cathode material for lithiumion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Moriya, Maki; Miyahara, Masahiko; Hokazono, Mana; Sasaki, Hirokazu; Nemoto, Atsushi; Katayama, Shingo; Akimoto, Yuji; Hirano, Shin-ichi; Ren, Yang

    2014-10-01

    The stable cycling performance with a high discharge capacity of similar to 190 mAh g(-1) in a carbon-hybridized Li2MnSiO4 nanostructured powder has prompted an experimental investigation of the charged/discharged structures using synchrotron-based and laboratory-based X-rays and atomic-pair distributionfunction (PDF) analyses. A novel method of in-situ spray pyrolysis of a precursor solution with glucose as a carbon source enabled the successful synthesis of the carbon-hybridized Li2(M)nSiO(4) nanoparticles. The XRD patters of the discharged (lithiated) samples exhibit a long-range ordered structure characteristic of the (beta) Li2MnSiO4 crystalline phase (space group Pmn2(1)) which dissipates in the charged (delithiated) samples. However, upon discharging the long-range ordered structure recovers in each cycle. The disordered structure, according to the PDF analysis, is mainly due to local distortions of the MnO4 tetrahedra which show a mean Mn-O nearest neighbor distance shorter than that of the long-range ordered phase. These results corroborate the notion of the smaller Mn3+/Mn4+ ionic radii in the Li extracted phase versus the larger Mn2+ ionic radius in Li inserted phase. Thus Li extraction/insertion drives the fluctuation between the disordered and the long-range ordered structures. (C) 2014 Elsevier B.V. All rights reserved.

  19. Super-hybrid composites - An emerging structural material

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1975-01-01

    Specimens of super-hybrids and advanced fiber composites were subjected to extensive tests to determine their mechanical properties, including impact and thermal fatigue. The super-hybrids were fabricated by a procedure similar to that reported by Chamis et al., (1975). Super-hybrids subjected to 1000 cycles of thermal fatigue from -100 to 300 F retained over 90% of their longitudinal flexural strength and over 75% of their transverse flexural strength; their transverse flexural strength may be as high as 8 times that of a commercially supplied boron/1100-Al composite. The thin specimen Izod longitudinal impact resistance of the super-hybrids was twice that of the boron/110-Al material. Super-hybrids subjected to transverse tensile loads exhibited nonlinear stress-strain relationships. The experimentally determined initial membrane (in-plane) and bending elastic properties of super-hybrids were predicted adequately by linear laminate analysis.

  20. Optical Waveguides from Organic/Inorganic Hybrid Materials

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Organic/inorganic material has attracted great attentions because its importance as photonic materials. We report on our recent results on organic/inorganic hybrid sol-gel materials and optical waveguides like splitter, thermo-optic switch and micro-cavity laser.

  1. Optical Waveguides from Organic/Inorganic Hybrid Materials

    Institute of Scientific and Technical Information of China (English)

    Liying Liu; Lei Xu; Wencheng Wang

    2003-01-01

    Organic/inorganic material has attracted great attentions because its importance as photonic materials. We report on our recent results on organic/inorganic hybrid sol-gel materials and optical waveguides like splitter,thermo-optic switch and micro-cavity laser.

  2. Hybrid S2/Carbon Epoxy Composite Armours Under Blast Loads

    Science.gov (United States)

    Dolce, F.; Meo, Michele; Wright, A.; French, M.; Bernabei, M.

    2012-06-01

    Civil and military structures, such as helicopters, aircrafts, naval ships, tanks or buildings are susceptible to blast loads as terroristic attacks increases, therefore there is the need to design blast resistant structures. During an explosion the peak pressure produced by shock wave is much greater than the static collapse pressure. Metallic structures usually undergo large plastic deformations absorbing blast energy before reaching equilibrium. Due to their high specific properties, fibre-reinforced polymers are being considered for energy absorption applications in blast resistant armours. A deep insight into the relationship between explosion loads, composite architecture and deformation/fracture behaviour will offer the possibility to design structures with significantly enhanced energy absorption and blast resistance performance. This study presents the results of a numerical investigation aimed at understanding the performance of a hybrid composite (glass/carbon fibre) plate subjected to blast loads using commercial LS-DYNA software. In particular, the paper deals with numerical 3D simulations of damages caused by air blast waves generated by C4 charges on two fully clamped rectangular plates made of steel and hybrid (S2/Carbon) composite, respectively. A Multi Materials Arbitrary Lagrangian Eulerian (MMALE) formulation was used to simulate the shock phenomenon. For the steel plates, the Johnson-Cook material model was employed. For the composite plates both in-plane and out-of-plane failure criteria were employed. In particular, a contact tiebreak formulation with a mixed mode failure criteria was employed to simulate delamination failure. As for the steel plates the results showed that excellent correlation with the experimental data for the two blast load conditions in terms of dynamic and residual deflection for two different C4 charges. For the composite plates the numerical results showed that, as expected, a wider delamination damage was observed

  3. Tailored single-walled carbon nanotube--CdS nanoparticle hybrids for tunable optoelectronic devices.

    Science.gov (United States)

    Li, Xianglong; Jia, Yi; Cao, Anyuan

    2010-01-26

    The integration of organic and inorganic building blocks into novel nanohybrids is an important tool to exploit innovative materials with desirable functionalities. For this purpose, carbon nanotube--nanoparticle nanoarchitectures are intensively studied. We report here an efficient noncovalent chemical route to density-controllably and uniformly assemble single-walled carbon nanotubes with CdS nanoparticles. The methodology not only promises the resulting hybrids will be solution-processable but also endows the hybrids with distinct optoelectronic properties including tunable photoresponse mediated by amine molecules. On the basis of these merits, reliable thin-film photoswitches and light-driven chemical sensors are demonstrated, which highlights the potential of tailored hybrids in the development of new tunable optoelectronic devices and sensors.

  4. Thermochemical Storage of Middle Temperature Wasted Heat by Functionalized C/Mg(OH2 Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Emanuela Mastronardo

    2017-01-01

    Full Text Available For the thermochemical performance implementation of Mg(OH2 as a heat storage medium, several hybrid materials have been investigated. For this study, high-performance hybrid materials have been developed by exploiting the authors’ previous findings. Expanded graphite (EG/carbon nanotubes (CNTs-Mg(OH2 hybrid materials have been prepared through Mg(OH2 deposition-precipitation over functionalized, i.e., oxidized, or un-functionalized EG or CNTs. The heat storage performances of the carbon-based hybrid materials have been investigated through a laboratory-scale experimental simulation of the heat storage/release cycles, carried out by a thermogravimetric apparatus. This study offers a critical evaluation of the thermochemical performances of developed materials through their comparison in terms of heat storage and output capacities per mass and volume unit. It was demonstrated that both EG and CNTs improves the thermochemical performances of the storage medium in terms of reaction rate and conversion with respect to pure Mg(OH2. With functionalized EG/CNTs-Mg(OH2, (i the potential heat storage and output capacities per mass unit of Mg(OH2 have been completely exploited; and (ii higher heat storage and output capacities per volume unit were obtained. That means, for technological applications, as smaller volume at equal stored/released heat.

  5. High value carbon materials from PET recycling

    Science.gov (United States)

    Parra, J. B.; Ania, C. O.; Arenillas, A.; Rubiera, F.; Pis, J. J.

    2004-11-01

    Poly(ethylene) terephthalate (PET), has become one of the major post-consumer plastic waste. In this work special attention was paid to minimising PET residues and to obtain a high value carbon material. Pyrolysis and subsequent activation of PET from post-consumer soft-drink bottles was performed. Activation was carried out at 925 °C under CO2 atmosphere to different burn-off degrees. Textural characterisation of the samples was carried out by performing N2 adsorption isotherms at -196 °C. The obtained carbons materials were mainly microporous, presenting low meso and macroporosity, and apparent BET surface areas of upto 2500 m2 g-1. The capacity of these materials for phenol adsorption and PAHs removal from aqueous solutions was measured and compared with that attained with commercial active carbons. Preliminary tests also showed high hydrogen uptake values, as good as the results obtained with high-tech carbon materials.

  6. Yeast-based microporous carbon materials for carbon dioxide capture.

    Science.gov (United States)

    Shen, Wenzhong; He, Yue; Zhang, Shouchun; Li, Junfen; Fan, Weibin

    2012-07-01

    A hierarchical microporous carbon material with a Brunauer-Emmett-Teller surface area of 1348 m(2) g(-1) and a pore volume of 0.67 cm(3) g(-1) was prepared from yeast through chemical activation with potassium hydroxide. This type of material contains large numbers of nitrogen-containing groups (nitrogen content >5.3 wt%), and, consequently, basic sites. As a result, this material shows a faster adsorption rate and a higher adsorption capacity of CO(2) than the material obtained by directly carbonizing yeast under the same conditions. The difference is more pronounced in the presence of N(2) or H(2)O, showing that chemical activation of discarded yeast with potassium hydroxide could afford high-performance microporous carbon materials for the capture of CO(2).

  7. Mode I fracture toughness of carbon-glass/epoxy interply hybrid composites

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Ha Na; Kim, Yon Jig [Chonbuk National University, Jeonju (Korea, Republic of)

    2015-05-15

    In this study, the fracture toughness of carbon-glass fiber reinforced epoxy interply hybrid composite was investigated. In this experiment, the interply hybrid composites were manufactured using a vacuum-assisted resin transfer molding (VARTM) process. The fracture toughness of the interply hybrid composites was decreased with increasing the number of glass fabrics. The decrease in fracture toughness with an increase in the glass fiber content can be expressed in the form of a linear equation. Test results showed that the arrangement of fiber significantly influences the fracture toughness of the composite material. Glass fiber was effective against improving the fracture toughness of the hybrid composite when the glass fibers are dispersed by multi layers rather than a single layer.

  8. CO2 capture in different carbon materials.

    Science.gov (United States)

    Jiménez, Vicente; Ramírez-Lucas, Ana; Díaz, José Antonio; Sánchez, Paula; Romero, Amaya

    2012-07-03

    In this work, the CO(2) capture capacity of different types of carbon nanofibers (platelet, fishbone, and ribbon) and amorphous carbon have been measured at 26 °C as at different pressures. The results showed that the more graphitic carbon materials adsorbed less CO(2) than more amorphous materials. Then, the aim was to improve the CO(2) adsorption capacity of the carbon materials by increasing the porosity during the chemical activation process. After chemical activation process, the amorphous carbon and platelet CNFs increased the CO(2) adsorption capacity 1.6 times, whereas fishbone and ribbon CNFs increased their CO(2) adsorption capacity 1.1 and 8.2 times, respectively. This increase of CO(2) adsorption capacity after chemical activation was due to an increase of BET surface area and pore volume in all carbon materials. Finally, the CO(2) adsorption isotherms showed that activated amorphous carbon exhibited the best CO(2) capture capacity with 72.0 wt % of CO(2) at 26 °C and 8 bar.

  9. On the isolation of elemental carbon (EC for micro-molar 14C accelerator mass spectrometry: development of a hybrid reference material for 14C-EC accuracy assurance, and a critical evaluation of the thermal optical kinetic (TOK EC isolation procedure

    Directory of Open Access Journals (Sweden)

    L. A. Currie

    2005-01-01

    Full Text Available The primary objective of the research reported here has been the development of a hybrid reference material (RM to serve as a test of accuracy for elemental carbon (EC isotopic (14C speciation measurements. Such measurements are vital for the quantitative apportionment of fossil and biomass sources of 'soot' (EC, the tracer of fire that has profound effects on health, atmospheric visibility, and climate. Previous studies of 14C-EC measurement quality, carried out with NIST SRM 1649a (Urban Dust, showed a range of results, but since the 'truth' was not known for this natural matrix RM, one had to rely on isotopic-chemical consistency evidence (14C in PAH, EC of measurement validity (Currie et al., 2002. Components of the new Hybrid RM (DiesApple, however, have known 14C and EC composition, and they are nearly orthogonal (isotopically and chemically. NIST SRM 2975 (Forklift Diesel Soot has little or no 14C, and its major compositional component is EC; SRM 1515 (Apple Leaves has the 14C content of biomass-C, and it has little or no EC. Thus, the Hybrid RM can serve as an absolute isotopic test for the absence of EC-mimicking pyrolysis-C (char from SRM 1515 in the EC isolate of the Hybrid RM, as well as a test for conservation of its dominant soot fraction throughout the isolation procedure. The secondary objective was to employ the Hybrid RM for the comparative evaluation of the thermal optical kinetic (TOK and thermal optical transmission (TOT methods for the isolation of EC for micro-molar carbon accelerator mass spectrometry (AMS. As part of this process, the relatively new TOK method was subjected to a critical evaluation and significant development. Key findings of our study are: (1 both methods exhibited biomass-C 'leakage'; for TOT, the EC fraction isolated for AMS contained about 8% of the original biomass-C; for TOK, the refractory carbon (RC isolated contained about 3% of the original biomass-C.; (2 the initial isothermal oxidation stage

  10. Advanced materials from natural materials: synthesis of aligned carbon nanotubes on wollastonites.

    Science.gov (United States)

    Zhao, Meng-Qiang; Zhang, Qiang; Huang, Jia-Qi; Nie, Jing-Qi; Wei, Fei

    2010-04-26

    The growth of carbon nanotubes (CNTs) on natural materials is a low-cost, environmentally benign, and materials-saving method for the large-scale production of CNTs. Directly building 3D CNT architectures on natural materials is a key issue for obtaining advanced materials with high added value. We report the fabrication of aligned CNT arrays on fibrous natural wollastonite. Strongly dispersed iron particles with small sizes were produced on a planar surface of soaked fibrous wollastonite by a reduction process. These particles then catalyzed the decomposition of ethylene, leading to the synchronous growth of CNTs to form leaf- and brush-like wollastonite/CNT hybrids. The as-obtained hybrids could be further transformed into porous SiO(2)/CNT hybrids by reaction with hydrochloric acid. Further treatment with hydrofluoric acid resulted in aligned CNT arrays, with purities as high as 98.7 %. The presented work is very promising for the fabrication of advanced materials with unique structures and properties that can be used as fillers, catalyst supports, or energy-absorbing materials.

  11. DNA meets synthetic polymers—highly versatile hybrid materials

    NARCIS (Netherlands)

    Alemdaroglu, Fikri E.; Herrmann, Andreas

    2007-01-01

    The combination of synthetic polymers and DNA has provided biologists, chemists and materials scientists with a fascinating new hybrid material. The challenges in preparing these molecular chimeras were overcome by different synthetic strategies that rely on coupling the nucleic acid moiety and the

  12. 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.

  13. Hybrid Electrodes of Carbon Nanotube and Reduced Graphene Oxide for Energy Storage Applications.

    Science.gov (United States)

    Choi, Eunmi; Chae, Su Jin; Kim, Areum; Kang, Keun Won; Oh, Min Seok; Kwon, Soon Hyeong; Yoon, Sung Pil; Pyo, Sung Gyu

    2015-11-01

    The choice of electrode materials in lithium ion batteries and supercapacitors is important for the stability, capacity, and cycle life of the device. Despite its low capacity, graphite has often been used as an electrode material due to its inherent stability. Due to an increasing demand for large-capacity energy storage systems, there is also a demand for the development of large-capacity Li ion batteries and supercapacitors. Therefore, carbonaceous materials like graphene and carbon nanotubes (CNTs), which have high stability as well as excellent electrical conductivity and mechanical strength, are receiving attention as new electrode materials. Recently, starting from simply applying graphene and CNTs as electrode materials and progressing to the development of hybrid materials, there have been increasing research efforts in enhancing the performance of Li ion batteries and supercapacitors through the use of carbonaceous materials. This paper will discuss new composite materials and electrode structures that use graphene and CNTs for applications in Li ion batteries and supercapacitors.

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

    African Journals Online (AJOL)

    NICO

    1Key Laboratory of Eco-Environment-Related Polymer Materials, Ministry of ... nitrogen-doped graphitic layer coated palygoriskite, was devel- ... The thin-film ..... 16 B. Seger, A. Kongkanand, K. Vinodgopal and P.V. Kamat, J. Electroanal.

  15. Hybrid And Smart Topologically Interlocking Materials

    OpenAIRE

    Khandelwal, Somesh

    2013-01-01

    This thesis explores the mechanical properties of a new class of multifunctional architectured materials, Topologically Interlocking Materials (TIMs). These materials are created as an assembly of unit elements arranged in an interlocking pattern such that the load transfer between unit elements occurs by contact only. In the absence of adhesive interaction, the tensile component of the load is carried by complementary tensile elements in the form of external constraints or integrated filamen...

  16. ZP maize hybrids as silage raw material

    Directory of Open Access Journals (Sweden)

    Terzić Dušanka

    2012-01-01

    Full Text Available Due to its yields, biomass quality and biomass suitability for ensiling, diversity of use in feedstuff, maize is one of the most important forage plants. In comparison with other forage plants, the production of silage maize results in the greatest accumulation of solar energy per area unit. The positive correlation between a high density of net energy and the concentration of net energy as well as between digestibility of organic matter and the concentration of net energy is achieved in the produced biomass of maize plant. The yield of silage maize in dependence on the genetic potential of yield and agroecological conditions of the production ranges from 12 to 25 tonnes of the total dry matter per hectare at physiological maturity for ensiling with the dry matter content of 35-42%. This study presents results obtained in the long-term scientific and research programme on the improvement of ZP maize hybrids utilisation carried out in the Department of Technological Research at the Maize Research Institute Zemun Polje. The overall presentation of biomass quality parameters of six ZP maize hybrids (ZP 158, ZP 173/8, ZP 377, ZP 440, ZP 555 and ZP 679 of different genetic backgrounds intended for silage production is given in this study. Besides, interrelationships among these factors as well as their effects on maize biomass digestibility were established.

  17. Hybrid materials science: a promised land for the integrative design of multifunctional materials.

    Science.gov (United States)

    Nicole, Lionel; Laberty-Robert, Christel; Rozes, Laurence; Sanchez, Clément

    2014-06-21

    For more than 5000 years, organic-inorganic composite materials created by men via skill and serendipity have been part of human culture and customs. The concept of "hybrid organic-inorganic" nanocomposites exploded in the second half of the 20th century with the expansion of the so-called "chimie douce" which led to many collaborations between a large set of chemists, physicists and biologists. Consequently, the scientific melting pot of these very different scientific communities created a new pluridisciplinary school of thought. Today, the tremendous effort of basic research performed in the last twenty years allows tailor-made multifunctional hybrid materials with perfect control over composition, structure and shape. Some of these hybrid materials have already entered the industrial market. Many tailor-made multiscale hybrids are increasingly impacting numerous fields of applications: optics, catalysis, energy, environment, nanomedicine, etc. In the present feature article, we emphasize several fundamental and applied aspects of the hybrid materials field: bioreplication, mesostructured thin films, Lego-like chemistry designed hybrid nanocomposites, and advanced hybrid materials for energy. Finally, a few commercial applications of hybrid materials will be presented.

  18. Hybrid materials science: a promised land for the integrative design of multifunctional materials

    Science.gov (United States)

    Nicole, Lionel; Laberty-Robert, Christel; Rozes, Laurence; Sanchez, Clément

    2014-05-01

    For more than 5000 years, organic-inorganic composite materials created by men via skill and serendipity have been part of human culture and customs. The concept of ``hybrid organic-inorganic'' nanocomposites exploded in the second half of the 20th century with the expansion of the so-called ``chimie douce'' which led to many collaborations between a large set of chemists, physicists and biologists. Consequently, the scientific melting pot of these very different scientific communities created a new pluridisciplinary school of thought. Today, the tremendous effort of basic research performed in the last twenty years allows tailor-made multifunctional hybrid materials with perfect control over composition, structure and shape. Some of these hybrid materials have already entered the industrial market. Many tailor-made multiscale hybrids are increasingly impacting numerous fields of applications: optics, catalysis, energy, environment, nanomedicine, etc. In the present feature article, we emphasize several fundamental and applied aspects of the hybrid materials field: bioreplication, mesostructured thin films, Lego-like chemistry designed hybrid nanocomposites, and advanced hybrid materials for energy. Finally, a few commercial applications of hybrid materials will be presented.

  19. A Review of the Synthesis and Photoluminescence Properties of Hybrid ZnO and Carbon Nanomaterials

    Directory of Open Access Journals (Sweden)

    Protima Rauwel

    2016-01-01

    Full Text Available Photoluminescent ZnO carbon nanomaterials are an emerging class of nanomaterials with unique optical properties. They each, ZnO and carbon nanomaterials, have an advantage of being nontoxic and environmentally friendly. Their cost-effective production methods along with simple synthesis routes are also of interest. Moreover, ZnO presents photoluminescence emission in the UV and visible region depending on the synthesis routes, shape, size, deep level, and surface defects. When combined with carbon nanomaterials, modification of surface defects in ZnO allows tuning of these photoluminescence properties to produce, for example, white light. Moreover, efficient energy transfer from the ZnO to carbon nanostructures makes them suitable candidates not only in energy harvesting applications but also in biosensors, photodetectors, and low temperature thermal imaging. This work reviews the synthesis and photoluminescence properties of 3 carbon allotropes: carbon quantum or nanodots, graphene, and carbon nanotubes when hybridized with ZnO nanostructures. Various synthesis routes for the hybrid materials with different morphologies of ZnO are presented. Moreover, differences in photoluminescence emission when combining ZnO with each of the three different allotropes are analysed.

  20. Heteronanostructured Co@carbon nanotubes-graphene ternary hybrids: synthesis, electromagnetic and excellent microwave absorption properties

    Science.gov (United States)

    Qi, Xiaosi; Hu, Qi; Cai, Hongbo; Xie, Ren; Bai, Zhongchen; Jiang, Yang; Qin, Shuijie; Zhong, Wei; Du, Youwei

    2016-11-01

    In order to explore high efficiency microwave absorption materials, heteronanostructured Co@carbon nanotubes-graphene (Co@CNTs-G) ternary hybrids were designed and produced through catalytic decomposition of acetylene at the designed temperature (400, 450, 500 and 550 °C) over Co3O4/reduced graphene oxide (Co3O4/RGO). By regulating the reaction temperatures, different CNT contents of Co@CNTs-G ternary hybrids could be synthesized. The investigations indicated that the as-prepared heteronanostructured Co@CNTs-G ternary hybrids exhibited excellent microwave absorption properties, and their electromagnetic and microwave absorption properties could be tuned by the CNT content. The minimum reflection loss (RL) value reached approximately ‑65.6, ‑58.1, ‑41.1 and ‑47.5 dB for the ternary hybrids synthesized at 400, 450, 500 and 550 °C, respectively. And RL values below ‑20 dB (99% of electromagnetic wave attenuation) could be obtained over the as-prepared Co@CNTs-G ternary hybrids in the large frequency range. Moreover, based on the obtained results, the possible enhanced microwave absorption mechanisms were discussed in details. Therefore, a simple approach was proposed to explore the high performance microwave absorbing materials as well as to expand the application field of graphene-based materials.

  1. Novel hybrid materials based on the vanadium oxide nanobelts

    Science.gov (United States)

    Zabrodina, G. S.; Makarov, S. G.; Kremlev, K. V.; Yunin, P. A.; Gusev, S. A.; Kaverin, B. S.; Kaverina, L. B.; Ketkov, S. Yu.

    2016-04-01

    Novel hybrid materials based on zinc phthalocyanine and nanostructured vanadium oxides have attracted extensive attention for the development of academic research and innovative industrial applications such as flexible electronics, optical sensors and heterogeneous catalysts. Vanadium oxides nanobelts were synthesized via a hydrothermal treatment V2O5·nH2O gel with surfactants (TBAB, CTAB) used as structure-directing agents, where CTAB - cetyltrimethylammonium bromide, TBAB - tetrabutylammonium bromide. Hybrid materials were prepared decoration of (CTA)0.33V2O5 flexible nanobelts with cationic zinc phthalocyanine by the ion-exchange route. Investigations of the thermal stability, morphologies and structures of the (CTA)0.33V2O5, (TBA)0.16V2O5 nanobelts and zinc phthalocyanine exchange product were carried out. The hybrid materials based on the nanostructured vanadium oxide and zinc phthalocyanine were tested as photocatalysts for oxidation of citronellol and 2-mercaptoethanol by dioxygen.

  2. Conjugated Polymers/DNA Hybrid Materials for Protein Inactivation.

    Science.gov (United States)

    Zhao, Likun; Zhang, Jiangyan; Xu, Huiming; Geng, Hao; Cheng, Yongqiang

    2016-09-01

    Chromophore-assisted light inactivation (CALI) is a powerful tool for analyzing protein functions due to the high degree of spatial and temporal resolution. In this work, we demonstrate a CALI approach based on conjugated polymers (CPs)/DNA hybrid material for protein inactivation. The target protein is conjugated with single-stranded DNA in advance. Single-stranded DNA can form CPs/DNA hybrid material with cationic CPs via electrostatic and hydrophobic interactions. Through the formation of CPs/DNA hybrid material, the target protein that is conjugated with DNA is brought into close proximity to CPs. Under irradiation, CPs harvest light and generate reactive oxygen species (ROS), resulting in the inactivation of the adjacent target protein. This approach can efficiently inactivate any target protein which is conjugated with DNA and has good specificity and universality, providing a new strategy for studies of protein function and adjustment of protein activity.

  3. Hybrid Porous Materials for Controlled Release and Catalysis

    OpenAIRE

    Liu, Rui

    2010-01-01

    First reported in 1992, ordered mesoporous materials exhibit unique features, such as regular pore geometry, high surface area, and large pore volume, and have shown great potential in various applications. This dissertation combines the knowledge from the field of ordered mesoporous materials and several other research areas to design advanced hybrid porous materials for controlled release and catalysis applications.The demand for better treatment of illness has led to ever-increasing effort...

  4. Hybrid Porous Materials for Controlled Release and Catalysis

    OpenAIRE

    Liu, Rui

    2010-01-01

    First reported in 1992, ordered mesoporous materials exhibit unique features, such as regular pore geometry, high surface area, and large pore volume, and have shown great potential in various applications. This dissertation combines the knowledge from the field of ordered mesoporous materials and several other research areas to design advanced hybrid porous materials for controlled release and catalysis applications.The demand for better treatment of illness has led to ever-increasing effort...

  5. Hybrid carbon nanostructure assemblage for high performance pseudo-capacitors

    Directory of Open Access Journals (Sweden)

    A. K. Mishra

    2012-06-01

    Full Text Available Investigation of novel nanocomposites for pseudo-capacitors with high capacitance and energy density is the spotlight of current energy research. In the present work, hybrid carbon nanostructure assemblage of graphene and multiwalled carbon nanotubes has been used as carbon support to nanostructured RuO2 and polyaniline for high energy supercapacitors. Maximum specific capacitances of 110, 235 and 440 F g−1 at the voltage sweep rate of 10 mV s−1 and maximum energy densities of 7, 12.5 and 20.5 Wh kg−1 were observed for carbon assemblage and its RuO2 and polyanilne decorated nanocomposites, respectively, with 1M H2SO4 as electrolyte.

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

    Directory of Open Access Journals (Sweden)

    Fawad Inam

    2010-01-01

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

  7. Simple method for mass production of polypyrrole/carbon nanotubes hybrid artificial muscle

    Directory of Open Access Journals (Sweden)

    Marcelo R. dos Santos

    2014-07-01

    Full Text Available Large scale preparation of hybrid electrical actuators represents an important step for the production of low cost devices. Interfacial polymerization of polypyrrole in the presence of multi-walled carbon nanotubes represents a simple technique in which strong interaction between components is established, providing composite materials with potential applications as actuators due to the synergistic interaction between the individual components, i.e., fast response of carbon nanotubes, high strain of polypyrrole, and diversity in the available geometry of resulting samples.

  8. The Cycle Performance of a Hybrid Carbon Battery.

    Science.gov (United States)

    Ahn, Sang-Yong; Kim, Sang-Chai; Jung, Ho-Young

    2016-02-01

    The behavior of a hybrid carbon battery is studied by using the Hg/Hg2SO4 reference electrode. The performance is confirmed in the discharge mode and a short-term cycle test. The capacities of the cell were 76.1, 60.3, 40.5, and 31.7 mAh at discharge currents of 150, 300, 600, and 900 mA, respectively. In the short-term cycle test, the capacity of the cell, 52.3 mAh at the first cycle, continuously increased to 66.7 mAh upon the fifth cycle (cut-off voltage 0.5 V in the deep cycle mode), indicating high feasibility of the hybrid carbon battery as a large-capacity energy storage system.

  9. Synthesis, characterization and application of functional carbon nano materials

    Science.gov (United States)

    Chu, Jin

    The synthesis, characterizations and applications of carbon nanomaterials, including carbon nanorods, carbon nanosheets, carbon nanohoneycombs and carbon nanotubes were demonstrated. Different growth techniques such as pulsed laser deposition, DC/RF sputtering, hot filament physical vapour deposition, evaporative casting and vacuum filtration methods were introduced or applied for synthesizing carbon nanomaterials. The morphology, chemical compositions, bond structures, electronic, mechanical and sensing properties of the obtained samples were investigated. Tilted well-aligned carbon micro- and nano- hybrid rods were fabricated on Si at different substrate temperatures and incident angles of carbon source beam using the hot filament physical vapour deposition technique. The morphologic surfaces and bond structures of the oblique carbon rod-like structures were investigated by scanning electron microscopy, field emission scanning electron microscopy, transmission electron diffraction and Raman scattering spectroscopy. The field emission behaviour of the fabricated samples was also tested. Carbon nanosheets and nanohoneycombs were also synthesized on Si substrates using a hot filament physical vapor deposition technique under methane ambient and vacuum, respectively. The four-point Au electrodes are then sputtered on the surface of the nanostructured carbon films to form prototypical humidity sensors. The sensing properties of prototypical sensors at different temperature, humidity, direct current, and alternative current voltage were characterized. Linear sensing response of sensors to relative humidity ranging from 11% to 95% is observed at room temperature. Experimental data indicate that the carbon nanosheets based sensors exhibit an excellent reversible behavior and long-term stability. It also has higher response than that of the humidity sensor with carbon nanohoneycombs materials. Conducting composite films containing carbon nanotubes (CNTs) were prepared in

  10. Performance of PbO2/activated carbon hybrid supercapacitor with carbon foam substrate

    Institute of Scientific and Technical Information of China (English)

    Wu Zhang; Yao Hui Qu; Li Jun Gao

    2012-01-01

    PbO2/activated carbon (AC) hybrid supercapacitor in H2SO4 with a carbon foam current collector is studied.The PbO2/AC hybrid is designed with electrodeposited PbO2 thin film as positive electrode to match with AC negative electrode.The discharge curve shows capacitive characteristics between 1.88 V and 0.65 V.The hybrid system exhibits excellent energy and powe performance,with specific energy of 43.6 Wh/kg at a power density of 654.2 W/kg.The use of carbon foam current collecto ensures stability of the PbO2 electrode in H2SO4 environment.After 2600 deep cycles at 15 C high rate of charge/discharge,the capacity remains nearly unchanged from its initial value.

  11. ARTIFICIAL NEURAL NETWORKS BASED GEARS MATERIAL SELECTION HYBRID INTELLIGENT SYSTEM

    Institute of Scientific and Technical Information of China (English)

    X.C. Li; W.X. Zhu; G. Chen; D.S. Mei; J. Zhang; K.M. Chen

    2003-01-01

    An artificial neural networks(ANNs) based gear material selection hybrid intelligent system is established by analyzing the individual advantages and weakness of expert system (ES) and ANNs and the applications in material select of them. The system mainly consists of tow parts: ES and ANNs. By being trained with much data samples,the back propagation (BP) ANN gets the knowledge of gear materials selection, and is able to inference according to user input. The system realizes the complementing of ANNs and ES. Using this system, engineers without materials selection experience can conveniently deal with gear materials selection.

  12. From spent Mg/Al layered double hydroxide to porous carbon materials.

    Science.gov (United States)

    Laipan, Minwang; Zhu, Runliang; Chen, Qingze; Zhu, Jianxi; Xi, Yunfei; Ayoko, Godwin A; He, Hongping

    2015-12-30

    Adsorption has been considered as an efficient method for the treatment of dye effluents, but proper disposal of the spent adsorbents is still a challenge. This work attempts to provide a facile method to reutilize the spent Mg/Al layered double hydroxide (Mg/Al-LDH) after the adsorption of orange II (OII). Herein, the spent hybrid was carbonized under the protection of nitrogen, and then washed with acid to obtain porous carbon materials. Thermogravimetric analysis results suggested that the carbonization could be well achieved above 600°C, as mass loss of the spent hybrid gradually stabilized. Therefore, the carbonization process was carried out at 600, 800, and 1000°C, respectively. Scanning electron microscope showed that the obtained carbon materials possessed a crooked flaky morphology. Nitrogen adsorption-desorption results showed that the carbon materials had large BET surface area and pore volume, e.g., 1426 m(2)/g and 1.67 cm(3)/g for the sample carbonized at 800°C. Moreover, the pore structure and surface chemistry compositions were tunable, as they were sensitive to the temperature. Toluene adsorption results demonstrated that the carbon materials had high efficiency in toluene removal. This work provided a facile approach for synthesizing porous carbon materials using spent Mg/Al-LDH.

  13. The synthesis of a copper/multi-walled carbon nanotube hybrid nanowire in a microfluidic reactor

    Science.gov (United States)

    Peng, Yitian; Chen, Quanfang

    2009-06-01

    Metallic nanowires are promising as components in nanoscale systems including nanoelectronics. However, the application of nanowires made of a single material is limited by the properties of the material used. We report here an effort to fabricate a hybrid copper-coated carbon nanotube (CNT)—Cu/CNT nanowire, using a microfluidic reactor. The fabrication of copper/multi-walled carbon nanotube (MWCNT) hybrid nanowires was realized by an electroless copper deposition technique in which MWCNT templates and an electrolyte were introduced separately into the microfluidic reactor. The morphology and structure of the Cu/MWCNT hybrid nanowire were studied by means of transmission electron microscopy (TEM), selected-area electron diffraction (SAED), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX), as well as XRD. Results reveal that the fabricated Cu/MWCNT hybrid nanowires are continuously covered by crystallized copper with a preferred crystal orientation along the (111) planes in the radial direction of the MWCNTs. These structural properties are attributed to the unique reaction environment including laminar flow and diffusion-controlled reaction.

  14. Carbon nanotube materials from hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Bekkedahl, T.A.; Cahill, A.F. [National Renewable Energy Laboratory, Golden, CO (United States)

    1995-09-01

    The lack of convenient and cost-effective hydrogen storage is a major impediment to wide scale use of hydrogen in the United States energy economy. Improvements in the energy densities of hydrogen storage systems, reductions in cost, and increased compatibility with available and forecasted systems are required before viable hydrogen energy use pathways can be established. Carbon-based hydrogen adsorption materials hold particular promise for meeting and exceeding the U.S. Department of Energy hydrogen storage energy density targets for transportation if concurrent increases in hydrogen storage capacity and carbon density can be achieved. These two goals are normally in conflict for conventional porous materials, but may be reconciled by the design and synthesis of new adsorbent materials with tailored pore size distributions and minimal macroporosity. Carbon nanotubes offer the possibility to explore new designs for adsorbents because they can be fabricated with small size distributions, and naturally tend to self-assemble by van der Waals forces. This year we report heats of adsorption for hydrogen on nanotube materials that are 2 and 3 times greater than for hydrogen on activated carbon. The hydrogen which is most strongly bound to these materials remains on the carbon surface to temperatures greater than 285 K. These results suggest that nanocapillary forces are active in stabilizing hydrogen on the surfaces of carbon nanotubes, and that optimization of the adsorbent will lead to effective storage at higher temperatures. In this paper we will also report on our activities which are targeted at understanding and optimizing the nucleation and growth of single wall nanotubes. These experiments were made possible by the development of a unique feedback control circuit which stabilized the plasma-arc during a synthesis run.

  15. Functional Carbon Materials for Electrochemical Energy Storage

    Science.gov (United States)

    Zhou, Huihui

    The ability to harvest and convert solar energy has been associated with the evolution of human civilization. The increasing consumption of fossil fuels since the industrial revolution, however, has brought to concerns in ecological deterioration and depletion of the fossil fuels. Facing these challenges, humankind is forced to seek for clean, sustainable and renewable energy resources, such as biofuels, hydraulic power, wind power, geothermal energy and other kinds of alternative energies. However, most alternative energy sources, generally in the form of electrical energy, could not be made available on a continuous basis. It is, therefore, essential to store such energy into chemical energy, which are portable and various applications. In this context, electrochemical energy-storage devices hold great promises towards this goal. The most common electrochemical energy-storage devices are electrochemical capacitors (ECs, also called supercapacitors) and batteries. In comparison to batteries, ECs posses high power density, high efficiency, long cycling life and low cost. ECs commonly utilize carbon as both (symmetric) or one of the electrodes (asymmetric), of which their performance is generally limited by the capacitance of the carbon electrodes. Therefore, developing better carbon materials with high energy density has been emerging as one the most essential challenges in the field. The primary objective of this dissertation is to design and synthesize functional carbon materials with high energy density at both aqueous and organic electrolyte systems. The energy density (E) of ECs are governed by E = CV 2/2, where C is the total capacitance and V is the voltage of the devices. Carbon electrodes with high capacitance and high working voltage should lead to high energy density. In the first part of this thesis, a new class of nanoporous carbons were synthesized for symmetric supercapacitors using aqueous Li2SO4 as the electrolyte. A unique precursor was adopted to

  16. Analysis of composition and microstructural uniformity of hybrid glass/carbon fibre composites

    DEFF Research Database (Denmark)

    Beauson, Justine; Markussen, Christen Malte; Madsen, Bo

    2013-01-01

    In hybrid fibre composites, the intermixing of the two types of fibres imposes challenges to obtain materials with a well-defined and uniform microstructure. In the present paper, the composition and the microstructural uniformity of hybrid glass/carbon fibre composites mixed at the fibre bundle...... fibre volume fractions are determined using volumetric calculations. A model is presented to predict the interrelation of volume fractions in hybrid fibre composites. The microstructural uniformity of the composites is analysed by the determined variation in composite volume fractions. Two analytical...... level are investigated. The different levels of compositions in the composites are defined and experimentally determined. The composite volume fractions are determined using an image analysis based procedure. The global fibre volume fractions are determined using a gravimetrical based method. The local...

  17. Strengthening in and fracture behaviour of CNT and carbon-fibrereinforced epoxy–matrix hybrid composite

    Indian Academy of Sciences (India)

    K CHANDRA SHEKAR; B ANJANEYA PRASAD; N ESWARA PRASAD

    2016-12-01

    Advanced materials such as continuous fibre-reinforced polymer matrix composites offer significant enhancements in strength and fracture resistance properties as compared with their bulk, monolithic counterparts. In the present work, mode-I (tensile) fracture behaviour of the neat epoxy (without nano- or hybrid reinforcements), nanocomposite (with amino-functionalized multi-walled carbon nanotube (MWCNT) reinforcement to neat epoxy) and hybrid composite (with amino MWCNT and carbon fibre reinforcements to neat epoxy) along with their flexural strength and interlaminar shear strength has been reported and discussed.Limited topological studies have also been conducted to understand the nature of material fracture and its dependence on the notch orientation. The results thus obtained are analysed and discussed in detail to elucidate:(i) alignment of fibre and its influence on the anisotropy in strength and fracture resistance, (ii) dependence of notch root radii on the apparent fracture toughness and concurrence to strain-controlled fracture and (iii) finally, the nature of J–R curves. The results thus obtained have revealed that the resistance to fracture is significantlyincreased with the addition of amino-functionalized MWCNTs and carbon fibres. In the hybrid composite, fracture resistance is greater in the longitudinal orientation of fibres than in the transverse orientation and it exhibits a significantly higher strength–fracture toughness combination.

  18. Tungsten disulfide-multiwalled carbon nanotube hybrid anode for lithium-ion battery.

    Science.gov (United States)

    Kartick, B; Srivastava, Suneel Kumar; Mahanty, Sourindra

    2014-05-01

    The present work is focused on the preparation of tungsten disulfide-multiwalled carbon nanotube (WS2-MWCNT) hybrids by simple dry grinding of WS2 and MWCNT in different proportion by weight (1:3, 1:1, 3:1). The as prepared hybrids have been characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high resolution transmission electron microscopy (HRTEM) and Raman analyses. XRD results indicated complete exfoliation of MWCNT among WS2 particles in WS2-MWCNT (3:1) and (1:1) hybrids. FESEM images showed the formation of a 3-D network in WS2-MWCNT (1:1) hybrid with uniform dispersion of MWCNT being evident from HRTEM images. Raman analysis also suggested significant interaction between WS2 and MWCNT. WS2-MWCNT (1:1) hybrid, when used as anode material in lithium ion battery, exhibited a high initial charge capacity (483 mA h g(-1)) and an improved cycling stability with over 80% retention of the first cycle capacity after 20 cycles compared to only 40% capacity retention in pristine WS2. Such enhanced electrochemical performance of WS2-MWCNT (1:1) hybrid has been attributed to synergistic effect of WS2 and MWCNT.

  19. Electron Field Emission from Nanostructured Carbon Materials

    Science.gov (United States)

    Gupta, Sanju

    2005-03-01

    Fabricating small structures has almost become fashionable and the rationale is that reducing one or more dimensions below some critical length changes the systems' physical properties drastically, where nanocrystalline diamond (n-D) and carbon nanotubes (CNTs) in the class of advanced carbon materials serve model examples. Emission of electrons at room temperature - cold electron emitters - are of vital importance for a variety of vacuum microelectronic devices - electron microscopes, photo multipliers, X-ray generators, lamps, and flat panel displays and microwave cathodes. Electron emitters may lead to otherwise difficult to obtain advantages in performance and/or design. This is the driving force to investigate the carbon-related materials as cold cathodes. In this talk, the performance of various forms of carbon in thin film form including diamond, n-D, and vertically aligned CNTs as cold cathodes for their potential use in field emission displays (FEDs) in terms of I-V characteristics and corresponding spatial imaging will be presented. Physics based models such as, NEA, surface modification, geometric enhancement, and microstructure alteration due to particle bombardment, and doping, will be described to support the experimental observations of electron field enhancement (low turn-on voltage, high current and emission site density) and its reliability from the abovementioned carbon-related materials. Other vacuum device applications such as thermionic power generators will be mentioned briefly.

  20. Hybrid/Tandem Laser-Arc Welding of Thick Low Carbon Martensitic Stainless Steel Plates =

    Science.gov (United States)

    Mirakhorli, Fatemeh

    High efficiency and long-term life of hydraulic turbines and their assemblies are of utmost importance for the hydropower industry. Usually, hydroelectric turbine components are made of thick-walled low carbon martensitic stainless steels. The assembly of large hydroelectric turbine components has been a great challenge. The use of conventional welding processes involves typical large groove design and multi-pass welding to fill the groove which exposes the weld to a high heat input creating relatively large fusion zone and heat affected zone. The newly-developed hybrid/tandem laser-arc welding technique is believed to offer a highly competitive solution to improve the overall hydro-turbine performance by combining the high energy density and fast welding speed of the laser welding technology with the good gap bridging and feeding ability of the gas metal arc welding process to increase the productivity and reduce the consumable material. The main objective of this research work is to understand different challenges appearing during hybrid laser-arc welding (HLAW) of thick gauge assemblies of low carbon 13%Cr- 4%Ni martensitic stainless steel and find a practical solution by adapting and optimizing this relatively new welding process in order to reduce the number of welding passes necessary to fill the groove gap. The joint integrity was evaluated in terms of microstructure, defects and mechanical properties in both as-welded and post-welded conditions. A special focus was given to the hybrid and tandem laser-arc welding technique for the root pass. Based on the thickness of the low carbon martensitic stainless steel plates, this work is mainly focused on the following two tasks: • Single pass hybrid laser-arc welding of 10-mm thick low carbon martensitic stainless steel. • Multi-pass hybrid/tandem laser-arc welding of 25-mm thick martensitic stainless steel.

  1. Hybrid Materials of Polymer Gels with Surfactants

    Institute of Scientific and Technical Information of China (English)

    Hu Yan; Kaoru Tsujii

    2005-01-01

    @@ 1 Introduction Polymer gels have been extensively studied[1~17] since the discovery of volume phase-transition of a gel by Tanaka[1~5]. As a unique soft material, gels attract much attention and are tried to be applied for drug-delivery systgems[6], actuators or chemo-mechanical devices[7~9] and so on. In particular, controlled-release of small molecules from a gel is now a subject of special interest[10].

  2. A Method for Determination of Metals in Hybrid Metal Oxide/Metal-Carbon Nanotubes Catalysts

    Directory of Open Access Journals (Sweden)

    Joanna Bok-Badura

    2017-01-01

    Full Text Available Carbon nanotubes (CNTs, due to their special structure and unique properties, are still one of the most interesting materials for scientists. Recently, carbon nanotubes were proposed as a new type of carbon support for catalysts. Fe, Pt, Ni, Co, and other metals anchored to CNTs are used in various reactions. Due to the fact that production processes are usually unpredictable and the total amount of metal/metal oxide deposited on the CNTs may only be estimated, the methods for examining the chemical composition are necessary. In this study, fast and simple inductively coupled plasma atomic emission spectrometry (ICP-AES with slurry nebulization was proposed for metal content determination in hybrid CeZrO2/CNT, Ni-CeZrO2/CNT, and Ni/CNT materials. Slurries were prepared by 30 min ultrasonication of appropriate amount of investigated material in 1% Triton X-100 solution. Optimal range of slurry concentration and optimal RF plasma power were established (40–400 mg L−1, 1.2 kW, resp.. Obtained results proved that this method may be applied for determination of Ce, Zr, and Ni in hybrid CNT-based materials.

  3. Brittle Destruction of Carbon Based Materials

    Science.gov (United States)

    Koza, Y.; Amouroux, S.; Bazylev, B. N.; Berthe, E.; Kuehnlein, W.; Linke, J.; Penkalla, H. J.; Singheiser, L.

    Erosion mechanisms for different carbon based materials (graphite, carbon fiber composites (CFCs), Si-doped CFC) have been studied under brittle destruction under intense transient thermal loads (ELMs, plasma disruptions, VDEs) with respect to material erosion in different particle emission regimes, characterization of emitted particles, and behavior of preheated samples. Furthermore, the experimental data were compared with 3-D numerical simulation on the onset of brittle destruction. From a morphological point of view, the resulting erosion patterns on the test samples and ejected particles differ significantly for the three materials. The isotropic graphite shows a homogeneous erosion profile with flat craters, while the CFC forms no crater and only preferential erosion in localized spots in the PAN fiber area while the pitch fiber strands remain almost undamaged. The particles originating from graphite samples which have been collected on TEM grids are composed of nano sized amorphous carbon. CFCs have been the source for sub Î 1/4 m sized agglomerated fragments of crystalline carbon or silicon particles with âe 1/4 50 nm diameter. Preheating of the test samples to 500 or 800°C results in a remarkable increase of the erosion depth and weight loss compared to the samples loaded at room temperature and identical heat fluxes. In particular, melting phenomena in the Si-doped CFC materials became essential at elevated temperatures.

  4. Novel hybrid materials based on the vanadium oxide nanobelts

    Energy Technology Data Exchange (ETDEWEB)

    Zabrodina, G.S., E-mail: kudgs@mail.ru [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Makarov, S.G.; Kremlev, K.V. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation); Yunin, P.A.; Gusev, S.A. [Institute for Physics of Microstructures Russian Academy of Sciences, Nizhny Novgorod 603087 (Russian Federation); Kaverin, B.S.; Kaverina, L.B. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Ketkov, S.Yu. [G.A. Razuvaev Institute of Organometallic Chemistry of Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); Lobachevsky State University, Nizhny Novgorod 603950 (Russian Federation)

    2016-04-15

    Graphical abstract: - Highlights: • Flat and curved vanadium oxide nanobelts have been synthesized. • Hybrid material was prepared via decoration of flexible nanobelts with zinc phthalocyanine. • Investigations of the thermal stability, morphologies and structures were carried out. - Abstract: Novel hybrid materials based on zinc phthalocyanine and nanostructured vanadium oxides have attracted extensive attention for the development of academic research and innovative industrial applications such as flexible electronics, optical sensors and heterogeneous catalysts. Vanadium oxides nanobelts were synthesized via a hydrothermal treatment V{sub 2}O{sub 5}·nH{sub 2}O gel with surfactants (TBAB, CTAB) used as structure-directing agents, where CTAB – cetyltrimethylammonium bromide, TBAB – tetrabutylammonium bromide. Hybrid materials were prepared decoration of (CTA){sub 0.33}V{sub 2}O{sub 5} flexible nanobelts with cationic zinc phthalocyanine by the ion-exchange route. Investigations of the thermal stability, morphologies and structures of the (CTA){sub 0.33}V{sub 2}O{sub 5}, (TBA){sub 0.16}V{sub 2}O{sub 5} nanobelts and zinc phthalocyanine exchange product were carried out. The hybrid materials based on the nanostructured vanadium oxide and zinc phthalocyanine were tested as photocatalysts for oxidation of citronellol and 2-mercaptoethanol by dioxygen.

  5. High electrochemical properties of graphene nanoribbons-hybridized manganese dioxide as cathode material for lithium battery

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiangyue; Fan, Zihan; Lin, Cunli; Jia, Lina; Lin, Baiwei; Wang, Jiaqi; Hu, Xiaolin, E-mail: linamethyst@fzu.edu.cn; Zhuang, Naifeng, E-mail: nfzhuang@fzu.edu.cn [Fuzhou University, College of Chemistry (China)

    2015-02-15

    Manganese dioxide crystallite and its composite hybridized with graphene nanoribbons (GNRs) are prepared by hydrothermal method. The effects of reaction temperature and time, surfactant, and reducing Mn resource are discussed. As the cathode material for Li battery, γ-MnO{sub 2} nanowire/nanorod hybridizing with (GNRs) (γ-MnO{sub 2}/GNRs) shows a higher discharge specific capacity than it covering with carbon nanotubes or graphene sheets. In addition, the discharge specific capacity of γ-MnO{sub 2}/GNRs is much higher than those of pure β-MnO{sub 2} and compact β-MnO{sub 2}/GNRs. The effects of crystal size, morphology, and GNR hybrid on the discharge specific capacity are discussed.

  6. Hybrid anisotropic materials for wind power turbine blades

    CERN Document Server

    Golfman, Yosif

    2012-01-01

    Based on rapid technological developments in wind power, governments and energy corporations are aggressively investing in this natural resource. Illustrating some of the crucial new breakthroughs in structural design and application of wind energy generation machinery, Hybrid Anisotropic Materials for Wind Power Turbine Blades explores new automated, repeatable production techniques that expand the use of robotics and process controls. These practices are intended to ensure cheaper fabrication of less-defective anisotropic material composites used to manufacture power turbine blades. This boo

  7. Quantum dot-based organic-inorganic hybrid materials for optoelectronic applications (Conference Presentation)

    Science.gov (United States)

    Lee, Kwang-Sup

    2016-10-01

    Our recent research involves the design, characterization and testing of devices constituting low bandgap conjugated polymers, surface-engineered quantum dots (QDs), carbon nanotube (CNT)-QDs, QDs decorated nanowires, and QD coupled conjugated polymers. The resulting hybrid materials can be used for facilitating the charge/energy transfer and enhancing the charge carrier mobility in highly efficient optoelectronic and photonic devices. Exploiting the full potential of quantum dots (QDs) in optoelectronic devices require efficient mechanisms for transfer of energy or electrons produced in the optically excited QDs. We propose semiconducting π-conjugated molecules as ligands to achieve energy or charge transfer. The hybridization of p-type π-conjugated molecules to the surface of n-type QDs can induce distinct luminescence and charge transport characteristics due to energy and/or charge transfer effects. QDs and π-conjugated molecule hybrids with controlled luminescent properties can be used for new active materials for light-emitting diodes and flexible displays. In addition, such hybrid systems with enhanced charge transfer efficiency can be used for nanoscale photovoltaic devices. We have also explored single nanoparticle based electronics using QDs and π-conjugated molecule hybrids with molecular-scale n-p or n-insulating (ins)-p-heterojunction structures.

  8. A Comprehensive Review of Gas Sensors Using Carbon Materials.

    Science.gov (United States)

    Kim, Min Il; Lee, Young-Seak

    2016-05-01

    In recent years, interest in carbon materials for use in gas sensors has increased. Carbon materials have unique electrical, optical and mechanical properties, making these materials very interesting. In this review, the properties of carbon materials are first introduced. Surface modification for carbon materials, fabrication for gas sensors, and the gas-sensing conditions and mechanisms according to the different types of carbon materials are chiefly described. In particular, this review focuses on the enhancement of the gas-sensing properties of carbon materials depending on the modification methods used and its mechanism.

  9. Materials design for electrocatalytic carbon capture

    Science.gov (United States)

    Tan, Xin; Tahini, Hassan A.; Smith, Sean C.

    2016-05-01

    We discuss our philosophy for implementation of the Materials Genome Initiative through an integrated materials design strategy, exemplified here in the context of electrocatalytic capture and separation of CO2 gas. We identify for a group of 1:1 X-N graphene analogue materials that electro-responsive switchable CO2 binding behavior correlates with a change in the preferred binding site from N to the adjacent X atom as negative charge is introduced into the system. A reconsideration of conductive N-doped graphene yields the discovery that the N-dopant is able to induce electrocatalytic binding of multiple CO2 molecules at the adjacent carbon sites.

  10. Multifunctional Carbon Electromagnetic Materials, Motors, and Actuators Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of the proposal is to apply multifunctional carbon electromagnetic materials, including carbon nanotube electrical thread (replaces copper wire) and...

  11. Hybrid fiber reinforcement and crack formation in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Pereira, E.B.; Fischer, Gregor; Barros, J.A.O.

    2011-01-01

    reinforcement systems. The research described in this paper shows that the multi-scale conception of cracking and the use of hybrid fiber reinforcements do not necessarily result in an improved tensile behavior of the composite. Particular material design requirements may nevertheless justify the use of hybrid......- to the macroscale. In this study, the performance of different fiber reinforced cementitious composites is assessed in terms of their tensile stress-crack opening behavior. The results obtained from this investigation allow a direct quantitative comparison of the behavior obtained from the different fiber...

  12. Hybrid supercapacitor-battery materials for fast electrochemical charge storage.

    Science.gov (United States)

    Vlad, A; Singh, N; Rolland, J; Melinte, S; Ajayan, P M; Gohy, J-F

    2014-03-07

    High energy and high power electrochemical energy storage devices rely on different fundamental working principles--bulk vs. surface ion diffusion and electron conduction. Meeting both characteristics within a single or a pair of materials has been under intense investigations yet, severely hindered by intrinsic materials limitations. Here, we provide a solution to this issue and present an approach to design high energy and high power battery electrodes by hybridizing a nitroxide-polymer redox supercapacitor (PTMA) with a Li-ion battery material (LiFePO4). The PTMA constituent dominates the hybrid battery charge process and postpones the LiFePO4 voltage rise by virtue of its ultra-fast electrochemical response and higher working potential. We detail on a unique sequential charging mechanism in the hybrid electrode: PTMA undergoes oxidation to form high-potential redox species, which subsequently relax and charge the LiFePO4 by an internal charge transfer process. A rate capability equivalent to full battery recharge in less than 5 minutes is demonstrated. As a result of hybrid's components synergy, enhanced power and energy density as well as superior cycling stability are obtained, otherwise difficult to achieve from separate constituents.

  13. Ablation Property of Ceramics/Carbon Fibers/Resin Novel Super-hybrid Composite

    Institute of Scientific and Technical Information of China (English)

    Jun QIU; Xiaoming CAO; Chong TIAN; Jinsong ZHANG

    2005-01-01

    A novel super-hybrid composite (NSHC) is prepared with three-dimension reticulated SiC ceramic (3DRC), high performance carbon fibers and modified phenolic resin (BPR) in this paper. Ablation performance of super-hybrid composite is studied. The results show that the NSHC has less linear ablation rate compared with pure BPR and CF/BPR composite, for example, its linear ablation rate is 50% of CF/BPR at the same fiber content. Mass ablation rate of the NSHC is slightly lower than that of pure BPR and CF/BPR composite because of their difference in the density. Scanning electron microscopic analysis indicates that 3DRC can increase anti-erosion capacity of materials because its special reticulated structure can control the deformation of materials and strengthen the stability of integral structure.

  14. Improved performance of cylindrical hybrid supercapacitor using activated carbon/ niobium doped hydrogen titanate

    Science.gov (United States)

    Lee, Jeong Hyun; Kim, Hong-Ki; Baek, Esther; Pecht, Michael; Lee, Seung-Hwan; Lee, Young-Hie

    2016-01-01

    A cylindrical hybrid supercapacitor is fabricated using activated carbon positive electrode and H2Ti12-xNbxO25 (0 ≤ x ≤ 0.6) negative electrode materials. The hybrid supercapacitor using H2Ti11.85Nb0.15O25 exhibits the best electrochemical performance. It has a capacitance of 78.4 F g-1, charge transfer resistance (Rct) of 0.03 Ω, capacitance retention of 91.4% after 1000 cycles at 3.0 A g-1 and energy density of 24.3 W h kg-1 at a power density of 1794.6 W kg-1. Therefore, the Nb doped HTO negative electrode material is a promising candidate as an energy storage system for electric vehicles (EVs).

  15. Dispersing perylene diimide/SWCNT hybrids: structural insights at the molecular level and fabricating advanced materials.

    Science.gov (United States)

    Tsarfati, Yael; Strauss, Volker; Kuhri, Susanne; Krieg, Elisha; Weissman, Haim; Shimoni, Eyal; Baram, Jonathan; Guldi, Dirk M; Rybtchinski, Boris

    2015-06-17

    The unique properties of carbon nanotubes (CNT) are advantageous for emerging applications. Yet, the CNT insolubility hampers their potential. Approaches based on covalent and noncovalent methodologies have been tested to realize stable dispersions of CNTs. Noncovalent approaches are of particular interest as they preserve the CNT's structures and properties. We report on hybrids, in which perylene diimide (PDI) amphiphiles are noncovalently immobilized onto single wall carbon nanotubes (SWCNT). The resulting hybrids were dispersed and exfoliated both in water and organic solvents in the presence of two different PDI derivatives, PP2b and PP3a. The dispersions were investigated using cryogenic transmission electron microscopy (cryo-TEM), providing unique structural insights into the exfoliation. A helical arrangement of PP2b assemblies on SWCNTs dominates in aqueous dispersions, while a single layer of PP2b and PP3a was found on SWCNTs in organic dispersions. The dispersions were probed by steady-state and time-resolved spectroscopies, revealing appreciable charge redistribution in the ground state, and an efficient electron transfer from SWCNTs to PDIs in the excited state. We also fabricated hybrid materials from the PP2b/SWCNT dispersions. A supramolecular membrane was prepared from aqueous dispersions and used for size-selective separation of gold nanoparticles. Hybrid buckypaper films were prepared from the organic dispersions. In the latter, high conductivity results from enhanced electronic communication and favorable morphology within the hybrid material. Our findings shed light onto SWCNT/dispersant molecular interactions, and introduce a versatile approach toward universal solution processing of SWCNT-based materials.

  16. Carbon Nanotube Composites: Strongest Engineering Material Ever?

    Science.gov (United States)

    Mayeaux, Brian; Nikolaev, Pavel; Proft, William; Nicholson, Leonard S. (Technical Monitor)

    1999-01-01

    The primary goal of the carbon nanotube project at Johnson Space Center (JSC) is to fabricate structural materials with a much higher strength-to-weight ratio than any engineered material today, Single-wall nanotubes present extraordinary mechanical properties along with new challenges for materials processing. Our project includes nanotube production, characterization, purification, and incorporation into applications studies. Now is the time to move from studying individual nanotubes to applications work. Current research at JSC focuses on structural polymeric materials to attempt to lower the weight of spacecraft necessary for interplanetary missions. These nanoscale fibers present unique new challenges to composites engineers. Preliminary studies show good nanotube dispersion and wetting by the epoxy materials. Results of tensile strength tests will also be reported. Other applications of nanotubes are also of interest for energy storage, gas storage, nanoelectronics, field emission, and biomedical uses.

  17. Epitaxially Grown Layered MFI–Bulk MFI Hybrid Zeolitic Materials

    KAUST Repository

    Kim, Wun-gwi

    2012-11-27

    The synthesis of hybrid zeolitic materials with complex micropore-mesopore structures and morphologies is an expanding area of recent interest for a number of applications. Here we report a new type of hybrid zeolite material, composed of a layered zeolite material grown epitaxially on the surface of a bulk zeolite material. Specifically, layered (2-D) MFI sheets were grown on the surface of bulk MFI crystals of different sizes (300 nm and 10 μm), thereby resulting in a hybrid material containing a unique morphology of interconnected micropores (∼0.55 nm) and mesopores (∼3 nm). The structure and morphology of this material, referred to as a "bulk MFI-layered MFI" (BMLM) material, was elucidated by a combination of XRD, TEM, HRTEM, SEM, TGA, and N2 physisorption techniques. It is conclusively shown that epitaxial growth of the 2-D layered MFI sheets occurs in at least two principal crystallographic directions of the bulk MFI crystal and possibly in the third direction as well. The BMLM material combines the properties of bulk MFI (micropore network and mechanical support) and 2-D layered MFI (large surface roughness, external surface area, and mesoporosity). As an example of the uses of the BMLM material, it was incorporated into a polyimide and fabricated into a composite membrane with enhanced permeability for CO2 and good CO2/CH4 selectivity for gas separations. SEM-EDX imaging and composition analysis showed that the polyimide and the BMLM interpenetrate into each other, thereby forming a well-adhered polymer/particle microstructure, in contrast with the defective interfacial microstructure obtained using bare MFI particles. Analysis of the gas permeation data with the modified Maxwell model also allows the estimation of the effective volume of the BMLM particles, as well as the CO2 and CH4 gas permeabilities of the interpenetrated layer at the BMLM/polyimide interface. © 2012 American Chemical Society.

  18. Nitrogen-incorporated ultrananocrystalline diamond and multi-layer-graphene-like hybrid carbon films

    Science.gov (United States)

    Tzeng, Yonhua; Yeh, Shoupu; Fang, Wei Cheng; Chu, Yuehchieh

    2014-03-01

    Nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) and multi-layer-graphene-like hybrid carbon films have been synthesized by microwave plasma enhanced chemical vapor deposition (MPECVD) on oxidized silicon which is pre-seeded with diamond nanoparticles. MPECVD of N-UNCD on nanodiamond seeds produces a base layer, from which carbon structures nucleate and grow perpendicularly to form standing carbon platelets. High-resolution transmission electron microscopy and Raman scattering measurements reveal that these carbon platelets are comprised of ultrananocrystalline diamond embedded in multilayer-graphene-like carbon structures. The hybrid carbon films are of low electrical resistivity. UNCD grains in the N-UNCD base layer and the hybrid carbon platelets serve as high-density diamond nuclei for the deposition of an electrically insulating UNCD film on it. Biocompatible carbon-based heaters made of low-resistivity hybrid carbon heaters encapsulated by insulating UNCD for possible electrosurgical applications have been demonstrated.

  19. A new family of sp3-hybridized carbon phases

    Science.gov (United States)

    Ning, Xu; Jian-Fu, Li; Bo-Long, Huang; Bao-Lin, Wang

    2016-01-01

    A new family of superhard carbon allotropes C48(2i + 1) is constructed by alternating even 4 and 8 membered rings. These new carbon allotropes are of a spatially antisymmetrical structure, compared with the symmetrical structures of bct-C4, Z-carbon, and P-carbon. Our calculations show that bulk moduli of C48(2i + 1) are larger than that of c-BN and smaller than that of cubic-diamond. C48(2i + 1) are transparent superhard materials possessing large Vicker hardness comparable to diamond. This work can help us understand the structural phase transformations of cold-compression graphite and carbon nanotubes. Project supported by the National Natural Science Foundation of China (Grant Nos. 11174242, 11204265, 11404278, 11147007, and 11274151), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK2012248), and the Scientific Research Foundation of Yancheng Institute of Technology, China (Grant No. KJC2014024).

  20. Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials

    CERN Document Server

    Levitsky, Igor A; Karachevtsev, Victor A

    2012-01-01

    Photophysics of Carbon Nanotubes Interfaced with Organic and Inorganic Materials describes physical, optical and spectroscopic properties of the emerging class of nanocomposites formed from carbon nanotubes (CNTs)  interfacing with organic and inorganic materials. The three main chapters detail novel trends in  photophysics related to the interaction of  light with various carbon nanotube composites from relatively simple CNT/small molecule assemblies to complex hybrids such as CNT/Si and CNT/DNA nanostructures.   The latest experimental results are followed up with detailed discussions and scientific and technological perspectives to provide a through coverage of major topics including: ·   Light harvesting, energy conversion, photoinduced charge separation  and transport  in CNT based nanohybrids · CNT/polymer composites exhibiting photoactuation; and ·         Optical  spectroscopy  and structure of CNT/DNA complexes. Including original data and a short review of recent research, Phot...

  1. Development and Optimization of Hybrid Friction Materials Consisting of Nanoclay and Carbon Nanotubes by using Analytical Hierarchy Process (AHP and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS under Fuzzy Atmosphere

    Directory of Open Access Journals (Sweden)

    Tej SINGH

    2013-07-01

    Full Text Available The tribo-performance of nanoclay and multi-walled carbon nanotube (MWNT filled and graphite lubricated phenolic composites, reinforced with a combination of lapinus and kevlar fibers, have been evaluated on a Kraus friction testing machine. The combined fuzzy analytical hierarchy process (FAHP and fuzzy technique for order preference by similarity to ideal solution (FTOPSIS approach, taking into account performance defining attributes (PDAs such as friction performance, wear, friction-fade, friction-recovery, stability coefficient, variability coefficient, friction fluctuations and temperature rise of the disc, was used for the performance assessment of fabricated friction composite materials. The weight of different PDAs were evaluated by FAHP; μ-performance (0.144, 0.255, 0.435, wear (0.144, 0.255, 0.435, fade-% (0.073, 0.15, 0.307, recovery-% (0.063, 0.126, 0.268, stability coefficient (0.037, 0.075, 0.156, variability coefficient (0.032, 0.063, 0.136, frictional fluctuations (0.023, 0.037, 0.069, and DTR (0.023, 0.037, 0.069 respectively.  FTOPSIS was employed to determine the optimal ranking of the friction composite materials as NC-7>NC-8>NC-6>NC-5>NC-3>NC-4>NC-2>NC-1. The alternative with kevlar: lapinus, 2.5:27.5 wt-% and graphite: nanoclay: carbon nanotube, 2.25:2.75 wt-% exhibits the optimal properties.

  2. Understanding supercapacitors based on nano-hybrid materials with interfacial conjugation

    Institute of Scientific and Technical Information of China (English)

    George Z. Chen

    2013-01-01

    The recent fast development of supercapacitors, also known scientifically as electrochemical capacitors, has benefited significantly from synthesis, characterisations and electrochemistry of nanoma-terials. Herein, the principle of supercapacitors is explained in terms of performance characteristics and charge storage mechanisms, i.e. double layer (or interfacial) capacitance and pseudo-capacitance. The semiconductor band model is applied to qualitatively account for the pseudo-capacitance in association with rectangular cyclic voltammograms (CVs) and linear galvanostatic charging and discharging plots (GCDs), aiming to differentiate supercapacitors from rechargeable batteries. The invalidity of using peak shaped CVs and non-linear GCDs for capacitance measurement is highlighted. A selective review is given to the nano-hybrid materials between carbon nanotubes and redox active materials such as electronically conducting polymers and transition metal oxides. A new concept,“interfacial conjugation”, is introduced to reflect the capacitance enhancement resulting from π-π stacking interactions at the interface between two materials with highly conjugated chemical bonds. The prospects of carbon nanotubes and graphenes for supercapacitor applications are briefly compared and discussed. Hopefully, this article can help readers to understand supercapacitors and nano-hybrid materials so that further developments in materials design and synthesis, and device engineering can be more efficient and objective.

  3. Solution-processed hybrid materials for light detection

    Science.gov (United States)

    Adinolfi, Valerio

    Inorganic semiconductors form the foundation of modern electronics and optoelectronics. These materials benefit from excellent optoelectronic properties, but applications are generally limited due to high cost of fabrication. More recently, organic semiconductors have emerged as a low-cost alternative for light emitting devices. Organic materials benefit from facile, low temperature fabrication and offer attractive features such as flexibility and transparency. However, these materials are inherently limited by poor electronic transport. In recent years, new materials have been developed to overcome the dichotomy between performance and the cost. Hybrid organic--inorganic semiconductors combine the superior electronic properties of inorganic materials with the facile assembly of organic systems to yield high-performance, low-cost electronics. This dissertation focuses on the development of solution-processed light detectors using hybrid material systems, particularly colloidal quantum dots (CQDs) and hybrid perovskites. First, advanced architectures for colloidal quantum dot light detectors are presented. These devices overcome the responsivity--speed--dark current trade-off that has limited past reports of CQD-based devices. The photo-junction field effect transistors presented in this work decrease the dark current of CQD detectors by two orders of magnitude, ultimately reducing power consumption (100x) and noise current (10x). The detector simultaneously benefits from high gain (˜10 electrons/photon) and fast time response (˜ 10 mus). This represents the first CQD-based three-terminal-junction device reported in the literature. Building on this success, hybrid perovskite devices are then presented. This material system has become a focal point of the semiconductor research community due to its relatively unexplored nature and attractive optoelectronic properties. Herein we present the first extensive electronic characterization of single crystal organolead

  4. An experimental study of nonlinear behaviour of capacitance in graphene/carbon nanotube hybrid films

    Science.gov (United States)

    Alsawafi, Suaad; Wang, Xiao; Jin, Jie; Song, Mo

    2016-06-01

    Graphene (G) and graphene oxide (GO)/carbon nanotubes (CNTs) hybrid films were fabricated as high performance electrode materials by a simple water solution casting method with different contents of single-wall CNT (SWCNT), multi wall CNT (MWCNT) and multi wall CNT with hydroxyl group (MWCNT-OH). The films with MWCNTs showed a layered, interconnected and well entangled structure at nano-scale. With increasing CNT contents, the capacitance of the G/MWCNT and GO/MWCNT films raised almost linearly and their resistance reduced. G/SWCNT and GO/SWCNT films did not form layered structures leading to a very low capacitance. Nonlinear behaviour of the capacitance with voltage has been observed in the G/MWCNT and GO/MWCNT hybrid films. The length and thickness of the hybrid film have significant influences on the capacitance. The capacitance and conductivity increase with increasing the thickness and decrease with increasing the length of the hybrid films. For the application of graphene/CNT hybrid films as electrodes, these characters could be taken into account.

  5. Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Song, Meng; Xu, Peng; Wang, Xu; Wu, Huizhen; Wang, Miao, E-mail: peizhao@zju.edu.cn, E-mail: miaowang@css.zju.edu.cn [Department of Physics, Zhejiang University, Hangzhou 310027 (China); Song, Yenan; Li, Zhenhua; Zhao, Pei, E-mail: peizhao@zju.edu.cn, E-mail: miaowang@css.zju.edu.cn [Institute of Applied Mechanics, Zhejiang University, Hangzhou 310027 (China); Shang, Xuefu [Department of Physics, Faculty of Science, Jiangsu University, Zhenjiang 212013 (China)

    2015-09-15

    Integrating carbon nanotubes (CNTs) and graphene into hybrid structures provides a novel approach to three dimensional (3D) materials with advantageous properties. Here we present a water-processing method to create integrated CNT/graphene hybrids and test their field emission properties. With an optimized mass ratio of CNTs to graphene, the hybrid shows a significantly enhanced field emission performance, such as turn-on electric field of 0.79 V/μm, threshold electric field of 1.05 V/μm, maximum current density of 0.1 mA/cm{sup 2}, and field enhancement factor of ∼1.3 × 10{sup 4}. The optimized mass ratio for field emission emphasizes the importance of both CNTs and graphene in the hybrid. We also hypothesize a possible mechanism for this enhanced field emission performance from the CNT/graphene hybrid. During the solution treatment, graphene oxide behaves as surfactant sheets for CNTs to form a well dispersed solution, which leads to a better organized 3D structure with more conducting channels for electron transport.

  6. Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties

    Directory of Open Access Journals (Sweden)

    Meng Song

    2015-09-01

    Full Text Available Integrating carbon nanotubes (CNTs and graphene into hybrid structures provides a novel approach to three dimensional (3D materials with advantageous properties. Here we present a water-processing method to create integrated CNT/graphene hybrids and test their field emission properties. With an optimized mass ratio of CNTs to graphene, the hybrid shows a significantly enhanced field emission performance, such as turn-on electric field of 0.79 V/μm, threshold electric field of 1.05 V/μm, maximum current density of 0.1 mA/cm2, and field enhancement factor of ∼1.3 × 104. The optimized mass ratio for field emission emphasizes the importance of both CNTs and graphene in the hybrid. We also hypothesize a possible mechanism for this enhanced field emission performance from the CNT/graphene hybrid. During the solution treatment, graphene oxide behaves as surfactant sheets for CNTs to form a well dispersed solution, which leads to a better organized 3D structure with more conducting channels for electron transport.

  7. Water-processed carbon nanotube/graphene hybrids with enhanced field emission properties

    Science.gov (United States)

    Song, Meng; Xu, Peng; Song, Yenan; Wang, Xu; Li, Zhenhua; Shang, Xuefu; Wu, Huizhen; Zhao, Pei; Wang, Miao

    2015-09-01

    Integrating carbon nanotubes (CNTs) and graphene into hybrid structures provides a novel approach to three dimensional (3D) materials with advantageous properties. Here we present a water-processing method to create integrated CNT/graphene hybrids and test their field emission properties. With an optimized mass ratio of CNTs to graphene, the hybrid shows a significantly enhanced field emission performance, such as turn-on electric field of 0.79 V/μm, threshold electric field of 1.05 V/μm, maximum current density of 0.1 mA/cm2, and field enhancement factor of ˜1.3 × 104. The optimized mass ratio for field emission emphasizes the importance of both CNTs and graphene in the hybrid. We also hypothesize a possible mechanism for this enhanced field emission performance from the CNT/graphene hybrid. During the solution treatment, graphene oxide behaves as surfactant sheets for CNTs to form a well dispersed solution, which leads to a better organized 3D structure with more conducting channels for electron transport.

  8. In situ hybridization of carbon nanotubes with bacterial cellulose for three-dimensional hybrid bioscaffolds.

    Science.gov (United States)

    Park, Subeom; Park, Jooyeon; Jo, Insu; Cho, Sung-Pyo; Sung, Dongchul; Ryu, Seungmi; Park, Minsung; Min, Kyung-Ah; Kim, Jangho; Hong, Suklyun; Hong, Byung Hee; Kim, Byung-Soo

    2015-07-01

    Carbon nanotubes (CNTs) have shown great potential in biomedical fields. However, in vivo applications of CNTs for regenerative medicine have been hampered by difficulties associated with the fabrication of three-dimensional (3D) scaffolds of CNTs due to CNTs' nano-scale nature. In this study, we devised a new method for biosynthesis of CNT-based 3D scaffold by in situ hybridizing CNTs with bacterial cellulose (BC), which has a structure ideal for tissue-engineering scaffolds. This was achieved simply by culturing Gluconacetobacter xylinus, BC-synthesizing bacteria, in medium containing CNTs. However, pristine CNTs aggregated in medium, which hampers homogeneous hybridization of CNTs with BC scaffolds, and the binding energy between hydrophobic pristine CNTs and hydrophilic BC was too small for the hybridization to occur. To overcome these problems, an amphiphilic comb-like polymer (APCLP) was adsorbed on CNTs. Unlike CNT-coated BC scaffolds (CNT-BC-Imm) formed by immersing 3D BC scaffolds in CNT solution, the APCLP-adsorbed CNT-BC hybrid scaffold (CNT-BC-Syn) showed homogeneously distributed CNTs throughout the 3D microporous structure of BC. Importantly, in contrast to CNT-BC-Imm scaffolds, CNT-BC-Syn scaffolds showed excellent osteoconductivity and osteoinductivity that led to high bone regeneration efficacy. This strategy may open a new avenue for development of 3D biofunctional scaffolds for regenerative medicine.

  9. Carbon Nanotubes Filled with Ferromagnetic Materials

    Directory of Open Access Journals (Sweden)

    Albrecht Leonhardt

    2010-08-01

    Full Text Available Carbon nanotubes (CNT filled with ferromagnetic metals like iron, cobalt or nickel are new and very interesting nanostructured materials with a number of unique properties. In this paper we give an overview about different chemical vapor deposition (CVD methods for their synthesis and discuss the influence of selected growth parameters. In addition we evaluate possible growth mechanisms involved in their formation. Moreover we show their identified structural and magnetic properties. On the basis of these properties we present different application possibilities. Some selected examples reveal the high potential of these materials in the field of medicine and nanotechnology.

  10. Amorphous titania/carbon composite electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Vaughey, John T.; Jansen, Andrew; Joyce, Christopher D.

    2017-05-09

    An isolated salt comprising a compound of formula (H.sub.2X)(TiO(Y).sub.2) or a hydrate thereof, wherein X is 1,4-diazabicyclo[2.2.2]octane (DABCO), and Y is oxalate anion (C.sub.2O.sub.4.sup.-2), when heated in an oxygen-containing atmosphere at a temperature in the range of at least about 275.degree. C. to less than about 400.degree. C., decomposes to form an amorphous titania/carbon composite material comprising about 40 to about 50 percent by weight titania and about 50 to about 60 percent by weight of a carbonaceous material coating the titania. Heating the composite material at a temperature of about 400 to 500.degree. C. crystallizes the titania component to anatase. The titania materials of the invention are useful as components of the cathode or anode of a lithium or lithium ion electrochemical cell.

  11. Carbon nanotube/biocompatible bola-amphiphile supramolecular biohybrid materials: preparation and their application in bacterial cell agglutination.

    Science.gov (United States)

    Yu, Guocan; Li, Jinying; Yu, Wei; Han, Chengyou; Mao, Zhengwei; Gao, Changyou; Huang, Feihe

    2013-11-26

    Supramolecular biohybrid materials were successfully constructed driven by non-covalent interactions between three biocompatible bolaform amphiphiles and single walled carbon nanotubes (SWNTs). The existence of galactoses in these supramolecular systems endowed the hybrid materials with interesting bio-function. By introducing the SWNTs as semi-flexible platforms, these supramolecular biohybrid materials display excellent agglutination ability for E. coli.

  12. Performance and Stability of Supercapacitor Modules based on Porous Carbon Electrodes in Hybrid Powertrain

    Institute of Scientific and Technical Information of China (English)

    GONG Xuan; XIE Changjun; ZOU Yaohui; QUAN Shuhai; PIOTR Bujlo; SHEN Di

    2014-01-01

    Hybrid power sources have attracted much attention in the electric vehicle area. Particularly, electric-electric hybrid powertrain system consisting of supercapacitor modules and lithium-ion batteries has been widely applied because of the high power density of supercapacitors. In this study, we design a hybrid powertrain system containing two porous carbon electrode-based supercapacitor modules in parallel and one lithium ion battery pack. With the construction of the testing station, the performance and stability of the used supercapacitor modules are investigated in correlation with the structure of the supercapacitor and the nature of the electrode materials applied. It has been shown that the responding time for voltage vibration from 20 V to 48.5 V during charging or discharging process decreases from about 490 s to 94 s with the increase in applied current from 20 A to 100 A. The capacitance of the capacitor modules is nearly independent on the applied current. With the designed setup, the energy efficiency can reach as high as 0.99. The results described here provide a guidance for material selection of supercapacitors and optimized controlling strategy for hybrid power system applied in electric vehicles.

  13. Dynamic nanocrystal response and high temperature growth of carbon nanotube-ferroelectric hybrid nanostructure

    Science.gov (United States)

    Kumar, Ashok; Scott, J. F.; Katiyar, R. S.

    2013-12-01

    A long standing problem related to the capping of carbon nanotubes (CNT) by inorganic materials at high temperature has been solved. In situ dynamic response of Pb(Zr0.52Ti0.48)O3 (PZT) nanocrystals attached to the wings of the outer surface of PZT/CNT hybrid-nanostructure has been demonstrated under a constant-energy high-resolution transmission electron microscopy (HRTEM) e-beam. PZT nanocrystals revealed that the crystal orientations, positions, faces, and hopping states change with time. HRTEM study has been performed to investigate the microstructure of hybrid nanostructures and nanosize polycrystal trapped across the wings. Raman spectroscopy was utilized to investigate the local structures, defects, crystal qualities and temperature dependent growth and degradation of hybrid nanostructures. Raman spectra indicate that MWCNT and PZT/MWCNT/n-Si possess good quality of CNT before and after PZT deposition until 650 °C. The monoclinic Cc/Cm phase of PZT which is optimum in piezoelectric properties was prominent in the hybrid structure and should be useful for device applications. An unusual hexagonal faceting oscillation of the nano-crystal perimeter on a 10-30 s period is also observed.A long standing problem related to the capping of carbon nanotubes (CNT) by inorganic materials at high temperature has been solved. In situ dynamic response of Pb(Zr0.52Ti0.48)O3 (PZT) nanocrystals attached to the wings of the outer surface of PZT/CNT hybrid-nanostructure has been demonstrated under a constant-energy high-resolution transmission electron microscopy (HRTEM) e-beam. PZT nanocrystals revealed that the crystal orientations, positions, faces, and hopping states change with time. HRTEM study has been performed to investigate the microstructure of hybrid nanostructures and nanosize polycrystal trapped across the wings. Raman spectroscopy was utilized to investigate the local structures, defects, crystal qualities and temperature dependent growth and degradation of

  14. Evaluation of hybrid composite materials in cylindrical specimen geometries

    Science.gov (United States)

    Liber, T.; Daniel, I. M.

    1976-01-01

    Static and fatigue properties of three composite materials and hybrids were examined. The materials investigated were graphite/epoxy, S-glass/epoxy, PRD-49 (Kevlar 49)/epoxy, and hybrids in angle-ply configurations. A new type of edgeless cylindrical specimen was developed. It is a flattened tube with two flat sides connected by curved sections and it is handled much like the standard flat coupon. Special specimen fabrication, tabbing, and tab region reinforcing techniques were developed. Axial modulus, Poisson's ratio, strength, and ultimate strain were obtained under static loading from flattened tube specimens of nine laminate configurations. In the case of graphite/epoxy the tubular specimens appeared to yield somewhat higher strength and ultimate strain values than flat specimens. Tensile fatigue tests were conducted with all nine types of specimens and S-N curves obtained. Specimens surviving 10 million cycles of tensile loading were subsequently tested statically to failure to determine residual properties.

  15. Hybrid carbon fiber/carbon nanotube composites for structural damping applications

    Science.gov (United States)

    Tehrani, M.; Safdari, M.; Boroujeni, A. Y.; Razavi, Z.; Case, S. W.; Dahmen, K.; Garmestani, H.; Al-Haik, M. S.

    2013-04-01

    Carbon nanotubes (CNTs) were grown on the surface of carbon fibers utilizing a relatively low temperature synthesis technique; graphitic structures by design (GSD). To probe the effects of the synthesis protocols on the mechanical properties, other samples with surface grown CNTs were prepared using catalytic chemical vapor deposition (CCVD). The woven graphite fabrics were thermally shielded with a thin film of SiO2 and CNTs were grown on top of this film. Raman spectroscopy and electron microscopy revealed the grown species to be multi-walled carbon nanotubes (MWCNTs). The damping performance of the hybrid CNT-carbon fiber-reinforced epoxy composite was examined using dynamic mechanical analysis (DMA). Mechanical testing confirmed that the degradations in the strength and stiffness as a result of the GSD process are far less than those encountered through using the CCVD technique and yet are negligible compared to the reference samples. The DMA results indicated that, despite the minimal degradation in the storage modulus, the loss tangent (damping) for the hybrid composites utilizing GSD-grown MWCNTs improved by 56% compared to the reference samples (based on raw carbon fibers with no surface treatment or surface grown carbon nanotubes) over the frequency range 1-60 Hz. These results indicated that the energy dissipation in the GSD-grown MWCNTs composite can be primarily attributed to the frictional sliding at the nanotube/epoxy interface and to a lesser extent to the stiff thermal shielding SiO2 film on the fiber/matrix interface.

  16. Organic-inorganic hybrid materials processing and applications

    OpenAIRE

    Schmidt, Helmut K.; Mennig, Martin; Nonninger, Ralph; Oliveira, Peter William de; Schirra, Hermann

    1999-01-01

    Hybrid materials as inorganic-organic nanostructured composites require tailored surface chemistry in order to obtain a homogeneous distribution of the nanoparticles in the matrix. For this reason, nanoparticles with organic functions have been synthesized, first, to provide the desired æ-potential at a given pH value, second, to avoid irreversible agglomeration due to the spacing effect, and third, to provide the appropriate surface chemistry. I could be shown that using this approach, it is...

  17. Hybrid material as contrast agent in magnetic resonance images

    OpenAIRE

    Botella Asunción, Pablo; Cabrera García, Alejandro

    2015-01-01

    [EN] The invention relates to a contrast agent of magnetic resonance based on a hybrid material formed by an organo-metallic core derived from Prussian blue and a silica cover, and optionally, molecules of a poly(ethylene glycol), a fluorescent agent, a radio nucleus and/or a substance that directs to specific receptors, cells or tissues, joined by covalent bonding to the surface of the inorganic cover.

  18. Hybrid material as contrast agent in magnetic resonance images

    OpenAIRE

    Botella Asunción, Pablo; Cabrera García, Alejandro

    2015-01-01

    [EN] The invention relates to a contrast agent of magnetic resonance based on a hybrid material formed by an organo-metallic core derived from Prussian blue and a silica cover, and optionally, molecules of a poly(ethylene glycol), a fluorescent agent, a radio nucleus and/or a substance that directs to specific receptors, cells or tissues, joined by covalent bonding to the surface of the inorganic cover.

  19. Reinforced Pericardium as a Hybrid Material for Cardiovascular Applications

    OpenAIRE

    Bracaglia, Laura G.; Yu, Li; Hibino, Narutoshi; Fisher, John P.

    2014-01-01

    Pericardium-based cardiovascular devices are currently bound by a 10-year maximum lifetime due to detrimental calcification and degradation. The goal of this work is to develop a novel synthetic material to create a lasting replacement for malfunctioning or diseased tissue in the cardiovascular system. This study couples poly(propylene fumarate) (PPF) and a natural biomaterial together in an unprecedented hybrid composite and evaluates the composite versus the standard glutaraldehyde-treated ...

  20. Non-covalently functionalized carbon nanostructures for synthesizing carbon-based hybrid nanomaterials.

    Science.gov (United States)

    Li, Haiqing; Song, Sing I; Song, Ga Young; Kim, Il

    2014-02-01

    Carbon nanostructures (CNSs) such as carbon nanotubes, graphene sheets, and nanodiamonds provide an important type of substrate for constructing a variety of hybrid nanomaterials. However, their intrinsic chemistry-inert surfaces make it indispensable to pre-functionalize them prior to immobilizing additional components onto their surfaces. Currently developed strategies for functionalizing CNSs include covalent and non-covalent approaches. Conventional covalent treatments often damage the structure integrity of carbon surfaces and adversely affect their physical properties. In contrast, the non-covalent approach offers a non-destructive way to modify CNSs with desired functional surfaces, while reserving their intrinsic properties. Thus far, a number of surface modifiers including aromatic compounds, small-molecular surfactants, amphiphilic polymers, and biomacromolecules have been developed to non-covalently functionalize CNS surfaces. Mediated by these surface modifiers, various functional components such as organic species and inorganic nanoparticles were further decorated onto their surfaces, resulting in versatile carbon-based hybrid nanomaterials with broad applications in chemical engineering and biomedical areas. In this review, the recent advances in the generation of such hybrid nanostructures based on non-covalently functionalized CNSs will be reviewed.

  1. Nanodevices based on Membrane-Carbon Nanotube Hybrid Structures

    Science.gov (United States)

    Jin, Hye Jun; Kim, Tae Hyun; Namgung, Seon; Hong, Seunghun; Lee, Sang Hun; Park, Tai Hyun

    2010-03-01

    Proteins in cell membrane have been drawing attention due to their versatile functionalities such as ion transfer for neuronal activity and selective binding for sensory systems. However, it is still very difficult to manipulate and study those proteins because they easily lose their functionalities without lipid membranes. We developed a method to coat lipid membranes containing various functional membrane proteins on single-walled carbon nanotube (swCNT)-based field effect transistors (FETs). In this hybrid structure, the activity of membrane proteins can be monitored by underlying swCNT-FETs, allowing us to easily study the functionalities of membrane proteins. Furthermore, we built advanced devices based on these hybrid structures. For an example, we coated lipid membrane containing `olfactory receptors' on swCNT-FETs, resulting in `bioelectric nose' systems. The bioelectric nose system had high sensitivity and human nose-like selectivity to odorant molecules. This talk will also discuss about the future prospect of these membrane-CNT hybrid structures.

  2. Impedance characterization of epoxy composite containing conductive hybrid carbon fillers

    Science.gov (United States)

    Othman, Raja Nor; Tawil, Siti Nooraya; Zailan, Suhaila

    2017-08-01

    Epoxy composites containg carbon fillers are prepared in this work with an intention to characterise their electrical properties. The performance of electrical conductivity of epoxy composites is assessed by adding various loadings of conductive carbon fillers into the neat epoxy. First, Carbon Black (CB) was incorporated within epoxy matrix at several loadings. The increase in the specific conductivity of more than five orders of magnitude was observed between 3 wt. % and 4 wt.% CB loading, recorded at 10 kHz frequency. As such, the critical percolation loading, pc was recorded in between 3 wt.% and 4 wt.%. For the samples containing CB at loading 4 wt.% and above, the conductivity remains independent of the frequency, indicating a purely ohmic behaviour. It is also observed that the specific conductivity values can be altered by increasing the hardener stirring time up to 15 minutes, where the pc was successfully lowered down to < 3 wt. % It was further intended to study the hybrid effects by adding CNT to the composites. The conductivity data showed that the composite becomes frequency independent, even at 2 wt. % carbon loading (1 wt. % CB + 1 wt. % CNT), demonstrating the roles contributed by high aspect ratio conductive CNT in enhancing the formation of percolated path at much lower loading.

  3. Photoresponse of hybrids made of carbon nanotubes and CdTe nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Zebli, Bernd; Vieyra, Hugo A.; Kotthaus, Joerg P. [Department fuer Physik and Center for NanoScience (CeNS), Ludwig-Maximilians-Universitaet Muenchen, Geschwister-Scholl-Platz 1, 80539 Munich (Germany); Carmeli, Itai [Department of Chemistry and Biochemistry, Tel-Aviv University, Tel-Aviv 69978 (Israel); Hartschuh, Achim [Department fuer Chemie, Physikalische Chemie, Butenandtstr. 5-13 E, 81377 Munich (Germany); Holleitner, Alexander W. [Walter-Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, 85748 Garching (Germany)

    2008-07-01

    We observe that the photoresponse of single-walled carbon nanotubes can be adjusted by the absorption characteristics of colloidal CdTe nanocrystals, which are bound to the side-walls of the carbon nanotubes via molecular recognition. To this end, the hybrid systems are characterized using charge transport measurements under resonant optical excitation of the carbon nanotubes and nanocrystals, respectively. We investigate the photoresponse of both ensembles of hybrid systems and single carbon-nanotube-nanocrystal-hybrids. The data suggest a bolometrically induced increase of the current in the carbon nanotubes, which is due to photon absorption in the nanocrystals.

  4. Sol-gel-derived hybrid materials multi-doped with rare-earth metal ions

    Science.gov (United States)

    Zelazowska, E.; Rysiakiewicz-Pasek, E.; Borczuch-Laczka, M.; Cholewa-Kowalska, K.

    2012-06-01

    Four different hybrid organic-inorganic materials based on TiO2-SiO2 matrices with organic additives and doped with rare-earth metal ions (III) from the group of europium, cerium, terbium, neodymium, dysprosium and samarium, were synthesized by sol-gel method. Tetraethyl orthosilicate, titanium (IV) isopropoxide and organic compounds, such as butyl acrylate, butyl methacrylate, ethyl acetoacetate, ethylene glycol dimethacrylate, ethyl acetate, propylene carbonate, organic solvents and certain inorganic salts were used in the synthesis. The inorganic part of the sols, which were used in the synthesis of all the hybrid materials, was prepared separately and then the organic parts were added. The materials obtained were aged for three weeks at room temperature and then heated in an electric oven for three hours at temperatures of 80 °C-150 °C. Scanning electron microscopy equipped with energy dispersive X-ray spectroscopy (SEM/EDX); X-ray diffraction (XRD); Fourier transform infrared spectroscopy (KBr technique); 29Si magic-angle spinning nuclear magnetic resonance; and fluorescence spectroscopy were used for the examination of morphology, microstructure and luminescence properties, respectively. Photoluminescence properties with relatively intense narrow emission lines of Tb, Eu, Dy, Nd, Sm respectively to the RE-ions doping, were observed for all the hybrid materials.

  5. Facile synthesis and application of poly(ionic liquid)-bonded silica hybrid materials.

    Science.gov (United States)

    Bi, Wentao; Tian, Minglei; Row, Kyung Ho

    2012-05-07

    Facile methods were developed to prepare hybrid poly(ionic liquid)-bonded silica for a wide range of applications, particularly in analytical chemistry. The hybrid material obtained was evaluated by comparing its adsorption capacity with other conventional separation materials. In addition, the hybrid material has the potential for industrial scale production.

  6. Light-weight sandwich panel honeycomb core with hybrid carbon-glass fiber composite skin for electric vehicle application

    Science.gov (United States)

    Cahyono, Sukmaji Indro; Widodo, Angit; Anwar, Miftahul; Diharjo, Kuncoro; Triyono, Teguh; Hapid, A.; Kaleg, S.

    2016-03-01

    The carbon fiber reinforced plastic (CFRP) composite is relative high cost material in current manufacturing process of electric vehicle body structure. Sandwich panels consisting polypropylene (PP) honeycomb core with hybrid carbon-glass fiber composite skin were investigated. The aim of present paper was evaluate the flexural properties and bending rigidity of various volume fraction carbon-glass fiber composite skins with the honeycomb core. The flexural properties and cost of panels were compared to the reported values of solid hybrid Carbon/Glass FRP used for the frame body structure of electric vehicle. The finite element model of represented sandwich panel was established to characterize the flexural properties of material using homogenization technique. Finally, simplified model was employed to crashworthiness analysis for engine hood of the body electric vehicle structure. The good cost-electiveness of honeycomb core with hybrid carbon-glass fiber skin has the potential to be used as a light-weight alternative material in body electric vehicle fabricated.

  7. Temperature dependent NIR emitting lanthanide-PMO/silica hybrid materials.

    Science.gov (United States)

    Kaczmarek, Anna M; Esquivel, Dolores; Ouwehand, Judith; Van Der Voort, Pascal; Romero-Salguero, Francisco J; Van Deun, Rik

    2017-06-28

    Two materials - a mesoporous silica (MS) and a periodic mesoporous organosilica (PMO) functionalized with dipyridyl-pyridazine (dppz) units were grafted with near-infrared (NIR) emitting lanthanide (Nd(3+), Er(3+), Yb(3+)) complexes in an attempt to obtain hybrid NIR emitting materials. The parent materials: dppz-vSilica and dppz-ePMO were prepared by a hetero Diels-Alder reaction between 3,6-di(2-pyridyl)-1,2,4,5-tetrazine (dptz) and the double bonds of either ethenylene-bridged PMO (ePMO) or vinyl-silica (vSilica) and subsequent oxidation. The dppz-vSilica is reported here for the first time. The prepared lanthanide-PMO/silica hybrid materials were studied in depth for their luminescence properties at room temperature and chosen Nd(3+) and Yb(3+) samples also at low temperature (as low as 10 K). We show that both the dppz-vSilica and dppz-ePMO materials can be used as "platforms" for obtaining porous materials showing NIR luminescence. To obtain NIR emission these materials can be excited either in the UV or Vis region (into the π→π* transitions of the ligands or directly into the f-f transitions of the Ln(3+) ions). More interestingly, when functionalized with Nd(3+) or Yb(3+)β-diketonate complexes these materials showed interesting luminescence properties over a wide temperature range (10-360 K). The Yb(3+) materials were investigated for their potential use as ratiometric temperature sensors.

  8. Materials design for electrocatalytic carbon capture

    Directory of Open Access Journals (Sweden)

    Xin Tan

    2016-05-01

    Full Text Available We discuss our philosophy for implementation of the Materials Genome Initiative through an integrated materials design strategy, exemplified here in the context of electrocatalytic capture and separation of CO2 gas. We identify for a group of 1:1 X–N graphene analogue materials that electro-responsive switchable CO2 binding behavior correlates with a change in the preferred binding site from N to the adjacent X atom as negative charge is introduced into the system. A reconsideration of conductive N-doped graphene yields the discovery that the N-dopant is able to induce electrocatalytic binding of multiple CO2 molecules at the adjacent carbon sites.

  9. Electroanalysis using modified hierarchical nanoporous carbon materials.

    Science.gov (United States)

    Rodriguez, Rusbel Coneo; Moncada, Angelica Baena; Acevedo, Diego F; Planes, Gabriel A; Miras, Maria C; Barbero, Cesar A

    2013-01-01

    The role of the electrode nanoporosity in electroanalytical processes is discussed and specific phenomena (slow double layer charging, local pH effects) which can be present in porous electrode are described. Hierarchical porous carbon (HPC) materials are synthesized using a hard template method. The three dimensional carbon porosity is examined using scanning electron microscopy on flat surfaces cut using a focused ion beam (FIB-SEM). The electrochemical properties of the HPC are measured using cyclic voltammetry, AC impedance, chronoamperometry and Probe Beam Deflection (PBD) techniques. Chronoamperometry measurements of HPC seems to fit a transmission line model. PBD data show evidence of local pH changes inside the pores, during double layer charging. The HPC are modified by in situ (chemical or electrochemical) formation of metal (Pt/Ru) or metal oxide (CoOx, Fe3O4) nanoparticles. Additionally, HPC loaded with Pt decorated magnetite (Fe3O4) nanoparticles is produced by galvanic displacement. The modified HPC materials are used for the electroanalysis of different substances (CO, O2, AsO3(-3)). The role of the nanoporous carbon substrate in the electroanalytical data is evaluated.

  10. Reinforced pericardium as a hybrid material for cardiovascular applications.

    Science.gov (United States)

    Bracaglia, Laura G; Yu, Li; Hibino, Narutoshi; Fisher, John P

    2014-11-01

    Pericardium-based cardiovascular devices are currently bound by a 10-year maximum lifetime due to detrimental calcification and degradation. The goal of this work is to develop a novel synthetic material to create a lasting replacement for malfunctioning or diseased tissue in the cardiovascular system. This study couples poly(propylene fumarate) (PPF) and a natural biomaterial together in an unprecedented hybrid composite and evaluates the composite versus the standard glutaraldehyde-treated tissue. The polymer reinforcement is hypothesized to provide initial physical protection from proteolytic enzymes and degradation, but leave the original collagen and elastin matrix unaltered. The calcification rate and durability of the hybrid material are evaluated in vitro and in an in vivo subdermal animal model. Results demonstrate that PPF is an effective support and leads to significantly less calcium deposition, important metrics when evaluating cardiovascular material. By avoiding chemical crosslinking of the tissue and associated side effects, PPF-reinforced pericardium as a biohybrid material offers a promising potential direction for further development in cardiovascular material alternatives. Eliminating the basis for the majority of cardiovascular prosthetic failures could revolutionize expectations for extent of cardiovascular repair.

  11. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Included among...

  12. Advanced Thermal Protection Systems (ATPS), Aerospace Grade Carbon Bonded Carbon Fiber Material Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Carbon bonded carbon fiber (CBCF) insulating material is the basis for several highly successful NASA developed thermal protection systems (TPS). Among the...

  13. Advanced materials based on carbon nanotube arrays, yarns and papers

    Science.gov (United States)

    Bradford, Phlip David

    Carbon nanotubes have hundreds of potential applications but require innovative processing techniques to manipulate the microscopic carbon dust into useful devices and products. This thesis describes efforts to process carbon nanotubes (CNTs) using novel methods with the goals of: (1) improving the properties of energy absorbing and composite carbon nanotube materials and (2) increasing understanding of fundamental structure-property relationships within these materials. Millimeter long CNTs, in the form of arrays, yarns and papers, were used to produce energy absorbing foams and high volume fraction CNT composites. Vertically aligned CNT arrays were grown on silicon substrates using chemical vapor deposition (CVD) of ethylene gas over iron nano-particles. The low density, millimeter thick arrays were tested under compression as energy absorbing foams. With additional CVD processing steps, it was possible to tune the compressive properties of the arrays. After the longest treatment, the compressive strength of the arrays was increased by a factor of 35 with a density increase of only six fold, while also imparting recovery from compression to the array. Microscopy revealed that the post-synthesis CVD treatment increased the number of CNT walls through an epitaxial type radial growth on the surface of the as-grown tubes. The increase in tube radius and mutual support between nanotubes explained the increases in compressive strength while an increase in nanotube roughness was proposed as the morphological change responsible for recovery in the array. Carbon nanotube yarns were used as the raw material for macroscopic textile preforms with a multi-level hierarchical carbon nanotube (CNT) structure: nanotubes, bundles, spun single yarns, plied yarns and 3-D braids. In prior tensile tests, composites produced from the 3-D braids exhibited unusual mechanical behavior effects. The proposed physical hypotheses explained those effects by molecular level interactions and

  14. Biocompatible multi-walled carbon nanotube–CdTe quantum dot–polymer hybrids for medical applications

    Energy Technology Data Exchange (ETDEWEB)

    Baslak, Canan, E-mail: cananbaslak@gmail.com [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Department of Chemistry, Faculty of Science, Selcuk University, 42075 Konya (Turkey); Demirel Kars, Meltem, E-mail: dmeltem@yahoo.com [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Sarayonu Vocational High School, Selcuk University, 42430 Konya (Turkey); Karaman, Mustafa; Kus, Mahmut [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Department of Chemical Engineering, Faculty of Engineering, Selcuk University, 42075 Konya (Turkey); Cengeloglu, Yunus; Ersoz, Mustafa [Advanced Technology Research and Application Center, Selcuk University, 42075 Konya (Turkey); Department of Chemistry, Faculty of Science, Selcuk University, 42075 Konya (Turkey)

    2015-04-15

    Herein we report the synthesis of polymer coated quantum dots (QDs)–carbon nanotube composite material with high biocompatibility and low cellular toxicity. The synthesized multi-walled carbon nanotube (MWCNT)–QD-(-poly(glycidyl methacrylate)) (pGMA) hybrids were characterized using X-ray photoelectron spectroscopy, laser scanning confocal microscopy, transmission electron microscopy and scanning electron microscopy. The results showed that quantum dots were well-distributed on nanotube surfaces in high density. The toxicological assessments of QDs and MWCNT–QD–polymer hybrids in human mammary carcinoma cells and their fluorescence imaging in living cell system were carried out. MWCNT–QD–polymer hybrids possess intense red fluorescence signal under confocal microscopy and good fluorescence stability over 6-h exposure in living cell system. The toxicity comparison of QDs and MWCNT–QD–polymer hybrids has shown that the existence of PGMA thin coating on MWCNT–QD hybrid surface decreased the cellular toxicity and increased biocompatibility. - Highlights: • We report that polymer coating of QDs on CNTs increased their biocompatibility by decreasing cellular toxicity. • QD–CNT polymer hybrid material may be proposed as a good diagnostic agent to visualize cancer cells which may be improved as a therapeutic carrier in future. • Coating QDs with polymer seems to be a right choice to be used in medicinal applications both for diagnosis and for therapy.

  15. Mesoporous and carbon hybrid structures from layered molecular precursors for Li-ion battery application: the case of β-In2S3.

    Science.gov (United States)

    Zhang, Ming-Jian; Tian, Lei-Lei; Li, Shuankui; Lin, Ling-Piao; Pan, Feng

    2016-04-04

    A new method was demonstrated to construct mesoporous and carbon hybrid structures of β-In2S3 from the thermal decomposition of layered molecular precursors. When applied to LIBs, they all exhibit good cycling stability and excellent rate performance due to the great uniformity of mesopores and pyrolysis carbon distributed in the materials.

  16. 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.

  17. Field emission from hybrid diamond-like carbon and carbon nanotube composite structures.

    Science.gov (United States)

    Zanin, H; May, P W; Hamanaka, M H M O; Corat, E J

    2013-12-11

    A thin diamond-like carbon (DLC) film was deposited onto a densely packed "forest" of vertically aligned multiwalled carbon nanotubes (VACNT). DLC deposition caused the tips of the CNTs to clump together to form a microstructured surface. Field-emission tests of this new composite material show the typical low threshold voltages for carbon nanotube structures (2 V μm(-1)) but with greatly increased emission current, better stability, and longer lifetime.

  18. Hybrid Carbon-Carbon Ablative Composites for Thermal Protection in Aerospace

    Directory of Open Access Journals (Sweden)

    P. Sanoj

    2014-01-01

    Full Text Available Composite materials have been steadily substituting metals and alloys due to their better thermomechanical properties. The successful application of composite materials for high temperature zones in aerospace applications has resulted in extensive exploration of cost effective ablative materials. High temperature heat shielding to body, be it external or internal, has become essential in the space vehicles. The heat shielding primarily protects the substrate material from external kinetic heating and the internal insulation protects the subsystems and helps to keep coefficient of thermal expansion low. The external temperature due to kinetic heating may increase to about maximum of 500°C for hypersonic reentry space vehicles while the combustion chamber temperatures in case of rocket and missile engines range between 2000°C and 3000°C. Composite materials of which carbon-carbon composites or the carbon allotropes are the most preferred material for heat shielding applications due to their exceptional chemical and thermal resistance.

  19. Metal octacarboxyphthalocyanine / multi-walled carbon nanotube hybrid for the development of dye solar cells

    CSIR Research Space (South Africa)

    Mphahlele, N

    2013-09-01

    Full Text Available octacarboxyphthalocyanines-multi-walled carbon nanotubes hybrid was prepared through non- covalent (Pi)p-(Pi)p stacking. The metallo-octacarboxyphthalocyanines-multi-walled carbon nanotubes hybrid was later employed in dye solar cells as a photosensitiser of choice...

  20. Synergetic Effects of Mechanical Properties on Graphene Nanoplatelet and Multiwalled Carbon Nanotube Hybrids Reinforced Epoxy/Carbon Fiber Composites

    OpenAIRE

    Pin-Ning Wang; Tsung-Han Hsieh; Chin-Lung Chiang; Ming-Yuan Shen

    2015-01-01

    Graphene nanoplatelets (GNPs) and carbon nanotubes (CNTs) are novel nanofillers possessing attractive characteristics, including robust compatibility with most polymers, high absolute strength, and cost effectiveness. In this study, an outstanding synergetic effect on the grapheme nanoplatelets (GNPs) and multiwalled carbon nanotubes (CNTs) hybrids were used to reinforce epoxy composite and epoxy/carbon fiber composite laminates to enhance their mechanical properties. The mechanical propertie...

  1. Carbon nanotube materials for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Parilla, P.A.; Jones, K.M.; Riker, G.; Heben, M.J. [National Renewable Energy Lab., Golden, CO (United States)

    1998-08-01

    Carbon single-wall nanotubes (SWNTs) are essentially elongated pores of molecular dimensions and are capable of adsorbing hydrogen at relatively high temperatures and low pressures. This behavior is unique to these materials and indicates that SWNTs are the ideal building block for constructing safe, efficient, and high energy density adsorbents for hydrogen storage applications. In past work the authors developed methods for preparing and opening SWNTs, discovered the unique adsorption properties of these new materials, confirmed that hydrogen is stabilized by physical rather than chemical interactions, measured the strength of interaction to be {approximately} 5 times higher than for adsorption on planar graphite, and performed infrared absorption spectroscopy to determine the chemical nature of the surface terminations before, during, and after oxidation. This year the authors have made significant advances in synthesis and characterization of SWNT materials so that they can now prepare gram quantities of high-purity SWNT samples and measure and control the diameter distribution of the tubes by varying key parameters during synthesis. They have also developed methods which purify nanotubes and cut nanotubes into shorter segments. These capabilities provide a means for opening the tubes which were unreactive to the oxidation methods that successfully opened tubes, and offer a path towards organizing nanotube segments to enable high volumetric hydrogen storage densities. They also performed temperature programmed desorption spectroscopy on high purity carbon nanotube material obtained from collaborator Prof. Patrick Bernier and finished construction of a high precision Seivert`s apparatus which will allow the hydrogen pressure-temperature-composition phase diagrams to be evaluated for SWNT materials.

  2. Properties of Multifunctional Hybrid Carbon Nanotube/Carbon Fiber Polymer Matrix Composites

    Science.gov (United States)

    Cano, Roberto J.; Kang, Jin Ho; Grimsley, Brian W.; Ratcliffe, James G.; Siochi, Emilie J.

    2016-01-01

    For aircraft primary structures, carbon fiber reinforced polymer (CFRP) composites possess many advantages over conventional aluminum alloys due to their light weight, higher strength- and stiffness-to-weight ratios, and low life-cycle maintenance costs. However, the relatively low electrical and thermal conductivities of CFRP composites fail to provide structural safety in certain operational conditions such as lightning strikes. Carbon nanotubes (CNT) offer the potential to enhance the multi-functionality of composites with improved thermal and electrical conductivity. In this study, hybrid CNT/carbon fiber (CF) polymer composites were fabricated by interleaving layers of CNT sheets with Hexcel® IM7/8852 prepreg. Resin concentrations from 1 wt% to 50 wt% were used to infuse the CNT sheets prior to composite fabrication. The interlaminar properties of the resulting hybrid composites were characterized by mode I and II fracture toughness testing. Fractographical analysis was performed to study the effect of resin concentration. In addition, multi-directional physical properties like thermal conductivity of the orthotropic hybrid polymer composite were evaluated.

  3. Carbon nanotube materials for hydrogen storage

    Energy Technology Data Exchange (ETDEWEB)

    Dillon, A.C.; Jones, K.M.; Heben, M.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-10-01

    Hydrogen burns pollution-free and may be produced from renewable energy resources. It is therefore an ideal candidate to replace fossil fuels as an energy carrier. However, the lack of a convenient and cost-effective hydrogen storage system greatly impedes the wide-scale use of hydrogen in both domestic and international markets. Although several hydrogen storage options exist, no approach satisfies all of the efficiency, size, weight, cost and safety requirements for transportation or utility use. A material consisting exclusively of micropores with molecular dimensions could simultaneously meet all of the requirements for transportation use if the interaction energy for hydrogen was sufficiently strong to cause hydrogen adsorption at ambient temperatures. Small diameter ({approx}1 mm) carbon single-wall nanotubes (SWNTs) are elongated micropores of molecular dimensions, and materials composed predominantly of SWNTs may prove to be the ideal adsorbent for ambient temperature storage of hydrogen. Last year the authors reported that hydrogen could be adsorbed on arc-generated soots containing 12{Angstrom} diameter nanotubes at temperatures in excess of 285K. In this past year they have learned that such adsorption does not occur on activated carbon materials, and that the cobalt nanoparticles present in their arc-generated soots are not responsible for the hydrogen which is stable at 285 K. These results indicate that enhanced adsorption forces within the internal cavities of the SWNTs are active in stabilizing hydrogen at elevated temperatures. This enhanced stability could lead to effective hydrogen storage under ambient temperature conditions. In the past year the authors have also demonstrated that single-wall carbon nanotubes in arc-generated soots may be selectively opened by oxidation in H{sub 2}O resulting in improved hydrogen adsorption, and they have estimated experimentally that the amount of hydrogen stored is {approximately}10% of the nanotube weight.

  4. Buckling of hybrid nanocomposites with embedded graphene and carbon nanotubes

    Science.gov (United States)

    Chandra, Y.; Saavedra Flores, E. I.; Scarpa, F.; Adhikari, S.

    2016-09-01

    With the aid of atomistic multiscale modelling and analytical approaches, buckling strength has been determined for carbon nanofibres/epoxy composite systems. Various nanofibres configurations considered are single walled carbon nano tube (SWCNT) and single layer graphene sheet (SLGS) and SLGS/SWCNT hybrid systems. Computationally, both eigen-value and non-linear large deformation-based methods have been employed to calculate the buckling strength. The non-linear computational model generated here takes into account of complex features such as debonding between polymer and filler (delamination under compression), nonlinearity in the polymer, strain-based damage criteria for the matrix, contact between fillers and interlocking of distorted filler surfaces with polymer. The effect of bridging nanofibres with an interlinking compound on the buckling strength of nano-composites has also been presented here. Computed enhancement in buckling strength of the polymer system due to nano reinforcement is found to be in the range of experimental and molecular dynamics based results available in open literature. The findings of this work indicate that carbon based nanofillers enhance the buckling strength of host polymers through various local failure mechanisms.

  5. Hybrid fiber reinforcement and crack formation in Cementitious Composite Materials

    DEFF Research Database (Denmark)

    Pereira, E.B.; Fischer, Gregor; Barros, J.A.O.

    2011-01-01

    reinforcement systems. The research described in this paper shows that the multi-scale conception of cracking and the use of hybrid fiber reinforcements do not necessarily result in an improved tensile behavior of the composite. Particular material design requirements may nevertheless justify the use of hybrid......The use of different types of fibers simultaneously for reinforcing cementitious matrices is motivated by the concept of a multi-scale nature of the crack propagation process. Fibers with different geometrical and mechanical properties are used to bridge cracks of different sizes from the micro......- to the macroscale. In this study, the performance of different fiber reinforced cementitious composites is assessed in terms of their tensile stress-crack opening behavior. The results obtained from this investigation allow a direct quantitative comparison of the behavior obtained from the different fiber...

  6. Quantifying Alumina Nanoparticle Dispersion in Hybrid Carbon Fiber Composites Using Photoluminescent Spectroscopy.

    Science.gov (United States)

    Hanhan, Imad; Selimov, Alex; Carolan, Declan; Taylor, Ambrose C; Raghavan, Seetha

    2017-02-01

    Composites modified with nanoparticles are of interest to many researchers due to the large surface-area-to-volume ratio of nano-scale fillers. One challenge with nanoscale materials that has received significant attention is the dispersion of nanoparticles in a matrix material. A random distribution of particles often ensures good material properties, especially as it relates to the thermal and mechanical performance of composites. Typical methods to quantify particle dispersion in a matrix material include optical, scanning electron, and transmission electron microscopy. These utilize images and a variety of analysis methods to describe particle dispersion. This work describes how photoluminescent spectroscopy can serve as an additional technique capable of quickly and comprehensively quantifying particle dispersion of photoluminescent particles in a hybrid composite. High resolution 2D photoluminescent maps were conducted on the front and back surfaces of a hybrid carbon fiber reinforced polymer containing varying contents of alumina nanoparticles. The photoluminescent maps were analyzed for the intensity of the alumina R1 fluorescence peak, and therefore yielded alumina particle dispersion based on changes in intensity from the embedded nanoparticles. A method for quantifying particle sedimentation is also proposed that compares the photoluminescent data of the front and back surfaces of each hybrid composite and assigns a single numerical value to the degree of sedimentation in each specimen. The methods described in this work have the potential to aid in the manufacturing processes of hybrid composites by providing on-site quality control options, capable of quickly and noninvasively providing feedback on nanoparticle dispersion and sedimentation.

  7. Novel Fabrication and Simple Hybridization of Exotic Material MEMS

    Energy Technology Data Exchange (ETDEWEB)

    Datskos, P.G.; Rajic, S.

    1999-11-13

    Work in materials other than silicon for MEMS applications has typically been restricted to metals and metal oxides instead of more ''exotic'' semiconductors. However, group III-V and II-VI semiconductors form a very important and versatile collection of material and electronic parameters available to the MEMS and MOEMS designer. With these materials, not only are the traditional mechanical material variables (thermal conductivity, thermal expansion, Young's modulus, etc.) available, but also chemical constituents can be varied in ternary and quaternary materials. This flexibility can be extremely important for both friction and chemical compatibility issues for MEMS. In addition, the ability to continually vary the bandgap energy can be particularly useful for many electronics and infrared detection applications. However, there are two major obstacles associated with alternate semiconductor material MEMS. The first issue is the actual fabrication of non-silicon devices and the second impediment is communicating with these novel devices. We will describe an essentially material independent fabrication method that is amenable to most group III-V and II-VI semiconductors. This technique uses a combination of non-traditional direct write precision fabrication processes such as diamond turning, ion milling, laser ablation, etc. This type of deterministic fabrication approach lends itself to an almost trivial assembly process. We will also describe in detail the mechanical, electrical, and optical self-aligning hybridization technique used for these alternate-material MEMS.

  8. Dynamic nanocrystal response and high temperature growth of carbon nanotube-ferroelectric hybrid nanostructure.

    Science.gov (United States)

    Kumar, Ashok; Scott, J F; Katiyar, R S

    2014-01-21

    A long standing problem related to the capping of carbon nanotubes (CNT) by inorganic materials at high temperature has been solved. In situ dynamic response of Pb(Zr0.52Ti0.48)O3 (PZT) nanocrystals attached to the wings of the outer surface of PZT/CNT hybrid-nanostructure has been demonstrated under a constant-energy high-resolution transmission electron microscopy (HRTEM) e-beam. PZT nanocrystals revealed that the crystal orientations, positions, faces, and hopping states change with time. HRTEM study has been performed to investigate the microstructure of hybrid nanostructures and nanosize polycrystal trapped across the wings. Raman spectroscopy was utilized to investigate the local structures, defects, crystal qualities and temperature dependent growth and degradation of hybrid nanostructures. Raman spectra indicate that MWCNT and PZT/MWCNT/n-Si possess good quality of CNT before and after PZT deposition until 650 °C. The monoclinic Cc/Cm phase of PZT which is optimum in piezoelectric properties was prominent in the hybrid structure and should be useful for device applications. An unusual hexagonal faceting oscillation of the nano-crystal perimeter on a 10-30 s period is also observed.

  9. Enhanced dielectric performance in polymer composite films with carbon nanotube-reduced graphene oxide hybrid filler.

    Science.gov (United States)

    Kim, Jin-Young; Kim, TaeYoung; Suk, Ji Won; Chou, Harry; Jang, Ji-Hoon; Lee, Jong Ho; Kholmanov, Iskandar N; Akinwande, Deji; Ruoff, Rodney S

    2014-08-27

    The electrical conductivity and the specific surface area of conductive fillers in conductor-insulator composite films can drastically improve the dielectric performance of those films through changing their polarization density by interfacial polarization. We have made a polymer composite film with a hybrid conductive filler material made of carbon nanotubes grown onto reduced graphene oxide platelets (rG-O/CNT). We report the effect of the rG-O/CNT hybrid filler on the dielectric performance of the composite film. The composite film had a dielectric constant of 32 with a dielectric loss of 0.051 at 0.062 wt% rG-O/CNT filler and 100 Hz, while the neat polymer film gave a dielectric constant of 15 with a dielectric loss of 0.036. This is attributed to the increased electrical conductivity and specific surface area of the rG-O/CNT hybrid filler, which results in an increase in interfacial polarization density between the hybrid filler and the polymer.

  10. Layered double hydroxide-oxidized carbon nanotube hybrids as highly efficient flame retardant nanofillers for polypropylene

    Science.gov (United States)

    Gao, Yanshan; Zhang, Yu; Williams, Gareth R.; O’Hare, Dermot; Wang, Qiang

    2016-01-01

    Aqueous miscible organic layered double hydroxides (AMO-LDHs) can act as organophilic inorganic flame retardant nanofillers for unmodified non-polar polymers. In this contribution, AMO [Mg3Al(OH)8](CO3)0.5·yH2O LDH–oxidized carbon nanotube (AMO-LDH–OCNT) hybrids are shown to perform better than the equivalent pure AMO-LDH. A synergistic effect between the AMO-LDH and OCNT was observed; this endows the hybrid material with enhanced flame retardancy, thermal stability, and mechanical properties. The thermal stability of polypropylene (PP) was significantly enhanced by adding AMO-LDH–OCNT hybrids. For PP mixed with AMO-LDH–OCNT hybrids to produce a composite with 10 wt% LDH and 2 wt% OCNT, the 50% weight loss temperature was increased by 43 °C. Further, a system with 10 wt% of AMO-LDH and 1 wt% OCNT showed a peak heat release rate (PHRR) reduction of 40%, greater than the PHRR reduction with PP/20 wt% AMO-LDH (31%). The degree of dispersion (mixability) between AMO-LDH and OCNT has a significant effect on the flame retardant performance of the hybrids. In addition, the incorporation of AMO-LDH–OCNT hybrids led to better mechanical properties, such as higher tensile strength (27.5 MPa) and elongation at break (17.9%), than those composites containing only AMO-LDH (25.6 MPa and 7.5%, respectively). PMID:27752096

  11. Layered double hydroxide-oxidized carbon nanotube hybrids as highly efficient flame retardant nanofillers for polypropylene

    Science.gov (United States)

    Gao, Yanshan; Zhang, Yu; Williams, Gareth R.; O'Hare, Dermot; Wang, Qiang

    2016-10-01

    Aqueous miscible organic layered double hydroxides (AMO-LDHs) can act as organophilic inorganic flame retardant nanofillers for unmodified non-polar polymers. In this contribution, AMO [Mg3Al(OH)8](CO3)0.5·yH2O LDH-oxidized carbon nanotube (AMO-LDH-OCNT) hybrids are shown to perform better than the equivalent pure AMO-LDH. A synergistic effect between the AMO-LDH and OCNT was observed; this endows the hybrid material with enhanced flame retardancy, thermal stability, and mechanical properties. The thermal stability of polypropylene (PP) was significantly enhanced by adding AMO-LDH-OCNT hybrids. For PP mixed with AMO-LDH-OCNT hybrids to produce a composite with 10 wt% LDH and 2 wt% OCNT, the 50% weight loss temperature was increased by 43 °C. Further, a system with 10 wt% of AMO-LDH and 1 wt% OCNT showed a peak heat release rate (PHRR) reduction of 40%, greater than the PHRR reduction with PP/20 wt% AMO-LDH (31%). The degree of dispersion (mixability) between AMO-LDH and OCNT has a significant effect on the flame retardant performance of the hybrids. In addition, the incorporation of AMO-LDH-OCNT hybrids led to better mechanical properties, such as higher tensile strength (27.5 MPa) and elongation at break (17.9%), than those composites containing only AMO-LDH (25.6 MPa and 7.5%, respectively).

  12. Report on Carbon Nano Material Workshop: Challenges and Opportunities

    Science.gov (United States)

    2013-01-22

    Lubricating Grease Thickened by Carbon Nanotubes, presented at Carbon Nano Materials and Applications Workshop, Rapid City, SD, October 31–November 1...Carbon Nano Material Workshop: Challenges and Opportunities S. Acharya a , J. Alvarado b , D. Banerjee b , W. E. Billups c , G. Chen d , B. A. Cola e...Carbon Nano Material Workshop: Challenges and Opportunities 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d

  13. Hybrid composite laminates reinforced with Kevlar/carbon/glass woven fabrics for ballistic impact testing.

    Science.gov (United States)

    Randjbaran, Elias; Zahari, Rizal; Jalil, Nawal Aswan Abdul; Majid, Dayang Laila Abang Abdul

    2014-01-01

    Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  14. Hybrid Composite Laminates Reinforced with Kevlar/Carbon/Glass Woven Fabrics for Ballistic Impact Testing

    Directory of Open Access Journals (Sweden)

    Elias Randjbaran

    2014-01-01

    Full Text Available Current study reported a facile method to investigate the effects of stacking sequence layers of hybrid composite materials on ballistic energy absorption by running the ballistic test at the high velocity ballistic impact conditions. The velocity and absorbed energy were accordingly calculated as well. The specimens were fabricated from Kevlar, carbon, and glass woven fabrics and resin and were experimentally investigated under impact conditions. All the specimens possessed equal mass, shape, and density; nevertheless, the layers were ordered in different stacking sequence. After running the ballistic test at the same conditions, the final velocities of the cylindrical AISI 4340 Steel pellet showed how much energy was absorbed by the samples. The energy absorption of each sample through the ballistic impact was calculated; accordingly, the proper ballistic impact resistance materials could be found by conducting the test. This paper can be further studied in order to characterise the material properties for the different layers.

  15. Porous carbon material containing CaO for acidic gas capture: preparation and properties.

    Science.gov (United States)

    Przepiórski, Jacek; Czyżewski, Adam; Pietrzak, Robert; Toyoda, Masahiro; Morawski, Antoni W

    2013-12-15

    A one-step process for the preparation of CaO-containing porous carbons is described. Mixtures of poly(ethylene terephthalate) with natural limestone were pyrolyzed and thus hybrid sorbents could be easily obtained. The polymeric material and the mineral served as a carbon precursor and CaO delivering agent, respectively. We discuss effects of the preparation conditions and the relative amounts of the raw materials used for the preparations on the porosity of the hybrid products. The micropore areas and volumes of the obtained products tended to decrease with increasing CaO contents. Increase in the preparation temperature entailed a decrease in the micropore volume, whereas the mesopore volume increased. The pore creation mechanism is proposed on the basis of thermogravimetric and temperature-programmed desorption measurements. The prepared CaO-containing porous carbons efficiently captured SO2 and CO2 from air. Washing out of CaO from the hybrid materials was confirmed as a suitable method to obtain highly porous carbon materials.

  16. 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.

  17. Functionalised hybrid materials of conducting polymers with individual wool fibers.

    Science.gov (United States)

    Kelly, Fern M; Johnston, James H; Borrmann, Thomas; Richardson, Michael J

    2008-04-01

    Composites of natural protein materials, such as merino wool, with the conducting polymers polypyrrole (PPy) and polyaniline (PAn) have been successfully synthesised. In doing so, hybrid materials have been produced in which the mechanical strength and flexibility of the fibers is retained whilst also incorporating the desired chemical and electrical properties of the polymer. Scanning electron microscopy shows PPy coatings to comprise individual polymer spheres, approximately 100 to 150 nm in diameter. The average size of the polymer spheres of PAn was observed to be approximately 50 to 100 nm in diameter. These spheres fuse together in a continuous sheet to coat the fibers in their entirety. The reduction of silver ions to silver metal nanoparticles onto the redox active polymer surface has also been successful and thus imparts anti-microbial properties to the hybrid materials. This gives rise to further applications requiring the inhibition of microbial growth. The chemical and physical characterisation of such products has been undertaken through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electrical conductivity, cyclic voltammetry, X-ray photoelectron spectroscopy (XPS) and the testing of their anti-microbial activity.

  18. Environmentally compatible solder materials for thick film hybrid assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Hosking, F.M.; Vianco, P.T.; Rejent, J.A.; Hernandez, C.L. [Sandia National Labs., Albuquerque, NM (United States). Materials and Process Sciences Center

    1997-02-01

    New soldering materials and processes have been developed over the last several years to address a variety of environmental issues. One of the primary efforts by the electronics industry has involved the development of alternative solders to replace the traditional lead-containing alloys. Sandia National Laboratories is developing such alternative solder materials for printed circuit board and hybrid microcircuit (HMC) applications. This paper describes the work associated with low residue, lead-free soldering of thick film HMC`s. The response of the different materials to wetting, aging, and mechanical test conditions was investigated. Hybrid test vehicles were designed and fabricated with a variety of chip capacitors and leadless ceramic chip carriers to conduct thermal, electrical continuity, and mechanical evaluations of prototype joints. Microstructural development along the solder and thick film interface, after isothermal solid state aging over a range of elevated temperatures and times, was quantified using microanalytical techniques. Flux residues on soldered samples were stressed (temperature-humidity aged) to identify potential corrosion problems. Mechanical tests also supported the development of a solder joint lifetime prediction model. Progress of this effort is summarized.

  19. 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.

  20. Thermal properties of graphene and nanostructured carbon materials

    Science.gov (United States)

    Balandin, Alexander A.

    2011-08-01

    Recent years have seen a rapid growth of interest by the scientific and engineering communities in the thermal properties of materials. Heat removal has become a crucial issue for continuing progress in the electronic industry, and thermal conduction in low-dimensional structures has revealed truly intriguing features. Carbon allotropes and their derivatives occupy a unique place in terms of their ability to conduct heat. The room-temperature thermal conductivity of carbon materials span an extraordinary large range -- of over five orders of magnitude -- from the lowest in amorphous carbons to the highest in graphene and carbon nanotubes. Here, I review the thermal properties of carbon materials focusing on recent results for graphene, carbon nanotubes and nanostructured carbon materials with different degrees of disorder. Special attention is given to the unusual size dependence of heat conduction in two-dimensional crystals and, specifically, in graphene. I also describe the prospects of applications of graphene and carbon materials for thermal management of electronics.

  1. Metallic nanoparticles deposited on carbon microspheres: novel materials for combinatorial electrochemistry and electroanalysis.

    Science.gov (United States)

    Baron, Ronan; Wildgoose, Gregory G; Compton, Richard G

    2009-04-01

    This review deals with the preparation of metallic nanoparticles on glassy carbon microspheres and the use of these new hybrid materials for combinatorial electrochemistry and electroanalysis. First, the preparation of gold, silver and palladium nanoparticles on glassy carbon microspheres by a simple electroless procedure is described. Then, different types of electrodes modified with glassy carbon microspheres are described. These are: (i) glassy carbon electrodes modified by a composite film of glassy carbon microspheres and multi-walled carbon nanotubes, (ii) basal plane pyrolylic graphite electrodes modified by the abrasive attachment of glassy carbon microspheres and (iii) carbon-epoxy composite electrodes loaded with glassy carbon microspheres. The three types of electrode architectures described consist of metallic nanoparticles embedded in a carbon matrix and each of the electrode macrodisc surfaces actually correspond to a random metallic nanoelectrode array. Carbon-epoxy composite electrodes have good characteristics for their use as practical sensors. Furthermore, the use of several kinds of metallic nanoparticles allows the construction of a multi-analyte electrode and the screening of electroactive materials by following a combinatorial approach.

  2. Photocurrent generation in carbon nanotube/cubic-phase HfO2 nanoparticle hybrid nanocomposites

    Directory of Open Access Journals (Sweden)

    Protima Rauwel

    2016-07-01

    Full Text Available A hybrid material consisting of nonfunctionalized multiwall carbon nanotubes (MWCNTs and cubic-phase HfO2 nanoparticles (NPs with an average diameter of 2.6 nm has been synthesized. Free standing HfO2 NPs present unusual optical properties and a strong photoluminescence emission in the visible region, originating from surface defects. Transmission electron microscopy studies show that these NPs decorate the MWCNTs on topological defect sites. The electronic structure of the C K-edge in the nanocomposites was probed by electron energy loss spectroscopy, highlighting the key role of the MWCNT growth defects in anchoring HfO2 NPs. A combined optical emission and absorption spectroscopy approach illustrated that, in contrast to HfO2 NPs, the metallic MWCNTs do not emit light but instead expose their discrete electronic structure in the absorption spectra. The hybrid material manifests characteristic absorption features with a gradual merger of the MWCNT π-plasmon resonance band with the intrinsic defect band and fundamental edge of HfO2. The photoluminescence of the nanocomposites indicates features attributed to combined effects of charge desaturation of HfO2 surface states and charge transfer to the MWCNTs with an overall reduction of radiative recombination. Finally, photocurrent generation under UV–vis illumination suggests that a HfO2 NP/MWCNT hybrid system can be used as a flexible nanodevice for light harvesting applications.

  3. Edge-enriched, porous carbon-based, high energy density supercapacitors for hybrid electric vehicles.

    Science.gov (United States)

    Kim, Yong Jung; Yang, Cheol-Min; Park, Ki Chul; Kaneko, Katsumi; Kim, Yoong Ahm; Noguchi, Minoru; Fujino, Takeshi; Oyama, Shigeki; Endo, Morinobu

    2012-03-12

    Supercapacitors can store and deliver energy by a simple charge separation, and thus they could be an attractive option to meet transient high energy density in operating fuel cells and in electric and hybrid electric vehicles. To achieve such requirements, intensive studies have been carried out to improve the volumetric capacitance in supercapacitors using various types and forms of carbons including carbon nanotubes and graphenes. However, conventional porous carbons are not suitable for use as electrode material in supercapacitors for such high energy density applications. Here, we show that edge-enriched porous carbons are the best electrode material for high energy density supercapacitors to be used in vehicles as an auxiliary powertrain. Molten potassium hydroxide penetrates well-aligned graphene layers vertically and consequently generates both suitable pores that are easily accessible to the electrolyte and a large fraction of electrochemically active edge sites. We expect that our findings will motivate further research related to energy storage devices and also environmentally friendly electric vehicles. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Interfacially synthesized PAni–PMo12 hybrid material for supercapacitor applications

    Indian Academy of Sciences (India)

    Arumugam Manivel; Abdullah M Asiri; Khalid Ahmad Alamry; Teresa Lana-Villarreal; Sambandam Anandan

    2014-06-01

    The concept of interfacial polymerization is utilized for the synthesis of polyaniline–phosphomolybdate (PAni–PMo12) molecular hybrids and it is well characterized. The electrical conductivity of the synthesized hybrid materials increases with increase in PMo12 wt%. The synthesized hybrid materials are evaluated as the active electrode materials for supercapacitor application. Cyclic voltammetric studies of the hybrid-modified electrode shows broad parallelogram-shaped peak as an evidence for pseudo-capacitive behaviour. The galvanostatic charge–discharge studies enlighten that interfacially synthesized hybrid materials loaded with PMo12 show relatively enhanced specific capacitance values than PMo12 free samples.

  5. Multifunctional electrocatalytic hybrid carbon nanocables with highly active edges on their walls.

    Science.gov (United States)

    Gusmão, Rui; Sofer, Zdeněk; Nováček, Michal; Luxa, Jan; Matějková, Stanislava; Pumera, Martin

    2016-03-28

    Graphene sheets exhibit fast heterogeneous electron transfer at the edges while at the basal plane the electron transfer is much slower. Carbon nanotubes (CNTs) represent fascinating quasi-1-dimensional materials due to their electronic and mechanical properties which enable the formation of (unlike graphene) robust, flexible and well defined three dimensional structures. Because CNTs are created from "rolled up" graphene sheets, exposing mostly inactive walls, they generally exhibit poor electrochemical properties. In contrast, graphene sheets can exhibit fast electron transfer rates but are often prone to "restacking" which hinders their true electrochemical potential. Here we obviate this problem by partial unzipping of CNTs, where their inner core creates nanocables with high electrical conductivity while the outer unzipped graphene layers full of edges and defects act as highly electroactive materials. Metallic nanoparticles are introduced into graphene oxide/CNT hybrid structures (GOCNT), so they do catalyze reactions which are not catalyzed by carbon. We show that in combination with trace metal doping, these nanocables act as efficient electrocatalysts towards oxidation of biomarkers and energy related applications, such as hydrogen evolution reaction. Such hybrid graphene/CNT/metallic nanoparticles present universal well-structured catalysts which should find wide applications in electrochemical devices. GOCNTs rich in oxygenated groups show much promise in pollution management, thus their adsorption behaviour was investigated to establish their ability to remove harmful heavy-metal pollutants. The results show an increasing trend in the concentration of oxygen functional groups, directly correlated with the GOCNT adsorption capacity.

  6. In vivo adsorption study of fluoxetine using carbon materials,

    OpenAIRE

    Nabais, Joao; Tinoco, Teresa; Morais, Julio

    2011-01-01

    The in vivo adsorption of fluoxetine by a commercial activated carbon and a laboratory prepared activated carbon fibre were studied. The results showthat the carbon materials tested are not toxic toWistar rats and both materials had a high efficacy in the in vivo adsorption of fluoxetine preventing toxicity of the drug overdose administered to the animals.

  7. Hybrid carbon fiber/carbon nanotube composites for structural damping applications.

    Science.gov (United States)

    Tehrani, M; Safdari, M; Boroujeni, A Y; Razavi, Z; Case, S W; Dahmen, K; Garmestani, H; Al-Haik, M S

    2013-04-19

    Carbon nanotubes (CNTs) were grown on the surface of carbon fibers utilizing a relatively low temperature synthesis technique; graphitic structures by design (GSD). To probe the effects of the synthesis protocols on the mechanical properties, other samples with surface grown CNTs were prepared using catalytic chemical vapor deposition (CCVD). The woven graphite fabrics were thermally shielded with a thin film of SiO2 and CNTs were grown on top of this film. Raman spectroscopy and electron microscopy revealed the grown species to be multi-walled carbon nanotubes (MWCNTs). The damping performance of the hybrid CNT-carbon fiber-reinforced epoxy composite was examined using dynamic mechanical analysis (DMA). Mechanical testing confirmed that the degradations in the strength and stiffness as a result of the GSD process are far less than those encountered through using the CCVD technique and yet are negligible compared to the reference samples. The DMA results indicated that, despite the minimal degradation in the storage modulus, the loss tangent (damping) for the hybrid composites utilizing GSD-grown MWCNTs improved by 56% compared to the reference samples (based on raw carbon fibers with no surface treatment or surface grown carbon nanotubes) over the frequency range 1-60 Hz. These results indicated that the energy dissipation in the GSD-grown MWCNTs composite can be primarily attributed to the frictional sliding at the nanotube/epoxy interface and to a lesser extent to the stiff thermal shielding SiO2 film on the fiber/matrix interface.

  8. Antithrombotic Protein Filter Composed of Hybrid Tissue-Fabric Material has a Long Lifetime.

    Science.gov (United States)

    Inoue, Yusuke; Yokota, Tomoyuki; Sekitani, Tsuyoshi; Kaneko, Akiko; Woo, Taeseong; Kobayashi, Shingo; Shibuya, Tomokazu; Tanaka, Masaru; Kosukegawa, Hiroyuki; Saito, Itsuro; Isoyama, Takashi; Abe, Yusuke; Yambe, Tomoyuki; Someya, Takao; Sekino, Masaki

    2017-05-01

    There are recent reports of hybrid tissue-fabric materials with good performance-high biocompatibility and high mechanical strength. In this study, we demonstrate the capability of a hybrid material as a long-term filter for blood proteins. Polyester fabrics were implanted into rats to fabricate hybrid tissue-fabric material sheets. The hybrid materials comprised biological tissue grown on the fabric. The materials were extracted from the rat's body, approximately 100 days post-implantation. The tissues were decellularized to prevent immunological rejection. An antithrombogenicity test was performed by dropping blood onto the hybrid material surface. The hybrid material showed lesser blood coagulation than polysulfone and cellulose. Blood plasma was filtered using the hybrid material to evaluate the protein removal percentage and the lifetime of the hybrid material in vitro. The hybrid material showed a comparable performance to conventional filters for protein removal. Moreover, the hybrid material could work as a protein filter for 1 month, which is six times the lifetime of polysulfone.

  9. 46 CFR 160.077-13 - Materials-Type I and Commercial Hybrid PFD.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 6 2010-10-01 2010-10-01 false Materials-Type I and Commercial Hybrid PFD. 160.077-13... Flotation Devices § 160.077-13 Materials—Type I and Commercial Hybrid PFD. (a) General. All commercial... material on each reversible side, if any. The material must be Type I material that is approved...

  10. Development of Novel Metal Hydride-Carbon Nanomaterial Based Nanocomposites as Anode Electrode Materials for Lithium Ion Battery

    Science.gov (United States)

    2014-06-30

    Final Progress Report (27-02-2012 To 26-02-2014) Project Title:- Development of novel metal hydride -carbon nanomaterial based nanocomposites as...anode electrode materials for Lithium ion battery Objectives:- The aim of this study is to develop metal hydride –carbon nanomaterial based...be as follows:- Milestone I • Synthesis of nanosized metal hydrides (NMH)-carbon nanotubes (CNT) hybridizing with G (NMH- CNT-G) nanocomposites

  11. Hybrid Titanium Composite Laminates: A New Aerospace Material

    Science.gov (United States)

    Johnson, W. S.; Cobb, Ted Q.; Lowther, Sharon; St.Clair, T. L.

    1998-01-01

    In the realm of aerospace design and performance, there are few boundaries in the never-ending drive for increased performance. This thirst for ever-increased performance of aerospace equipment has driven the aerospace and defense industries into developing exotic, extremely high-performance composites that are pushing the envelope in terms of strength-to-weight ratios, durability, and several other key measurements. To meet this challenge of ever-increasing improvement, engineers and scientists at NASA-Langley Research Center (NASA-LaRC) have developed a high-temperature metal laminate based upon titanium, carbon fibers, and a thermoplastic resin. This composite, known as the Hybrid Titanium Composite Laminate, or HTCL, is the latest chapter in a significant, but relatively short, history of metal laminates.

  12. Growth Mechanism of a Hybrid Structure Consisting of a Graphite Layer on Top of Vertical Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Nicolo' Chiodarelli

    2012-01-01

    Full Text Available Graphene and carbon nanotubes (CNTs are both carbon-based materials with remarkable optical and electronic properties which, among others, may find applications as transparent electrodes or as interconnects in microchips, respectively. This work reports on the formation of a hybrid structure composed of a graphitic carbon layer on top of vertical CNT in a single deposition process. The mechanism of deposition is explained according to the thickness of catalyst used and the atypical growth conditions. Key factors dictating the hybrid growth are the film thickness and the time dynamic through which the catalyst film dewets and transforms into nanoparticles. The results support the similarities between chemical vapor deposition processes for graphene, graphite, and CNT.

  13. Preparation and characterization of functional material based on hybrid polymer composites

    Science.gov (United States)

    Agusu, La; Amiruddin; Taswito, Chen Chen; Herdianto; Zamrun, Muh.

    2016-08-01

    The microstructures and properties of hybrid polymer composites based on polyaniline (PANi)/γ-Fe2O3 nanoparticles/TiO2/carbon have been investigated for multifunctional applications such as heavy metal removal and initial study for radar absorbing material application. γ-Fe2O3 nanoparticles with spherical shape were synthetized by a coprecipitation method from iron sand. By activating the polyethylene glycol (PEG-400) coated carbon of coconut shell, the homogenous shape and size of carbon was achieved. Then, γ- Fe2O3, TiO2, and carbon were mixed with PANi by an in situ polymerization method at low temperature 0-5 oC. Characterization process involved XRD, SEM, FTIR, VSM, and DC conductivity measurements. For radar absorber application, the functionalized polymer composites showed good electrical conductivity 0.45 S/cm to absorb the incoming electromagnetic energy. An efficient and effective reduction of Pb2+ ion from the water has been achieved by using this material.

  14. Three-dimensional helical carbon materials: Microcoiled carbon fibers, carbon nanocoils, carbon nanotubes: Synthesis, properties and applications

    Science.gov (United States)

    Xie, Jining

    Materials with a 3D-helical/spiral-structure in micron size have recently aroused a great deal of interests because of their helical morphology and unique properties. However, materials with a 3D helical structure are not commonly observed among industrially available materials. Researchers have been trying to synthesize various micro- and nano-sized 3D helical materials and are exploring the mechanisms, nature, and properties of these materials. Yet a systematic study on 3D helical carbon materials in micro- and nano-size has been missing. This research work is intended as a first step to fill this gap. Among various 3D helical materials, carbon element has stimulated great interests. Micro coiled carbon fibers, carbon nanocoils, and carbon nanotubes are major types of 3D helical carbon materials ranging from micron to nano size. Synthesis of these 3D helical carbon materials by a catalytic chemical vapor deposition method is presented in this thesis. It involves a pyrolysis of hydrocarbon gas (e.g. acetylene) over transition metals, such as Ni, Fe, and Co, at high reaction temperature (500--1000°C). Besides the conventional thermal filament chemical vapor deposition method, a novel microwave chemical vapor deposition (MWCVD) method has been developed to synthesize micro- and nano-sized 3D helical carbon materials economically. The faster heating and cooling processes associated with microwave CVD have potential for large-scale production in the near future. Compared with previously reported microwave plasma enhanced chemical vapor deposition (MWPECVD) method, this method does not require high vacuum and much higher deposition rate is another major advantage. It has been found in this work that microwave plays an important role on coil morphology formation for micro coiled carbon fibers and carbon nanocoils. The large temperature gradient around the catalytic particles could be the reason. Different reaction factors have been checked to optimize the deposition

  15. Perovskite-fullerene hybrid materials suppress hysteresis in planar diodes.

    KAUST Repository

    Xu, Jixian

    2015-05-08

    Solution-processed planar perovskite devices are highly desirable in a wide variety of optoelectronic applications; however, they are prone to hysteresis and current instabilities. Here we report the first perovskite-PCBM hybrid solid with significantly reduced hysteresis and recombination loss achieved in a single step. This new material displays an efficient electrically coupled microstructure: PCBM is homogeneously distributed throughout the film at perovskite grain boundaries. The PCBM passivates the key PbI3(-) antisite defects during the perovskite self-assembly, as revealed by theory and experiment. Photoluminescence transient spectroscopy proves that the PCBM phase promotes electron extraction. We showcase this mixed material in planar solar cells that feature low hysteresis and enhanced photovoltage. Using conductive AFM studies, we reveal the memristive properties of perovskite films. We close by positing that PCBM, by tying up both halide-rich antisites and unincorporated halides, reduces electric field-induced anion migration that may give rise to hysteresis and unstable diode behaviour.

  16. ELABORATION AND CHARACTERIZATION OF HYBRID MATERIALS ORGANIC / INORGANIC

    Directory of Open Access Journals (Sweden)

    O BOUBEKKA

    2010-12-01

    Full Text Available Hybrid materials "organic-inorganic" are the subject of immense interest, allowing both to combine some properties of an inorganic material and a polymer. In this work we have carried out a study on conductive polymers, in general, emphasizing the polyaniline. On the other hand, we have presented the inorganic compounds (NbSe2, and ternary compound Nn3Sn SnNb5Se9. From the chemical method, we had to synthesize the following mixtures: PANI/NbSe2, PANI /, Nn3Sn PANI / SnNb5Se9. The structural study of these new compounds are produced by X-ray diffraction and infrared. The morphology of the resulting mixtures to be studied by scanning electron microscopy.

  17. Quantum materials. Lateral semiconductor nanostructures, hybrid systems and nanocrystals

    Energy Technology Data Exchange (ETDEWEB)

    Heitmann, Detlef (ed.) [Hamburg Univ. (Germany). Inst. fuer Angewandte Physik

    2010-07-01

    Semiconductor nanostructures are ideal systems to tailor the physical properties via quantum effects, utilizing special growth techniques, self-assembling, wet chemical processes or lithographic tools in combination with tuneable external electric and magnetic fields. Such systems are called ''Quantum Materials''.The electronic, photonic, and phononic properties of these systems are governed by size quantization and discrete energy levels. The charging is controlled by the Coulomb blockade. The spin can be manipulated by the geometrical structure, external gates and by integrating hybrid ferromagnetic emitters.This book reviews sophisticated preparation methods for quantum materials based on III-V and II-VI semiconductors and a wide variety of experimental techniques for the investigation of these interesting systems. It highlights selected experiments and theoretical concepts and gives such a state-of-the-art overview about the wide field of physics and chemistry that can be studied in these systems. (orig.)

  18. Controlling the Morphology of Nano-Hybrid Materials

    Directory of Open Access Journals (Sweden)

    Abdullah I.A. Jaafari

    2010-01-01

    Full Text Available Problem statement: It is known that layer double hydroxide is one of the nano ordered layered compounds and possesses plate-like morphology if carefully crystallized. Approach: In this study, Co-Sn LDH consisting of divalent and tetravalent cations was prepared with new morphology. XRD patterns of the prepared Co-Sn LDH showed that the interlayer spacing of the LDH was 0.78 nm and SEM image showed nano-needles structure. Results: By intercalation reaction with monocarboxylic acids at room temperature, XRD patterns indicated that the interlayered spacing increased to 3-4.8 nm and formed organic-inorganic nano-hybrid materials. Also, SEM images showed that the nano-needles structure of Co-Sn LDH changes to plate like-structure. Conclusion: Thermal analyses (TG, DTG and DTA and Infrared spectrum confirmed the intercalation processes of n-capric acid and n-stearic acid inside Co-Sn LDH and the formation of nano-hybrid materials.

  19. 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.

  20. Ternary Hybrid Material for High-Performance Lithium-Sulfur Battery.

    Science.gov (United States)

    Fan, Qi; Liu, Wen; Weng, Zhe; Sun, Yueming; Wang, Hailiang

    2015-10-14

    The rechargeable lithium-sulfur battery is a promising option for energy storage applications because of its low cost and high energy density. The electrochemical performance of the sulfur cathode, however, is substantially compromised because of fast capacity decay caused by polysulfide dissolution/shuttling and low specific capacity caused by the poor electrical conductivities of the active materials. Herein we demonstrate a novel strategy to address these two problems by designing and synthesizing a carbon nanotube (CNT)/NiFe2O4-S ternary hybrid material structure. In this unique material architecture, each component synergistically serves a specific purpose: The porous CNT network provides fast electron conduction paths and structural stability. The NiFe2O4 nanosheets afford strong binding sites for trapping polysulfide intermediates. The fine S nanoparticles well-distributed on the CNT/NiFe2O4 scaffold facilitate fast Li(+) storage and release for energy delivery. The hybrid material exhibits balanced high performance with respect to specific capacity, rate capability, and cycling stability with outstandingly high Coulombic efficiency. Reversible specific capacities of 1350 and 900 mAh g(-1) are achieved at rates of 0.1 and 1 C respectively, together with an unprecedented cycling stability of ∼0.009% capacity decay per cycle over more than 500 cycles.

  1. 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.

  2. Hot Extrusion of A356 Aluminum Metal Matrix Composite with Carbon Nanotube/Al2O3 Hybrid Reinforcement

    Science.gov (United States)

    Kim, H. H.; Babu, J. S. S.; Kang, C. G.

    2014-05-01

    Over the years, the attention of material scientists and engineers has shifted from conventional composite materials to nanocomposite materials for the development of light weight and high-performance devices. Since the discovery of carbon nanotubes (CNTs), many researchers have tried to fabricate metal matrix composites (MMCs) with CNT reinforcements. However, CNTs exhibit low dispersibility in metal melts owing to their poor wettability and large surface-to-volume ratio. The use of an array of short fibers or hybrid reinforcements in a preform could overcome this problem and enhance the dispersion of CNTs in the matrix. In this study, multi-walled CNT/Al2O3 preform-based aluminum hybrid composites were fabricated using the infiltration method. Then, the composites were extruded to evaluate changes in its mechanical properties. In addition, the dispersion of reinforcements was investigated using a hardness test. The required extrusion pressure of hybrid MMCs increased as the Al2O3/CNT fraction increased. The deformation resistance of hybrid material was over two times that of the original A356 aluminum alloy material due to strengthening by the Al2O3/CNTs reinforcements. In addition, an unusual trend was detected; primary transition was induced by the hybrid reinforcements, as can be observed in the pressure-displacement curve. Increasing temperature of the material can help increase formability. In particular, temperatures under 623 K (350 °C) and over-incorporating reinforcements (Al2O3 20 pct, CNTs 3 pct) are not recommended owing to a significant increase in the brittleness of the hybrid material.

  3. Hybrid materials and polymer electrolytes for electrochromic device applications.

    Science.gov (United States)

    Thakur, Vijay Kumar; Ding, Guoqiang; Ma, Jan; Lee, Pooi See; Lu, Xuehong

    2012-08-08

    Electrochromic (EC) materials and polymer electrolytes are the most imperative and active components in an electrochromic device (ECD). EC materials are able to reversibly change their light absorption properties in a certain wavelength range via redox reactions stimulated by low direct current (dc) potentials of the order of a fraction of volts to a few volts. The redox switching may result in a change in color of the EC materials owing to the generation of new or changes in absorption band in visible region, infrared or even microwave region. In ECDs the electrochromic layers need to be incorporated with supportive components such as electrical contacts and ion conducting electrolytes. The electrolytes play an indispensable role as the prime ionic conduction medium between the electrodes of the EC materials. The expected applications of the electrochromism in numerous fields such as reflective-type display and smart windows/mirrors make these materials of prime importance. In this article we have reviewed several examples from our research work as well as from other researchers' work, describing the recent advancements on the materials that exhibit visible electrochromism and polymer electrolytes for electrochromic devices. The first part of the review is centered on nanostructured inorganic and conjugated polymer-based organic-inorganic hybrid EC materials. The emphasis has been to correlate the structures, morphologies and interfacial interactions of the EC materials to their electronic and ionic properties that influence the EC properties with unique advantages. The second part illustrates the perspectives of polymer electrolytes in electrochromic applications with emphasis on poly (ethylene oxide) (PEO), poly (methyl methacrylate) (PMMA) and polyvinylidene difluoride (PVDF) based polymer electrolytes. The requirements and approaches to optimize the formulation of electrolytes for feasible electrochromic devices have been delineated. Copyright © 2012 WILEY

  4. Hierarchically porous silicon–carbon–nitrogen hybrid materials towards highly efficient and selective adsorption of organic dyes

    Science.gov (United States)

    Meng, Lala; Zhang, Xiaofei; Tang, Yusheng; Su, Kehe; Kong, Jie

    2015-01-01

    The hierarchically macro/micro-porous silicon–carbon–nitrogen (Si–C–N) hybrid material was presented with novel functionalities of totally selective and highly efficient adsorption for organic dyes. The hybrid material was conveniently generated by the pyrolysis of commercial polysilazane precursors using polydivinylbenzene microspheres as sacrificial templates. Owing to the Van der Waals force between sp2-hybridized carbon domains and triphenyl structure of dyes, and electrostatic interaction between dyes and Si-C-N matrix, it exhibites high adsorption capacity and good regeneration and recycling ability for the dyes with triphenyl structure, such as methyl blue (MB), acid fuchsin (AF), basic fuchsin and malachite green. The adsorption process is determined by both surface adsorption and intraparticle diffusion. According to the Langmuir model, the adsorption capacity is 1327.7 mg·g−1 and 1084.5 mg·g−1 for MB and AF, respectively, which is much higher than that of many other adsorbents. On the contrary, the hybrid materials do not adsorb the dyes with azo benzene structures, such as methyl orange, methyl red and congro red. Thus, the hierarchically porous Si–C–N hybrid material from a facile and low cost polymer-derived strategy provides a new perspective and possesses a significant potential in the treatment of wastewater with complex organic pollutants. PMID:25604334

  5. Carbon The Future Material for Advanced Technology Applications

    CERN Document Server

    Messina, Giacomo

    2006-01-01

    Carbon-based materials and their applications constitute a burgeoning topic of scientific research among scientists and engineers attracted from diverse areas such as applied physics, materials science, biology, mechanics, electronics and engineering. Further development of current materials, advances in their applications, and discovery of new forms of carbon are the themes addressed by the frontier research in these fields. This book covers all the fundamental topics concerned with amorphous and crystalline C-based materials, such as diamond, diamond-like carbon, carbon alloys, carbon nanotubes. The goal is, by coherently progressing from growth - and characterisation techniques to technological applications for each class of material, to fashion the first comprehensive state-of-the-art review of this fast evolving field of research in carbon materials.

  6. Influence of exopolymeric materials on bacterially induced mineralization of carbonates.

    Science.gov (United States)

    Bains, Amrita; Dhami, Navdeep Kaur; Mukherjee, Abhijit; Reddy, M Sudhakara

    2015-04-01

    Microbially induced calcium carbonate precipitation is an immensely growing technology for restoration and remediation of building materials. The investigation on role of exopolymeric substances and biofilms in microbially induced calcium carbonate precipitation suggested that these exopolymeric materials play major role in carbonate precipitation in Bacillus megaterium SS3 along with enzymes urease and carbonic anhydrase. The concentration of EPS directly affects the precipitation of carbonate precipitates which might be due to capturing of Ca(2+) ions by acting as nucleation site. Components of the media and presence of calcium also play crucial role in production of exopolymeric substances along with affecting the morphology of carbonate precipitates.

  7. Designed amyloid fibers as materials for selective carbon dioxide capture.

    Science.gov (United States)

    Li, Dan; Furukawa, Hiroyasu; Deng, Hexiang; Liu, Cong; Yaghi, Omar M; Eisenberg, David S

    2014-01-07

    New materials capable of binding carbon dioxide are essential for addressing climate change. Here, we demonstrate that amyloids, self-assembling protein fibers, are effective for selective carbon dioxide capture. Solid-state NMR proves that amyloid fibers containing alkylamine groups reversibly bind carbon dioxide via carbamate formation. Thermodynamic and kinetic capture-and-release tests show the carbamate formation rate is fast enough to capture carbon dioxide by dynamic separation, undiminished by the presence of water, in both a natural amyloid and designed amyloids having increased carbon dioxide capacity. Heating to 100 °C regenerates the material. These results demonstrate the potential of amyloid fibers for environmental carbon dioxide capture.

  8. Mechanical Behavior of Nanostructured Hybrids Based on Poly(Vinyl Alcohol/Bioactive Glass Reinforced with Functionalized Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    H. S. Mansur

    2012-01-01

    Full Text Available This study reports the synthesis and characterization of novel tridimensional porous hybrids based on PVA combined with bioactive glass and reinforced by chemically functionalized carbon nanotubes (CNT for potential use in bone tissue engineering. The functionalization of CNT was performed by introducing carboxylic groups in multiwall nanotubes. This process aimed at enhancing the affinity of CNTs with the water-soluble PVA polymer derived by the hydrogen bonds formed among alcohol (PVA and carboxylic groups (CNT–COOH. In the sequence, the CNT–COOH (0.25 wt% were used as the nanostructure modifier for the hybrid system based on PVA associated with the bioactive glass (BaG. The mechanical properties of the nanostructured hybrids reinforced with CNT–COOH were evaluated by axial compression tests, and they were compared to reference hybrid. The averaged yield stresses of macroporous hybrids were (2.3 ± 0.9 and (4.4 ± 1.0 MPa for the reference and the CNT reinforced materials, respectively. Moreover, yield strain and Young's modulus were significantly enhanced by about 30% for the CNT–COOH hybrids. Hence, as far as the mechanical properties are concerned, the results have clearly showed the feasibility of utilizing these new hybrids reinforced with functionalized CNT in repairing cancellous bone tissues.

  9. Influence of Material Distribution on Impact Resistance of Hybrid Composites

    Science.gov (United States)

    Abatan, Ayu; Hu, Hurang

    1998-01-01

    Impact events occur in a wide variety of circumstances. A typical example is a bullet impacting a target made of composite material. These impact events produce time-varying loads on a structure that can result in damage. As a first step to understanding the damage resistance issue in composite laminates, an accurate prediction of the transient response during an impact event is necessary. The analysis of dynamic loadings on laminated composite plates has undergone considerable development recently. Rayleigh-Ritz energy method was used to determine the impact response of laminated plates. The impact response of composite plates using shear deformation plate theory was analyzed. In recent work a closed-form solution was obtained for a rectangular plate with four edges simply supported subjected to a center impact load using classical plate theory. The problem was further investigated and the analysis results compared of both classical plate theory and shear deformation theory, and found that classical plate theory predicts very accurate results for the range of small deformations considered. In this study, the influence of cross sectional material distribution on the comparative impact responses of hybrid metal laminates subjected to low and medium velocity impacts is investigated. A simple linear model to evaluate the magnitude of the impact load is proposed first, and it establishes a relation between the impact velocity and the impact force. Then a closed-form solution for impact problem is presented. The results were compared with the finite element analysis results. For an 11 layer-hybrid laminate, the impact response as a function of material distribution in cross-section is presented. With equal areal weight, the effect of the number of laminate layers on the impact resistance is also investigated. Finally, the significance of the presented results is discussed.

  10. Electromagnetic characteristics of carbon nanotube film materials

    Directory of Open Access Journals (Sweden)

    Zhang Wei

    2015-08-01

    Full Text Available Carbon nanotube (CNT possesses remarkable electrical conductivity, which shows great potential for the application as electromagnetic shielding material. This paper aims to characterize the electromagnetic parameters of a high CNT loading film by using waveguide method. The effects of layer number of CNT laminate, CNT alignment and resin impregnation on the electromagnetic characteristics were analyzed. It is shown that CNT film exhibits anisotropic electromagnetic characteristic. Pristine CNT film shows higher real part of complex permittivity, conductivity and shielding effectiveness when the polarized direction of incident wave is perpendicular to the winding direction of CNT film. For the CNT film laminates, complex permittivity increases with increasing layer number, and correspondingly, shielding effectiveness decreases. The five-layer CNT film shows extraordinary shielding performance with shielding effectiveness ranging from 67 dB to 78 dB in X-band. Stretching process induces the alignment of CNTs. When aligned direction of CNTs is parallel to the electric field, CNT film shows negative permittivity and higher conductivity. Moreover, resin impregnation into CNT film leads to the decrease of conductivity and shielding effectiveness. This research will contribute to the structural design for the application of CNT film as electromagnetic shielding materials.

  11. Carbon-based electrode materials for DNA electroanalysis.

    Science.gov (United States)

    Kato, Dai; Niwa, Osamu

    2013-01-01

    This review addresses recent studies of newly developed carbon-based electrode materials and their use for DNA electroanalysis. Recently, new carbon materials including carbon nanotubes (CNT), graphene and diamond-based nanocarbon electrodes have been actively developed as sensing platforms for biomolecules, such as DNA and proteins. Electrochemical techniques using these new material-based electrodes can provide very simple and inexpensive sensing platforms, and so are expected to be used as one of the "post-light" DNA analysis methods, which include coulometric detection, amperometric detection with electroactive tags or intercalators, and potentiometric detection. DNA electroanalysis using these new carbon materials is summarized in view of recent advances on electrodes.

  12. Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

    Science.gov (United States)

    Woodworth James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  13. Graphene-Multiwalled Carbon Nanotube Hybrids Synthesized by Gamma Radiations: Application as a Glucose Sensor

    Directory of Open Access Journals (Sweden)

    Leila Shahriary

    2014-01-01

    Full Text Available Three-dimensional hybrid nanomaterial of graphene-multiwalled carbon nanotubes (G-MWCNTs was synthesized using gamma rays emitted by a 60Co source with a dose rate of 3.95 Gy min−1. The products were characterized by fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis, photoluminescence (PL, and micro-Raman spectroscopy, X-ray diffraction analysis (XRD, scanning electron microscopy (SEM, and transmission electron microscopy (TEM. FTIR and UV-Vis analysis reveals the formation of hybrid nanomaterial which is confirmed by XRD, micro-Raman analysis, and PL. SEM micrograph depicts the composite structure of graphene layers and MWCNTs, while the TEM micrograph exhibits graphene layers covered by MWCNTs. The G-MWCNTs hybrid used as electrode for electrochemical studies in K3Fe(CN6 shows enhancement in electrocatalytic behavior, compared to each individual starting material, therefore, has been applied for amperometric sensing of glucose in alkaline solution and exhibits sensitivity of 12.5 μAmM-1 cm−2 and low detection limit 1.45 μM (S/N=3 in a linear range of 0.1 to 14 mM (R2=0.985.

  14. Effective Removal of Tetracycline Antibiotics from Water using Hybrid Carbon Membranes

    Science.gov (United States)

    Liu, Ming-Kai; Liu, Ying-Ya; Bao, Dan-Dan; Zhu, Gen; Yang, Guo-Hai; Geng, Jun-Feng; Li, Hai-Tao

    2017-03-01

    Antibiotic residues in drinking water have become a global problem, especially in developing countries. However, effective purification of water contaminated by antibiotics remains a great challenge. Here, we investigated the removing of tetracycline by carbon nanomaterials with different structures and surface functionalities. The result shows that a membrane of thick graphene oxide (GO) and activated carbon (AC) with a thickness of 15 μm can effectively remove 98.9% of tetracycline hydrochloride (TCH) from water by vacuum filtration. Structural analysis indicated that the AC nanoparticles were uniformly inserted into the GO interstitial sites without any aggregations. Also, GO sheets were loosened by the encapsulated AC nanoparticles, leading to the formation of numerous tiny pores (3-10 nm) that acted as channels for fluid passage, whereas the carbons and chemical groups on the GO surface adsorbed TCH. GO/AC membrane exhibits the best adsorption efficiency among the investigated materials, including pure GO, AC, carbon nanotube (CNT), and CNT/AC and GO/CNT hybrids.

  15. Effective Removal of Tetracycline Antibiotics from Water using Hybrid Carbon Membranes

    Science.gov (United States)

    Liu, Ming-kai; Liu, Ying-ya; Bao, Dan-dan; Zhu, Gen; Yang, Guo-hai; Geng, Jun-feng; Li, Hai-tao

    2017-01-01

    Antibiotic residues in drinking water have become a global problem, especially in developing countries. However, effective purification of water contaminated by antibiotics remains a great challenge. Here, we investigated the removing of tetracycline by carbon nanomaterials with different structures and surface functionalities. The result shows that a membrane of thick graphene oxide (GO) and activated carbon (AC) with a thickness of 15 μm can effectively remove 98.9% of tetracycline hydrochloride (TCH) from water by vacuum filtration. Structural analysis indicated that the AC nanoparticles were uniformly inserted into the GO interstitial sites without any aggregations. Also, GO sheets were loosened by the encapsulated AC nanoparticles, leading to the formation of numerous tiny pores (3–10 nm) that acted as channels for fluid passage, whereas the carbons and chemical groups on the GO surface adsorbed TCH. GO/AC membrane exhibits the best adsorption efficiency among the investigated materials, including pure GO, AC, carbon nanotube (CNT), and CNT/AC and GO/CNT hybrids. PMID:28255174

  16. Cycle Analysis of Micro Gas Turbine-Molten Carbonate Fuel Cell Hybrid System

    Science.gov (United States)

    Kimijima, Shinji; Kasagi, Nobuhide

    A hybrid system based on a micro gas turbine (µGT) and a high-temperature fuel cell, i.e., molten carbonate fuel cell (MCFC) or solid oxide fuel cell (SOFC), is expected to achieve a much higher efficiency than conventional distributed power generation systems. In this study, a cycle analysis method and the performance evaluation of a µGT-MCFC hybrid system, of which the power output is 30kW, are investigated to clarify its feasibility. We developed a general design strategy in which a low fuel input to a combustor and higher MCFC operating temperature result in a high power generation efficiency. A high recuperator temperature effectiveness and a moderate steam-carbon ratio are the requirements for obtaining a high material strength in a turbine. In addition, by employing a combustor for complete oxidation of MCFC effluents without additional fuel input, i.e., a catalytic combustor, the power generation efficiency of a µGT-MCFC is achieved at over 60%(LHV).

  17. An overview of carbon materials for flexible electrochemical capacitors.

    Science.gov (United States)

    He, Yongmin; Chen, Wanjun; Gao, Caitian; Zhou, Jinyuan; Li, Xiaodong; Xie, Erqing

    2013-10-07

    Under the background of the quick development of lightweight, flexible, and wearable electronic devices in our society, a flexible and highly efficient energy management strategy is needed for their counterpart energy-storage systems. Among them, flexible electrochemical capacitors (ECs) have been considered as one of the most promising candidates because of their significant advantages in power and energy densities, and unique properties of being flexible, lightweight, low-cost, and environmentally friendly compared with current energy storage devices. In a common EC, carbon materials play an irreplaceable and principal role in its energy-storage performance. Up till now, most progress towards flexible ECs technologies has mostly benefited from the continuous development of carbon materials. As a result, in view of the dual remarkable highlights of ECs and carbon materials, a summary of recent research progress on carbon-based flexible EC electrode materials is presented in this review, including carbon fiber (CF, consisting of carbon microfiber-CMF and carbon nanofiber-CNF) networks, carbon nanotube (CNT) and graphene coatings, CNT and/or graphene papers (or films), and freestanding three-dimensional (3D) flexible carbon-based macroscopic architectures. Furthermore, some promising carbon materials for great potential applications in flexible ECs are introduced. Finally, the trends and challenges in the development of carbon-based electrode materials for flexible ECs and their smart applications are analyzed.

  18. Multiwalled carbon nanotube hybrids as MRI contrast agents

    Directory of Open Access Journals (Sweden)

    Nikodem Kuźnik

    2016-07-01

    Full Text Available Magnetic resonance imaging (MRI is one of the most commonly used tomography techniques in medical diagnosis due to the non-invasive character, the high spatial resolution and the possibility of soft tissue imaging. Contrast agents, such as gadolinium complexes and superparamagnetic iron oxides, are administered to spotlight certain organs and their pathologies. Many new models have been proposed that reduce side effects and required doses of these already clinically approved contrast agents. These new candidates often possess additional functionalities, e.g., the possibility of bioactivation upon action of particular stimuli, thus serving as smart molecular probes, or the coupling with therapeutic agents and therefore combining both a diagnostic and therapeutic role. Nanomaterials have been found to be an excellent scaffold for contrast agents, among which carbon nanotubes offer vast possibilities. The morphology of multiwalled carbon nanotubes (MWCNTs, their magnetic and electronic properties, the possibility of different functionalization and the potential to penetrate cell membranes result in a unique and very attractive candidate for a new MRI contrast agent. In this review we describe the different issues connected with MWCNT hybrids designed for MRI contrast agents, i.e., their synthesis and magnetic and dispersion properties, as well as both in vitro and in vivo behavior, which is important for diagnostic purposes. An introduction to MRI contrast agent theory is elaborated here in order to point to the specific expectations regarding nanomaterials. Finally, we propose a promising, general model of MWCNTs as MRI contrast agent candidates based on the studies presented here and supported by appropriate theories.

  19. Substrate integrated Lead-Carbon hybrid ultracapacitor with flooded, absorbent glass mat and silica-gel electrolyte configurations

    OpenAIRE

    Banerjee, A.; Ravikumar, MK; Jalajakshi, A; Kumar, Suresh P; Gaffoor, SA; Shukla, AK

    2012-01-01

    Lead-Carbon hybrid ultracapacitors (Pb-C HUCs) with flooded, absorbent-glass-mat (AGM) and silica-gel sulphuric acid electrolyte configurations are developed and performance tested. Pb-C HUCs comprise substrate-integrated PbO2 (SI-PbO2) as positive electrodes and high surface-area carbon with graphite-sheet substrate as negative electrodes. The electrode and silica-gel electrolyte materials are characterized by XRD, XPS, SEM, TEM, Rheometry, BET surface area, and FTIR spectroscopy in conjunct...

  20. Effect of Carbon Containing Materials on Pure Carbon Reaction-bonded SiC

    Institute of Scientific and Technical Information of China (English)

    JI Xiaoli; WEI Lei; SUN Feng

    2008-01-01

    Petroleum coke, graphite, gas carbon and lower sulfur carbon black were used to prepare reaction-bonded silicon carbide. The influences of different carbon containing materials on properties of carbonaceous precursors, sintering process, and microstructure of the prepared SiC were researched. The results show that:(1)With the density of carbon containing materials increasing, the porosity of carbonaceous precursors decreases and the infiltrating process of liquid silicon is more difficult.(2)The reaction between carbon containing materials and liquid silicon, the volume effect is more obvious with the density of carbon containing materials increasing.(3)As the carbon containing materials density decreasing, residual carbon in reaction bonded SiC also decreases.

  1. 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.

  2. Structure of Solvent-Free Nanoparticle−Organic Hybrid Materials

    KAUST Repository

    Yu, Hsiu-Yu

    2010-11-16

    We derive the radial distribution function and the static structure factor for the particles in model nanoparticleorganic hybrid materials composed of nanoparticles and attached oligomeric chains in the absence of an intervening solvent. The assumption that the oligomers form an incompressible fluid of bead-chains attached to the particles that is at equilibrium for a given particle configuration allows us to apply a density functional theory for determining the equilibrium configuration of oligomers as well as the distribution function of the particles. A quasi-analytic solution is facilitated by a regular perturbation analysis valid when the oligomer radius of gyration R g is much greater than the particle radius a. The results show that the constraint that each particle carries its own share of the fluid attached to itself yields a static structure factor that approaches zero as the wavenumber approaches zero. This result indicates that each particle excludes exactly one other particle from its neighborhood. © 2010 American Chemical Society.

  3. Preparation of Poly(p-phenylene sulfi de)/Carbon Composites with Enhanced Thermal Conductivity and Electrical Insulativity via Hybrids of Boron Nitride and Carbon Fillers

    Institute of Scientific and Technical Information of China (English)

    WU Jieli; WANG Jinwen; CHEN Feng

    2015-01-01

    The present work enhanced the thermal conductivity of poly(p-phenylene sulfi de)/expanded graphites and poly(p-phenylene sulfi de)/carbon nanotubes, by incorporating composites with hexagonal boron nitride, which simultaneously succeeded in raising the electrical conductivity of the systems. A two-step mechanical processing method which includes rotating solid-state premixing and inner mixing was adopted to improve dispersion of the hybrids, contributing to the formation of an interspered thermal conductive network. Similar synergic effect in thermal conductivity enhancement was discovered in the hybrid systems regardless of the dimension difference between the two carbonfi llers. Such is postulated to be the one satisfying advantage generated by the afore-mentioned network; the other is the insulativity of the hybrid systems given by the effective blockage of hexagonal boron nitride as an insulating material in our network.

  4. Hyaluronan and calcium carbonate hybrid nanoparticles for colorectal cancer chemotherapy

    Science.gov (United States)

    Bai, Jinghui; Xu, Jian; Zhao, Jian; Zhang, Rui

    2017-09-01

    A hybrid drug delivery system (DDS) composed of hyaluronan and calcium carbonate (CC) was developed. By taking advantage of the tumor-targeting ability of hyaluronan and the drug-loading property of CC, the well-formed hyaluronan–CC nanoparticles were able to serve as a DDS targeting colorectal cancer with a decent drug loading content, which is beneficial in the chemotherapy of colorectal cancer. In this study, hyaluronan–CC nanoparticles smaller than 100 nm were successfully developed to load the wide-range anti-cancer drug adriamycin (Adr) to construct hyaluronan–CC/Adr nanoparticles. On the other hand, we also found that hyaluronan–CC/Adr nanoparticles can possibly increase the uptake ratio of Adr into HT29 colorectal cancer cells when compared with hyaluronan-free nanoparticles (CC/Adr) via the CD44 receptor-mediated endocytosis via competitive uptake and in vivo imaging assays. Note that both in vitro (CCK-8 assay on HT29 cells) and in vivo (anti-cancer assay on HT-29 tumor-bearing nude mice model) experiments revealed that hyaluronan–CC/Adr nanoparticles exhibited stronger anti-cancer activity than free Adr or CC/Adr nanoparticles with minimized toxic side effects and preferable cancer-suppression potential.

  5. Amyloid-carbon hybrid membranes for universal water purification

    Science.gov (United States)

    Bolisetty, Sreenath; Mezzenga, Raffaele

    2016-04-01

    Industrial development, energy production and mining have led to dramatically increased levels of environmental pollutants such as heavy metal ions, metal cyanides and nuclear waste. Current technologies for purifying contaminated waters are typically expensive and ion specific, and there is therefore a significant need for new approaches. Here, we report inexpensive hybrid membranes made from protein amyloid fibrils and activated porous carbon that can be used to remove heavy metal ions and radioactive waste from water. During filtration, the concentration of heavy metal ions drops by three to five orders of magnitude per passage and the process can be repeated numerous times. Notably, their efficiency remains unaltered when filtering several ions simultaneously. The performance of the membrane is enabled by the ability of the amyloids to selectively absorb heavy metal pollutants from solutions. We also show that our membranes can be used to recycle valuable heavy metal contaminants by thermally reducing ions trapped in saturated membranes, leading to the creation of elemental metal nanoparticles and films.

  6. Amyloid-carbon hybrid membranes for universal water purification.

    Science.gov (United States)

    Bolisetty, Sreenath; Mezzenga, Raffaele

    2016-04-01

    Industrial development, energy production and mining have led to dramatically increased levels of environmental pollutants such as heavy metal ions, metal cyanides and nuclear waste. Current technologies for purifying contaminated waters are typically expensive and ion specific, and there is therefore a significant need for new approaches. Here, we report inexpensive hybrid membranes made from protein amyloid fibrils and activated porous carbon that can be used to remove heavy metal ions and radioactive waste from water. During filtration, the concentration of heavy metal ions drops by three to five orders of magnitude per passage and the process can be repeated numerous times. Notably, their efficiency remains unaltered when filtering several ions simultaneously. The performance of the membrane is enabled by the ability of the amyloids to selectively absorb heavy metal pollutants from solutions. We also show that our membranes can be used to recycle valuable heavy metal contaminants by thermally reducing ions trapped in saturated membranes, leading to the creation of elemental metal nanoparticles and films.

  7. Measurement of contact resistance in CdSe-single-walled carbon nanotube hybrids.

    Science.gov (United States)

    Shin, Minkyung; Ahn, Juwon; Park, Taehee; Yi, Whikun

    2014-08-01

    The CdSe-single-walled carbon nanotube (SWNT) hybrids are synthesized for measuring contact resistance between CdSe quantum dots and SWNTs in two hybrid samples, i.e., spray-deposited CdSe on SWNTs, and pyrene-self assembled CdSe on SWNTs. Currents are measured through indium-tin oxide (ITO), CdSe-SWNT hybrids and the tip of conductive AFM (c-AFM) with and without light at 532 and 655 nm.

  8. Hybrid Quantum-Classical Approach to Correlated Materials

    Science.gov (United States)

    Bauer, Bela; Wecker, Dave; Millis, Andrew J.; Hastings, Matthew B.; Troyer, Matthias

    2016-07-01

    Recent improvements in the control of quantum systems make it seem feasible to finally build a quantum computer within a decade. While it has been shown that such a quantum computer can in principle solve certain small electronic structure problems and idealized model Hamiltonians, the highly relevant problem of directly solving a complex correlated material appears to require a prohibitive amount of resources. Here, we show that by using a hybrid quantum-classical algorithm that incorporates the power of a small quantum computer into a framework of classical embedding algorithms, the electronic structure of complex correlated materials can be efficiently tackled using a quantum computer. In our approach, the quantum computer solves a small effective quantum impurity problem that is self-consistently determined via a feedback loop between the quantum and classical computation. Use of a quantum computer enables much larger and more accurate simulations than with any known classical algorithm, and will allow many open questions in quantum materials to be resolved once a small quantum computer with around 100 logical qubits becomes available.

  9. Carbon fiber CVD coating by carbon nanostructured for space materials protection against atomic oxygen

    Science.gov (United States)

    Pastore, Roberto; Bueno Morles, Ramon; Micheli, Davide

    2016-07-01

    adhesion and durability in the environment. Though these coatings are efficient in protecting polymer composites, their application imposes severe constraints. Their thermal expansion coefficients may differ markedly from those of polymer composite substrates: as a result, cracks develop in the coatings on thermal cycling and AO can penetrate through them to the substrate. In addition to the technicalities of forming an effective barrier, such factors as cost, convenience of application and ease of repair are important considerations in the selection of a coating for a particular application. The latter issues drive the aerospace research toward the development of novel light composite materials, like the so called polymer nanocomposites, which are materials with a polymer matrix and a filler with at least one dimension less than 100 nanometers. Current interest in nanocomposites has been generated and maintained because nanoparticle-filled polymers exhibit unique combinations of properties not achievable with traditional composites. These combinations of properties can be achieved because of the small size of the fillers, the large surface area the fillers provide, and in many cases the unique properties of the fillers themselves. In particular, the carbon fiber-based polymeric composite materials are the basic point of interest: the aim of the present study is to find new solution to produce carbon fiber-based composites with even more upgraded performances. One intriguing strategy to tackle such an issue has been picked out in the coupling between the carbon fibers and the carbon nanostructures. That for two main reasons: first, carbon nanostructures have shown fancy potentialities for any kind of technological applications since their discovery, second, the chemical affinity between fiber and nanostructure (made of the same element) should be a likely route to approach the typical problems due to thermo-mechanical compatibility. This work is joined in such framework

  10. Synthesis and properties of core–shell fluorescent hybrids with distinct morphologies based on carbon dots

    KAUST Repository

    Markova, Zdenka

    2012-01-01

    Fluorescent core-shell nanohybrids with the shells derived from carbon dots and cores differing in the chemical nature and morphology were synthesized. Hybrid nanoparticles combine fluorescence with other functionalities such as magnetic response on a single platform. These hybrids can be used in various bioapplications as demonstrated with labeling of stem cells. © The Royal Society of Chemistry 2012.

  11. Nanostructured metal/carbon hybrids for electrocatalysis by direct carbonization of inverse micelle multilayers.

    Science.gov (United States)

    Jang, Yu Jin; Jang, Yoon Hee; Han, Sang-Beom; Khatua, Dibyendu; Hess, Claudia; Ahn, Hyungju; Ryu, Du Yeol; Shin, Kwanwoo; Park, Kyung-Won; Steinhart, Martin; Kim, Dong Ha

    2013-02-26

    A synthetic strategy for the fabrication of graphitic carbon nanomaterials containing highly dispersed arrays of metal nanoparticles is reported. This synthetic strategy involves successive deposition of inverse micelle monolayers containing a metal precursor and reduction of the latter, followed by direct carbonization of the obtained multilayer structure of inverse micelles containing metal nanoparticles. Thus, a "direct-carbonization" concept, in which the block copolymer simultaneously serves as soft template and as carbon source, was combined with a multilayer buildup protocol. The inner architecture of the multilayer structures consisting of carbon and metal nanoparticles was studied by X-ray reflectivity, grazing incidence small-angle X-ray scattering, and cross-sectional transmission electron microscopy imaging. The hexagonal near ordering of the metal nanoparticles in the block copolymer micelle multilayers was by and large conserved after carbonization. The resulting carbon structures containing multilayers of highly dispersed metal nanoparticles exhibit superior electrocatalytic activity in formic acid and methanol oxidation, suggesting that they are promising electrode materials for fuel cells.

  12. Environmental effects on the hybrid glass fiber/carbon fiber composites

    Science.gov (United States)

    Tsai, Yun-I.

    2009-12-01

    Fiber reinforced polymer composites (FRPCs) have been widely used to replace conventional metals due to the high specific strength, fatigue resistance, and light weight. In the power distribution industry, an advanced composites rod has been developed to replace conventional steel cable as the load-bearing core of overhead conductors. Such conductors, called aluminum conductor composite core (ACCC) significantly increases the transmitting efficiency of existing power grid system without extensive rebuilding expenses, while meeting future demand for electricity. In general, the service life of such overhead conductors is required to be at least 30 years. Therefore, the long-term endurance of the composite core in various environments must be well-understood. Accelerated aging by hygrothermal exposure was conducted to determine the effect of moisture on the glass fiber (GF)/carbon fiber (CF) hybrid composites. The influence of water immersion and humid air exposure on mechanical properties is investigated. Results indicated that immersion in water is the most severe environment for such hybrid GF/CF composites, and results in greater saturation and degradation of properties. When immersed directly in water, the hybrid GF/CF composites exhibit a moisture uptake behavior that is more complex than composite materials reinforced with only one type of fiber. The unusual diffusion behavior is attributed to a higher packing density of fibers at the annular GF/CF interface, which acts as a temporary moisture barrier. Moisture uptake leads to the mechanical and thermal degradation of such hybrid GF/CF composites. Findings presented here indicate that the degradation is a function of exposure temperature, time, and moisture uptake level. Results also indicate that such hybrid GF/CF composites recover short beam shear (SBS) strength and glass transition temperature (Tg) values comparable to pre-aged samples after removal of the absorbed moisture. In the hygrothermal environment

  13. Single-Walled Carbon Nanotube-Polyamidoamine Dendrimer Hybrids for Heterogeneous Catalysis.

    Science.gov (United States)

    Giacalone, Francesco; Campisciano, Vincenzo; Calabrese, Carla; La Parola, Valeria; Syrgiannis, Zois; Prato, Maurizio; Gruttadauria, Michelangelo

    2016-04-26

    We report the synthesis and catalytic properties of single-walled carbon nanotube-polyamidoamine dendrimers hybrids (SWCNT-PAMAM), prepared via a convergent strategy. The direct reaction of cystamine-based PAMAM dendrimers (generations 2.5 and 3.0) with pristine SWCNTs in refluxing toluene, followed by immobilization and reduction of [PdCl4](2-), led to the formation of highly dispersed small palladium nanoparticles homogeneously confined throughout the nanotube length. One of these functional materials proved to be an efficient catalyst in Suzuki and Heck reactions, able to promote the above processes down to 0.002 mol % showing a turnover number (TON) of 48 000 and a turnover frequency (TOF) of 566 000 h(-1). In addition, the hybrid material could be recovered and recycled for up to 6 times. No leaching of the metal has been detected during the Suzuki coupling. Additional experiments carried out on the spent catalyst permitted to suggest that a "release and catch" mechanism is operative in both reactions, although during Heck reaction small catalytically active soluble Pd species are also present.

  14. Oxygen- and Lithium-Doped Hybrid Boron-Nitride/Carbon Networks for Hydrogen Storage.

    Science.gov (United States)

    Shayeganfar, Farzaneh; Shahsavari, Rouzbeh

    2016-12-20

    Hydrogen storage capacities have been studied on newly designed three-dimensional pillared boron nitride (PBN) and pillared graphene boron nitride (PGBN). We propose these novel materials based on the covalent connection of BNNTs and graphene sheets, which enhance the surface and free volume for storage within the nanomaterial and increase the gravimetric and volumetric hydrogen uptake capacities. Density functional theory and molecular dynamics simulations show that these lithium- and oxygen-doped pillared structures have improved gravimetric and volumetric hydrogen capacities at room temperature, with values on the order of 9.1-11.6 wt % and 40-60 g/L. Our findings demonstrate that the gravimetric uptake of oxygen- and lithium-doped PBN and PGBN has significantly enhanced the hydrogen sorption and desorption. Calculations for O-doped PGBN yield gravimetric hydrogen uptake capacities greater than 11.6 wt % at room temperature. This increased value is attributed to the pillared morphology, which improves the mechanical properties and increases porosity, as well as the high binding energy between oxygen and GBN. Our results suggest that hybrid carbon/BNNT nanostructures are an excellent candidate for hydrogen storage, owing to the combination of the electron mobility of graphene and the polarized nature of BN at heterojunctions, which enhances the uptake capacity, providing ample opportunities to further tune this hybrid material for efficient hydrogen storage.

  15. EFFECT OF CLIMATIC FACTOR ON THE MECHANICAL BEHAVIOUR OF AEOLIAN BLADES: APPLICATION OF HYBRID COMPOSITE MATERIALS

    Directory of Open Access Journals (Sweden)

    F. Mili

    2015-08-01

    Full Text Available The great interest which the wind power brings in the development of the various economic sectors encourages to contribute in the improvement of the hydrothermal and mechanical performances of the blades of wind rotors with horizontal axis. The use of composite materials involves a profit of substantial weight, strength to the directional constraints that the blade will undergo during its work and a reduction of the aerodynamic and mechanical losses. The adoption of composite materials with unidirectional reinforcement carbon/epoxy makes it possible to get for the structure a high wear resistance and a reduction of the phenomenon of bearing pressure created around the airfoil of the blade moving relative compared to the speed of the wind. The evaluation of the behavior of such composites with [+θ/- θ]4S stacking sequence, with the combined effect of the temperature, the moisture and the tensile effort constitutes the principal axis of this contribution. In order to minimize the costs, our analysis will direct towards hybrid composite materials glass-carbon/epoxy being presented in the form of symmetrical laminates [+q/0°]2S and antisymmetric [+q/0°/90°/-q]. The results obtained showed that their use contributes to the improvement of their thermomechanical behavior by involving profits of performance, weight, cost savings and energy.

  16. Investigation of the Mechanical Properties of Hybrid Carbon-Hemp Laminated Composites Used as Thermal Insulation for Different Industrial Applications

    Directory of Open Access Journals (Sweden)

    M. L. Scutaru

    2014-04-01

    Full Text Available Carbon-hemp composite laminate provides good thermal properties. For this reason this type of material is presently being used for various applications like insulator for airplanes, spaceships, nuclear reactors, and so forth. Unfortunately their mechanical properties are less studied. These characteristics are very important since they should be guaranteed also for important mechanical stress in addition to the thermal one. The present paper presents a study regarding the impact testing of some hybrid composite laminate panels based on polyester resin reinforced with both carbon and hemp fabric. The effects of different impact speeds on the mechanical behavior of these panels have been analyzed. The paper lays stress on the characterization of this hybrid composite laminate regarding the impact behavior of these panels by dropping a weight with low velocity.

  17. Characterization of exposures to nanoscale particles and fibers during solid core drilling of hybrid carbon nanotube advanced composites.

    Science.gov (United States)

    Bello, Dhimiter; Wardle, Brian L; Zhang, Jie; Yamamoto, Namiko; Santeufemio, Christopher; Hallock, Marilyn; Virji, M Abbas

    2010-01-01

    This work investigated exposures to nanoparticles and nanofibers during solid core drilling of two types of advanced carbon nanotube (CNT)-hybrid composites: (1) reinforced plastic hybrid laminates (alumina fibers and CNT); and (2) graphite-epoxy composites (carbon fibers and CNT). Multiple real-time instruments were used to characterize the size distribution (5.6 nm to 20 microm), number and mass concentration, particle-bound polyaromatic hydrocarbons (b-PAHs), and surface area of airborne particles at the source and breathing zone. Time-integrated samples included grids for electron microscopy characterization of particle morphology and size resolved (2 nm to 20 microm) samples for the quantification of metals. Several new important findings herein include generation of airborne clusters of CNTs not seen during saw-cutting of similar composites, fewer nanofibers and respirable fibers released, similarly high exposures to nanoparticles with less dependence on the composite thickness, and ultrafine (composite material.

  18. Quantitative monitoring of the removal of non-encapsulated material external to filled carbon nanotube samples.

    Science.gov (United States)

    Martincic, Markus; Pach, Elzbieta; Ballesteros, Belén; Tobias, Gerard

    2015-12-21

    The endohedral functionalization of carbon nanotubes with both organic and inorganic materials allows the development of tailored functional hybrids whose properties benefit from the synergistic effects of the constituent compounds. Bulk filling of carbon nanotubes (CNTs) results in samples that contain a large amount of non-encapsulated material external to the CNTs. The presence of the external material is detrimental to the processing and application of the resulting hybrids. Here we introduce the use of UV-Vis spectroscopy to monitor the cleaning process, i.e. the elimination of non-encapsulated compounds. Chrome azurol S has been employed to assess the bulk removal of external samarium(iii) chloride from filled single-walled carbon nanotubes. Chrome azurol S is of interest since it can be used to quantify a large variety of materials in a fast, accurate and reliable manner. The parameters that control the cleaning process have been optimized, including the time, temperature, volume and sonication, to achieve a fast and complete removal of the external material.

  19. Selective determination of ascorbic acid with a novel hybrid material based 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid and the Dawson type ion [P{sub 2}Mo{sub 18}O{sub 62}]{sup 6-} immobilized on glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Ammam, Malika, E-mail: Malika.Ammam@uoit.c [Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4 (Canada); Easton, E. Bradley [Faculty of Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4 (Canada)

    2011-02-28

    In this study, we synthesized a new hybrid material using well-Dawson K{sub 6}[P{sub 2}Mo{sub 18}O{sub 62}].nH{sub 2}O and a room temperature ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF{sub 4}]). CHN elemental analysis showed that one mole of [P{sub 2}Mo{sub 18}O{sub 62}]{sup 6-} reacts with 6 moles of [BMIM]{sup +} to form [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62}. FT-IR spectra showed the presence of both 1-butyl-3-methylimidazolium cation and the Dawson anion. TG analysis displayed a relative thermal stability of the hybrid material compared to the parent Dawson POM. The new hybrid material [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62} was immobilized on glassy carbon (GC) electrode and the modified electrode was investigated by cyclic voltammetry and amperometry. Compared to the electrochemical behavior of dissolved [P{sub 2}Mo{sub 18}O{sub 62}]{sup 6-}, a slight shift in the redox peaks towards negative potentials is observed for the immobilized [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62}. The relationship between the peak currents of the deposited [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62} film and scan rate is shown to be linear, which demonstrates a surface-confined electron transfer processes. [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62} modified electrode showed high sensitivities towards pH and shown to be active even at neutral pH. [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62} modified GC electrode was subjected to cyclic voltammetry and amperometry in the presence of ascorbic acid (AA) and found to exhibit a remarkable catalytic activity towards the oxidation of AA. The catalytic oxidation peak of AA at [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62} modified GC electrode occurs at low potential of {approx}0 V vs Ag/AgCl at neutral pH and shifts to more positive potentials when pH decreases. Comparison between [BMIM]{sub 6}P{sub 2}Mo{sub 18}O{sub 62} and [P{sub 2}Mo{sub 18}O{sub 62}]{sup 6-} modified GC films towards the oxidation of AA suggests that

  20. Field Sensing Characteristic Research of Carbon Fiber Smart Material

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiaoyu; Lü Yong; CHEN Jianzhong; LI Zhuoqiu

    2015-01-01

    In order to research the field sensing characteristic of the carbon fiber smart material, the Tikhonov regularization principle and the modiifed Newton-Raphson(MNR) algorithm were adopted to solve the inverse problem of the electrical resistance tomography (ERT). An ERT system of carbon fiber smart material was developed. Field sensing characteristic was researched with the experiment. The experimental results show that the speciifc resistance distribution of carbon ifber smart material is highly consistent with the distribution of structural strain. High resistance zone responds to high strain area, and the speciifc resistance distribution of carbon ifber smart material relfects the distribution of sample strain in covering area. Monitoring by carbon ifber smart material on complicated strain status in sample ifeld domain is realized through theoretical and experimental study.

  1. Influence of the hybrid material size in silicon oxycarbide materials characteristics; Influencia del tamano del material hibrido en las caracteristicas de los oxicarburos de silicio obtenidos

    Energy Technology Data Exchange (ETDEWEB)

    Mazo, M. A.; Palencia, C.; Nistal, A.; Rubio, F.; Rubio, J.; Oteo, J. L.

    2012-11-01

    In this work has been investigated the influence of the TEOS/PDMS hybrid size during the pyrolysis process to obtain the related silicon oxycarbide glasses. Hybrids monolithic pieces (100 mm x 50 mm x 5 mm), were crushed (1 mm x 1 mm x 1 mm) and grounded in agate or attrition to 16 and 3 {mu}m, respectively. Then, they were pyrolyzed at 1100 degree centigrade to obtain silicon oxycarbide glasses (SiOC). These materials present structural and microstructural differences. The monolithic sample showed the highest %C into the silica network (34 %), and after grounding in agate mortar decreased to 26 %. However the attrition milled sample reached %C values similar to the monolithic (32 %). This agrees with FT-IR band at 880 cm-1 assigned to Si-C bonds formation and related to higher carbon content into silica network. The carbon free phase displays a domain size of 3.44 nm which increased to 3.66 nm for the attrition milled. This result is due to a higher graphitization degree. The SiOC monolithic sample morphology displays spherical interconnected particles with pores of 12 {mu}m. This morphology disappeared for the SiOC attrition milled sample, formed by irregular particles of 3 {mu}m. (Author) 38 refs.

  2. High abrasion resistance coating materials from organic/inorganic hybrid materials produced by the sol-gel method

    OpenAIRE

    1990-01-01

    A series of new high abrasion resistance coating materials have been prepared utilizing organic/inorganic hybrid materials formed by cohydrolyzing a metal alkoxide sol (e.g. silicon, aluminum, titanium, or zirconium metal alkoxide sol) with one or more bis(trialkoxysilane-containing) organic components or related functionalized species. These hybrid materials show optical clarity and improve the abrasion resistance of polymer substrates when applied as coatings and cured on such substrates.

  3. Novel hybrid nanostructured materials of magnetite nanoparticles and pectin

    Science.gov (United States)

    Sahu, Saurabh; Dutta, Raj Kumar

    2011-04-01

    A novel hybrid nanostructured material comprising superparamagnetic magnetite nanoparticles (MNPs) and pectin was synthesized by crosslinking with Ca2+ ions to form spherical calcium pectinate nanostructures, referred as MCPs, which were typically found to be 100-150 nm in size in dried condition, confirmed from transmission electron microscopy and scanning electron microscopy. The uniform size distribution was revealed from dynamic light scattering measurement. In aqueous medium the MCPs showed swelling behavior with an average size of 400 nm. A mechanism of formation of spherical MCPs is outlined constituting a MNP-pectin interface encapsulated by calcium pectinate at the periphery, by using an array of characterization techniques like zeta potential, thermogravimetry, Fourier transformed infrared and X-ray photoelectron spectroscopy. The MCPs were stable in simulated gastrointestinal fluid and ensured minimal loss of magnetic material. They exhibited superparamagnetic behavior, confirmed from zero field cooled and field cooled profiles and showed high saturation magnetization (Ms) of 46.21 emu/g at 2.5 T and 300 K. Ms decreased with increasing precursor pectin concentrations, attributed to quenching of magnetic moments by formation of a magnetic dead layer on the MNPs.

  4. Hybrid metal organic scintillator materials system and particle detector

    Science.gov (United States)

    Bauer, Christina A.; Allendorf, Mark D.; Doty, F. Patrick; Simmons, Blake A.

    2011-07-26

    We describe the preparation and characterization of two zinc hybrid luminescent structures based on the flexible and emissive linker molecule, trans-(4-R,4'-R') stilbene, where R and R' are mono- or poly-coordinating groups, which retain their luminescence within these solid materials. For example, reaction of trans-4,4'-stilbenedicarboxylic acid and zinc nitrate in the solvent dimethylformamide (DMF) yielded a dense 2-D network featuring zinc in both octahedral and tetrahedral coordination environments connected by trans-stilbene links. Similar reaction in diethylformamide (DEF) at higher temperatures resulted in a porous, 3-D framework structure consisting of two interpenetrating cubic lattices, each featuring basic to zinc carboxylate vertices joined by trans-stilbene, analogous to the isoreticular MOF (IRMOF) series. We demonstrate that the optical properties of both embodiments correlate directly with the local ligand environments observed in the crystal structures. We further demonstrate that these materials produce high luminescent response to proton radiation and high radiation tolerance relative to prior scintillators. These features can be used to create sophisticated scintillating detection sensors.

  5. Hybrid carbon/glass fiber composites: Micromechanical analysis of structure–damage resistance relationships

    DEFF Research Database (Denmark)

    Mishnaevsky, Leon; Dai, Gaoming

    2014-01-01

    A computational study of the effect of microstructure of hybrid carbon/glass fiber composites on their strength is presented. Unit cells with hundreds of randomly located and misaligned fibers of various properties and arrangements are subject to tensile and compression loading, and the evolution...... of fiber damages is analyzed in numerical experiments. The effects of fiber clustering, matrix properties, nanoreinforcement, load sharing rules on the strength and damage resistance of composites are studied. It was observed that hybrid composites under uniform displacement loading might have lower...... strength than pure composites, while the strength of hybrid composites under inform force loading increases steadily with increasing the volume content of carbon fibers....

  6. Hybrid-Type Organic Thermoelectric Materials Containing Nanoparticles as a Carrier Transport Promoter

    Science.gov (United States)

    Oshima, Keisuke; Inoue, Junta; Sadakata, Shifumi; Shiraishi, Yukihide; Toshima, Naoki

    2017-05-01

    Carbon nanotubes (CNTs) have recently received much attention as thermoelectric materials. Although the carrier mobility within a single CNT is very high, the charge carrier transport between CNTs is quite slow. We have utilized nanoparticles (NPs) for promotion of the carrier transport between CNTs for improving their thermoelectric performance. Poly(vinyl chloride) (PVC) was used as a binder of the CNTs. Thus, hybrid-type organic thermoelectric materials containing the NPs were constructed from Pd NPs, CNTs, and PVC. The thermoelectric properties were slightly improved in the three-component films by only mixing the separately-prepared Pd NPs. The NPs of a polymer complex, poly(nickel 1,1,2,2-ethenetetrathiolate) (n-PETT), were also used as a charge carrier transport promoter instead of the Pd NPs to produce n-PETT/CNT/PVC hybrid films. Treatment of the three-component films with methanol produced a high thermoelectric power factor and low thermal conductivity, resulting in a high "apparent" thermoelectric performance ( ZT ˜ 0.3 near room temperature) although the thermal conductivity was measured in the through-plane direction, which is a different direction from that for the electrical conductivity.

  7. Hybrid-Type Organic Thermoelectric Materials Containing Nanoparticles as a Carrier Transport Promoter

    Science.gov (United States)

    Oshima, Keisuke; Inoue, Junta; Sadakata, Shifumi; Shiraishi, Yukihide; Toshima, Naoki

    2016-08-01

    Carbon nanotubes (CNTs) have recently received much attention as thermoelectric materials. Although the carrier mobility within a single CNT is very high, the charge carrier transport between CNTs is quite slow. We have utilized nanoparticles (NPs) for promotion of the carrier transport between CNTs for improving their thermoelectric performance. Poly(vinyl chloride) (PVC) was used as a binder of the CNTs. Thus, hybrid-type organic thermoelectric materials containing the NPs were constructed from Pd NPs, CNTs, and PVC. The thermoelectric properties were slightly improved in the three-component films by only mixing the separately-prepared Pd NPs. The NPs of a polymer complex, poly(nickel 1,1,2,2-ethenetetrathiolate) (n-PETT), were also used as a charge carrier transport promoter instead of the Pd NPs to produce n-PETT/CNT/PVC hybrid films. Treatment of the three-component films with methanol produced a high thermoelectric power factor and low thermal conductivity, resulting in a high "apparent" thermoelectric performance (ZT ˜ 0.3 near room temperature) although the thermal conductivity was measured in the through-plane direction, which is a different direction from that for the electrical conductivity.

  8. Flexible carbon nanotube--Cu2O hybrid electrodes for li-ion batteries.

    Science.gov (United States)

    Goyal, Anubha; Reddy, Arava L M; Ajayan, Pulickel M

    2011-06-20

    This study demonstrates the formation of a flexible and free-standing carbon nanotube-copper oxide-poly(vinylidene fluoride) (CNT-Cu(2) O-PVDF) nanocomposite and its application as an electrode-separator material for Li-ion batteries. Binder-free hybrid electrodes are obtained by conformally coating CNTs with Cu(2) O via electrodeposition and then embedding the resulting architecture into a porous poly(vinylidene fluoride-hexafluoropropylene) PVDF-HFP-SiO(2) polymer electrolyte membrane. The synergistic presence of high-capacity transition metal oxides and conductive CNTs results in twice the reversible areal capacity of 2.3 mAh cm(-2) as compared to 1.2 mAh cm(-2) for pure CNTs.

  9. EVALUATION OF CARBON DIOXIDE CAPTURE FROM EXISTING COAL FIRED PLANTS BY HYBRID SORPTION USING SOLID SORBENTS

    Energy Technology Data Exchange (ETDEWEB)

    Benson, Steven; Palo, Daniel; Srinivasachar, Srivats; Laudal, Daniel

    2014-12-01

    Under contract DE-FE0007603, the University of North Dakota conducted the project Evaluation of Carbon Dioxide Capture from Existing Coal Fired Plants by Hybrid Sorption Using Solid Sorbents. As an important element of this effort, an Environmental Health and Safety (EH&S) Assessment was conducted by Barr Engineering Co. (Barr) in association with the University of North Dakota. The assessment addressed air and particulate emissions as well as solid and liquid waste streams. The magnitude of the emissions and waste streams was estimated for evaluation purposes. EH&S characteristics of materials used in the system are also described. This document contains data based on the mass balances from both the 40 kJ/mol CO2 and 80 kJ/mol CO2 desorption energy cases evaluated in the Final Technical and Economic Feasibility study also conducted by Barr Engineering.

  10. The optoelectronic properties of a photosystem I-carbon nanotube hybrid system

    Energy Technology Data Exchange (ETDEWEB)

    Kaniber, Simone M; Holleitner, Alexander W [Walter Schottky Institut, Technische Universitaet Muenchen, Am Coulombwall 3, D-85748 Garching (Germany); Simmel, Friedrich C [LMU Munich, Geschwister-Scholl-Platz 1, D-80539 Muenchen (Germany); Carmeli, Itai, E-mail: holleitner@wsi.tum.d, E-mail: itai@post.tau.ac.i [Chemistry Department and NIBN, Ben Gurion University, 84105 Be' er Sheva (Israel)

    2009-08-26

    The photoconductance properties of photosystem I (PSI) covalently bound to carbon nanotubes (CNTs) are measured. We demonstrate that the PSI forms active electronic junctions with the CNTs, enabling control of the CNTs' photoconductance by the PSI. In order to electrically contact the photoactive proteins, a cysteine mutant is generated at one end of the PSI by genetic engineering. The CNTs are covalently bound to this reactive group using carbodiimide chemistry. We detect an enhanced photoconductance signal of the hybrid material at photon wavelengths resonant to the absorption maxima of the PSI compared to non-resonant wavelengths. The measurements prove that it is feasible to integrate photosynthetic proteins into optoelectronic circuits at the nanoscale.

  11. Multifunctional electrocatalytic hybrid carbon nanocables with highly active edges on their walls

    Science.gov (United States)

    Gusmão, Rui; Sofer, Zdeněk; Nováček, Michal; Luxa, Jan; Matějková, Stanislava; Pumera, Martin

    2016-03-01

    Graphene sheets exhibit fast heterogeneous electron transfer at the edges while at the basal plane the electron transfer is much slower. Carbon nanotubes (CNTs) represent fascinating quasi-1-dimensional materials due to their electronic and mechanical properties which enable the formation of (unlike graphene) robust, flexible and well defined three dimensional structures. Because CNTs are created from ``rolled up'' graphene sheets, exposing mostly inactive walls, they generally exhibit poor electrochemical properties. In contrast, graphene sheets can exhibit fast electron transfer rates but are often prone to ``restacking'' which hinders their true electrochemical potential. Here we obviate this problem by partial unzipping of CNTs, where their inner core creates nanocables with high electrical conductivity while the outer unzipped graphene layers full of edges and defects act as highly electroactive materials. Metallic nanoparticles are introduced into graphene oxide/CNT hybrid structures (GOCNT), so they do catalyze reactions which are not catalyzed by carbon. We show that in combination with trace metal doping, these nanocables act as efficient electrocatalysts towards oxidation of biomarkers and energy related applications, such as hydrogen evolution reaction. Such hybrid graphene/CNT/metallic nanoparticles present universal well-structured catalysts which should find wide applications in electrochemical devices. GOCNTs rich in oxygenated groups show much promise in pollution management, thus their adsorption behaviour was investigated to establish their ability to remove harmful heavy-metal pollutants. The results show an increasing trend in the concentration of oxygen functional groups, directly correlated with the GOCNT adsorption capacity.Graphene sheets exhibit fast heterogeneous electron transfer at the edges while at the basal plane the electron transfer is much slower. Carbon nanotubes (CNTs) represent fascinating quasi-1-dimensional materials due to

  12. Cell response to single-walled carbon nanotubes in hybrid porous collagen sponges.

    Science.gov (United States)

    Mao, Hongli; Kawazoe, Naoki; Chen, Guoping

    2015-02-01

    Three-dimensional (3D) porous collagen sponges incorporated with single-walled carbon nanotubes (SWCNTs) were prepared and used for 3D culture of bovine articular chondrocytes (BACs). The pore structures of the sponges were controlled by using ice particulates as a porogen material. The responses of cells to SWCNTs were investigated in this 3D cell culture system by evaluation of cell functions and cellular uptake of SWCNTs. The results showed that cells adhered and spatially distributed in the porous sponges. The incorporation of SWCNTs in the porous sponges promoted cell proliferation and production of sulfated glycosaminoglycans (sGAG). Confocal Raman imaging revealed that SWCNTs could be internalized by cells. The hybrid porous sponges not only provided nanostructured pore surfaces to facilitate cell proliferation and extracellular matrix (ECM) secretion but also supplied nanomaterials for cellular uptake which may be useful for biomedical applications.

  13. Carbon materials for drug delivery & cancer therapy

    Directory of Open Access Journals (Sweden)

    Zhuang Liu

    2011-07-01

    Full Text Available Carbon nanotubes and graphene are both low-dimensional sp2 carbon nanomaterials exhibiting many unique physical and chemical properties that are interesting in a wide range of areas including nanomedicine. Since 2004, carbon nanotubes have been extensively explored as drug delivery carriers for the intracellular transport of chemotherapy drugs, proteins, and genes. In vivo cancer treatment with carbon nanotubes has been demonstrated in animal experiments by several different groups. Recently, graphene, another allotrope of carbon, has also shown promise in various biomedical applications. In this article, we will highlight recent research on these two categories of closely related carbon nanomaterials for applications in drug delivery and cancer therapy, and discuss the opportunities and challenges in this rapidly growing field.

  14. Piezoresistive Carbon-based Hybrid Sensor for Body-Mounted Biomedical Applications

    Science.gov (United States)

    Melnykowycz, M.; Tschudin, M.; Clemens, F.

    2017-02-01

    For body-mounted sensor applications, the evolution of soft condensed matter sensor (SCMS) materials offer conformability andit enables mechanical compliance between the body surface and the sensing mechanism. A piezoresistive hybrid sensor and compliant meta-material sub-structure provided a way to engineer sensor physical designs through modification of the mechanical properties of the compliant design. A piezoresistive fiber sensor was produced by combining a thermoplastic elastomer (TPE) matrix with Carbon Black (CB) particles in 1:1 mass ratio. Feedstock was extruded in monofilament fiber form (diameter of 300 microns), resulting in a highly stretchable sensor (strain sensor range up to 100%) with linear resistance signal response. The soft condensed matter sensor was integrated into a hybrid design including a 3D printed metamaterial structure combined with a soft silicone. An auxetic unit cell was chosen (with negative Poisson’s Ratio) in the design in order to combine with the soft silicon, which exhibits a high Poisson’s Ratio. The hybrid sensor design was subjected to mechanical tensile testing up to 50% strain (with gauge factor calculation for sensor performance), and then utilized for strain-based sensing applications on the body including gesture recognition and vital function monitoring including blood pulse-wave and breath monitoring. A 10 gesture Natural User Interface (NUI) test protocol was utilized to show the effectiveness of a single wrist-mounted sensor to identify discrete gestures including finger and hand motions. These hand motions were chosen specifically for Human Computer Interaction (HCI) applications. The blood pulse-wave signal was monitored with the hand at rest, in a wrist-mounted. In addition different breathing patterns were investigated, including normal breathing and coughing, using a belt and chest-mounted configuration.

  15. Two-dimensional carbon-coated graphene/metal oxide hybrids for enhanced lithium storage.

    Science.gov (United States)

    Su, Yuezeng; Li, Shuang; Wu, Dongqing; Zhang, Fan; Liang, Haiwei; Gao, Pengfei; Cheng, Chong; Feng, Xinliang

    2012-09-25

    Metal oxides (MOs) have been widely investigated as promising high-capacity anode material for lithium ion batteries, but they usually exhibit poor cycling stability and rate performance due to the huge volume change induced by the alloying reaction with lithium. In this article, we present a double protection strategy by fabricating a two-dimensional (2D) core-shell nanostructure to improve the electrochemical performance of metal oxides in lithium storage. The 2D core-shell architecture is constructed by confining the well-defined graphene based metal oxides nanosheets (G@MO) within carbon layers. The resulting 2D carbon-coated graphene/metal oxides nanosheets (G@MO@C) inherit the advantages of graphene, which possesses high electrical conductivity, large aspect ratio, and thin feature. Furthermore, the carbon shells can tackle the deformation of MO nanoparticles while keeping the overall electrode highly conductive and active in lithium storage. As the result, the produced G@MO@C hybrids exhibit outstanding reversible capacity and excellent rate performance for lithium storage (G@SnO(2)@C, 800 mAh g(-1) at the rate of 200 mA g(-1) after 100 cycles; G@Fe(3)O(4)@C, 920 mAh g(-1) at the rate of 200 mA g(-1) after 100 cycles).

  16. Modeling elastic and thermal properties of 2.5D carbon fiber and carbon/SiC hybrid matrix composites by homogenization method

    Directory of Open Access Journals (Sweden)

    Luiz Claudio Pardini

    2010-08-01

    Full Text Available Advanced carbon fiber hybrid carbon-ceramic matrix composites are realizing their potential in many thermostructural components for aerospace vehicles. This work presents ab-initio predictions of elastic constants and thermal properties for 2.5D carbon fiber reinforced carbon-silicon carbide hybrid matrix composites, by using the homogenization technique. The homogenization technique takes properties of individual components of the composites (fiber and matrix and characteristics of the geometrical architecture of the preform to perform calculations. Ab-initio modeling of mechanical and thermal properties is very attractive, especially during the material development stage, when larger samples may be prohibitively expensive or impossible to fabricate. Modeling is also useful when bigger samples would be prohibitively expensive or impractical. Thermostructural composites made of 2.5D preforms are easy to manufacture in relation to 3D preforms. Besides, 2.5D preforms are also resistant to thermo cycling and have high resistance to crack propagation in relation to ply stacked composites such as unidirectional (1D and bidirectional (2D structures. The calculations were performed by setting an overall carbon fiber volume fraction at 40, 45 and 50 for a 2D stacked composite, and volume fraction in Z-direction of 2, 4 and 6.

  17. Facile synthesis of MOF-5 confined in SBA-15 hybrid material with enhanced hydrostability.

    Science.gov (United States)

    Wu, Chia-Ming; Rathi, Monika; Ahrenkiel, S Phil; Koodali, Ranjit T; Wang, Zhenqiang

    2013-02-11

    A MOF-5 [Zn(4)O(BDC)(3); BDC = 1,4-benzenedicarboxylate]@SBA-15 hybrid material has been prepared by using SBA-15 as a matrix. This hybrid material exhibits improved hydrostability under ambient conditions and unique gas adsorption behavior compared with pristine MOF-5.

  18. Laser-induced forward transfer of hybrid carbon nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Palla-Papavlu, A. [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); National Institute for Lasers, Plasma, and Radiation Physics, Lasers Department, Atomistilor 409, 077125 Magurele (Romania); University of Bucharest, Faculty of Physics, 405 Atomistilor Street, 077125 Magurele (Romania); Filipescu, M., E-mail: mihaela.filipescu@inflpr.ro [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); National Institute for Lasers, Plasma, and Radiation Physics, Lasers Department, Atomistilor 409, 077125 Magurele (Romania); Vizireanu, S. [National Institute for Lasers, Plasma, and Radiation Physics, Lasers Department, Atomistilor 409, 077125 Magurele (Romania); Vogt, L. [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland); Antohe, S. [University of Bucharest, Faculty of Physics, 405 Atomistilor Street, 077125 Magurele (Romania); Academy of Romanian Scientists, Splaiul Independentei 54, 050094 Bucharest (Romania); Dinescu, M. [National Institute for Lasers, Plasma, and Radiation Physics, Lasers Department, Atomistilor 409, 077125 Magurele (Romania); Wokaun, A.; Lippert, T. [Paul Scherrer Institut, General Energy Research Department, 5232 Villigen-PSI (Switzerland)

    2016-06-30

    Highlights: • Rapid prototyping of carbon nanowalls (CNW) and functionalized CNWs is described. • CNW and CNW:SnO{sub 2} pixels are successfully printed by laser-induced forward transfer. • Flexible (polyimide) and rigid (glass) supports are used as substrates. • 4 μm thick CNW and CNW:SnO{sub 2} pixels maintain their morphology and structure after LIFT. - Abstract: Chemically functionalized carbon nanowalls (CNWs) are promising materials for a wide range of applications, i.e. gas sensors, membranes for fuel cells, or as supports for catalysts. However, the difficulty of manipulation of these materials hinders their integration into devices. In this manuscript a procedure for rapid prototyping of CNWs and functionalized CNWs (i.e. decorated with SnO{sub 2} nanoparticles) is described. This procedure enables the use of laser-induced forward transfer (LIFT) as a powerful technique for printing CNWs and CNW:SnO{sub 2} pixels onto rigid and flexible substrates. A morphological study shows that for a large range of laser fluences i.e. 500–700 mJ/cm{sup 2} it is possible to transfer thick (4 μm) CNW and CNW:SnO{sub 2} pixels. Micro-Raman investigation of the transferred pixels reveals that the chemical composition of the CNWs and functionalized CNWs does not change as a result of the laser transfer. Following these results one can envision that CNWs and CNW:SnO{sub 2} pixels obtained by LIFT can be ultimately applied in technological applications.

  19. Hybrid calcium carbonate/polymer microparticles containing silver nanoparticles as antibacterial agents

    Energy Technology Data Exchange (ETDEWEB)

    Dlugosz, Maciej; Bulwan, Maria; Kania, Gabriela; Nowakowska, Maria; Zapotoczny, Szczepan, E-mail: zapotocz@chemia.uj.edu.pl [Jagiellonian University, Faculty of Chemistry (Poland)

    2012-12-15

    We report here on synthesis and characterization of novel hybrid material consisting of silver nanoparticles (nAgs) embedded in calcium carbonate microparticles ({mu}-CaCO{sub 3}) serving as carriers for sustained release. nAgs are commonly used as antimicrobial agents in many commercial products (textiles, cosmetics, and drugs). Although they are considered to be safe, their interactions with human organisms are still not fully understood; therefore it is important to apply them with caution and limit their presence in the environment. The synthesis of the new material was based on the co-precipitation of CaCO{sub 3} and nAg in the presence of poly(sodium 4-styrenesulfonate). Such designed system enables sustained release of nAg to the environment. This hybrid colloidal material (nAg/{mu}-CaCO{sub 3}) was characterized by microscopic and spectroscopic methods. The release of nAg from {mu}-CaCO{sub 3} microparticles was followed in water at various pH values. Microbiological tests confirmed the effectiveness of these microparticles as an antibacterial agent. Importantly, the material can be stored as a dry powder and subsequently re-suspended in water without the risk of losing its antimicrobial activity. nAg/{mu}-CaCO{sub 3} was applied here to insure bacteriostatic properties of down feathers that may significantly prolong their lifetime in typical applications. Such microparticles may be also used as, e.g., components of coatings and paints protecting various surfaces against microorganism colonization.

  20. Effect of CeO2 Addition on Hybrid Direct Carbon Fuel Cell Performance

    DEFF Research Database (Denmark)

    Ippolito, Davide; Deleebeeck, Lisa; Kammer Hansen, Kent

    2017-01-01

    The effect of CeO2 infiltration into the anode or CeO2 mixed with the carbon-fuel on the performance of a Hybrid Direct Carbon Fuel Cell (HDCFC) was studied through the use of polarization curves and electrochemical impedance spectroscopy. The use CeO2 in both ways helped to increase the cell...

  1. Hybrid direct carbon fuel cell anode processes investigated using a 3-electrode half-cell setup

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Arenillas, A.; Menendez, J.A.

    2015-01-01

    A 3-electrode half-cell setup consisting of a yttria-stabilized zirconia (YSZ) electrolyte support was employed to investigate the chemical and electrochemical processes occurring in the vicinity of a model hybrid direct carbon fuel cell (HDCFC) anode (Ni-YSZ) in contact with a molten carbon...

  2. Effect of CeO2 Infiltration on Hybrid Direct Carbon Fuel Cell Performance

    DEFF Research Database (Denmark)

    Ippolito, Davide; Deleebeeck, Lisa; Kammer Hansen, Kent

    2014-01-01

    The effect of CeO2 infiltration into the anode or CeO2 mixed with the carbon-fuel on the performance of a Hybrid Direct Carbon Fuel Cell (HDCFC) was studied through the use of polarization curves and electrochemical impedance spectroscopy. The use CeO2 in both ways helped to increase the cell...

  3. Carbon Sequestration Potential in Aboveground Biomass of Hybrid Eucalyptus Plantation Forest

    Directory of Open Access Journals (Sweden)

    Siti Latifah

    2013-04-01

    Full Text Available Forests are a significant part of the global carbon cycle. Forests sequester carbon by conducting photosynthesis, which is the process of converting light energy to chemical energy and storing it in the chemical bonds of sugar. Carbon sequestration through forestry has the potential to play a significant role in ameliorating global environmental problems such as atmospheric accumulation of GHG's and climate change.  The present investigation was carried out to determine carbon sequestration potential of hybrid Eucalyptus. This study was conducted primarily to develop a prediction model of carbon storage capacity for plantation forest of hybrid Eucalyptus in Aek Nauli, Simalungun District, North Sumatera. Models were tested and assessed for statistical validity and accuracy in predicting biomass and carbon, based on determination coefficient (R and correlation coefficient (r, aggregative deviation percentage (AgD, and the average deviation percentage (AvD. The best general model to estimate the biomass of hybrid Eucalyptus was Y = 1351,09x^0,876. e^(0,094.  Results showed that hybrid Eucalyptus had an average above-ground biomass in year 0 (the land without the eucalyptus trees up to year 3 as large as 1.36, 11.56, 43.18, and 63.84 t ha. The carbon content of hybrid Eucalyptus were 0.61, 5.2, 19.43 t^(-1, and 28,73  t^(-1 C ha while the carbon sequestration potential were 2.23, 19.08, 71.31, and 105.43 t^(-1 CO  ha^(-1 respectively.Keywords: biomass, carbon stock, model, hybrid Eucalyptus, plantation forest

  4. Carbon nanotubes grown on bulk materials and methods for fabrication

    Science.gov (United States)

    Menchhofer, Paul A.; Montgomery, Frederick C.; Baker, Frederick S.

    2011-11-08

    Disclosed are structures formed as bulk support media having carbon nanotubes formed therewith. The bulk support media may comprise fibers or particles and the fibers or particles may be formed from such materials as quartz, carbon, or activated carbon. Metal catalyst species are formed adjacent the surfaces of the bulk support material, and carbon nanotubes are grown adjacent the surfaces of the metal catalyst species. Methods employ metal salt solutions that may comprise iron salts such as iron chloride, aluminum salts such as aluminum chloride, or nickel salts such as nickel chloride. Carbon nanotubes may be separated from the carbon-based bulk support media and the metal catalyst species by using concentrated acids to oxidize the carbon-based bulk support media and the metal catalyst species.

  5. Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  6. Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

    Science.gov (United States)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  7. MORPHOLOGY, CONDUCTIVITY AND ELECTROCHEMICAL PROPERTIES OF HYDROTHERMAL CARBONIZED POROUS CARBON MATERIALS

    Directory of Open Access Journals (Sweden)

    N. I. Nagirna

    2016-07-01

    Full Text Available The paper studies the morphology, conductivity and electrochemical properties of carbon materials, obtained from raw plant materials at different condition of hydrothermal carbonization, using low-temperature porometry, impedance spectroscopy and galvanostatic charge/discharge. It is set, that in porous structure of carbon materials micropores are dominant; when carbonization temperature increased the specific surface and pore volume decrease more than 10 times. The temperature growth results in increasing the electrical conductivity of the carbon material more than 6 orders. It is found, that the maximal value of specific capacity (1138 mА·h/g has an electrochemical system based on porous carbon carbonized at 1023 K.

  8. [Carbon fiber-reinforced plastics as implant materials].

    Science.gov (United States)

    Bader, R; Steinhauser, E; Rechl, H; Siebels, W; Mittelmeier, W; Gradinger, R

    2003-01-01

    Carbon fiber-reinforced plastics have been used clinically as an implant material for different applications for over 20 years.A review of technical basics of the composite materials (carbon fibers and matrix systems), fields of application,advantages (e.g., postoperative visualization without distortion in computed and magnetic resonance tomography), and disadvantages with use as an implant material is given. The question of the biocompatibility of carbon fiber-reinforced plastics is discussed on the basis of experimental and clinical studies. Selected implant systems made of carbon composite materials for treatments in orthopedic surgery such as joint replacement, tumor surgery, and spinal operations are presented and assessed. Present applications for carbon fiber reinforced plastics are seen in the field of spinal surgery, both as cages for interbody fusion and vertebral body replacement.

  9. Carbon nanotube-nucleobase hybrids: nanorings from uracil-modified single-walled carbon nanotubes.

    Science.gov (United States)

    Singh, Prabhpreet; Toma, Francesca Maria; Kumar, Jitendra; Venkatesh, V; Raya, Jesus; Prato, Maurizio; Verma, Sandeep; Bianco, Alberto

    2011-06-06

    Single-walled carbon nanotubes (SWCNTs) have been covalently functionalized with uracil nucleobase. The hybrids have been characterized by using complementary spectroscopic and microscopic techniques including solid-state NMR spectroscopy. The uracil-functionalized SWCNTs are able to self-assemble into regular nanorings with a diameter of 50-70 nm, as observed by AFM and TEM. AFM shows that the rings do not have a consistent height and thickness, which indicates that they may be formed by separate bundles of CNTs. The simplest model for the nanoring formation likely involves two bundles of CNTs interacting with each other via uracil-uracil base-pairing at both CNT ends. These nanorings can be envisaged for the development of advanced electronic circuits.

  10. Functional Carbon Nanotube/Mesoporous Carbon/MnO2 Hybrid Network for High-Performance Supercapacitors

    Directory of Open Access Journals (Sweden)

    Tao Tao

    2014-01-01

    Full Text Available A functional carbon nanotube/mesoporous carbon/MnO2 hybrid network has been developed successfully through a facile route. The resulting composites exhibited a high specific capacitance of 351 F/g at 1 A g−1, with intriguing charge/discharge rate performance and cycling stability due to a synergistic combination of large surface area and excellent electron-transport capabilities of MnO2 with the good conductivity of the carbon nanotube/mesoporous carbon networks. Such composite shows great potential to be used as electrodes for supercapacitors.

  11. Carbonization kinetics of La2O3-Mo cathode materials

    Institute of Scientific and Technical Information of China (English)

    王金淑; 周美玲; 左铁镛; 张久兴; 聂祚仁; 胡延槽

    2001-01-01

    The carbonization kinetics of La2O3-Mo cathode materials was studied by thermal analysis method. Three-stage model of the carbonization was presented. The carbonization rate is initially controlled by chemical reaction, then by chemical reaction mixed with diffusion, finally by diffusion. The experimental data are processed according to this model and the correlation coefficients of the kinetic curves are satisfactory. The apparent activation energy of carbonization of La2O3-Mo cathode materials was obtained. At the same time, the empirical expressions of the rate constant against temperature in the temperature range of 1393~1493K were deduced.

  12. Laser-induced forward transfer of hybrid carbon nanostructures

    Science.gov (United States)

    Palla-Papavlu, A.; Filipescu, M.; Vizireanu, S.; Vogt, L.; Antohe, S.; Dinescu, M.; Wokaun, A.; Lippert, T.

    2016-06-01

    Chemically functionalized carbon nanowalls (CNWs) are promising materials for a wide range of applications, i.e. gas sensors, membranes for fuel cells, or as supports for catalysts. However, the difficulty of manipulation of these materials hinders their integration into devices. In this manuscript a procedure for rapid prototyping of CNWs and functionalized CNWs (i.e. decorated with SnO2 nanoparticles) is described. This procedure enables the use of laser-induced forward transfer (LIFT) as a powerful technique for printing CNWs and CNW:SnO2 pixels onto rigid and flexible substrates. A morphological study shows that for a large range of laser fluences i.e. 500-700 mJ/cm2 it is possible to transfer thick (4 μm) CNW and CNW:SnO2 pixels. Micro-Raman investigation of the transferred pixels reveals that the chemical composition of the CNWs and functionalized CNWs does not change as a result of the laser transfer. Following these results one can envision that CNWs and CNW:SnO2 pixels obtained by LIFT can be ultimately applied in technological applications.

  13. A Carbon-Sulfur Hybrid with Pomegranate-like Structure for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Shi, Yanting; Lv, Wei; Niu, Shuzhang; He, Yanbing; Zhou, Guangmin; Chen, Guohua; Li, Baohua; Yang, Quan-Hong; Kang, Feiyu

    2016-05-01

    A carbon-sulfur hybrid with pomegranate-like core-shell structure, which demonstrates a high rate performance and relatively high cyclic stability, is obtained through carbonization of a carbon precursor in the presence of a sulfur precursor (FeS2 ) and a following oxidation of FeS2 to sulfur by HNO3 . Such a structure effectively protects the sulfur and leaves enough buffer space after Fe(3+) removal and, at the same time, has an interconnected conductive network. The capacity of the obtained hybrid is 450 mA h g(-1) under the current density of 5 C. This work provides a simple strategy to design and prepare various high-performance carbon-sulfur hybrids for lithium-sulfur batteries.

  14. Aerogel Hybrid Composite Materials: Designs and Testing for Multifunctional Applications

    Science.gov (United States)

    Williams, Martha K.; Fesmire, James E.

    2016-01-01

    This webinar will introduce the broad spectrum of aerogel composites and their diverse performance properties such as reduced heat transfer to energy storage, and expands specifically on the aerogel/fiber laminate systems and testing methodologies. The multi-functional laminate composite system, AeroFiber, and its construction is designed by varying the type of fiber (e.g. polyester, carbon, Kevlar®, Spectra® or Innegral(TradeMark) and combinations thereof), the aerogel panel type and thickness, and overall layup configuration. The combination and design of materials may be customized and tailored to achieve a range of desired properties in the resulting laminate system. Multi-functional properties include structural strength, impact resistance, reduction in heat transfer, increased fire resistance, mechanical energy absorption, and acoustic energy dampening. Applications include aerospace, aircraft, automotive, boating, building and construction, lightweight portable structures, liquefied natural gas, cryogenics, transportation and energy, sporting equipment, and military protective gear industries.

  15. Electron field emission characteristics of graphene/carbon nanotubes hybrid field emitter

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Leifeng, E-mail: chlf@hdu.edu.cn [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); He, Hong; Yu, Hua; Cao, Yiqi [College of Materials and Environmental Engineering, Hangzhou Dianzi University, Hangzhou 310018 (China); Lei, Da, E-mail: leida126@126.com [Ordos College of Inner Mongolia University, Inner Mongolia University, Ordos 017000 (China); Menggen, QiQiGe [Ordos College of Inner Mongolia University, Inner Mongolia University, Ordos 017000 (China); Wu, Chaoxing; Hu, Liqin [College of Physics and Information Engineering, Fuzhou University, Fuzhou 350002 (China)

    2014-10-15

    The graphene (GP) and multi-walled carbon nanotubes (MCNTs) hybrid nanostructure emitter was constructed by a larger scale electrophoretic deposition (EPD) method. The field emission (FE) performance of the hybrid emitter is greatly improved compared with that of only GP or MCNTs emitter. The low turn-on electric field (EF), the low threshold EF and the reliability FE properties are obtained from the hybrid emitter. The better FE properties result from the improved electrical properties. For further enhancement FE of hybrids, Ag Nanoparticles (NPs) were decorated on the hybrids and FE characteristics were also studied. These studies indicate that we can use the hybrid nanostructure to improve conductivity and contact resistance, which results in enhancement of the FE properties.

  16. Sliding Wear Properties of Hybrid Aluminium Composite Reinforced by Particles of Palm Shell Activated Carbon and Slag

    Directory of Open Access Journals (Sweden)

    Zamri Yusoff

    2011-09-01

    Full Text Available In present work, dry sliding wear tests were conducted on hybrid composite reinforced with natural carbon based particles such as palm shell activated carbon (PSAC and slag. Hybrid composites containing 5 -20 wt.% of both reinforcements with average particles sizes about 125μm were prepared by conventional powder metallurgy technique, which involves the steps of mixing, compacting and sintering. Dry sliding experiments were conducted in air at room temperature using a pin-on-disc self-built attach to polisher machine. The disc which acted as the mating surface material was made of mild steel (120 HV cut from commercial mild steel sheet (2 mm thickness into 100mm diameter. The influence of the applied load was investigated under a constant sliding velocity of 0.1m/s with the applied loads at 3N, 11N and 51N. The contribution of the reinforcement content and the applied load as well as the sliding distance on the wear process and the wear rate have been investigated. The contribution of synergic factors such as applied load, sliding distance and reinforcement content (wt.% have been studied using analysis of variance (ANOVA. All synergic factors contribute to the wear process of all tested composites. Among synergic factors, the applied load is the highest contribution to wear process on both composites (Al/PSAC and Al/Slag and hybrid composite. The degree of improvement of wear resistance of hybrid composite is strongly dependent on the reinforcement content.

  17. Surface analysis of carbon black waste materials from tire residues

    Science.gov (United States)

    Lee, W. H.; Kim, J. Y.; Ko, Y. K.; Reucroft, P. J.; Zondlo, J. W.

    1999-03-01

    X-ray photoelectron spectroscopy (XPS) has been used to obtain surface chemical state information on two carbon black waste materials in terms of the surface element distribution/concentration and chemical structure. Small amounts of sulfur in the form of CS 2 were detected on the surface (less than 1.7 mass %). C-H/C-C was the major carbon functional component on the surface of carbon black samples but other functional forms of carbon were also present such as CO and C-O. The surface of the carbon black obtained from a hydropyrolysis process was highly oxidized primarily in the form of carbon based oxygen groups. On the other hand, surface oxygen atoms on the surface of the carbon black obtained from a pyrolysis process in the absence of H 2 were in the form of both metal oxides and carbon based oxygen groups.

  18. Energy and charge transfer in nanoscale hybrid materials.

    Science.gov (United States)

    Basché, Thomas; Bottin, Anne; Li, Chen; Müllen, Klaus; Kim, Jeong-Hee; Sohn, Byeong-Hyeok; Prabhakaran, Prem; Lee, Kwang-Sup

    2015-06-01

    Hybrid materials composed of colloidal semiconductor quantum dots and π-conjugated organic molecules and polymers have attracted continuous interest in recent years, because they may find applications in bio-sensing, photodetection, and photovoltaics. Fundamental processes occurring in these nanohybrids are light absorption and emission as well as energy and/or charge transfer between the components. For future applications it is mandatory to understand, control, and optimize the wide parameter space with respect to chemical assembly and the desired photophysical properties. Accordingly, different approaches to tackle this issue are described here. Simple organic dye molecules (Dye)/quantum dot (QD) conjugates are studied with stationary and time-resolved spectroscopy to address the dynamics of energy and ultra-fast charge transfer. Micellar as well as lamellar nanostructures derived from diblock copolymers are employed to fine-tune the energy transfer efficiency of QD donor/dye acceptor couples. Finally, the transport of charges through organic components coupled to the quantum dot surface is discussed with an emphasis on functional devices.

  19. Thermal transport in novel carbon allotropes with s p2 or s p3 hybridization: An ab initio study

    Science.gov (United States)

    Yue, Sheng-Ying; Qin, Guangzhao; Zhang, Xiaoliang; Sheng, Xianlei; Su, Gang; Hu, Ming

    2017-02-01

    Thermal transport in most carbon allotropes is determined by phonons. The properties of the atomic bonds will influence the phonon transport process directly. In this paper we studied two novel carbon allotropes as examples, one novel allotrope phase is topological semimetal in an s p2 bonding network with a 16-atom body-centered orthorhombic unit cell (BCO-C16) [Phys. Rev. Lett. 116, 195501 (2016), 10.1103/PhysRevLett.116.195501] and the other novel allotrope is derived by substituting each atom in diamond with a carbon tetrahedron (T-carbon) [Phys. Rev. Lett. 106, 155703 (2011), 10.1103/PhysRevLett.106.155703], which possesses an s p3 bonding network. Graphene and diamond with standard s p2 and s p3 hybridization, respectively, are also examined for comparison. We explored the related properties of the atomic bonds of these allotropes with the density functional theory, i.e., the atomic orbital hybridization, effective spring constants of atomic bonds, the anharmonicity of atomic bonds, etc. By comparing the results, we unveiled the veil behind different lattice thermal conductivities of these allotropes at atomic bond levels (BCO-C16 vs graphene and T-carbon vs diamond), despite their similar hybridization. In addition, within the framework of a phonon Boltzmann transport equation, the mode level phonon transport properties of the four carbon allotropes are also studied in detail, which are well consistent with the information from atomic bonds. We expect that the method of analyzing the strength and anharmonicity of atomic bonds here will be helpful for studying the thermal transport in crystalline materials in the future.

  20. Probing the structure and function of biopolymer-carbon nanotube hybrids with molecular dynamics

    Science.gov (United States)

    Johnson, Robert R.

    2009-12-01

    Nanoscience deals with the characterization and manipulation of matter on the atomic/molecular size scale in order to deepen our understanding of condensed matter and develop revolutionary technology. Meeting the demands of the rapidly advancing nanotechnological frontier requires novel, multifunctional nanoscale materials. Among the most promising nanomaterials to fulfill this need are biopolymer-carbon nanotube hybrids (Bio-CNT). Bio-CNT consists of a single-walled carbon nanotube (CNT) coated with a self-assembled layer of biopolymers such as DNA or protein. Experiments have demonstrated that these nanomaterials possess a wide range of technologically useful properties with applications in nanoelectronics, medicine, homeland security, environmental safety and microbiology. However, a fundamental understanding of the self-assembly mechanics, structure and energetics of Bio-CNT is lacking. The objective of this thesis is to address this deficiency through molecular dynamics (MD) simulation, which provides an atomic-scale window into the behavior of this unique nanomaterial. MD shows that Bio-CNT composed of single-stranded DNA (ssDNA) self-assembles via the formation of high affinity contacts between DNA bases and the CNT sidewall. Calculation of the base-CNT binding free energy by thermodynamic integration reveals that these contacts result from the attractive pi--pi stacking interaction. Binding affinities follow the trend G > A > T > C. MD reveals that long ssDNA sequences are driven into a helical wrapping about CNT with a sub-10 nm pitch by electrostatic and torsional interactions in the backbone. A large-scale replica exchange molecular dynamics simulation reveals that ssDNA-CNT hybrids are disordered. At room temperature, ssDNA can reside in several low-energy conformations that contain a sequence-specific arrangement of bases detached from CNT surface. MD demonstrates that protein-CNT hybrids composed of the Coxsackie-adenovirus receptor are biologically

  1. Novel hybrid nanostructured materials of magnetite nanoparticles and pectin

    Energy Technology Data Exchange (ETDEWEB)

    Sahu, Saurabh [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India); Dutta, Raj Kumar, E-mail: duttafcy@iitr.ernet.i [Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247 667 (India)

    2011-04-15

    A novel hybrid nanostructured material comprising superparamagnetic magnetite nanoparticles (MNPs) and pectin was synthesized by crosslinking with Ca{sup 2+} ions to form spherical calcium pectinate nanostructures, referred as MCPs, which were typically found to be 100-150 nm in size in dried condition, confirmed from transmission electron microscopy and scanning electron microscopy. The uniform size distribution was revealed from dynamic light scattering measurement. In aqueous medium the MCPs showed swelling behavior with an average size of 400 nm. A mechanism of formation of spherical MCPs is outlined constituting a MNP-pectin interface encapsulated by calcium pectinate at the periphery, by using an array of characterization techniques like zeta potential, thermogravimetry, Fourier transformed infrared and X-ray photoelectron spectroscopy. The MCPs were stable in simulated gastrointestinal fluid and ensured minimal loss of magnetic material. They exhibited superparamagnetic behavior, confirmed from zero field cooled and field cooled profiles and showed high saturation magnetization (M{sub s}) of 46.21 emu/g at 2.5 T and 300 K. M{sub s} decreased with increasing precursor pectin concentrations, attributed to quenching of magnetic moments by formation of a magnetic dead layer on the MNPs. - Research highlights: > In the present investigation we have developed a facile route to synthesize a novel, low cost calcium pectinate nanostructure functionalized with SPIONs (magnetite nanoparticles). > Though there are sufficient scientific illustrations on polymer as well as biopolymers coated on SPIONs for various biomedical applications, the one presented here, is novel of its kind as it is considered to offer a new dimension to the magnetic responsive properties of calcium pectinate nanomaterials towards biomedical applications, especially as a potential carrier for magnetically targeted drug delivery to colon specific sites. > The synthesis of these nanostructured

  2. Batteries: Recent Advances in Carbon Materials

    Directory of Open Access Journals (Sweden)

    I. Francis Cheng

    2017-01-01

    Full Text Available We welcome readers to this Special Issue of C. From the standpoint of economics of energy storage, carbon electrodes offer the practicality of large-scale applications with the promise of improved performance.[...

  3. Electrically engineered polymer-carbon hybrid heterojunction for high-performance printed transistors

    Science.gov (United States)

    Kim, Do Hwan; Kang, Gyu Won; Shin, Hyeon-Jin; Kim, Woo-Jae

    2014-10-01

    Molecularly hybridized materials composed of polymer semiconductors (PSCs) and single-walled carbon nanotubes (SWNTs) may provide a new platform to exploit an advantageous combination of semiconductors, which yields electrical properties that are not available in a single component system. In this talk, we demonstrate high-performance ink-jet printed hybrid transistors with an electrically engineered heterostructure by using specially designed PSCs and semiconducting SWNTs (sc-SWNTs) whose system achieved a high mobility of 0.23 cm2V-1s-1, no Von shift, a low off-current, and good bias-stability. We also revealed that binding energy between PSCs and sc-SWNT was strongly affected by side-chain length of PSCs, leading to the formation of homogeneous nanohybrid film. Eventually, understanding of electrostatic interactions in the heterostructure and experimental results suggest criteria for the design of nanohybrid heterostructures. Acknowledgement. This work was supported by a grant (Code No. 2011-0031628) from the Center for Advanced Soft Electronics under the Global Frontier Research Program of the Ministry of Science, ICT and Future Planning, Korea. The authors acknowledge Prof. Kilwon Cho for collaboration on the analysis of x-ray diffraction.

  4. Advanced Carbon Materials for Environmental and Energy Applications

    KAUST Repository

    Dua, Rubal

    2014-05-01

    Carbon based materials, including porous carbons and carbon layer composites, are finding increased usage in latest environmental and energy related research. Among porous carbon materials, hierarchical porous carbons with multi-modal porosity are proving out to be an effective solution for applications where the traditional activated carbons fail. Thus, there has been a lot of recent interest in developing low-cost, facile, easy to scale-up, synthesis techniques for producing such multi-modal porous carbons. This dissertation offers two novel synthesis techniques: (i) ice templating integrated with hard templating, and (ii) salt templating coupled with hard templating, for producing such hierarchically porous carbons. The techniques offer tight control and tunability of porosity (macro- meso- and microscale) in terms of both size and extent. The synthesized multi-modal porous carbons are shown to be an effective solution for three important environment related applications – (i) Carbon dioxide capture using amine supported hierarchical porous carbons, (ii) Reduction in irreversible fouling of membranes used for wastewater reuse through a deposition of a layer of hierarchical porous carbons on the membrane surface, (iii) Electrode materials for electrosorptive applications. Finally, because of their tunability, the synthesized multi-modal porous carbons serve as excellent model systems for understanding the effect of different types of porosity on the performance of porous carbons for these applications. Also, recently, there has been a lot of interest in developing protective layer coatings for preventing photo-corrosion of semiconductor structures (in particular Cu2O) used for photoelectrochemical water splitting. Most of the developed protective strategies to date involve the use of metals or co-catalyst in the protective layer. Thus there is a big need for developing low-cost, facile and easy to scale protective coating strategies. Based on the expertise

  5. Highly selective and active CO2 reduction electrocatalysts based on cobalt phthalocyanine/carbon nanotube hybrid structures

    Science.gov (United States)

    Zhang, Xing; Wu, Zishan; Zhang, Xiao; Li, Liewu; Li, Yanyan; Xu, Haomin; Li, Xiaoxiao; Yu, Xiaolu; Zhang, Zisheng; Liang, Yongye; Wang, Hailiang

    2017-01-01

    Electrochemical reduction of carbon dioxide with renewable energy is a sustainable way of producing carbon-neutral fuels. However, developing active, selective and stable electrocatalysts is challenging and entails material structure design and tailoring across a range of length scales. Here we report a cobalt-phthalocyanine-based high-performance carbon dioxide reduction electrocatalyst material developed with a combined nanoscale and molecular approach. On the nanoscale, cobalt phthalocyanine (CoPc) molecules are uniformly anchored on carbon nanotubes to afford substantially increased current density, improved selectivity for carbon monoxide, and enhanced durability. On the molecular level, the catalytic performance is further enhanced by introducing cyano groups to the CoPc molecule. The resulting hybrid catalyst exhibits >95% Faradaic efficiency for carbon monoxide production in a wide potential range and extraordinary catalytic activity with a current density of 15.0 mA cm−2 and a turnover frequency of 4.1 s−1 at the overpotential of 0.52 V in a near-neutral aqueous solution. PMID:28272403

  6. Highly selective and active CO2 reduction electrocatalysts based on cobalt phthalocyanine/carbon nanotube hybrid structures

    Science.gov (United States)

    Zhang, Xing; Wu, Zishan; Zhang, Xiao; Li, Liewu; Li, Yanyan; Xu, Haomin; Li, Xiaoxiao; Yu, Xiaolu; Zhang, Zisheng; Liang, Yongye; Wang, Hailiang

    2017-03-01

    Electrochemical reduction of carbon dioxide with renewable energy is a sustainable way of producing carbon-neutral fuels. However, developing active, selective and stable electrocatalysts is challenging and entails material structure design and tailoring across a range of length scales. Here we report a cobalt-phthalocyanine-based high-performance carbon dioxide reduction electrocatalyst material developed with a combined nanoscale and molecular approach. On the nanoscale, cobalt phthalocyanine (CoPc) molecules are uniformly anchored on carbon nanotubes to afford substantially increased current density, improved selectivity for carbon monoxide, and enhanced durability. On the molecular level, the catalytic performance is further enhanced by introducing cyano groups to the CoPc molecule. The resulting hybrid catalyst exhibits >95% Faradaic efficiency for carbon monoxide production in a wide potential range and extraordinary catalytic activity with a current density of 15.0 mA cm-2 and a turnover frequency of 4.1 s-1 at the overpotential of 0.52 V in a near-neutral aqueous solution.

  7. Exploring the Role of Plant Genetics to Enhance Soil Carbon Sequestration in Hybrid Poplar Plantations

    Science.gov (United States)

    Wullschleger, S. D.; Garten, C. T.; Classen, A. T.

    2008-12-01

    Atmospheric CO2 concentrations have increased in recent decades and are projected to increase even further during the coming century. These projections have prompted scientists and policy-makers to consider how plants and soils can be used to stabilize CO2 concentrations. Although storing carbon in terrestrial ecosystems represents an attractive near-term option for mitigating rising atmospheric CO2 concentrations, enhancing the sequestration potential of managed systems will require advancements in understanding the fundamental mechanisms that control rates of carbon transfer and turnover in plants and soils. To address this challenge, a mathematical model was constructed to evaluate how changes in particular plant traits and management practices could affect soil carbon storage beneath hybrid poplar (Populus) plantations. The model was built from four sub-models that describe aboveground biomass, root biomass, soil carbon dynamics, and soil nitrogen transformations for trees growing throughout a user-defined rotation. Simulations could be run over one or multiple rotations. A sensitivity analysis of the model indicated changes in soil carbon storage were affected by variables that could be linked to hybrid poplar traits like rates of aboveground production, partitioning of carbon to coarse and fine roots, and rates of root decomposition. A higher ratio of belowground to aboveground production was especially important and correlated directly with increased soil carbon storage. Faster decomposition rates for coarse and fine dead roots resulted in a greater loss of carbon to the atmosphere as CO2 and less residual organic carbon for transfer to the fast soil carbon pool. Hence, changes in root chemistry that prolonged dead root decomposition rates, a trait that is under potential genetic control, were predicted to increase soil carbon storage via higher soil carbon inputs. Nitrogen limitation of both aboveground biomass production and soil carbon sequestration was

  8. Synthesis, characterization and catalytic activity of carbon-silica hybrid catalyst from rice straw

    Science.gov (United States)

    Janaun, J.; Safie, N. N.; Siambun, N. J.

    2016-07-01

    The hybrid-carbon catalyst has been studied because of its promising potential to have high porosity and surface area to be used in biodiesel production. Silica has been used as the support to produce hybrid carbon catalyst due to its mesoporous structure and high surface area properties. The chemical synthesis of silica-carbon hybrid is expensive and involves more complicated preparation steps. The presence of natural silica in rice plants especially rice husk has received much attention in research because of the potential as a source for solid acid catalyst synthesis. But study on rice straw, which is available abundantly as agricultural waste is limited. In this study, rice straw undergone pyrolysis and functionalized using fuming sulphuric acid to anchor -SO3H groups. The presence of silica and the physiochemical properties of the catalyst produced were studied before and after sulphonation. The catalytic activity of hybrid carbon silica acid catalyst, (H-CSAC) in esterification of oleic acid with methanol was also studied. The results showed the presence of silica-carbon which had amorphous structure and highly porous. The carbon surface consisted of higher silica composition, had lower S element detected as compared to the surface that had high carbon content but lower silica composition. This was likely due to the fact that Si element which was bonded to oxygen was highly stable and unlikely to break the bond and react with -SO3H ions. H-CSAC conversions were 23.04 %, 35.52 % and 34.2 7% at 333.15 K, 343.15 K and 353.15 K, respectively. From this research, rice straw can be used as carbon precursor to produce hybrid carbon-silica catalyst and has shown catalytic activity in biodiesel production. Rate equation obtained is also presented.

  9. Synthesis, Characterization and Utility of Carbon Nanotube Based Hybrid Sensors in Bioanalytical Applications

    Science.gov (United States)

    Badhulika, Sushmee

    The detection of gaseous analytes and biological molecules is of prime importance in the fields of environmental pollution control, food and water - safety and analysis; and medical diagnostics. This necessitates the development of advanced and improved technology that is reliable, inexpensive and suitable for high volume production. The conventional sensors are often thin film based which lack sensitivity due to the phenomena of current shunting across the charge depleted region when an analyte binds with them. One dimensional (1-D) nanostructures provide a better alternative for sensing applications by eliminating the issue of current shunting due to their 1-D geometries and facilitating device miniaturization and low power operations. Carbon nanotubes (CNTs) are 1-D nanostructures that possess small size, high mechanical strength, high electrical and thermal conductivity and high specific area that have resulted in their wide spread applications in sensor technology. To overcome the issue of low sensitivity of pristine CNTs and to widen their scope, hybrid devices have been fabricated that combine the synergistic properties of CNTs along with materials like metals and conducting polymers (CPs). CPs exhibit electronic, magnetic and optical properties of metals and semiconductors while retaining the processing advantages of polymers. Their high chemical sensitivity, room temperature operation and tunable charge transport properties has made them ideal for use as transducing elements in chemical sensors. In this dissertation, various CNT based hybrid devices such as CNT-conducting polymer and graphene-CNT-metal nanoparticles based sensors have been developed and demonstrated towards bioanalytical applications such as detection of volatile organic compounds (VOCs) and saccharides. Electrochemical polymerization enabled the synthesis of CPs and metal nanoparticles in a simple, cost effective and controlled way on the surface of CNT based platforms thus resulting in

  10. Advanced hybrid supercapacitor based on a mesoporous niobium pentoxide/carbon as high-performance anode.

    Science.gov (United States)

    Lim, Eunho; Kim, Haegyeom; Jo, Changshin; Chun, Jinyoung; Ku, Kyojin; Kim, Seongseop; Lee, Hyung Ik; Nam, In-Sik; Yoon, Songhun; Kang, Kisuk; Lee, Jinwoo

    2014-09-23

    Recently, hybrid supercapacitors (HSCs), which combine the use of battery and supercapacitor, have been extensively studied in order to satisfy increasing demands for large energy density and high power capability in energy-storage devices. For this purpose, the requirement for anode materials that provide enhanced charge storage sites (high capacity) and accommodate fast charge transport (high rate capability) has increased. Herein, therefore, a preparation of nanocomposite as anode material is presented and an advanced HSC using it is thoroughly analyzed. The HSC comprises a mesoporous Nb2O5/carbon (m-Nb2O5-C) nanocomposite anode synthesized by a simple one-pot method using a block copolymer assisted self-assembly and commercial activated carbon (MSP-20) cathode under organic electrolyte. The m-Nb2O5-C anode provides high specific capacity with outstanding rate performance and cyclability, mainly stemming from its enhanced pseudocapacitive behavior through introduction of a carbon-coated mesostructure within a voltage range from 3.0 to 1.1 V (vs Li/Li(+)). The HSC using the m-Nb2O5-C anode and MSP-20 cathode exhibits excellent energy and power densities (74 W h kg(-1) and 18,510 W kg(-1)), with advanced cycle life (capacity retention: ∼90% at 1000 mA g(-1) after 1000 cycles) within potential range from 1.0 to 3.5 V. In particular, we note that the highest power density (18,510 W kg(-1)) of HSC is achieved at 15 W h kg(-1), which is the highest level among similar HSC systems previously reported. With further study, the HSCs developed in this work could be a next-generation energy-storage device, bridging the performance gap between conventional batteries and supercapacitors.

  11. Multi-walled carbon nanotubes and metal-organic framework nanocomposites as novel hybrid electrode materials for the determination of nano-molar levels of lead in a lab-on-valve format.

    Science.gov (United States)

    Wang, Yang; Wu, Yichun; Xie, Jing; Ge, Huali; Hu, Xiaoya

    2013-09-07

    Metal-organic frameworks have been the subject of intense research because of their unique physicochemical properties. The presented study investigates the application of multi-wall carbon nanotubes and metal-organic frameworks (MWCNTs@Cu3(BTC)2) nanoparticles-modified electrode for the determination of trace levels of lead. The nanocomposites were prepared by solvothermal synthesis and characterized in detail. The experimental procedure was carried out by accumulating lead on the electrode surface and subsequently measuring with differential pulse anodic stripping voltammetry in a lab-on-valve format. The main parameters affecting the analytical performance, including the amount of MWCNTs@Cu3(BTC)2 suspension, supporting electrolyte and its pH, stripping mode, and flow rate, have been investigated in detail. Under the optimum conditions, the oxidation peak current displayed a calibration response for lead over a concentration range from 1.0 × 10(-9) to 5.0 × 10(-8) mol L(-1) with a excellent detection limit of 7.9 × 10(-10) mol L(-1). The relative standard deviation of 7 successive scans was 3.10% for 1.0 × 10(-8) mol L(-1) lead. The established method showed a great improvement in sensitivity and sample throughput for lead analysis.

  12. Polylactide-based bionanocomposites: a promising class of hybrid materials.

    Science.gov (United States)

    Sinha Ray, Suprakas

    2012-10-16

    Polylactide (PLA) is the oldest and potentially one of the most interesting and useful biodegradable man-made polymers because of its renewable origin, controlled synthesis, good mechanical properties, and inherent biocompatibility. The blending of PLA with functional nanoparticles can yield a new class of hybrid materials, commonly known as bionanocomposites, where 1-5% nanoparticles by volume are molecularly dispersed within the PLA matrix. The dispersed nanoparticles with their large surface areas and low percolation thresholds both can improve the properties significantly in comparison with neat PLA and can introduce new value-added properties. Recently, researchers have made extraordinary progress in the practical processing and development of products from PLA bionanocomposites. The variation of the nanofillers with different functionalities can lead to many bionanocomposite applications including environmentally friendly packaging, materials for construction, automobiles, and tissue regeneration, and load-bearing scaffolds for bone reconstruction. This Account focuses on these recent research efforts, processing techniques, and key research challenges in the development of PLA-based bionanocomposites for use in applications from green plastics to biomedical applications. Growing concerns over environmental issues and high demand for advanced polymeric materials with balanced properties have led to the development of bionanocomposites of PLA and natural origin fillers, such as nanoclays. The combination of nanoclays with the PLA matrix allows us to develop green nanocomposites that possess several superior properties. For example, adding ∼5 vol % clay to PLA improved the storage modulus, tensile strength, break elongation, crystallization rate, and other mechanical properties. More importantly, the addition of clay decreases the gas and water vapor permeation, increases the heat distortion temperature and scratch resistance, and controls the biodegradation

  13. Carbon as a hard template for nano material catalysts

    Institute of Scientific and Technical Information of China (English)

    Kake Zhu; Junming Sun; He Zhang; Jun Liu; Yong Wang

    2012-01-01

    As one of the naturally abundant elements,carbon can present in different molecular structures (allotropes) and thus lead to various physical/chemical properties of carbon-based materials which have found wide applications in a variety of fields including electrochemistry,optical,adsorption and catalysis,etc.On the other hand,its different allotropes also endow carbon-based materials with various morphostructures,which have been recently explored to prepare oxides and zeolites/zeotypes with tailored structures.In this review,we mainly summarize the recent advances in using carbon materials as hard templates to synthesize structural materials.Specifically,we focus on the development in the synthetic strategies,such as endotemplating,exotemplating approaches and using carbon materials as chemical reagents for the synthesis of metal carbides or nitrides,with an emphasis laid on the control of morphostructure.Meanwhile,the applications of the obtained materials will be highlighted,especially,in the field of heterogeneous catalysis where enhanced performances have been achieved with the materials derived from carbon-templated methods.

  14. Damage Mechanisms/Failure Mechanics of Carbon-Carbon Composite Materials.

    Science.gov (United States)

    1979-09-01

    cutting method was used to minimize material waste, not because * carbon-carbon is difficult to machine . 2.2 Tension Testing 2.2.1 Specimen Configuration...was made to bond the strain gages to fiber bundles if possible rather than to a layer of matrix material. Ex- tensometers were also employed to measure

  15. Characteristic evaluation of Al2O3/CNTs hybrid materials for micro-electrical discharge machining

    Institute of Scientific and Technical Information of China (English)

    Hyun-Seok TAK; Chang-Seung HA; Ho-Jun LEE; Hyung-Woo LEE; Young-Keun JEONG; Myung-Chang KANG

    2011-01-01

    The characteristic evaluation of aluminum oxide (Al2O3)/carbon nanotubes (CNTs) hybrid composites for micro-electrical discharge machining (EDM) was described. Alumina matrix composites reinforced with CNTs were fabricated by a catalytic chemical vapor deposition method. Al2O3 composites with different CNT concentrations were synthesized. The electrical characteristic of Al2O3/CNTs composites was examined. These composites were machined by the EDM process according to the various EDM parameters, and the characteristics of machining were analyzed using field emission scanning electron microscope (FESEM). The electrical conductivity has a increasing tendency as the CNTs content is increased and has a critical point at 5% Al2O3 (volume fraction). In the machining accuracy, many tangles of CNT in Al2O3/CNTs composites cause violent spark. Thus, it causes the poor dimensional accuracy and circularity. The results show that conductivity of the materials and homogeneous distribution of CNTs in the matrix are important factors for micro-EDM of Al2O3/CNTs hybrid composites.

  16. Supercapacitors based on carbon materials and ionic liquids

    OpenAIRE

    2006-01-01

    This paper presents performance of supercapacitor built from different carbon materials. The general principle of supercapacitor and formula connected with its operation are also described. The role of carbon nanotexture has been underlined selecting carbons prepared by template techniques. It has been demonstrated that mainly micropores and small mesopores play important role for charging of electrical double layer, however, interconnectivity of pores is crucial for charge propagation. The p...

  17. Hybrid organic-inorganic materials: from self-organization to nanocrystals

    OpenAIRE

    Figus, Cristina

    2010-01-01

    The advantage of inorganic–organic hybrids is that they can combine the properties of organic and inorganic components in one material; this provides the opportunity to invent new materials with a large spectrum properties. The synthesis of hybrid materials through the precise structure control from the molecular to the macroscopic level is a key point for a variety of applications. 3-Glycidoxypropyltrimethoxysilane (GPTMS) is one of the most common precursors for the prepar...

  18. Wet Chemistry Synthesis of Multidimensional Nanocarbon-Sulfur Hybrid Materials with Ultrahigh Sulfur Loading for Lithium-Sulfur Batteries.

    Science.gov (United States)

    Du, Wen-Cheng; Yin, Ya-Xia; Zeng, Xian-Xiang; Shi, Ji-Lei; Zhang, Shuai-Feng; Wan, Li-Jun; Guo, Yu-Guo

    2016-02-17

    An optimized nanocarbon-sulfur cathode material with ultrahigh sulfur loading of up to 90 wt % is realized in the form of sulfur nanolayer-coated three-dimensional (3D) conducting network. This 3D nanocarbon-sulfur network combines three different nanocarbons, as follows: zero-dimensional carbon nanoparticle, one-dimensional carbon nanotube, and two-dimensional graphene. This 3D nanocarbon-sulfur network is synthesized by using a method based on soluble chemistry of elemental sulfur and three types of nanocarbons in well-chosen solvents. The resultant sulfur-carbon material shows a high specific capacity of 1115 mA h g(-1) at 0.02C and good rate performance of 551 mA h g(-1) at 1C based on the mass of sulfur-carbon composite. Good battery performance can be attributed to the homogeneous compositing of sulfur with the 3D hierarchical hybrid nanocarbon networks at nanometer scale, which provides efficient multidimensional transport pathways for electrons and ions. Wet chemical method developed here provides an easy and cost-effective way to prepare sulfur-carbon cathode materials with high sulfur loading for application in high-energy Li-S batteries.

  19. Characterization of Zeolite in Zeolite-Geopolymer Hybrid Bulk Materials Derived from Kaolinitic Clays

    Directory of Open Access Journals (Sweden)

    Hayami Takeda

    2013-05-01

    Full Text Available Zeolite-geopolymer hybrid materials have been formed when kaolin was used as a starting material. Their characteristics are of interest because they can have a wide pore size distribution with micro- and meso-pores due to the zeolite and geopolymer, respectively. In this study, Zeolite-geopolymer hybrid bulk materials were fabricated using four kinds of kaolinitic clays (a halloysite and three kinds of kaolinite. The kaolinitic clays were first calcined at 700 °C for 3 h to transform into the amorphous aluminosilicate phases. Alkali-activation treatment of the metakaolin yielded bulk materials with different amounts and types of zeolite and different compressive strength. This study investigated the effects of the initial kaolinitic clays on the amount and types of zeolite in the resultant geopolymers as well as the strength of the bulk materials. The kaolinitic clays and their metakaolin were characterized by XRD analysis, chemical composition, crystallite size, 29Si and 27Al MAS NMR analysis, and specific surface area measurements. The correlation between the amount of zeolite formed and the compressive strength of the resultant hybrid bulk materials, previously reported by other researchers was not positively observed. In the studied systems, the effects of Si/Al and crystalline size were observed. When the atomic ratio of Si/Al in the starting kaolinitic clays increased, the compressive strength of the hybrid bulk materials increased. The crystallite size of the zeolite in the hybrid bulk materials increased with decreasing compressive strength of the hybrid bulk materials.

  20. Characterization of carbon fiber composite materials for RF applications

    Science.gov (United States)

    Riley, Elliot J.; Lenzing, Erik H.; Narayanan, Ram M.

    2014-05-01

    Carbon Fiber Composite (CFC) materials have been used for decades in the aerospace, automotive, and naval industries. They have often been used because of their mechanical advantages. These advantageous characteristics have typically included low weight and high strength. It is also a benefit that CFC materials can be made into nearly any shape or size. With the abundant use of CFC materials, it seems desirable to better under- stand the electromagnetic applications of these materials. CFC materials consist of a non-conductive resin or epoxy in addition to conductive carbon fibers. The carbon fibers can be oriented and layered in many different configurations. The specific orientation and layering of the carbon fibers has a direct impact on its electrical characteristics. One specific characteristic of interest is the conductivity of CFC materials. The work in this paper deals with probing the conductivity characteristics of CFC materials for applications in antenna and radar design. Multiple layouts of carbon fiber are investigated. The DC conductivity was measured by applying a conductive epoxy to sample edges and using a milliohm meter. Shielding effectiveness was then predicted based on fundamental electromagnetics for conducting media. Finally, prototype dipole antennas made from CFC materials were investigated.

  1. Phthalocyanine-Carbon Nanostructure Materials Assembled through Supramolecular Interactions.

    Science.gov (United States)

    Bottari, Giovanni; Suanzes, Juan A; Trukhina, Olga; Torres, Tomas

    2011-04-21

    The use of self-assembly for the construction of materials based on phthalocyanines and carbon nanostructures-fullerenes, single-walled carbon nanotubes, and graphene-has demonstrated to be a versatile strategy for the preparation of novel, multifunctional systems. Photophysical studies carried out on these photo- and electroactive supramolecular ensembles have revealed the occurrence of an efficient photoinduced electron-transfer process, thus paving the way for the utilization of these materials as active components in optoelectronic devices. This Perspective highlights the recent progress in the preparation of such materials and the potential use of these systems for the construction of nanostructured materials with singular physicochemical properties.

  2. Photochromic ordered mesoporous hybrid materials based on covalently grafted polyoxometalates.

    Science.gov (United States)

    Luo, Xiujuan; Yang, Chun

    2011-05-07

    Novel polyoxometalate (POM)-grafting mesoporous hybrid silicas, XW(11)/MHS (X=P, Si) and TBAPW(11)Si(2)/MHS, have been prepared respectively by co-condensation and post-synthesis routes based on the employment of Keggin-type monovacant XW(11) or a Si-substituted compound TBAPW(11)Si(2) as POM precursors. Upon characterization of the samples by FT-IR, XRD, ICP-AES, TEM and N(2) adsorption-desorption measurement, it was found that Keggin units were retained perfectly in ordered hexagonal mesopore channels with SBA-15 architecture and immobilized by covalent linkages on the mesopore wall. These materials, especially the co-condensed samples, exhibited stable and reversible photochromic properties under UV irradiation although no special organic component was supplied additionally as an electron donor. An investigation of the photochromism revealed that the photochromic response depended on the centre atom of the POM species (i.e., the redox potential of the POM), the content of the POM and the synthetic route of the sample, while the bleaching process was correlated not only to the redox potential but also to the pore size of the sample. The photochromic mechanism was also studied in detail by cyclic voltammetry, ESR, FT-IR and XPS techniques. It was found that the remaining P123 template acted as a reducing agent and was oxidized during the photochromic process accompanied by the reduction of the POM to heteropolyblue. Thus, a close contact between the POM and the remaining P123 chain in the sample is necessary. Low close-contact degree results in poor photochromic behavior of the post-synthesized sample and impregnated samples.

  3. HYDROTHERMALLY SELF-ADVANCING HYBRID COATINGS FOR MITIGATING CORROSION OF CARBON STEEL.

    Energy Technology Data Exchange (ETDEWEB)

    SUGAMA, T.

    2006-11-22

    Hydrothermally self-advancing hybrid coatings were prepared by blending two starting materials, water-borne styrene acrylic latex (SAL) as the matrix and calcium aluminate cement (CAC) as the hydraulic filler, and then their usefulness was evaluated as the room temperature curable anti-corrosion coatings for carbon steel in CO{sub 2}-laden geothermal environments at 250 C. The following two major factors supported the self-improving mechanisms of the coating during its exposure in an autoclave: First was the formation of a high temperature stable polymer structure of Ca-complexed carboxylate groups containing SAL (Ca-CCG-SAL) due to hydrothermal reactions between SAL and CAC; second was the growth with continuing exposure time of crystalline calcite and boehmite phases coexisting with Ca-CCG-SAL. These two factors promoted the conversion of the porous microstructure in the non-autoclaved coating into a densified one after 7 days exposure. The densified microstructure not only considerably reduced the conductivity of corrosive ionic electrolytes through the coatings' layers, but also contributed to the excellent adherence of the coating to underlying steel' s surface that, in turn, retarded the cathodic oxygen reduction reaction at the corrosion site of steel. Such characteristics including the minimum uptake of corrosive electrolytes by the coating and the retardation of the cathodic corrosion reaction played an important role in inhibiting the corrosion of carbon steel in geothermal environments.

  4. Hybrid carbon nanotube yarn artificial muscle inspired by spider dragline silk

    Science.gov (United States)

    Chun, Kyoung-Yong; Hyeong Kim, Shi; Kyoon Shin, Min; Hoon Kwon, Cheong; Park, Jihwang; Tae Kim, Youn; Spinks, Geoffrey M.; Lima, Márcio D.; Haines, Carter S.; Baughman, Ray H.; Jeong Kim, Seon

    2014-02-01

    Torsional artificial muscles generating fast, large-angle rotation have been recently demonstrated, which exploit the helical configuration of twist-spun carbon nanotube yarns. These wax-infiltrated, electrothermally powered artificial muscles are torsionally underdamped, thereby experiencing dynamic oscillations that complicate positional control. Here, using the strategy spiders deploy to eliminate uncontrolled spinning at the end of dragline silk, we have developed ultrafast hybrid carbon nanotube yarn muscles that generated a 9,800 r.p.m. rotation without noticeable oscillation. A high-loss viscoelastic material, comprising paraffin wax and polystyrene-poly(ethylene-butylene)-polystyrene copolymer, was used as yarn guest to give an overdamped dynamic response. Using more than 10-fold decrease in mechanical stabilization time, compared with previous nanotube yarn torsional muscles, dynamic mirror positioning that is both fast and accurate is demonstrated. Scalability to provide constant volumetric torsional work capacity is demonstrated over a 10-fold change in yarn cross-sectional area, which is important for upscaled applications.

  5. A Carbon Nanotube Reporter of miRNA Hybridization Events In Vivo

    Science.gov (United States)

    Harvey, Jackson D.; Jena, Prakrit V.; Baker, Hanan A.; Zerze, Gül H.; Williams, Ryan M.; Galassi, Thomas V.; Roxbury, Daniel; Mittal, Jeetain

    2017-01-01

    MicroRNAs and other small oligonucleotides in biofluids are promising disease biomarkers, yet conventional assays require complex processing steps that are unsuitable for point-of-care testing or for implantable or wearable sensors. Single-walled carbon nanotubes are an ideal material for implantable sensors, owing to their emission in the near-infrared spectral region, photostability and exquisite sensitivity. Here, we report an engineered carbon-nanotube-based sensor capable of real-time optical quantification of hybridization events of microRNA and other oligonucleotides. The mechanism of the sensor arises from competitive effects between displacement of both oligonucleotide charge groups and water from the nanotube surface, which result in a solvatochromism-like response. The sensor, which allows for detection via single-molecule sensor elements and for multiplexing by using multiple nanotube chiralities, can monitor toehold-based strand-displacement events, which reverse the sensor response and regenerate the sensor complex. We also show that the sensor functions in whole urine and serum, and can non-invasively measure DNA and microRNA after implantation in live mice. PMID:28845337

  6. Synthesis, characterization and bioevaluation of drug-collagen hybrid materials for biomedical applications.

    Science.gov (United States)

    Voicu, Georgeta; Geanaliu-Nicolae, Ruxandra-Elena; Pîrvan, Adrian-Alexandru; Andronescu, Ecaterina; Iordache, Florin

    2016-08-30

    This work presents a study based on the preparation and characterization of drug-collagen hybrid materials. Materials used for obtaining drug-collagen hybrids were collagen type I (Coll) as matrix and fludarabine (F) and epirubicin (E) as hydrophilic active substances. After incorporation of drugs into Coll in different ratios, the obtained hybrid materials (Coll/F and Coll/E) could be used according to our results as potential drug delivery systems in medicine for the topical (local) treatment of cancerous tissues (e.g. the treatment of breast, stomach, lung, colorectal or advanced ovarian cancer). The materials were characterized considering their composition (by XRD, FT-IR and DTA-TG) and their morphology (by SEM). The delivery of drug was assessed by UV-vis. The in vitro citotoxicity demonstrates an antitumoral activity of the obtained hybrid materials and their potential use for biomedical applications as drug delivery systems in tumoral treatments.

  7. Living hybrid materials capable of energy conversion and CO2 assimilation.

    Science.gov (United States)

    Meunier, Christophe F; Rooke, Joanna C; Léonard, Alexandre; Xie, Hao; Su, Bao-Lian

    2010-06-14

    This paper reviews our work on the fabrication of photobiochemical hybrid materials via immobilisation of photosynthetically active entities within silica materials, summarising the viability and productivity of these active entities post encapsulation and evaluating their efficiency as the principal component of a photobioreactor. Immobilisation of thylakoids extracted from spinach leaves as well as whole cells such as A. thaliana, Synechococcus and C. caldarium was carried out in situ using sol-gel methods. In particular, a comprehensive overview is given of the efforts to find the most biocompatible inorganic precursors that can extend the lifetime of the organisms upon encapsulation. The effect of matrix-cell interactions on cell lifetime and the photosynthetic efficiency of the resultant materials are discussed. Precursors based on alkoxides, commonly used in "Chimie Douce" to form porous silica gel, release by-products which are often cytotoxic. However by controlling the formation of gels from aqueous silica precursors and silica nanoparticles acting as "cements" one can significantly enhance the life span of the entrapped organelles and cells. Adapted characteristic techniques have shown survival times of up to 5 months with the photosynthetic production of oxygen recorded as much as 17 weeks post immobilisation. These results constitute a significant advance towards the final goal, long-lasting semi-artificial photobioreactors that can advantageously exploit solar radiation to convert polluting carbon dioxide into useful biofuels, sugars or medical metabolites.

  8. Carbon Nanotubes: Miracle of Materials Science?

    Science.gov (United States)

    Files, Bradley S.; Mayeaux, Brian M.

    1999-01-01

    Article to be sent to Advanced Materials and Processes, journal of ASM International, as attached. This is a news-type technical journal for a large organization of scientists, engineers, salesmen, and managers. The article is quite general, meant to be an introduction to the properties of nanotubes. This is a materials science organization, therefore the article is geared toward using nanotubes for materials uses. Pictures have not been included in this version.

  9. 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.

  10. A role of nanotube dangling pyrrole and oxygen functions in the electrochemical synthesis of polypyrrole/MWCNTs hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Krukiewicz, Katarzyna, E-mail: katarzyna.krukiewicz@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Herman, Artur P., E-mail: artur.herman@polsl.pl [Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, Gliwice 44-100 (Poland); Turczyn, Roman, E-mail: roman.turczyn@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Szymańska, Katarzyna, E-mail: katarzyna.szymanska@polsl.pl [Department of Chemical and Process Engineering, Silesian University of Technology, Strzody 7, 44-100 Gliwice (Poland); Koziol, Krzysztof K.K., E-mail: kk292@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Boncel, Sławomir, E-mail: slawomir.boncel@polsl.pl [Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, Gliwice 44-100 (Poland); Zak, Jerzy K., E-mail: jerzy.zak@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland)

    2014-10-30

    Highlights: • The effect of MWCNT functionalization on properties of PPy composites was explained. • The behavior of pristine, pyrrole-modified and oxidized MWCNT was explained. • Functionalization of MWCNT improved their dispersibility and processability. • Different mechanisms of (f-)MWCNT incorporation into PPy composites were explained. • Orientation of growing PPy chains was tailored through the addition of (f-)MWCNT. - Abstract: The effect of the functionalization of multi-walled carbon nanotubes (MWCNTs) on the process of electrochemical co-deposition of MWCNTs and polypyrrole (PPy), as well as the morphology of obtained composites have been demonstrated. As the nanotube components of the hybrids, three types of MWCNT were used, namely c-CVD derived (pristine) MWCNTs, their oxidized counterparts MWCNT-Ox and pyrrole-modified MWCNT-Py. The stability of pristine and functionalized MWCNTs (f-MWCNT) dispersions in tetrahydrofuran and water was studied together with the description of the process of formation PPy/(f-)MWCNT hybrid materials via electrochemical co-deposition. The structural and morphological properties of the hybrids were characterized by Raman spectroscopy, scanning electron microscopy and atomic force microscopy revealing substantial differences among hybrid materials in their surface morphology and the influence of MWCNT functionalization on the orientation of growing PPy chains.

  11. Large-scale complementary macroelectronics using hybrid integration of carbon nanotubes and IGZO thin-film transistors.

    Science.gov (United States)

    Chen, Haitian; Cao, Yu; Zhang, Jialu; Zhou, Chongwu

    2014-06-13

    Carbon nanotubes and metal oxide semiconductors have emerged as important materials for p-type and n-type thin-film transistors, respectively; however, realizing sophisticated macroelectronics operating in complementary mode has been challenging due to the difficulty in making n-type carbon nanotube transistors and p-type metal oxide transistors. Here we report a hybrid integration of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors to achieve large-scale (>1,000 transistors for 501-stage ring oscillators) complementary macroelectronic circuits on both rigid and flexible substrates. This approach of hybrid integration allows us to combine the strength of p-type carbon nanotube and n-type indium-gallium-zinc-oxide thin-film transistors, and offers high device yield and low device variation. Based on this approach, we report the successful demonstration of various logic gates (inverter, NAND and NOR gates), ring oscillators (from 51 stages to 501 stages) and dynamic logic circuits (dynamic inverter, NAND and NOR gates).

  12. Advanced fiber-composite hybrids--A new structural material

    Science.gov (United States)

    Chamis, C. C.; Lark, R. F.; Sullivan, T. L.

    1974-01-01

    Introduction of metal foil as part of matrix and fiber composite, or ""sandwich'', improves strength and stiffness for multidirectional loading, improves resistance to cyclic loading, and improves impact and erosion resistance of resultant fiber-composite hybrid structure.

  13. Microscopic origin of entropy-driven polymorphism in hybrid organic-inorganic perovskite materials

    Science.gov (United States)

    Butler, Keith T.; Svane, Katrine; Kieslich, Gregor; Cheetham, Anthony K.; Walsh, Aron

    2016-11-01

    Entropy is a critical, but often overlooked, factor in determining the relative stabilities of crystal phases. The importance of entropy is most pronounced in softer materials, where small changes in free energy can drive phase transitions, which has recently been demonstrated in the case of organic-inorganic hybrid-formate perovskites. In this Rapid Communication we demonstrate the interplay between composition and crystal structure that is responsible for the particularly pronounced role of entropy in determining polymorphism in hybrid organic-inorganic materials. Using ab initio based lattice dynamics, we probe the origins and effects of vibrational entropy of four archetype perovskite (A B X3 ) structures. We consider an inorganic material (SrTiO3), an A -site hybrid-halide material (CH3NH3) PbI3 , a X -site hybrid material KSr (BH4)3 , and a mixed A - and X -site hybrid-formate material (N2H5) Zn (HCO2)3 , comparing the differences in entropy between two common polymorphs. The results demonstrate the importance of low-frequency intermolecular modes in determining the phase stability in these materials. The understanding gained allows us to propose a general principle for the relative stability of different polymorphs of hybrid materials as temperature is increased.

  14. Hybrid microcircuit technology handbook materials, processes, design, testing and production

    CERN Document Server

    Licari, James J

    1998-01-01

    The Hybrid Microcircuit Technology Handbook integrates the many diverse technologies used in the design, fabrication, assembly, and testing of hybrid segments crucial to the success of producing reliable circuits in high yields. Among these are: resistor trimming, wire bonding, die attachment, cleaning, hermetic sealing, and moisture analysis. In addition to thin films, thick films, and assembly processes, important chapters on substrate selections, handling (including electrostatic discharge), failure analysis, and documentation are included. A comprehensive chapter of design guidelines will

  15. Impact resistance of hybrid composite fan blade materials

    Science.gov (United States)

    Friedrich, L. A.

    1974-01-01

    Improved resistance to foreign object damage was demonstrated for hybrid composite simulated blade specimens. Transply metallic reinforcement offered additional improvement in resistance to gelatin projectile impacts. Metallic leading edge protection permitted equivalent-to-titanium performance of the hybrid composite simulated blade specimen for impacts with 1.27 cm and 2.54 cm (0.50 and 1.00 inch) diameter gelatin spheres.

  16. Electrochemical and Optical Evaluation of Noble Metal-and Carbon-ITO Hybrid Optically Transparent Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Zudans, Imants; Paddock, Jean R.; Kuramitz, Hideki; Maghasi, Anne T.; Wansapura, Chamika M.; Conklin, Sean D.; Kaval, Necati; Shtoyko, Tanya; Monk, David J.; Bryan, Samuel A.; Hubler, Timothy L.; Richardson, John N.; Seliskar, Carl J.; Heineman, William R.

    2004-04-15

    Optically transparent hybrid electrodes were constructed by sputtering or thermally evaporating layers of varying thickness of Au, Pd, Pt, or C onto an existing conductive indium-tin oxide (ITO) layer on glass. These electrodes were characterized using UV-Vis spectroscopy and cyclic voltammetry; redox probes examined were potassium ferricyanide, tris-(2, 2'-bipyridyl)ruthenium(II) chloride, hydroquinone, and para-aminophenol (PAP). Each type of hybrid was evaluated and compared with other hybrids, as well as with bare ITO electrodes and commercially available Au, Pt, and glassy carbon disk electrodes. Our results indicated that these hybrid electrodes are reasonably robust, easy to prepare, and extend the capabilities of bare ITO surfaces with respect to the electrochemical response (especially for organic redox probes), while giving up little in the way of optical transparency. Because of these characteristics, hybrid electrodes should be especially suited to many spectroelectrochemical applications.

  17. Structural features of carbon materials synthesized by different methods

    Science.gov (United States)

    Streletskii, O. A.; Ivanenko, I. P.; Khvostov, V. V.; Savchenko, N. F.; Nishchak, O. Yu.; Aleksandrov, A. F.

    2016-10-01

    This paper presents the results of investigations of three types of carbon structures synthesized by different methods, such as arc discharge plasma enhanced chemical vapor deposition of carbon in a magnetic field, chemical dehydrohalogenation of the poly(vinyl chloride)/poly(vinylidene chloride) precursor, and pulsed plasma ion assisted deposition. It has been found that the samples prepared by different methods have a common feature, i.e., the presence of three-dimensional clusters based on sp 2- or sp 3-bonds surrounded by quasi-one-dimensional carbon chains. It has been shown that the structure of carbon materials changes depending on the synthesis conditions.

  18. Iron–carbon hybrid capacitor: A proof-of-concept study

    Indian Academy of Sciences (India)

    V R Chari; S R Aravamuthan; A K Shukla

    2014-10-01

    In the present study, cost-intensive Ni electrode is replaced by high surface-area activated carbon (AC) cathode and the possibility of the Fe anode, used in Ni–Fe battery, to function as Fe–C hybrid capacitor has been examined. The electrochemical properties of Fe–C hybrid capacitor assembly are studied using cyclic voltammetry (CV) and galvanostatic charge–discharge cycles. Over 100 galvanostatic charge–discharge cycles for Fe–C hybrid capacitor are carried out and a maximum capacitance of 24 F g-1 is observed.

  19. Functional carbon nitride materials — design strategies for electrochemical devices

    Science.gov (United States)

    Kessler, Fabian K.; Zheng, Yun; Schwarz, Dana; Merschjann, Christoph; Schnick, Wolfgang; Wang, Xinchen; Bojdys, Michael J.

    2017-06-01

    In the past decade, research in the field of artificial photosynthesis has shifted from simple, inorganic semiconductors to more abundant, polymeric materials. For example, polymeric carbon nitrides have emerged as promising materials for metal-free semiconductors and metal-free photocatalysts. Polymeric carbon nitride (melon) and related carbon nitride materials are desirable alternatives to industrially used catalysts because they are easily synthesized from abundant and inexpensive starting materials. Furthermore, these materials are chemically benign because they do not contain heavy metal ions, thereby facilitating handling and disposal. In this Review, we discuss the building blocks of carbon nitride materials and examine how strategies in synthesis, templating and post-processing translate from the molecular level to macroscopic properties, such as optical and electronic bandgap. Applications of carbon nitride materials in bulk heterojunctions, laser-patterned memory devices and energy storage devices indicate that photocatalytic overall water splitting on an industrial scale may be realized in the near future and reveal a new avenue of 'post-silicon electronics'.

  20. Tetrapropylammonium ion influence on the synthesis of Pt Ru/carbon hybrids by hydrothermal carbonization; Influencia do ion tetrapropilamonio na sintese de hibridos PtRu/carbono por carbonizacao hidrotermica

    Energy Technology Data Exchange (ETDEWEB)

    Tusi, M.M.; Polanco, N.S.O.; Brandalise, M.; Correa, O.V.; Silva, A.C.; Oliveira Neto, A.; Linardi, M.; Spinace, E.V., E-mail: espinace@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    PtRu/Carbon hybrid materials were prepared by hydrothermal carbonization using starch as carbon source and reducing agent and H{sub 2}PtCl{sub 6}.6H{sub 2}O e RuCl{sub 3}.xH{sub 2}O as metals source and catalyst of the carbonization process. The materials were prepared in the following conditions: without pH adjustment, in the absence and in the presence of tetrapropylammonium chloride (TPACl), and adjusting the pH using potassium hydroxide (KOH) or tetrapropylammonium hydroxide (TPAOH). The obtained materials were treated under argon atmosphere at 900 deg C and characterized by SEM/EDX, BET isotherm, XRD and TEM. The electro-oxidation of methanol was studied by chronoamperometry. The material prepared using TPAOH showed the best performance for methanol electro-oxidation. (author)

  1. A study on the cytotoxicity of carbon-based materials.

    Science.gov (United States)

    Saha, Dipendu; Heldt, Caryn L; Gencoglu, Maria F; Vijayaragavan, K Saagar; Chen, Jihua; Saksule, Ashish

    2016-11-01

    With an aim to understand the origin and key contributing factors towards carbon-induced cytotoxicity, we have studied five different carbon samples with diverse surface area, pore width, shape and size, conductivity and surface functionality. All the carbon materials were characterized with surface area and pore size distribution, X-ray photoelectron spectroscopy (XPS) and electron microscopic imaging. We performed cytotoxicity study in Caco-2 cells by colorimetric assay, oxidative stress analysis by reactive oxygen species (ROS) detection, cellular metabolic activity measurement by adenosine triphosphate (ATP) depletion and visualization of cellular internalization by TEM imaging. The carbon materials demonstrated a varying degree of cytotoxicity in contact with Caco-2 cells. The lowest cell survival rate was observed for nanographene, which possessed the minimal size amongst all the carbon samples under this study. None of the carbons induced oxidative stress to the cells as indicated by the ROS generation results. Cellular metabolic activity study revealed that the carbon materials caused ATP depletion in cells and nanographene caused the highest depletion. Visual observation by TEM imaging indicated the cellular internalization of nanographene. This study confirmed that the size is the key cause of carbon-induced cytotoxicity and it is probably caused by the ATP depletion within the cell. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. (Bio)hybrid materials based on optically active particles

    Science.gov (United States)

    Reitzig, Manuela; Härtling, Thomas; Opitz, Jörg

    2014-03-01

    In this contribution we provide an overview of current investigations on optically active particles (nanodiamonds, upconversion phospors) for biohybrid and sensing applications. Due to their outstanding properties nanodiamonds gain attention in various application elds such as microelectronics, optical monitoring, medicine, and biotechnology. Beyond the typical diamond properties such as high thermal conductivity and extreme hardness, the carbon surface and its various functional groups enable diverse chemical and biological surface functionalization. At Fraunhofer IKTS-MD we develop a customization of material surfaces via integration of chemically modi ed nanodiamonds at variable surfaces, e.g bone implants and pipelines. For the rst purpose, nanodiamonds are covalently modi ed at their surface with amino or phosphate functionalities that are known to increase adhesion to bone or titanium alloys. The second type of surface is approached via mechanical implementation into coatings. Besides nanodiamonds, we also investigate the properties of upconversion phosphors. In our contribution we show how upconversion phosphors are used to verify sterilization processes via a change of optical properties due to sterilizing electron beam exposure.

  3. Evaluation of electrode materials for all-copper hybrid flow batteries

    Science.gov (United States)

    Leung, Puiki; Palma, Jesus; Garcia-Quismondo, Enrique; Sanz, Laura; Mohamed, M. R.; Anderson, Marc

    2016-04-01

    This work evaluates a number of two- and three-dimensional electrodes for the reactions of an all-copper hybrid flow battery. Half- and full-cell experiments are conducted by minimizing the crossover effect of the copper(II) species. The battery incorporates a Nafion® cation exchange membrane and the negative electrolyte is maintained at the monovalent (colourless) state by the incorporating copper turnings in the electrolyte reservoir. Under such conditions, the half-cell coulombic efficiencies of the negative electrode reactions are all higher than 90% regardless of electrode materials and the state-of-charge (SOC). With charge-discharge cycling the half-cell from a 0% SOC, the coulombic efficiencies of the positive electrode reactions are lower than 76% with the planar carbon electrode, which further decrease in shorter charge-discharge cycles. Polarization and half-cell charge-discharge experiments suggest that the high-surface-area electrodes effectively reduce the overpotentials and improve the coulombic efficiencies of both electrode reactions. When copper fibres and carbon felt are used as the negative and positive electrodes, the average coulombic and voltage efficiencies of an all-copper flow battery are as high as c.a. 99% and c.a. 60% at 50 mA cm-2 for 35 cycles.

  4. Sensitive determination of carbendazim in orange juice by electrode modified with hybrid material.

    Science.gov (United States)

    Razzino, Claudia A; Sgobbi, Lívia F; Canevari, Thiago C; Cancino, Juliana; Machado, Sergio A S

    2015-03-01

    This paper describes the application of a glassy carbon electrode modified with a thin film of mesoporous silica/multiwalled carbon nanotubes for voltammetric determination of the fungicide carbendazim (CBZ). The hybrid material, (SiO2/MWCNT), was obtained by a sol-gel process using HF as the catalyst. The amperometric response to CBZ was measured at +0.73 V vs. Ag/AgCl by square wave voltammetry at pH 8.0. SiO2/MWCNT/GCE responded to CBZ in the linear range from 0.2 to 4.0 μmol L(-1). The calculated detection limit was 0.056 μmol L(-1), obtained using statistical methods. The SiO2/MWCNT/GCE sensor presented as the main characteristics high sensitivity, low detection limit and robustness, allowing CBZ determination in untreated real samples. In addition, this strategy afforded remarkable selectivity for CBZ against ascorbic and citric acid which are the main compounds of the orange juice. The excellent sensitivity and selectivity yielded feasible application for CBZ detection in orange juice sample.

  5. Hybrid Quantum Device with Nitrogen-Vacancy Centers in Diamond Coupled to Carbon Nanotubes

    Science.gov (United States)

    Li, Peng-Bo; Xiang, Ze-Liang; Rabl, Peter; Nori, Franco

    2016-07-01

    We show that nitrogen-vacancy (NV) centers in diamond interfaced with a suspended carbon nanotube carrying a dc current can facilitate a spin-nanomechanical hybrid device. We demonstrate that strong magnetomechanical interactions between a single NV spin and the vibrational mode of the suspended nanotube can be engineered and dynamically tuned by external control over the system parameters. This spin-nanomechanical setup with strong, intrinsic, and tunable magnetomechanical couplings allows for the construction of hybrid quantum devices with NV centers and carbon-based nanostructures, as well as phonon-mediated quantum information processing with spin qubits.

  6. Laser irradiation of carbon-tungsten materials

    Science.gov (United States)

    Marcu, A.; Avotina, L.; Marin, A.; Lungu, C. P.; Grigorescu, C. E. A.; Demitri, N.; Ursescu, D.; Porosnicu, C.; Osiceanu, P.; Kizane, G.; Grigoriu, C.

    2014-09-01

    Carbon-tungsten layers deposited on graphite by thermionic vacuum arc (TVA) were directly irradiated with a femtosecond terawatt laser. The morphological and structural changes produced in the irradiated area by different numbers of pulses were systematically explored, both along the spots and in their depths. Although micro-Raman and Synchrotron-x-ray diffraction investigations have shown no carbide formation, they have shown the unexpected presence of embedded nano-diamonds in the areas irradiated with high fluencies. Scanning electron microscopy images show a cumulative effect of the laser pulses on the morphology through the ablation process. The micro-Raman spatial mapping signalled an increased percentage of sp3 carbon bonding in the areas irradiated with laser fluencies around the ablation threshold. In-depth x-ray photoelectron spectroscopy investigations suggested a weak cumulative effect on the percentage increase of the sp2-sp3 transitions with the number of laser pulses just for nanometric layer thicknesses.

  7. Hybrid direct carbon fuel cells and their reaction mechanisms - a review

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2014-01-01

    with carbon capture and storage (CCS) due to the high purity of CO2 emitted in the exhaust gas. Direct carbon (or coal) fuel cells (DCFCs) are directly fed with solid carbon to the anode chamber. The fuel cell converts the carbon at the anode and the oxygen at the cathode into electricity, heat and reaction...... is discussed on the fuel cell stack and system levels. The range of DCFC types can be roughly broken down into four fuel cell types: aqueous hydroxide, molten hydroxide, molten carbonate and solid oxide fuel cells. Emphasis is placed on the electrochemical reactions occurring at the anode and the proposed...... mechanism(s) of these reactions for molten carbonate, solid oxide and hybrid direct carbon fuel cells. Additionally, the criteria of choosing the ‘best’ DCFC technology is explored, including system design (continuous supply of solid fuel), performance (power density, efficiency), environmental burden...

  8. Material efficient production of complex (hybrid) components using semi solid forming processes

    Science.gov (United States)

    Riedmüller, Kim Rouven; Liewald, Mathias

    2016-10-01

    By means of lightweight design and lightweight material structures, weight of single components and of resulting component assemblies should be reduced and, additionally, existing functionalities, reliabilities and material properties should be preserved. Therefore, on the one hand novel materials and hybrid material combinations are investigated and on the other hand weight reduction is realized by material efficient component designs. With regard to the manufacturing of such complex component geometries with high dimensional accuracy and relating to the realization of hybrid material concepts, semi solid forming technology offers promising prospects. This paper deals with two research projects recently conducted at the Institute for Metal Forming Technology (IFU, University of Stuttgart) in the field of this forming technology. First project is concerned with the manufacturing of hybrid components with integrated sensor and/or actuator functions and second project is in the field of material efficient manufacturing.

  9. Preparation and characterization of carbon pillared clay material

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Carbon pillared clay material was prepared from montmorillonite modified by C19H42BrN and C10H16ClN. SEM, FT-IR, XRD, N2 adsorption-desorption, thermal-gravimetric analysis and differential scanning calorimetry were employed to characterize the pore structure and test the effect of surfactant. The results show that organic modifier combines with montmorillonite particles by covalent bond and ion embedded. The microstructure of carbon pillared material looks like needle slice. The most probable pore size distribution is about 1.7 nm. The clay material slice mainly consists of two-dimensional aperture supported by a carbonization pillar. The high-temperature stability of carbon pillared clay is im- proved.

  10. Preparation and characterization of carbon pillared clay material

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZengZhi; YANG ChunWei; NIU JunJie

    2009-01-01

    Carbon pillared clay material was prepared from montmorillonite modified by C19H42BrN and C10H16CIN.SEM, FT-IR, XRD, N2 adsorption-desorption, thermal-gravimetric analysis and differential scanning calorimetry were employed to characterize the pore structure and test the effect of surfactant. The re-sults show that organic modifier combines with montmorillonite particles by covalent bond and ion embedded. The microstructure of carbon pillared material looks like needle slice. The most probable pore size distribution is about 1.7 nm, The clay material slice mainly consists of two-dimensional ap-erture supported by a carbonization pillar. The high-temperature stability of carbon pillared clay is im-proved.

  11. 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.

  12. 21 CFR 872.3680 - Polytetrafluoroethylene (PTFE) vitreous carbon materials.

    Science.gov (United States)

    2010-04-01

    ... materials. 872.3680 Section 872.3680 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3680 Polytetrafluoroethylene (PTFE) vitreous carbon materials. (a) Identification. Polytetrafluoroethylene (PTFE)...

  13. Fe3O4/carbon coated silicon ternary hybrid composite as supercapacitor electrodes

    Science.gov (United States)

    Oh, Ilgeun; Kim, Myeongjin; Kim, Jooheon

    2015-02-01

    In this study, Fe3O4/carbon-coated Si ternary hybrid composites were fabricated. A carbon layer was directly formed on the surface of Si by the thermal vapor deposition. The carbon-coating layer not only prevented the contact between Si and reactive electrolyte but also provided anchoring sites for the deposition of Fe3O4. Fe3O4 nanoparticles were deposited on the surface of carbon-coated Si by the hydrazine reducing method. The morphology and structure of Fe3O4 and carbon layer were characterized via X-ray diffractometry, field emission scanning electron microscopy, field emission transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analyses. These characterizations indicate that a carbon layer was fully coated on the Si particles, and Fe3O4 particles were homogeneously deposited on the carbon-coated Si particles. The Fe3O4/carbon-coated Si electrode exhibited enhanced electrochemical performance, attributed to the high conductivity and stability of carbon layer and pseudocapacitive reaction of Fe3O4. The proposed ternary-hybrid composites may be potentially useful for the fabrication of high-performance electrodes.

  14. Hybrid carbon nanoparticles modified core-shell silica: a high efficiency carbon-based phase for hydrophilic interaction liquid chromatography.

    Science.gov (United States)

    Ibrahim, Mohammed E A; Wahab, M Farooq; Lucy, Charles A

    2014-04-11

    Hydrophilic interaction liquid chromatography (HILIC) is a fast growing separation technique for hydrophilic and polar analytes. In this work, we combine the unique selectivity of carbon surfaces with the high efficiency of core-shell silica. First, 5 μm core-shell silica is electrostatically coated with 105 nm cationic latex bearing quaternary ammonium groups. Then 50 nm anionic carbon nanoparticles are anchored onto the surface of the latex coated core-shell silica particles to produce a hybrid carbon-silica phase. The hybrid phase shows different selectivity than ten previously classified HILIC column chemistries and 36 stationary phases. The hybrid HILIC phase has shape selectivity for positional isomeric pairs (phthalic/isophthalic and 1-naphthoic/2-naphthoic acids). Fast and high efficiency HILIC separations of biologically important carboxylates, phenols and pharmaceuticals are reported with efficiencies up to 85,000 plates m(-1). Reduced plate height of 1.9 (95,000 plates m(-1)) can be achieved. The hybrid phase is stable for at least 3 months of usage and storage under typical HILIC eluents.

  15. Friction and wear behavior of carbon fiber reinforced brake materials

    Institute of Scientific and Technical Information of China (English)

    Du-qing CHENG; Xue-tao WANG; Jian ZHU; Dong-bua QIU; Xiu-wei CHENG; Qing-feng GUAN

    2009-01-01

    A new composite brake material was fabri-cated with metallic powders, barium sulphate and modified phenolic resin as the matrix and carbon fiber as the reinforced material. The friction, wear and fade character-istics of this composite were determined using a D-MS friction material testing machine. The surface structure of carbon fiber reinforced friction materials was analyzed by scanning electronic microscopy (SEM). Glass fiber-reinforced and asbestos fiber-reinforced composites with the same matrix were also fabricated for comparison. The carbon fiber-reinforced friction materials (CFRFM) shows lower wear rate than those of glass fiber- and asbestos fiber-reinforced composites in the temperature range of 100℃-300℃. It is interesting that the frictional coefficient of the carbon fiber-reinforced friction materials increases as frictional temperature increases from 100℃ to 300℃, while the frictional coefficients of the other two composites decrease during the increasing temperatures. Based on the SEM observation, the wear mechanism of CFRFM at low temperatures included fiber thinning and pull-out. At high temperature, the phenolic matrix was degraded and more pull-out enhanced fiber was demonstrated. The properties of carbon fiber may be the main reason that the CFRFM possess excellent tribological performances.

  16. Carbon nanotube prepared from carbon monoxide by CVD method and its application as electrode materials

    Institute of Scientific and Technical Information of China (English)

    AN Yuliang; YUAN Xia; CHENG Shinan; GEN Xin

    2006-01-01

    Carbon nanotubes with larger inner diameter were synthesized by the chemical vapor deposition of carbon monoxide (CO) on iron catalyst using H2S as promoting agent.It is found that the structure and morphology of carbon nanotubes can be tailored, to some degree, by varying the experimental conditions such as precursor components and process parameters.The results show that the presence of H2S may play key role for growing Y-branched carbon nanotubes.The products were characterized by SEM, TEM, and Raman spectroscopy, respectively.Furthermore, the obtained carbon nanotubes were explored as electrode materials for supercapacitor.

  17. Deoiled asphalt as carbon source for preparation of various carbon materials by chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xuguang; Yang, Yongzhen; Lin, Xian; Xu, Bingshe; Zhang, Yan [Key Laboratory of Interface Science and Engineering in Advanced Materials of Taiyuan University of Technology, Ministry of Education, Taiyuan 030024 (China)

    2006-10-15

    Various carbon materials, including vapor grown carbon fibers (VGCFs) and carbon trees, were synthesized by chemical vapor deposition in argon atmosphere, using deoiled asphalt as carbon source and ferrocene as catalyst. Pure carbon microbeads (CMBs) were also obtained by this method in the absence of ferrocene. The influence of different growth parameters, such as ferrocene content, reaction temperature, retention time and argon flow rate, was investigated, with respect to morphology and product yield. The products were characterized by field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and Raman spectroscopy. (author)

  18. Flexible field emission of nitrogen-doped carbon nanotubes/reduced graphene hybrid films.

    Science.gov (United States)

    Lee, Duck Hyun; Lee, Jin Ah; Lee, Won Jong; Kim, Sang Ouk

    2011-01-03

    The outstanding flexible field emission properties of carbon hybrid films made of vertically aligned N-doped carbon nanotubes grown on mechanically compliant reduced graphene films are demonstrated. The bottom-reduced graphene film substrate enables the conformal coating of the hybrid film on flexible device geometry and ensures robust mechanical and electrical contact even in a highly deformed state. The field emission properties are precisely examined in terms of the control of the bending radius, the N-doping level, and the length or wall-number of the carbon nanotubes and analyzed with electric field simulations. This high-performance flexible carbon field emitter is potentially useful for diverse, flexible field emission devices.

  19. Obtaining New Dental Materials Reinforced with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    I.V. Zaporotskova

    2014-07-01

    Full Text Available The article seeks to explore the change of strength properties of composite polymer material on the basis of fast-hardening dental plastic "Carbogen", when reinforcing its coal-native nanotubes. Were discussed peculiarities of composition of Carboante, ways of creation of polymeric composition deposits by doping their carbon nanotubes, the results of measuring the strength characteristic characteristics obtained new polymer materials. On the basis of the analysis of the practical and the theoretical-sky research, conclusions were drawn on the feasibility of a new filling material with the use of carbon nanotubes with unique strength characteristics and use of their in dentistry.

  20. New strategies for the selective functionalization of carbon materials

    Directory of Open Access Journals (Sweden)

    M. Pérez-Mendoza

    2012-03-01

    Full Text Available Selectively surface-modified solids can play a crucialrole in the development of new materials devised togive effective answers to the new technologydemands of the more sustainable 21st-centuryindustry. This has brought about a concentration ofresearch efforts on the elaboration of specificchemical functionality on solid surfaces. Nevertheless,the introduction of specific surface functionalizationon carbon materials has not yet realized the degreeof sophistication and control that other solid materialshave reached. This article reviews the latest researchdeveloped under the CARB-NANOMETAL project(at the Universities of Granada and Jaén towardsthe designing of new strategies for the selectivefunctionalization of carbon materials.

  1. Hybrid Nonlinear Optical Materials for Applications in Power Limiting and Photorefractive Devices

    Science.gov (United States)

    2010-03-01

    Final 3. DATES COVERED (From - To) 04/01/2007 to 11/30/2009 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER FA9550-07-1-0307 Hybrid Nonlinear Optical Materials for...Hybrid  Nonlinear   Optical   Materials  for Applications in Power  Limiting and Photorefractive devices      Prime Contract: FA95500710307

  2. Synthesis and cation-exchange properties of a bis-zwitterionic lamellar hybrid material

    Energy Technology Data Exchange (ETDEWEB)

    Besson, E. [ICSM Marcoule, UMR 5257, F-30207 Bagnols Sur Ceze, (France); Mehdi, A.; Reye, C.; Corriu, Robert J. P. [Univ Montpellier 2, Inst Charles Gerhardt Montpellier, CNRS-UM2-ENSCM-UM1, UMR 5253, Chim Mol et Org Sol, F-34095 Montpellier 5, (France); Chollet, H. [CEA Valduc, Dept Traitement Mat Nucl, F-21120 Is Sur Tille, (France); Guilard, R. [ICMUB, CNRS, UMR 5260, F-21078 Dijon, (France)

    2008-07-01

    The synthesis of a bis-zwitterionic lamellar hybrid material containing ammonium carboxylate groups is described. Cation-exchange properties of this material towards transition metal and lanthanide ions were studied as well as the regeneration and reuse of the material. (authors)

  3. Multifunctional hybrid nanocomposites based on carbon nanotubes and chemically modified graphene

    OpenAIRE

    Bosch Navarro, Concepcion

    2013-01-01

    La Tesis trata del desarrollo de materiales híbridos multifuncionales basados en nanotubos de carbono y grafeno con interés en magnetismo molecular y electrónica molecular This Thesis deals with the chemistry and development of new hybrid multifunctional systems based on carbon nanotubes (CNTs) and graphene (G). To introduce both types of carbon nanoforms a brief historical overview of these systems has been briefly given at the Preface. Next and prior to the presentation of ...

  4. Adsorption of ciprofloxacin on surface-modified carbon materials.

    Science.gov (United States)

    Carabineiro, S A C; Thavorn-Amornsri, T; Pereira, M F R; Figueiredo, J L

    2011-10-01

    The adsorption capacity of ciprofloxacin (CPX) was determined on three types of carbon-based materials: activated carbon (commercial sample), carbon nanotubes (commercial multi-walled carbon nanotubes) and carbon xerogel (prepared by the resorcinol/formaldehyde approach at pH 6.0). These materials were used as received/prepared and functionalised through oxidation with nitric acid. The oxidised materials were then heat treated under inert atmosphere (N2) at different temperatures (between 350 and 900°C). The obtained samples were characterised by adsorption of N2 at -196 °C, determination of the point of zero charge and by temperature programmed desorption. High adsorption capacities ranging from approximately 60 to 300 mgCPxgC(-1) were obtained (for oxidised carbon xerogel, and oxidised thermally treated activated carbon Norit ROX 8.0, respectively). In general, it was found that the nitric acid treatment of samples has a detrimental effect in adsorption capacity, whereas thermal treatments, especially at 900 °C after oxidation, enhance adsorption performance. This is due to the positive effect of the surface basicity. The kinetic curves obtained were fitted using 1st or 2nd order models, and the Langmuir and Freundlich models were used to describe the equilibrium isotherms obtained. The 2nd order and the Langmuir models, respectively, were shown to present the best fittings.

  5. h-BN Nanosheets as 2D Substrates to Load 0D Fe3O4 Nanoparticles: A Hybrid Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Duan, Zhi-Qiang; Liu, Yi-Tao; Xie, Xu-Ming; Ye, Xiong-Ying; Zhu, Xiao-Dong

    2016-03-18

    h-BN, as an isoelectronic analogue of graphene, has improved thermal mechanical properties. Moreover, the liquid-phase production of h-BN is greener since harmful oxidants/reductants are unnecessary. Here we report a novel hybrid architecture by employing h-BN nanosheets as 2D substrates to load 0D Fe3O4 nanoparticles, followed by phenol/formol carbonization to form a carbon coating. The resulting carbon-encapsulated h-BN@Fe3O4 hybrid architecture exhibits synergistic interactions: 1) The h-BN nanosheets act as flexible 2D substrates to accommodate the volume change of the Fe3O4 nanoparticles; 2) The Fe3O4 nanoparticles serve as active materials to contribute to a high specific capacity; and 3) The carbon coating not only protects the hybrid architecture from deformation but also keeps the whole electrode highly conductive. The synergistic interactions translate into significantly enhanced electrochemical performances, laying a basis for the development of superior hybrid anode materials.

  6. Hybrid Effect Evaluation of Steel Fiber and Carbon Fiber on the Performance of the Fiber Reinforced Concrete

    OpenAIRE

    Weimin Song; Jian Yin

    2016-01-01

    Fiber reinforcement is an important method to enhance the performance of concrete. In this study, the compressive test and impact test were conducted, and then the hybrid effect between steel fiber (SF) and carbon fiber (CF) was evaluated by employing the hybrid effect index. Compressive toughness and impact toughness of steel fiber reinforced concrete (SFRC), carbon fiber reinforced concrete (CFRC) and hybrid fiber reinforced concrete (HFRC) were explored at steel fiber volume fraction 0.5%,...

  7. Catalytic properties of carbon materials for wet oxidation of aniline

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Helder T. [Laboratorio de Catalise e Materiais (LCM), Laboratorio Associado LSRE/LCM, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Departamento de Tecnologia Quimica e Biologica, Escola Superior de Tecnologia e de Gestao, Instituto Politecnico de Braganca, Campus de Santa Apolonia, 5300-857 Braganca (Portugal); Machado, Bruno F.; Ribeiro, Andreia; Moreira, Ivo; Rosario, Marcio; Silva, Adrian M.T.; Figueiredo, Jose L. [Laboratorio de Catalise e Materiais (LCM), Laboratorio Associado LSRE/LCM, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Faria, Joaquim L. [Laboratorio de Catalise e Materiais (LCM), Laboratorio Associado LSRE/LCM, Departamento de Engenharia Quimica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal)], E-mail: jlfaria@fe.up.pt

    2008-11-30

    A mesoporous carbon xerogel with a significant amount of oxygen functional groups and a commercial activated carbon, were tested in the catalytic wet air oxidation of aniline at 200 deg. C and 6.9 bar of oxygen partial pressure. Both carbon materials showed high activity in aniline and total organic carbon removal, a clear increase in the removal efficiency relatively to non-catalytic wet air oxidation being observed. The best results in terms of aniline removal were obtained with carbon xerogel, an almost complete aniline conversion after 1 h oxidation with high selectivity to non-organic compounds being achieved. The materials were characterized by thermogravimetric analysis, temperature programmed desorption, N{sub 2} adsorption and scanning electron microscopy, in order to relate their performances to the chemical and textural characteristics. It was concluded that the removal efficiency, attributed to both adsorption and catalytic activity, is related to the mesoporous character of the materials and to the presence of specific oxygen containing functional groups at their surface. The effect of catalytic activity was found to be more important in the removal of aniline than the effect of adsorption at the materials surface. The results obtained indicate that mesoporous carbon xerogels are promising catalysts for CWAO processes.

  8. Catalytic properties of carbon materials for wet oxidation of aniline.

    Science.gov (United States)

    Gomes, Helder T; Machado, Bruno F; Ribeiro, Andreia; Moreira, Ivo; Rosário, Márcio; Silva, Adrián M T; Figueiredo, José L; Faria, Joaquim L

    2008-11-30

    A mesoporous carbon xerogel with a significant amount of oxygen functional groups and a commercial activated carbon, were tested in the catalytic wet air oxidation of aniline at 200 degrees C and 6.9 bar of oxygen partial pressure. Both carbon materials showed high activity in aniline and total organic carbon removal, a clear increase in the removal efficiency relatively to non-catalytic wet air oxidation being observed. The best results in terms of aniline removal were obtained with carbon xerogel, an almost complete aniline conversion after 1h oxidation with high selectivity to non-organic compounds being achieved. The materials were characterized by thermogravimetric analysis, temperature programmed desorption, N(2) adsorption and scanning electron microscopy, in order to relate their performances to the chemical and textural characteristics. It was concluded that the removal efficiency, attributed to both adsorption and catalytic activity, is related to the mesoporous character of the materials and to the presence of specific oxygen containing functional groups at their surface. The effect of catalytic activity was found to be more important in the removal of aniline than the effect of adsorption at the materials surface. The results obtained indicate that mesoporous carbon xerogels are promising catalysts for CWAO processes.

  9. Hydrogen storage by carbon materials synthesized from oil seeds and fibrous plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Sharon, Maheshwar; Bhardwaj, Sunil; Jaybhaye, Sandesh [Nanotechnology Research Center, Birla College, Kalyan 421304 (India); Soga, T.; Afre, Rakesh [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya (Japan); Sathiyamoorthy, D.; Dasgupta, K. [Powder Metallurgy Division, BARC, Trombay 400 085 (India); Sharon, Madhuri [Monad Nanotech Pvt. Ltd., A702 Bhawani Tower, Powai, Mumbai 400 076 (India)

    2007-12-15

    Carbon materials of various morphologies have been synthesized by pyrolysis of various oil-seeds and plant's fibrous materials. These materials are characterized by SEM and Raman. Surface areas of these materials are determined by methylene blue method. These carbon porous materials are used for hydrogen storage. Carbon fibers with channel type structure are obtained from baggas and coconut fibers. It is reported that amongst the different plant based precursors studied, carbon from soyabean (1.09 wt%) and baggas (2.05 wt%) gave the better capacity to store hydrogen at 11kg/m{sup 2} pressure of hydrogen at room temperature. Efforts are made to correlate the hydrogen adsorption capacity with intensities and peak positions of G- and D-band obtained with carbon materials synthesized from plant based precursors. It is suggested that carbon materials whose G-band is around 1575cm{sup -1} and the intensity of D-band is less compared to G-band, may be useful material for hydrogen adsorption study. (author)

  10. Fabrication, testing, and analysis of anisotropic carbon/glass hybrid composites: volume 1: technical report.

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, Kyle K. (Wetzel Engineering, Inc. Lawrence, Kansas); Hermann, Thomas M. (Wichita state University, Wichita, Kansas); Locke, James (Wichita state University, Wichita, Kansas)

    2005-11-01

    Anisotropic carbon/glass hybrid composite laminates have been fabricated, tested, and analyzed. The laminates have been fabricated using vacuum-assisted resin transfer molding (VARTM). Five fiber complexes and a two-part epoxy resin system have been used in the study to fabricate panels of twenty different laminate constructions. These panels have been subjected to physical testing to measure density, fiber volume fraction, and void fraction. Coupons machined from these panels have also been subjected to mechanical testing to measure elastic properties and strength of the laminates using tensile, compressive, transverse tensile, and in-plane shear tests. Interlaminar shear strength has also been measured. Out-of-plane displacement, axial strain, transverse strain, and inplane shear strain have also been measured using photogrammetry data obtained during edgewise compression tests. The test data have been reduced to characterize the elastic properties and strength of the laminates. Constraints imposed by test fixtures might be expected to affect measurements of the moduli of anisotropic materials; classical lamination theory has been used to assess the magnitude of such effects and correct the experimental data for the same. The tensile moduli generally correlate well with experiment without correction and indicate that factors other than end constraints dominate. The results suggest that shear moduli of the anisotropic materials are affected by end constraints. Classical lamination theory has also been used to characterize the level of extension-shear coupling in the anisotropic laminates. Three factors affecting the coupling have been examined: the volume fraction of unbalanced off-axis layers, the angle of the off-axis layers, and the composition of the fibers (i.e., carbon or glass) used as the axial reinforcement. The results indicate that extension/shear coupling is maximized with the least loss in axial tensile stiffness by using carbon fibers oriented 15{sup

  11. Computer-Aided Process Model For Carbon/Phenolic Materials

    Science.gov (United States)

    Letson, Mischell A.; Bunker, Robert C.

    1996-01-01

    Computer program implements thermochemical model of processing of carbon-fiber/phenolic-matrix composite materials into molded parts of various sizes and shapes. Directed toward improving fabrication of rocket-engine-nozzle parts, also used to optimize fabrication of other structural components, and material-property parameters changed to apply to other materials. Reduces costs by reducing amount of laboratory trial and error needed to optimize curing processes and to predict properties of cured parts.

  12. Radiation Exposure Effects and Shielding Analysis of Carbon Nanotube Materials

    Science.gov (United States)

    Wilkins, Richard; Armendariz, Lupita (Technical Monitor)

    2002-01-01

    Carbon nanotube materials promise to be the basis for a variety of emerging technologies with aerospace applications. Potential applications to human space flight include spacecraft shielding, hydrogen storage, structures and fixtures and nano-electronics. Appropriate risk analysis on the properties of nanotube materials is essential for future mission safety. Along with other environmental hazards, materials used in space flight encounter a hostile radiation environment for all mission profiles, from low earth orbit to interplanetary space.

  13. Covalent Crosslinking of Carbon Nanotube Materials for Improved Tensile Strength

    Science.gov (United States)

    Baker, James S.; Miller, Sandi G.; Williams, Tiffany A.; Meador, Michael A.

    2013-01-01

    Carbon nanotubes have attracted much interest in recent years due to their exceptional mechanical properties. Currently, the tensile properties of bulk carbon nanotube-based materials (yarns, sheets, etc.) fall far short of those of the individual nanotube elements. The premature failure in these materials under tensile load has been attributed to inter-tube sliding, which requires far less force than that needed to fracture individual nanotubes.1,2 In order for nanotube materials to achieve their full potential, methods are needed to restrict this tube-tube shear and increase inter-tube forces.Our group is examining covalent crosslinking between the nanotubes as a means to increase the tensile properties of carbon nanotube materials. We are working with multi-walled carbon nanotube (MWCNT) sheet and yarn materials obtained from commercial sources. Several routes to functionalize the nanotubes have been examined including nitrene, aryl diazonium, and epoxide chemistries. The functional nanotubes were crosslinked through small molecule or polymeric bridges. Additionally, electron beam irradiation induced crosslinking of the non-functional and functional nanotube materials was conducted. For example, a nanotube sheet material containing approximately 3.5 mol amine functional groups exhibited a tensile strength of 75 MPa and a tensile modulus of 1.16 GPa, compared to 49 MPa and 0.57 GPa, respectively, for the as-received material. Electron beam irradiation (2.2x 1017 ecm2) of the same amine-functional sheet material further increased the tensile strength to 120 MPa and the modulus to 2.61 GPa. This represents approximately a 150 increase in tensile strength and a 360 increase in tensile modulus over the as-received material with only a 25 increase in material mass. Once we have optimized the nanotube crosslinking methods, the performance of these materials in polymer matrix composites will be evaluated.

  14. Three-dimensional Aerographite-GaN hybrid networks: Single step fabrication of porous and mechanically flexible materials for multifunctional applications

    Science.gov (United States)

    Schuchardt, Arnim; Braniste, Tudor; Mishra, Yogendra K.; Deng, Mao; Mecklenburg, Matthias; Stevens-Kalceff, Marion A.; Raevschi, Simion; Schulte, Karl; Kienle, Lorenz; Adelung, Rainer; Tiginyanu, Ion

    2015-03-01

    Three dimensional (3D) elastic hybrid networks built from interconnected nano- and microstructure building units, in the form of semiconducting-carbonaceous materials, are potential candidates for advanced technological applications. However, fabrication of these 3D hybrid networks by simple and versatile methods is a challenging task due to the involvement of complex and multiple synthesis processes. In this paper, we demonstrate the growth of Aerographite-GaN 3D hybrid networks using ultralight and extremely porous carbon based Aerographite material as templates by a single step hydride vapor phase epitaxy process. The GaN nano- and microstructures grow on the surface of Aerographite tubes and follow the network architecture of the Aerographite template without agglomeration. The synthesized 3D networks are integrated with the properties from both, i.e., nanoscale GaN structures and Aerographite in the form of flexible and semiconducting composites which could be exploited as next generation materials for electronic, photonic, and sensors applications.

  15. Hybrid materials: Magnetite-Polyethylenimine-Montmorillonite, as magnetic adsorbents for Cr(VI) water treatment.

    Science.gov (United States)

    Larraza, Iñigo; López-Gónzalez, Mar; Corrales, Teresa; Marcelo, Gema

    2012-11-01

    Hybrid materials formed by the combination of a sodium rich Montmorillonite (MMT), with magnetite nanoparticles (40 nm, Fe(3)O(4) NPs) coated with Polyethylenimine polymer (PEI 800 g/mol or PEI 25000 g/mol) were prepared. The intercalation of the magnetite nanoparticles coated with PEI among MMT platelets was achieved by cationic exchange. The resulting materials presented a high degree of exfoliation of the MMT sheets and a good dispersion of Fe(3)O(4) NPs on both the surface and among the layers of MMT. The presence of amine groups in the PEI structure not only aids the exfoliation of the MMT layers, but also gives to the hybrid material the necessary functionality to interact with heavy metals. These hybrid materials were used as magnetic sorbent for the removal of hexavalent chromium from water. The effect that pH, Cr(VI) concentration, and adsorbent material composition have on the Cr(VI) removal efficiency was studied. A complete characterization of the materials was performed. The hybrid materials showed a slight dependence of the removal efficiency with the pH in a wide range (1-9). A maximum amount of adsorption capacity of 8.8 mg/g was determined by the Langmuir isotherm. Results show that these hybrid materials can be considered as potential magnetic adsorbent for the Cr(VI) removal from water in a wide range of pH.

  16. Studies on 12 V substrate-integrated lead-carbon hybrid ultracapacitors

    Indian Academy of Sciences (India)

    A Banerjee; A K Shukla

    2015-05-01

    A cost-effective 12 V substrate-integrated lead-carbon hybrid ultracapacitor is developed and performance tested. These hybrid ultracapacitors employ flexible-graphite sheets as negative plate currentcollectors that are coated amperometrically with a thin layer of conducting polymer, namely poly-aniline to provide good adhesivity to activated-carbon layer. The positive plate of the hybrid ultracapacitors comprise conventional lead-sheet that is converted electrochemically into a substrate-integrated lead-dioxide electrode. 12 V substrate-integrated lead-carbon hybrid ultracapacitors both in absorbent-glass-mat and polymeric silicagel electrolyte configurations are fabricated and characterized. It is possible to realize 12 V configurations with capacitance values of ∼200 F and ∼300 F, energy densities of ∼1.9 Wh kg−1 and ∼2.5 Wh kg−1 and power densities of ∼2 kW kg−1 and ∼0.8 kW kg−1, respectively, having faradaic-efficiency values of ∼90 % with cycle-life in excess of 100,000 cycles. The effective cost of the mentioned hybrid ultracapacitors is estimated to be about ∼4 US$/Wh as compared to ∼20 US$/Wh for commercially available ultracapacitors.

  17. Embodied energy of construction materials: integrating human and capital energy into an IO-based hybrid model.

    Science.gov (United States)

    Dixit, Manish K; Culp, Charles H; Fernandez-Solis, Jose L

    2015-02-01

    Buildings alone consume approximately 40% of the annual global energy and contribute indirectly to the increasing concentration of atmospheric carbon. The total life cycle energy use of a building is composed of embodied and operating energy. Embodied energy includes all energy required to manufacture and transport building materials, and construct, maintain, and demolish a building. For a systemic energy and carbon assessment of buildings, it is critical to use a whole life cycle approach, which takes into account the embodied as well as operating energy. Whereas the calculation of a building's operating energy is straightforward, there is a lack of a complete embodied energy calculation method. Although an input-output-based (IO-based) hybrid method could provide a complete and consistent embodied energy calculation, there are unresolved issues, such as an overdependence on price data and exclusion of the energy of human labor and capital inputs. This paper proposes a method for calculating and integrating the energy of labor and capital input into an IO-based hybrid method. The results demonstrate that the IO-based hybrid method can provide relatively complete results. Also, to avoid errors, the total amount of human and capital energy should not be excluded from the calculation.

  18. Multiscale experimental mechanics of hierarchical carbon-based materials.

    Science.gov (United States)

    Espinosa, Horacio D; Filleter, Tobin; Naraghi, Mohammad

    2012-06-05

    Investigation of the mechanics of natural materials, such as spider silk, abalone shells, and bone, has provided great insight into the design of materials that can simultaneously achieve high specific strength and toughness. Research has shown that their emergent mechanical properties are owed in part to their specific self-organization in hierarchical molecular structures, from nanoscale to macroscale, as well as their mixing and bonding. To apply these findings to manmade materials, researchers have devoted significant efforts in developing a fundamental understanding of multiscale mechanics of materials and its application to the design of novel materials with superior mechanical performance. These efforts included the utilization of some of the most promising carbon-based nanomaterials, such as carbon nanotubes, carbon nanofibers, and graphene, together with a variety of matrix materials. At the core of these efforts lies the need to characterize material mechanical behavior across multiple length scales starting from nanoscale characterization of constituents and their interactions to emerging micro- and macroscale properties. In this report, progress made in experimental tools and methods currently used for material characterization across multiple length scales is reviewed, as well as a discussion of how they have impacted our current understanding of the mechanics of hierarchical carbon-based materials. In addition, insight is provided into strategies for bridging experiments across length scales, which are essential in establishing a multiscale characterization approach. While the focus of this progress report is in experimental methods, their concerted use with theoretical-computational approaches towards the establishment of a robust material by design methodology is also discussed, which can pave the way for the development of novel materials possessing unprecedented mechanical properties.

  19. Influence of nanoclay-carbon black hybrid fillers on cure and properties of natural rubber compounds

    NARCIS (Netherlands)

    Sapkota, J.; Poikelispää, M.; Das, A.; Dierkes, W.K.; Vuorinen, J.

    2013-01-01

    The influence of organically modified nanoclay-carbon black (CB) hybrid filler on the curing behavior of natural rubber (NR) was explored in this investigation. Here an effort was paid to understand the curing kinetics of organomodified nanoclay filled rubber compounds. On the basis of two different

  20. Hybrid Graphene and Single-Walled Carbon Nanotube Films for Enhanced Phase-Change Heat Transfer.

    Science.gov (United States)

    Seo, Han; Yun, Hyung Duk; Kwon, Soon-Yong; Bang, In Cheol

    2016-02-10

    Nucleate boiling is an effective heat transfer method in power generation systems and cooling devices. In this letter, hybrid graphene/single-walled carbon nanotube (SWCNT), graphene, and SWCNT films deposited on indium tin oxide (ITO) surfaces were fabricated to investigate the enhancement of nucleate boiling phenomena described by the critical heat flux and heat transfer coefficient. The graphene films were grown on Cu foils and transferred to ITO surfaces. Furthermore, SWCNTs were deposited on the graphene layer to fabricate hybrid graphene/SWCNT films. We determined that the hybrid graphene/SWCNT film deposited on an ITO surface is the most effective heat transfer surface in pool boiling because of the interconnected network of carbon structures.

  1. Dynamic Simulation of Carbonate Fuel Cell-Gas Turbine Hybrid Systems

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R.A. (U. of California, Irvine, CA); Brouwer, J. (U. of California, Irvine, CA); Liese, E.A.; Gemmen, R.S.

    2006-04-01

    Hybrid fuel cell/gas turbine systems provide an efficient means of producing electricity from fossil fuels with ultra low emissions. However, there are many significant challenges involved in integrating the fuel cell with the gas turbine and other components of this type of system. The fuel cell and the gas turbine must maintain efficient operation and electricity production while protecting equipment during perturbations that may occur when the system is connected to the utility grid or in stand-alone mode. This paper presents recent dynamic simulation results from two laboratories focused on developing tools to aid in the design and dynamic analyses of hybrid fuel cell systems. The simulation results present the response of a carbonate fuel cell/gas turbine, or molten carbonate fuel cell/gas turbine, (MCFC/GT) hybrid system to a load demand perturbation. Initial results suggest that creative control strategies will be needed to ensure a flexible system with wide turndown and robust dynamic operation.

  2. Hydrothermal carbonization: a greener route towards the synthesis of advanced carbon materials

    Directory of Open Access Journals (Sweden)

    M.M. Titirici

    2012-09-01

    Full Text Available This review paper provides an overview of thehydrothermal carbonisation (HTC technology, a“green” and versatile strategy for the synthesis ofadvanced carbon materials suitable for a wide varietyof applications of high impact in the current society.We will focus on the carbon formation mechanism,chemical and structural properties of hydrothermalcarbons, porosity development, nanostructuring,functionalisation and applications.

  3. Energy storage in hybrid organic-inorganic materials hexacyanoferrate-doped polypyrrole as cathode in reversible lithium cells

    DEFF Research Database (Denmark)

    Torres-Gomez, G,; Skaarup, Steen; West, Keld

    2000-01-01

    A study of the hybrid oganic-inorganic hexacyanoferrate-polypyrrole material as a cathode in rechargeable lithium cells is reported as part of a series of functional hybrid materials that represent a new concept in energy storage. The effect of synthesis temperatures of the hybrid in the specific...

  4. Computerized calculation of material balances in carbonization

    Energy Technology Data Exchange (ETDEWEB)

    Chistyakov, A.M.

    1980-09-01

    Charge formulations and carbonisation schedules are described by empirical formulae used to calculate the yield of coking products. An algorithm is proposed for calculating the material balance, and associated computer program. The program can be written in conventional languages, e.g. Fortran, Algol etc. The information obtained can be used for on-line assessment of the effects of charge composition and properties on the coke and by-products yields, as well as the effects of the carbonisation conditions.

  5. Substrate integrated Lead-Carbon hybrid ultracapacitor with flooded, absorbent glass mat and silica-gel electrolyte configurations

    Indian Academy of Sciences (India)

    A Banerjee; M K Ravikumar; A Jalajakshi; P Suresh Kumar; S A Gaffoor; A K Shukla

    2012-07-01

    Lead-Carbon hybrid ultracapacitors (Pb-C HUCs) with flooded, absorbent-glass-mat (AGM) and silica-gel sulphuric acid electrolyte configurations are developed and performance tested. Pb-C HUCs comprise substrate-integrated PbO2 (SI-PbO2) as positive electrodes and high surface-area carbon with graphite-sheet substrate as negative electrodes. The electrode and silica-gel electrolyte materials are characterized by XRD, XPS, SEM, TEM, Rheometry, BET surface area, and FTIR spectroscopy in conjunction with electrochemistry. Electrochemical performance of SI-PbO2 and carbon electrodes is studied using cyclic voltammetry with constant-current charge and discharge techniques by assembling symmetric electrical-double-layer capacitors and hybrid Pb-C HUCs with a dynamic Pb(porous)/PbSO4 reference electrode. The specific capacitance values for 2 V Pb-C HUCs are found to be 166 F/g, 102 F/g and 152 F/g with a faradaic efficiency of 98%, 92% and 88% for flooded, AGM and gel configurations, respectively.

  6. Si doped T6 carbon structure as an anode material for Li-ion batteries: An ab initio study

    Science.gov (United States)

    Rajkamal, A.; Kumar, E. Mathan; Kathirvel, V.; Park, Noejung; Thapa, Ranjit

    2016-11-01

    First-principles calculations are performed to identify the pristine and Si doped 3D metallic T6 carbon structure (having both sp2 and sp3 type hybridization) as a new carbon based anode material. The π electron of C2 atoms (sp2 bonded) forms an out of plane network that helps to capture the Li atom. The highest Li storage capacity of Si doped T6 structure with conformation Li1.7Si1C5 produces theoretical specific capacity of 632 mAh/g which substantially exceeding than graphite. Also, open-circuit voltage (OCV) with respect to Li metal shows large negative when compared to the pristine T6 structure. This indicates modifications in terms of chemical properties are required in anode materials for practical application. Among various doped (Si, Ge, Sn, B, N) configuration, Si doped T6 structure provides a stable positive OCV for high Li concentrations. Likewise, volume expansion study also shows Si doped T6 structure is more stable with less pulverization and substantial capacity losses in comparison with graphite and silicon as an anode materials. Overall, mixed hybridized (sp2 + sp3) Si doped T6 structure can become a superior anode material than present sp2 hybridized graphite and sp3 hybridized Si structure for modern Lithium ion batteries.

  7. Improved Composites Using Crosslinked, Surface-Modified Carbon Nanotube Materials

    Science.gov (United States)

    Baker, James Stewart

    2014-01-01

    Individual carbon nanotubes (CNTs) exhibit exceptional tensile strength and stiffness; however, these properties have not translated well to the macroscopic scale. Premature failure of bulk CNT materials under tensile loading occurs due to the relatively weak frictional forces between adjacent CNTs, leading to poor load transfer through the material. When used in polymer matrix composites (PMCs), the weak nanotube-matrix interaction leads to the CNTs providing less than optimal reinforcement.Our group is examining the use of covalent crosslinking and surface modification as a means to improve the tensile properties of PMCs containing carbon nanotubes. Sheet material comprised of unaligned multi-walled carbon nanotubes (MWCNT) was used as a drop-in replacement for carbon fiber in the composites. A variety of post-processing methods have been examined for covalently crosslinking the CNTs to overcome the weak inter-nanotube shear interactions, resulting in improved tensile strength and modulus for the bulk sheet material. Residual functional groups from the crosslinking chemistry may have the added benefit of improving the nanotube-matrix interaction. Composites prepared using these crosslinked, surface-modified nanotube sheet materials exhibit superior tensile properties to composites using the as received CNT sheet material.

  8. Protein Adsorption on Hybrids of Thermoresponsive Polymers and Single-Walled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Kazuo Umemura

    2016-01-01

    Full Text Available Poly(N-isopropylacrylamide (PNIPAAm is one of the most popular thermoresponsive polymers. Adsorption of RecA proteins onto hybrids of PNIPAAm and single-walled carbon nanotubes (SWNTs was observed in the presence and absence of DNA molecules. Although RecA molecules were adsorbed efficiently onto the hybrid surfaces at 37°C, even in the absence of DNA molecules, the adsorption of RecA was inhibited at 4°C. These results suggest that the thermoresponsive functions of PNIPAAm were effective, even on the SWNT surfaces, which supports the possibility of developing nanobiodevices using PNIPAAm-SWNT hybrids. However, although RecA is a DNA binding protein, there was no significant difference in the adsorption of RecA onto PNIPAAm-SWNT surfaces with and without DNA molecules. This study provides fundamental information for potential biological applications of PNIPAAm-SWNT hybrids.

  9. Novel transparent zirconium-based hybrid material with multilayered nanostructures: studies of surface dewettability toward alkane liquids.

    Science.gov (United States)

    Masheder, Benjamin; Urata, Chihiro; Cheng, Dalton F; Hozumi, Atsushi

    2013-01-01

    We have successfully prepared unique inorganic-organic hybrid materials that demonstrate excellent transparency and dewettability toward various alkane liquids (n-hexadecane, n-dodecane and n-decane) without relying on conventional surface roughening and perfluorination. Such coatings were made using a novel family of hybrid materials generated by substituting carboxylic acids, with a range of alkyl chain lengths (CH(3)(CH(2))(x-2)COOH where x = total carbon number, i.e., 10, 12, 14, 16, 18, 22, or 24, into zirconium (Zr) tetra-propoxide complexes. This precursor was then mixed with acetic acid and spincast to produce transparent thin Zr-carboxylic acid (ZrCA(x)) hybrid films using a nonhydrolytic sol-gel process. Fourier transform infrared spectroscopy provided proof of Zr-O-Zr network formation in the films upon casting and also followed changes to the physical nature (liquid-like or solid-like) of the alkyl chain assemblies depending upon alkyl chain length. X-ray diffractometry revealed that the hybrid films prepared using the longer chain carboxylic acids (ZrCA(x≥18)) spontaneously self-assembled into lamella structures with d-spacings ranging from 29.5 to 32.7 Angstroms, depending on the length of the alkyl chain. On the other hand the remaining films (ZrCA(xoleophobicity among the seven hybrid films. In particular, small volume alkane droplets (5 μL) could be easily set in motion to move across and off ZrCA(14) film surfaces without pinning at low tilt angles (~6°).

  10. Experimental Studies of Carbon Nanotube Materials for Space Radiators

    Science.gov (United States)

    SanSoucie, MIchael P.; Rogers, Jan R.; Craven, Paul D.; Hyers, Robert W.

    2012-01-01

    Game ]changing propulsion systems are often enabled by novel designs using advanced materials. Radiator performance dictates power output for nuclear electric propulsion (NEP) systems. Carbon nanotubes (CNT) and carbon fiber materials have the potential to offer significant improvements in thermal conductivity and mass properties. A test apparatus was developed to test advanced radiator designs. This test apparatus uses a resistance heater inside a graphite tube. Metallic tubes can be slipped over the graphite tube to simulate a heat pipe. Several sub ]scale test articles were fabricated using CNT cloth and pitch ]based carbon fibers, which were bonded to a metallic tube using an active braze material. The test articles were heated up to 600 C and an infrared (IR) camera captured the results. The test apparatus and experimental results are presented here.

  11. Mesoporous Carbon-based Materials for Alternative Energy Applications

    Science.gov (United States)

    Cross, Kimberly Michelle

    Increasing concerns for the escalating issues activated by the effect of carbon dioxide emissions on the global climate from extensive use of fossil fuels and the limited amount of fossil resources has led to an in-depth search for alternative energy systems, primarily based on nuclear or renewable energy sources. Recent innovations in the production of more efficient devices for energy harvesting, storage, and conversion are based on the incorporation of nanostructured materials into electrochemical systems. The aforementioned nano-electrochemical energy systems hold particular promise for alternative energy transportation related technologies including fuel cells, hydrogen storage, and electrochemical supercapacitors. In each of these devices, nanostructured materials can be used to increase the surface area where the critical chemical reactions occur within the same volume and mass, thereby increasing the energy density, power density, electrical efficiency, and physical robustness of the system. Durable corrosion resistant carbon support materials for fuel cells have been designed by adding conductive low cost carbon materials with chemically robust ceramic materials. Since a strict control of the pore size is mandatory to optimize properties for improved performance, chemical activation agents have been utilized as porogens to tune surface areas, pore size distributions, and composition of carbon-based mesoporous materials. Through the use of evaporative self-assembly methods, both randomly disordered and surfactant-templated, ordered carbon-silica nanocomposites have been synthesized with controlled surface area, pore volume, and pore size ranging from 50-800 m2/g, 0.025-0.75 cm3/g, and 2-10 nm, respectively. Multi-walled carbon nanotubes (MWNTs) ranging from 0.05-1.0 wt. % were added to the aforementioned carbon-silica nanocomposites, which provided an additional increase in surface area and improved conductivity. Initially, a conductivity value of 0.0667 S

  12. Carbon nanofibers as hydrogen adsorbing materials for power sources

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, M.O.; Kolbasov, G.Ya. [Institute of General and Inorganic Chemistry of the Ukrainian National Academy of Sciences, Prospekt Palladina 32/34, Kyiv 142 (Ukraine); Melezhyk, A.V. [TM Spetsmash Ltd., vul. Viskoznaya 5, build. 23, 02660 Kyiv (Ukraine)

    2008-01-21

    Porous carbon nanofibers are synthesized by CVD method from acetylene with use of iron-containing catalysts. Activation of the nanofibers in melted potassium hydroxide results in increasing surface area from initial 300-400 m{sup 2} g{sup -1} to 1700 m{sup 2} g{sup -1}. As follows from XRD data, activated nanofibers do not contain regular packages of graphene layers, but retain high electric conductivity. Deposition of copper improves electrochemical hydrogen storing characteristics of carbon nanofibers. Carbon nanomaterials obtained can be used as hydrogen storing materials in batteries instead of hydride forming metals. (author)

  13. Growth of Carbon Nanostructure Materials Using Laser Vaporization

    Science.gov (United States)

    Zhu, Shen; Su, Ching-Hua; Lehozeky, S.

    2000-01-01

    Since the potential applications of carbon nanotubes (CNT) was discovered in many fields, such as non-structure electronics, lightweight composite structure, and drug delivery, CNT has been grown by many techniques in which high yield single wall CNT has been produced by physical processes including arc vaporization and laser vaporization. In this presentation, the growth mechanism of the carbon nanostructure materials by laser vaporization is to be discussed. Carbon nanoparticles and nanotubes have been synthesized using pulsed laser vaporization on Si substrates in various temperatures and pressures. Two kinds of targets were used to grow the nanostructure materials. One was a pure graphite target and the other one contained Ni and Co catalysts. The growth temperatures were 600-1000 C and the pressures varied from several torr to 500 torr. Carbon nanoparticles were observed when a graphite target was used, although catalysts were deposited on substrates before growing carbon films. When the target contains catalysts, carbon nanotubes (CNT) are obtained. The CNT were characterized by scanning electron microscopy, x-ray diffraction, optical absorption and transmission, and Raman spectroscopy. The temperature-and pressure-dependencies of carbon nanotubes' growth rate and size were investigated.

  14. Polynuclear Nickel Hexacyanoferrate/Graphitized Mesoporous Carbon Hybrid Chemically Modified Electrode for Selective Hydrazine Detection

    OpenAIRE

    Palani Barathi; Annamalai Senthil Kumar; Minnal Ranjan Babu Karthick

    2011-01-01

    A hybrid polynuclear nickel hexacyanoferrate (NiHCFe)/graphitized mesoporous carbon- (GMC-) modified glassy carbon electrode (GCE/NiHCFe@GMC) has been prepared by a sequential method using electrodeposited Ni on a GMC-modified glassy carbon electrode (GCE/Ni@GMC) as a template and [Fe(CN)6]3− as an in-situ chemical precipitant, without any additional interlinking agent. Physicochemical and electrochemical characterizations reveal the presence of NiHCFe units within the porous sites of the GM...

  15. Carbon materials as catalysts for the ozonation of organic pollutants in water

    OpenAIRE

    Pereira, M. F. R.; Gonçalves,A.G.; Órfão, J. J. M.

    2014-01-01

    [EN] A brief overview about the use of carbon materials as metal free ozonation catalysts is presented. Carbon materials (activated carbons, carbon xerogels, carbon nanofibers and carbon nanotubes) have been shown to be active catalysts in the ozonation of a wide range of organic pollutants. Carbon materials with surface basic properties (i.e. high electron density) and with large pores are the most promising for this process.

  16. Hybrid silica luminescent materials based on lanthanide-containing lyotropic liquid crystal with polarized emission

    Energy Technology Data Exchange (ETDEWEB)

    Selivanova, N.M., E-mail: natsel@mail.ru [Kazan National Research Technological University, 68 Karl Marx Str., Kazan 420015 (Russian Federation); Vandyukov, A.E.; Gubaidullin, A.T. [A.E. Arbuzov Institute of Organic and Physical Chemistry of the Kazan Scientific Center of the Russian Academy of Sciences, 8 Acad. Arbuzov Str., Kazan 420088 (Russian Federation); Galyametdinov, Y.G. [Kazan National Research Technological University, 68 Karl Marx Str., Kazan 420015 (Russian Federation)

    2014-11-14

    This paper represents the template method for synthesis of hybrid silica films based on Ln-containing lyotropic liquid crystal and characterized by efficient luminescence. Luminescence films were prepared in situ by the sol–gel processes. Lyotropic liquid crystal (LLC) mesophases C{sub 12}H{sub 25}O(CH{sub 2}CH{sub 2}O){sub 10}H/Ln(NO{sub 3}){sub 3}·6H{sub 2}O/H{sub 2}O containing Ln (III) ions (Dy, Tb, Eu) were used as template. Polarized optical microscopy, X-ray powder diffraction, and FT-IR-spectroscopy were used for characterization of liquid crystal mesophases and hybrid films. The morphology of composite films was studied by the atomic force microscopy method (AFM). The optical properties of the resulting materials were evaluated. It was found that hybrid silica films demonstrate significant increase of their lifetime in comparison with an LLC system. New effects of linearly polarized emission revealed for Ln-containing hybrid silica films. Polarization in lanthanide-containing hybrid composites indicates that silica precursor causes orientation of emitting ions. - Highlights: • We suggest a new simple approach for creating luminescence hybrid silica films. • Ln-containing hybrid silica films demonstrate yellow, green and red emissions. • Tb(III)-containing hybrid film have a high lifetime. • We report effects of linearly polarized emission in hybrid film.

  17. Adsorptive removal of antibiotics from aqueous solution using carbon materials.

    Science.gov (United States)

    Yu, Fei; Li, Yong; Han, Sheng; Ma, Jie

    2016-06-01

    Antibiotics, an important type of environmental contamination, have attracted many researchers to the study of their removal from aqueous solutions. Adsorption technology is a fast, efficient, and economical physicochemical method that is extensively used in wastewater treatment. From original activated carbon and carbon nanotubes to the latest graphene-based materials, carbon-based materials have been widely used as highly effective adsorbents for contaminant removal from aqueous solution because of their large specific surface area, high porosity, and high reaction activity. In this article, adsorption removal methods for four major types of antibiotic (tetracyclines, sulfonamides, macrolides, and quinolones) are reviewed. We also provide an overview of the application development of carbon materials as adsorbents for antibiotic removal from aqueous solution. The most promising works are discussed, and the main challenges in preparing high-performance adsorbents and the development tendency of adsorbents are also analyzed. This work provides theoretical guidance for subsequent research in the design and modification of carbon materials for applications in the adsorption removal of antibiotics from aqueous solution.

  18. A universal model for nanoporous carbon supercapacitors applicable to diverse pore regimes, carbon materials, and electrolytes.

    Science.gov (United States)

    Huang, Jingsong; Sumpter, Bobby G; Meunier, Vincent

    2008-01-01

    Supercapacitors, commonly called electric double-layer capacitors (EDLCs), are emerging as a novel type of energy-storage device with the potential to substitute batteries in applications that require high power densities. In response to the latest experimental breakthrough in nanoporous carbon supercapacitors, we propose a heuristic theoretical model that takes pore curvature into account as a replacement for the EDLC model, which is based on a traditional parallel-plate capacitor. When the pore size is in the mesopore regime (2-50 nm), counterions enter mesoporous carbon materials and approach the pore wall to form an electric double-cylinder capacitor (EDCC); in the micropore regime (50 nm) at which pores are large enough so that pore curvature is no longer significant, the EDCC model can be reduced naturally to the EDLC model. We present density functional theory calculations and detailed analyses of available experimental data in various pore regimes, which show the significant effects of pore curvature on the supercapacitor properties of nanoporous carbon materials. It is shown that the EDCC/EWCC model is universal for carbon supercapacitors with diverse carbon materials, including activated carbon materials, template carbon materials, and novel carbide-derived carbon materials, and with diverse electrolytes, including organic electrolytes, such as tetraethylammonium tetrafluoroborate (TEABF(4)) and tetraethylammonium methylsulfonate (TEAMS) in acetonitrile, aqueous H(2)SO(4) and KOH electrolytes, and even an ionic liquid electrolyte, such as 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI). The EDCC/EWCC model allows the supercapacitor properties to be correlated with pore size, specific surface area, Debye length, electrolyte concentration and dielectric constant, and solute ion size It may lend support for the systematic optimization of the properties of carbon supercapacitors through experiments. On the basis of the insight

  19. A Numerical Study on Electrical Percolation of Polymer-Matrix Composites with Hybrid Fillers of Carbon Nanotubes and Carbon Black

    Directory of Open Access Journals (Sweden)

    Yuli Chen

    2014-01-01

    Full Text Available The electrical percolation of polymer-matrix composites (PMCs containing hybrid fillers of carbon nanotubes (CNTs and carbon black (CB is estimated by studying the connection possibility of the fillers using Monte Carlo simulation. The 3D simulation model of CB-CNT hybrid filler is established, in which CNTs are modeled by slender capped cylinders and CB groups are modeled by hypothetical spheres with interspaces because CB particles are always agglomerated. The observation on the effects of CB and CNT volume fractions and dimensions on the electrical percolation threshold of hybrid filled composites is then carried out. It is found that the composite electrical percolation threshold can be reduced by increasing CNT aspect ratio, as well as increasing the diameter ratio of CB groups to CNTs. And adding CB into CNT composites can decrease the CNT volume needed to convert the composite conductivity, especially when the CNT volume fraction is close to the threshold of PMCs with only CNT filler. Different from previous linear assumption, the nonlinear relation between CB and CNT volume fractions at composite percolation threshold is revealed, which is consistent with the synergistic effect observed in experiments. Based on the nonlinear relation, the estimating equation for the electrical percolation threshold of the PMCs containing CB-CNT hybrid fillers is established.

  20. Electrical Resistance Behavior of Vinylester Composites Filled with Glass-carbon Hybrid Fibers

    Institute of Scientific and Technical Information of China (English)

    WANG Jun; ZHANG Lianmeng; XU Renxin; DUAN Huajun; YANG Xiaoli; WANG Xiang

    2009-01-01

    Vinylester (bismethacryloxy derivative of a bisphenol-A type EP resin, VE) composites with glass-carbon hybrid fibers (CF-GF) weight fraction of 50%, were prepared by the compress molding method. The distribution of carbon fiber in the hybrids was observed by stereomicroscope. The electrical resistance behavior of the composites filled with different carbon fiber (CF) weight contents (0.5% to 20%) was studied. The experimental results show that the electrical resistance behaviors of CF-GF/VE composites are different with those of CF/VE composites because carbon fibers' conducting networks are broken by the glass fibers in the CF-GF/VE composites. The carbon fibers distribute uniformly in the networks of glass fibers (GF) like single silk and form the semi-continuous conducting networks. Composite filled with GF-CF hybrid has a higher percolation threshold than that filled with pure CF. At that time, the resistivity of CF-GF/VE composites varies little with the temperature increasing. The temperature coefficient of resistivity in GF-CF/VE composite is less than 317 ppm and the variation of the resistivity after ten thermal cycles from 20 ℃to 240 ℃ is less than 1.96%.

  1. Carbon-based nanomaterials: multifunctional materials for biomedical engineering.

    Science.gov (United States)

    Cha, Chaenyung; Shin, Su Ryon; Annabi, Nasim; Dokmeci, Mehmet R; Khademhosseini, Ali

    2013-04-23

    Functional carbon-based nanomaterials (CBNs) have become important due to their unique combinations of chemical and physical properties (i.e., thermal and electrical conductivity, high mechanical strength, and optical properties), and extensive research efforts are being made to utilize these materials for various industrial applications, such as high-strength materials and electronics. These advantageous properties of CBNs are also actively investigated in several areas of biomedical engineering. This Perspective highlights different types of carbon-based nanomaterials currently used in biomedical applications.

  2. Reactivity improvement of magnesium by carbon nano-material mixing

    Energy Technology Data Exchange (ETDEWEB)

    Aikawa, Kenji [Tokai Univ. (Japan). Course of Metallurgical Engineering; Niimuma, Hideki; Uchida, Haru-Hisa [Tokai Univ. (Japan). Dept. of Human Development; Nishi, Yoshitake [Tokai Univ. (Japan). Dept. of Materials Science

    2010-07-01

    Proposing magnesium as a hydrogen storage material, we demonstrate quite interesting results of carbon nano-materials mixed into magnesium by mechanical milling in this study. Higher hydrogen reactivity can be obtained by multi wall carbon nano-tube (MWCNT) mixing which may enlarge the diffusion path in the sample powder particles. As a result, Mg with 0, 10, 20, 40 and 60 mass% of MWCNT exhibits drastically modified hydrogen absorption and desorption kinetics with more than 5 mass% H (including weight of catalyst) at 573-673K within 10min. under 6MPa of H{sub 2}. (orig.)

  3. Synergy effects of hybrid carbon system on properties of composite bipolar plates for fuel cells

    Science.gov (United States)

    Kim, Jong Wan; Kim, Nam Hoon; Kuilla, Tapas; Kim, Tae Jin; Rhee, Kyong Yop; Lee, Joong Hee

    A hybrid carbon system of graphite powder (GP) and continuous carbon fibre fabric (CFF) is used for an epoxy composite to improve the electrical conductivity, mechanical properties and mouldability of a composite bipolar plate. These improvements are achieved simultaneously by inserting several layers of CFF into the GP/epoxy composite to enhance the mechanical properties and in-plane conductivity. The electrical properties, flexural strength and mouldability of the composite plates are measured as a function of conducting filler content and number of CFF layers. The composites show improved electrical conductivity, flexural properties and mouldability. Composites with 70-75 vol.% carbon fillers have the highest electrical conductivity with reasonable flexural properties. These results suggest that the poor mouldability and low through-plane electrical conductivity of the continuous fibre composite bipolar plate, as well as the weak flexural properties of GP composites, can be overcome by incorporating a GP/CFF hybrid system.

  4. Unique combination of zero-one-two dimensional carbon-titania hybrid for cold cathode application

    Science.gov (United States)

    Banerjee, D.; Kumar, D.; Das, N. S.; Sarkar, S.; Chattopadhyay, K. K.

    2015-11-01

    A unique multi-dimensional hybrid system has been developed by incorporating titania nanoparticle into chemically synthesized amorphous carbon nanotubes (a-CNTs)-amorphous graphene composites. The as-synthesized samples were characterized by x-ray diffraction, scanning and transmission electron microscopy; Raman spectroscopy and photoluminescence spectroscopy. The microscopic studies confirm the attachment of the TiO2 nanoparticles on carbon structures. The performance of the both the pure and hybrid samples as cold cathode emitter has been investigated and it has been found that cold emission performance of the pure carbon system improves considerably after TiO2 nanoparticles being added to it giving a turn on field as low as 2.1 V/μm and enhancement factor 2746. The enhancement of field emission characteristic after TiO2 addition was justified from the 'ANSYS- Maxwell' software based simulation study.

  5. Probing the Salt Concentration Dependent Nucelobase Distribution in a Single-Stranded DNA-Single-Walled Carbon Nanotube Hybrid with Molecular Dynamics.

    Science.gov (United States)

    Ghosh, Soumadwip; Patel, Nisheet; Chakrabarti, Rajarshi

    2016-01-28

    The hybrids of single-walled carbon nanotube (SWCNT) and single stranded DNA (ssDNA) are novel nanoscale materials having remarkable applications in nanotechnology. The absorption of nucleobases on the surface of a SWCNT depends strongly on the ionic strength of the medium. In this paper, using atomistic molecular dynamics we have shown that at low salt concentration ssDNA wraps on the surface of SWCNT through hydrophobic π-π stacking between the DNA bases and the sp(2)-hybridized carbon atoms of the carbon nanotube. At high salt concentration, however, the DNA molecule adopts a partially folded structure and the ssDNA-SWCNT wrapping gets weakened significantly due to the self-stacking of the DNA bases. Our study can find relevance in CNT mediated gene delivery processes where subsequent unwrapping of the gene from its carrier is anticipated across the cell membrane regulated by an existing salt concentration gradient.

  6. Self-assembly of cobalt-centered metal organic framework and multiwalled carbon nanotubes hybrids as a highly active and corrosion-resistant bifunctional oxygen catalyst

    Science.gov (United States)

    Fang, Yiyun; Li, Xinzhe; Li, Feng; Lin, Xiaoqing; Tian, Min; Long, Xuefeng; An, Xingcai; Fu, Yan; Jin, Jun; Ma, Jiantai

    2016-09-01

    Metal organic frameworks (MOF) derived carbonaceous materials have emerged as promising bifunctional oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) catalysts for electrochemical energy conversion and storage. But previous attempts to overcome the poor electrical conductivity of MOFs hybrids involve a harsh high-template pyrolytic process to in situ form carbon, which suffer from extremely complex operation and inevitable carbon corrosion at high positive potentials when OER is operated. Herein, a self-assembly approach is presented to synthesize a non-precious metal-based, high active and strong durable Co-MOF@CNTs bifunctional catalyst for OER and ORR. CNTs not only improve the transportation of the electrons but also can sustain the harsh oxidative environment of OER without carbon corrosion. Meanwhile, the unique 3D hierarchical structure offers a large surface area and stable anchoring sites for active centers and CNTs, which enables the superior durability of hybrid. Moreover, a synergistic catalysis of Co(II), organic ligands and CNTs will enhance the bifunctional electrocatalytic performance. Impressively, the hybrid exhibits comparable OER and ORR catalytic activity to RuO2 and 20 wt% Pt/C catalysts and superior stability. This facile and versatile strategy to fabricating MOF-based hybrids may be extended to other electrode materials for fuel cell and water splitting applications.

  7. Spectroscopic investigation of nitrogen-functionalized carbon materials

    Energy Technology Data Exchange (ETDEWEB)

    Wood, Kevin N. [Department of Metallurgical and Materials Engineering, Colorado School of Mines, 1500 Illinois Street Golden CO 80401 USA; Department of Mechanical Engineering, University of Michigan, Ann Arbor MI 48109 USA; Christensen, Steven T. [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; Nordlund, Dennis [Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, 2575 Sand Hill Rd Menlo Park CA 94023 USA; Dameron, Arrelaine A. [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; Ngo, Chilan [Department of Chemistry and Geochemistry, Colorado School of Mines, 1012 14th Street Golden CO 80401 USA; Dinh, Huyen [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; Gennett, Thomas [National Renewable Energy Laboratory, 15013 Denver West Pkwy Golden CO 80401 USA; O' Hayre, Ryan [Department of Metallurgical and Materials Engineering, Colorado School of Mines, 1500 Illinois Street Golden CO 80401 USA; Pylypenko, Svitlana [Department of Chemistry and Geochemistry, Colorado School of Mines, 1012 14th Street Golden CO 80401 USA

    2016-04-07

    Carbon materials are used in a diverse set of applications ranging from pharmaceuticals to catalysis. Nitrogen modification of carbon powders has shown to be an effective method for enhancing both surface and bulk properties of as-received material for a number of applications. Unfortunately, control of the nitrogen modification process is challenging and can limit the effectiveness and reproducibility of N-doped materials. Additionally, the assignment of functional groups to specific moieties on the surface of nitrogen-modified carbon materials is not straightforward. Herein, we complete an in-depth analysis of functional groups present at the surface of ion-implanted Vulcan and Graphitic Vulcan through the use of X-ray photoelectron spectroscopy (XPS) and near edge X-ray adsorption fine structure spectroscopy (NEXAFS). Our results show that regardless of the initial starting materials used, nitrogen ion implantation conditions can be tuned to increase the amount of nitrogen incorporation and to obtain both similar and reproducible final distributions of nitrogen functional groups. The development of a well-controlled/reproducible nitrogen implantation pathway opens the door for carbon supported catalyst architectures to have improved numbers of nucleation sites, decreased particle size, and enhanced catalyst-support interactions.

  8. Nanoscale Structure of Self-Assembling Hybrid Materials of Inorganic and Electronically Active Organic Phases

    Energy Technology Data Exchange (ETDEWEB)

    Sofos, M.; Goswami, D.A. Stone D.K.; Okasinski, J.S.; Jin, H.; Bedzyk, M.J.; Stupp, S.I. (NWU)

    2008-10-06

    Hybrid materials with nanoscale structure that incorporates inorganic and organic phases with electronic properties offer potential in an extensive functional space that includes photovoltaics, light emission, and sensing. This work describes the nanoscale structure of model hybrid materials with phases of silica and electronically active bola-amphiphile assemblies containing either oligo(p-phenylene vinylene) or oligo(thiophene) segments. The hybrid materials studied here were synthesized by evaporation-induced self-assembly and characterized by X-ray scattering techniques. Grazing-incidence X-ray scattering studies of these materials revealed the formation of two-dimensional hexagonally packed cylindrical micelles of the organic molecules with diameters between 3.1 and 3.6 nm and cylindrical axes parallel to the surface. During the self-assembly process at low pH, the cylindrical aggregates of conjugated molecules become surrounded by silica giving rise to a hybrid structure with long-range order. Specular X-ray reflectivity confirmed the long-range periodicity of the hybrid films within a specific range of molar ratios of tetraethyl orthosilicate to cationic amphiphile. We did not observe any long-range ordering in fully organic analogues unless quaternary ammonium groups were replaced by tertiary amines. These observations suggest that charge screening in these biscationic conjugated molecules by the mineral phase is a key factor in the evolution of long range order in the self-assembling hybrids.

  9. Carbon nanotube-based superconducting and ferromagnetic hybrid systems

    NARCIS (Netherlands)

    Man, H.T.

    2006-01-01

    Carbon Nanotubes are molecules with exceptional physical properties that are most useful for applications in the growing field of nanotechnology. In addition, because of its special electrical properties, they are extremely useful for experiments on the fundamental properties of one-dimensional elec

  10. Wear and Friction Characteristics of AlN/Diamond-Like Carbon Hybrid Coatings on Aluminum Alloy

    Science.gov (United States)

    Nakamura, Masashi; Kubota, Sadayuki; Suzuki, Hideto; Haraguchi, Tadao

    2015-10-01

    The use of diamond-like carbon (DLC) coatings has the potential to greatly improve the wear resistance and friction of aluminum alloys, but practical application has so far been limited by poor adhesion due to large difference in hardness and elasticity between the two materials. This study investigates the deposition of DLC onto an Al-alloy using an intermediate AlN layer with a graded hardness to create a hybrid coating. By controlling the hardness of the AlN film, it was found that the wear life of the DLC film could be improved 80-fold compared to a DLC film deposited directly onto Al-alloy. Furthermore, it was demonstrated through finite element simulation that creating a hardness gradient in the AlN intermediate layer reduces the distribution of stress in the DLC film, while also increasing the force of adhesion between the DLC and AlN layers. Given that both the DLC and AlN films were deposited using the same unbalanced magnetron sputtering method, this process is considered to represent a simple and effective means of improving the wear resistance of Al-alloy components commonly used within the aerospace and automotive industries.

  11. Performance of a 60 F carbon nanotubes-based supercapacitor for hybrid power sources

    Institute of Scientific and Technical Information of China (English)

    Xiaofeng Wang; Dianbo Ruan; Zheng You; Yiqiang Lu; Qiqian Sha

    2005-01-01

    A supercapacitor based on charge storage at the interface between a high surface area carbon nanotube electrode and a LiClO4/PC electrolyte was assembled. The performance of the capacitor depends on not only the material used in the cell but also the construction of the cell. From a constant charge-discharge test, the capacitance of 60 F was obtained. The performance of the power power supercapacitor were demonstrated with a cell of the maximum operating voltage of 2.5 V. A hybrid power source consisting of a lithium ionic battery and the 60 F supercapacitor was demonstrated to power successfully a simulated power load encountered in GSM portable communication equipment. The addition of the supercapacitor to the power train of a cellular phone results in significantly more energy from the battery being used by the load. The experiments indicate that more than 33.8% energy is utilized by load and less stored energy is dissipated within the battery for each charge-discharge cycle.

  12. Preparation and toxicological assessment of functionalized carbon nanotube-polymer hybrids.

    Directory of Open Access Journals (Sweden)

    Nikos D Koromilas

    Full Text Available Novel Carbon Nanotube-Polymer Hybrids were synthesized as potential materials for the development of membranes for water treatment applications in the field of Membrane Bioreactors (MBRs. Due to the toxicological concerns regarding the use of nanomaterials in water treatment as well as the rising demand for safe drinking water to protect public health, we studied the functionalization of MWCNTs and Thin-MWCNTs as to control their properties and increase their ability of embedment into porous anisotropic polymeric membranes. Following the growth of the hydrophilic monomer on the surface of the properly functionalized CNTs, that act as initiator for the controlled radical polymerization (ATRP of sodium styrene sulfonate (SSNa, the antimicrobial quaternized phosphonium and ammonium salts were attached on CNTs-g-PSSNa through non-covalent bonding. In another approach the covalent attachment of quaternized ammonium polymeric moieties of acrylic acid-vinyl benzyl chloride copolymers with N,N-dimethylhexadecylamine (P(AA12-co-VBCHAM on functionalized CNTs has also been attempted. Finally, the toxicological assessment in terms of cell viability and cell morphological changes revealed that surface characteristics play a major role in the biological response of functionalized CNTs.

  13. Properties of carbon impurities in ZnO: A hybrid functional study

    Science.gov (United States)

    Li, Ping; Luo, Weidong

    2016-08-01

    The mechanism of the room temperature (RT) ferromagnetism in C-doped ZnO and the trend that the higher the C concentration, the smaller the saturation magnetic moment (Ms), have remained controversial and puzzling for a long time. Using density-functional calculations with hybrid functional, we qualitatively understand these experimental phenomena. The substitutional CO defects dominate in Zn-rich conditions and n -type materials. They carry 1 or 2 μB/C , depending on the position of the Fermi level. In low C concentrations and at RT, the CO defects are kept isolated and prefer to couple ferromagnetically, thus the Ms is larger. As the C concentration increases, nonmagnetic C2 dimers form through binding of two CO defects or binding of one CO defect with one interstitial C, thus decreasing the Ms. Our results also suggest that the ferromagnetism from CO defects can be quenched by higher annealing temperatures. Furthermore, the p -type conductivity from carbon dopant is not supported in the present study.

  14. Fabrication of Carbon Nanotube/SiO2and Carbon Nanotube/SiO2/Ag Nanoparticles Hybrids by Using Plasma Treatment

    Directory of Open Access Journals (Sweden)

    Li Haiqing

    2009-01-01

    Full Text Available Abstract Based on plasma-treated single wall carbon nanotubes (SWCNTs, SWCNT/SiO2and thiol groups-functionalized SWCNT/SiO2hybrids have been fabricated through a sol–gel process. By means of thiol groups, Ag nanoparticles have been in situ synthesized and bonded onto the SiO2shell of SWCNT/SiO2in the absence of external reducing agent, resulting in the stable carbon nanotube/SiO2/Ag nanoparticles hybrids. This strategy provides a facile, low–cost, and green methodology for the creation of carbon nanotube/inorganic oxides-metal nanoparticles hybrids.

  15. Carbon-Carbon Composites as Recuperator Material for Direct Gas Brayton Systems

    Energy Technology Data Exchange (ETDEWEB)

    RA Wolf

    2006-07-19

    Of the numerous energy conversion options available for a space nuclear power plant (SNPP), one that shows promise in attaining reliable operation and high efficiency is the direct gas Brayton (GB) system. In order to increase efficiency, the GB system incorporates a recuperator that accounts for nearly half the weight of the energy conversion system (ECS). Therefore, development of a recuperator that is lighter and provides better performance than current heat exchangers could prove to be advantageous. The feasibility of a carbon-carbon (C/C) composite recuperator core has been assessed and a mass savings of 60% and volume penalty of 20% were projected. The excellent thermal properties, high-temperature capabilities, and low density of carbon-carbon materials make them attractive in the GB system, but development issues such as material compatibility with other structural materials in the system, such as refractory metals and superalloys, permeability, corrosion, joining, and fabrication must be addressed.

  16. Soft templating strategies for the synthesis of mesoporous materials: inorganic, organic-inorganic hybrid and purely organic solids.

    Science.gov (United States)

    Pal, Nabanita; Bhaumik, Asim

    2013-03-01

    With the discovery of MCM-41 by Mobil researchers in 1992 the journey of the research on mesoporous materials started and in the 21st century this area of scientific investigation have extended into numerous branches, many of which contribute significantly in emerging areas like catalysis, energy, environment and biomedical research. As a consequence thousands of publications came out in large varieties of national and international journals. In this review, we have tried to summarize the published works on various synthetic pathways and formation mechanisms of different mesoporous materials viz. inorganic, organic-inorganic hybrid and purely organic solids via soft templating pathways. Generation of nanoscale porosity in a solid material usually requires participation of organic template (more specifically surfactants and their supramolecular assemblies) called structure-directing agent (SDA) in the bottom-up chemical reaction process. Different techniques employed for the syntheses of inorganic mesoporous solids, like silicas, metal doped silicas, transition and non-transition metal oxides, mixed oxides, metallophosphates, organic-inorganic hybrids as well as purely organic mesoporous materials like carbons, polymers etc. using surfactants are depicted schematically and elaborately in this paper. Moreover, some of the frontline applications of these mesoporous solids, which are directly related to their functionality, composition and surface properties are discussed at the appropriate places.

  17. Nanographene-constructed carbon nanofibers grown on graphene sheets by chemical vapor deposition: high-performance anode materials for lithium ion batteries.

    Science.gov (United States)

    Fan, Zhuang-Jun; Yan, Jun; Wei, Tong; Ning, Guo-Qing; Zhi, Lin-Jie; Liu, Jin-Cheng; Cao, Dian-Xue; Wang, Gui-Ling; Wei, Fei

    2011-04-26

    We report on the fabrication of 3D carbonaceous material composed of 1D carbon nanofibers (CNF) grown on 2D graphene sheets (GNS) via a CVD approach in a fluidized bed reactor. Nanographene-constructed carbon nanofibers contain many cavities, open tips, and graphene platelets with edges exposed, providing more extra space for Li(+) storage. More interestingly, nanochannels consisting of graphene platelets arrange almost perpendicularly to the fiber axis, which is favorable for lithium ion diffusion from different orientations. In addition, 3D interconnected architectures facilitate the collection and transport of electrons during the cycling process. As a result, the CNF/GNS hybrid material shows high reversible capacity (667 mAh/g), high-rate performance, and cycling stability, which is superior to those of pure graphene, natural graphite, and carbon nanotubes. The simple CVD approach offers a new pathway for large-scale production of novel hybrid carbon materials for energy storage.

  18. Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials

    Science.gov (United States)

    Salama, Ahmed; Neumann, Mike; Günter, Christina

    2014-01-01

    Summary Cellulose/calcium phosphate hybrid materials were synthesized via an ionic liquid-assisted route. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis show that, depending on the reaction conditions, cellulose/hydroxyapatite, cellulose/chlorapatite, or cellulose/monetite composites form. Preliminary studies with MC3T3-E1 pre-osteoblasts show that the cells proliferate on the hybrid materials suggesting that the ionic liquid-based process yields materials that are potentially useful as scaffolds for regenerative therapies. PMID:25247137

  19. Ionic liquid-assisted formation of cellulose/calcium phosphate hybrid materials

    Directory of Open Access Journals (Sweden)

    Ahmed Salama

    2014-09-01

    Full Text Available Cellulose/calcium phosphate hybrid materials were synthesized via an ionic liquid-assisted route. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, infrared spectroscopy, and thermogravimetric analysis/differential thermal analysis show that, depending on the reaction conditions, cellulose/hydroxyapatite, cellulose/chlorapatite, or cellulose/monetite composites form. Preliminary studies with MC3T3-E1 pre-osteoblasts show that the cells proliferate on the hybrid materials suggesting that the ionic liquid-based process yields materials that are potentially useful as scaffolds for regenerative therapies.

  20. Titanium oxo-clusters: precursors for a Lego-like construction of nanostructured hybrid materials.

    Science.gov (United States)

    Rozes, Laurence; Sanchez, Clément

    2011-02-01

    Titanium oxo-clusters, well-defined monodispersed nano-objects, are appropriate nano-building blocks for the preparation of organic-inorganic materials by a bottom up approach. This critical review proposes to present the different structures of titanium oxo-clusters referenced in the literature and the different strategies followed to build up hybrid materials with these versatile building units. In particular, this critical review cites and reports on the most important papers in the literature, concentrating on recent developments in the field of synthesis, characterization, and the use of titanium oxo-clusters for the construction of advanced hybrid materials (137 references).