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Cell Applications (cell + application)
Kinds of Cell Applications Selected AbstractsOptimization of a Nanoporous Silicon Layer for Solar Cell ApplicationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2008Guk-Hwan An A pyramidal structure and an n/p junction-formed wafer were used for the porous silicon (PS) layer formation. The pyramidal structure was adopted to maximize the light confinement with the PS layer. Also, in order to apply the PS layer to the solar cell directly, the n/p junction was adopted. To optimize the PS layer on this new type of surface, three kinds of solutions, ethanol, N,N -dimethylformamide, and formamide (FA), were used with hydrofluoric acid as a base of electrolyte. Various current densities were applied for PS layer formation with various anodizing durations. The reflectance and the microstructure were used as criteria for the selection of the most suitable PS layer. Consequently, an effective reflectance of 2.4% was obtained with 50 mA/cm2 and 10 s under the FA-based electrolyte condition. The result was expected to be used as an antireflection coating for solar cell applications. [source] Anomalous Oxidation States in Multilayers for Fuel Cell ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 16 2010James M. Perkins Abstract Significant recent interest has been directed towards the relationship between interfaces and reports of enhanced ionic conductivity. To gain a greater understanding of the effects of hetero-interfaces on ionic conductivity, advanced analytical techniques including electron microscopy (TEM/STEM), electron energy loss spectroscopy (EELS), and secondary ion mass spectrometry (SIMS) are used to characterize CeO2/Ce0.85Sm0.15O2 multilayer thin films grown by pulsed laser deposition. High quality growth is observed, but ionic conductivity measured by impedance spectroscopy and 18O tracer experiments is consistent with bulk materials. EELS analysis reveals the unusual situation of layers containing only Ce(IV) adjacent to layers containing both Ce(III) and Ce(IV). Post oxygen annealing induced oxygen diffusion and mixed oxidation states in both layers, but only in the vicinity of low angle grain boundaries perpendicular to the layers. The implications of the anomalous behavior of the Ce oxidation states on the design of novel electrolytes for solid oxide fuel cells is discussed. [source] High-Performance Alkaline Polymer Electrolyte for Fuel Cell ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 2 2010Jing Pan Abstract Although the proton exchange membrane fuel cell (PEMFC) has made great progress in recent decades, its commercialization has been hindered by a number of factors, among which is the total dependence on Pt-based catalysts. Alkaline polymer electrolyte fuel cells (APEFCs) have been increasingly recognized as a solution to overcome the dependence on noble metal catalysts. In principle, APEFCs combine the advantages of and alkaline fuel cell (AFC) and a PEMFC: there is no need for noble metal catalysts and they are free of carbonate precipitates that would break the waterproofing in the AFC cathode. However, the performance of most alkaline polyelectrolytes can still not fulfill the requirement of fuel cell operations. In the present work, detailed information about the synthesis and physicochemical properties of the quaternary ammonia polysulfone (QAPS), a high-performance alkaline polymer electrolyte that has been successfully applied in the authors' previous work to demonstrate an APEFC completely free from noble metal catalysts (S. Lu, J. Pan, A. Huang, L. Zhuang, J. Lu, Proc. Natl. Acad. Sci. USA2008, 105, 20611), is reported. Monitored by NMR analysis, the synthetic process of QAPS is seen to be simple and efficient. The chemical and thermal stability, as well as the mechanical strength of the synthetic QAPS membrane, are outstanding in comparison to commercial anion-exchange membranes. The ionic conductivity of QAPS at room temperature is measured to be on the order of 10,2,S cm,1. Such good mechanical and conducting performances can be attributed to the superior microstructure of the polyelectrolyte, which features interconnected ionic channels in tens of nanometers diameter, as revealed by HRTEM observations. The electrochemical behavior at the Pt/QAPS interface reveals the strong alkaline nature of this polyelectrolyte, and the preliminary fuel cell test verifies the feasibility of QAPS for fuel cell applications. [source] Comparison between Nafion® and a Nafion® Zirconium Phosphate Nano-Composite in Fuel Cell ApplicationsFUEL CELLS, Issue 3-4 2006F. Bauer Abstract A comparative investigation of the electrical, mechanical, and chemical behaviour of zirconium phosphate-Nafion® composite membranes and Nafion® by means of ex-situ measurements, as well as with fuel cell operation, reveals a slight reduction of ionic conductivity, a significant improvement of mechanical stability, and increased water retention for the composite materials. The overall efficiency at 130,°C is increased during direct methanol fuel cell (DMFC) operation because the reduction in the ionic conductivity is overcompensated for by the decrease in methanol crossover. With H2 as the fuel, the slight reduction in overall efficiency corresponds to the decrease in ionic conductivity. The dimensional stability of the membrane and the membrane electrode assembly (MEA) is significantly improved for operating temperatures above 100,°C. A model for the microstructure-property relation for PFSA-Zr(HPO4)2,·,n,H2O composite membranes is presented, based on the experimental results from membranes with varying filler contents and distributions, obtained through different synthesis routes. It is aimed at the improvement of water distribution in the membrane upon fuel cell operation. [source] Intramolecular Donor,Acceptor Regioregular Poly(hexylphenanthrenyl-imidazole thiophene) Exhibits Enhanced Hole Mobility for Heterojunction Solar Cell ApplicationsADVANCED MATERIALS, Issue 20 2009Yao-Te Chang PHPIT, a new kind of intramolecular donor,acceptor side-chain-tethered hexylphenanthrenyl-imidazole polythiophene is synthesized. The more-balanced electron and hole mobilities and the enhanced visible- and internal-light absorptions in the devices consisting of annealed PHPIT/PCBM blends both contribute to a much higher short-circuit current density, which in turn led to a power conversion efficiency as high as 4.1%. [source] Electrophoretic Deposition of YSZ Particles on Non-Conducting Porous NiO,YSZ Substrates for Solid Oxide Fuel Cell ApplicationsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 10 2006Laxmidhar Besra This paper reports a method of performing electrophoretic deposition (EPD) on non-conducting substrates overcoming the requirement of a conducting substrate through the use of porous substrates. The conductivity of the substrate is therefore no longer a limiting factor in the application of EPD. This method is applicable to the fabrication of thick or thin layers of ceramic or metal for various applications. As an example, thin and dense yttria-stabilized zirconia (YSZ) layers have been deposited on a non-conducting NiO,YSZ substrate by EPD from a non-aqueous suspension. A solid oxide fuel cell constructed on these sintered bilayers exhibited power densities of 384 and 611 mW/cm2 at 750° and 850°C, respectively. [source] Preparation of Polybenzimidazole/Lithium Hydrazinium Sulfate Composite Membranes for High-Temperature Fuel Cell ApplicationsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 12 2010Jung-Woo Jung Abstract PBI-LiHzS composite membranes were prepared by casting N,N'-DMAc solutions containing PBI and LiHzS, where the LiHzS contents in the membranes were between 2.5 and 10,wt.-%. LiHzS was obtained by reacting hydrazine sulfate and lithium carbonate in water. PBI-LiHzS composite membranes were thermally stable up to approximately 300,°C and their acid-absorbing capabilities were comparable to those of the pure PBI membranes. The proton conductivity of PBI-LiHzS composite membranes (2.12,×,10,2 S,·,cm,1 at 180,°C and 0% RH) was higher than that of pure PBI membranes when used at the same acid doping levels. The mechanical stability of the composite membranes having less than 5,wt.-% of LiHzS was found to be close to that of pure PBI membranes. [source] Copolymers of Poly(2,5-benzimidazole) and Poly[2,2,-(p -phenylene)-5,5,-bibenzimidazole] for High-Temperature Fuel Cell ApplicationsMACROMOLECULAR MATERIALS & ENGINEERING, Issue 11 2008Sung-Kon Kim Abstract Copolymers of poly(2,5-benzimidazole) (ABPBI) and poly[2,2,-(p -phenylene)-5,5,-bibenzimidazole] (pPBI) were synthesized for use as fuel cell membranes to take advantage of the properties of both constituents. The composition of the copolymers were controlled by changing the feed ratio of 3,4-diaminobenzoic acid and terephthalic acid with 3,3,-diaminobenzidine in the polycondensation reaction. The copolymer membranes showed higher conductivities, better mechanical properties, and larger acid absorbing abilities than commercial poly[2,2,-(m -phenylene)-5,5,-bibenzimidazole] membranes. [source] Polybenzimidazoles for High Temperature Fuel Cell ApplicationsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 15 2004Hyoung-Juhn Kim Abstract Summary: Fuel cells were designed for high temperature operations. Poly[2,2,-(m -phenylene)-5,5,-bibenzimidazole] (PBI) was synthesized in a solution of P2O5, CH3SO3H, and CF3SO3H. The PBI was dissolved in a mixture of CF3CO2H and H3PO4 and the solution was used for the preparation of Pt catalyst slurry for membrane electrode assembly. The single cell showed a current density of 280 mA,·,cm,2 at a cell voltage of 0.5 V with feeds of H2 and O2 at 160,°C and without external humidification. [source] Highly Efficient Quantum-Dot-Sensitized Solar Cell Based on Co-Sensitization of CdS/CdSeADVANCED FUNCTIONAL MATERIALS, Issue 4 2009Yuh-Lang Lee Abstract Cadmium sulfide (CdS) and cadmium selenide (CdSe) quantum dots (QDs) are sequentially assembled onto a nanocrystalline TiO2 film to prepare a CdS/CdSe co-sensitized photoelectrode for QD-sensitized solar cell application. The results show that CdS and CdSe QDs have a complementary effect in the light harvest and the performance of a QDs co-sensitized solar cell is strongly dependent on the order of CdS and CdSe respected to the TiO2. In the cascade structure of TiO2/CdS/CdSe electrode, the re-organization of energy levels between CdS and CdSe forms a stepwise structure of band-edge levels which is advantageous to the electron injection and hole-recovery of CdS and CdSe QDs. An energy conversion efficiency of 4.22% is achieved using a TiO2/CdS/CdSe/ZnS electrode, under the illumination of one sun (AM1.5,100,mW cm,2). This efficiency is relatively higher than other QD-sensitized solar cells previously reported in the literature. [source] Sulfonated poly(ether sulfone)s with binaphthyl units as proton exchange membranes for fuel cell applicationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 21 2009Kazuya Matsumoto Abstract Sulfonated poly(ether sulfone)s containing binaphthyl units (BNSHs) were successfully prepared for fuel cell application. BNSHs, which have very simple structures, were easily synthesized by postsulfonation of poly(1,1,-dinaphthyl ether phenyl sulfone)s and gave tough, flexible, and transparent membranes by solvent casting. The BNSH membranes showed low water uptake compared to a typical sulfonated poly(ether ether sulfone) (BPSH-40) membrane with a similar ion exchange capacity (IEC) value and water insolubility, even with a high IEC values of 3.19 mequiv/g because of their rigid and bulky structures. The BNSH-100 membrane (IEC = 3.19 mequiv/g) exhibited excellent proton conductivity, which was comparable to or even higher than that of Nafion 117, over a range of 30,95% relative humidity (RH). The excellent proton conductivity, especially under low RH conditions, suggests that the BNSH-100 membrane has excellent proton paths because of its high IEC value, and water insolubility due to the high hydrophobicity of the binaphthyl structure. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5827,5834, 2009 [source] Different nanostructure cathode catalysts application for direct methanol fuel cellPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 12 2007Sharmin Sultana Dipti Abstract Direct methanol fuel cell (DMFC) belongs to the same family of energy conversion device and the application of new hydrogen storage nanomaterials such as carbon nanotube (CNTs) supported catalysts is being addressed in an increasing industrial approach. In this present study, multiwall carbon nanotube supported Pt and Pt-Ni nanoparticles were prepared as cathode catalysts for direct methanol fuel cell application. Transmission electron microscopy and X-ray diffraction analyses indicated the formation of well-dispersed Pt and Pt-Ni nanoparticles having sizes of around 2 , 4 nm on carbon nanotube. Furthermore, the electrochemical characterization by the cyclic voltammetry (CV) demonstrated that these catalysts have higher catalytic activity and the methanol oxidation reaction of the Pt-Ni/CNTs is respectively almost similar and slightly higher than Pt/CNTs electrocatalysts. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Recent Development of Active Nanoparticle Catalysts for Fuel Cell ReactionsADVANCED FUNCTIONAL MATERIALS, Issue 8 2010Vismadeb Mazumder Abstract This review focuses on the recent advances in the synthesis of nanoparticle (NP) catalysts of Pt-, Pd- and Au-based NPs as well as composite NPs. First, new developments in the synthesis of single-component Pt, Pd and Au NPs are summarized. Then the chemistry used to make alloy and composite NP catalysts aiming to enhance their activity and durability for fuel cell reactions is outlined. The review next introduces the exciting new research push in developing CoN/C and FeN/C as non-Pt catalysts. Examples of size-, shape- and composition-dependent catalyses for oxygen reduction at cathode and formic acid oxidation at anode are highlighted to illustrate the potentials of the newly developed NP catalysts for fuel cell applications. [source] High-Performance Alkaline Polymer Electrolyte for Fuel Cell ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 2 2010Jing Pan Abstract Although the proton exchange membrane fuel cell (PEMFC) has made great progress in recent decades, its commercialization has been hindered by a number of factors, among which is the total dependence on Pt-based catalysts. Alkaline polymer electrolyte fuel cells (APEFCs) have been increasingly recognized as a solution to overcome the dependence on noble metal catalysts. In principle, APEFCs combine the advantages of and alkaline fuel cell (AFC) and a PEMFC: there is no need for noble metal catalysts and they are free of carbonate precipitates that would break the waterproofing in the AFC cathode. However, the performance of most alkaline polyelectrolytes can still not fulfill the requirement of fuel cell operations. In the present work, detailed information about the synthesis and physicochemical properties of the quaternary ammonia polysulfone (QAPS), a high-performance alkaline polymer electrolyte that has been successfully applied in the authors' previous work to demonstrate an APEFC completely free from noble metal catalysts (S. Lu, J. Pan, A. Huang, L. Zhuang, J. Lu, Proc. Natl. Acad. Sci. USA2008, 105, 20611), is reported. Monitored by NMR analysis, the synthetic process of QAPS is seen to be simple and efficient. The chemical and thermal stability, as well as the mechanical strength of the synthetic QAPS membrane, are outstanding in comparison to commercial anion-exchange membranes. The ionic conductivity of QAPS at room temperature is measured to be on the order of 10,2,S cm,1. Such good mechanical and conducting performances can be attributed to the superior microstructure of the polyelectrolyte, which features interconnected ionic channels in tens of nanometers diameter, as revealed by HRTEM observations. The electrochemical behavior at the Pt/QAPS interface reveals the strong alkaline nature of this polyelectrolyte, and the preliminary fuel cell test verifies the feasibility of QAPS for fuel cell applications. [source] Poly(vinyl alcohol),polyacrylamide blends with cesium salts of heteropolyacid as a polymer electrolyte for direct methanol fuel cell applicationsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010M. Helen Abstract A class of inorganic,organic hybrid membranes with low methanol permeability characteristics for possible direct methanol fuel cell (DMFC) applications was architected, formulated, and fabricated through the blending of poly(vinyl alcohol) (PVA) and polyacrylamide (PAM) followed by crosslinking with glutaraldehyde (Glu). Cesium salts of different heteropolyacids, including phosphomolybdic acid (PMA), phosphotungstic acid (PWA), and silicotungstic acid (SWA), were incorporated into the polymer network to form corresponding hybrid membrane materials, namely, PVA,PAM,CsPMA,Glu, PVA,PAM,CsPWA,Glu, and PVA,PAM,CsSWA,Glu, respectively (where "Cs" together with a heteropolyacid abbreviation indicates the cesium salt of that acid). All the three hybrid polymer membranes fabricated exhibited excellent swelling, thermal, oxidative, and additive stability properties with desired proton conductivities in the range 10,2 S/cm at 50% relative humidity. A dense network formation was achieved through the blending of PVA and PAM and by crosslinking with Glu, which led to an order of magnitude decrease in the methanol permeability compared to the state-of-the-art commercial Nafion 115 membrane. The hybrid membrane containing CsSWA exhibited a very low methanol permeability (1.4 × 10,8 cm2/s) compared to other membranes containing cesium salt of heteropolyacids such as PMA and PWA. The feasibility of these hybrid membranes as proton-conducting electrolytes in DMFC was investigated, and the preliminary results were compared with those of Nafion 115. The results illustrate the attractive features and suitability of the fabricated hybrid membranes as an electrolyte for DMFC applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Tracking bio-molecules in live cells using quantum dotsJOURNAL OF BIOPHOTONICS, Issue 4 2008Yun-Pei Chang Abstract Single particle tracking (SPT) techniques were developed to explore bio-molecules dynamics in live cells at single molecule sensitivity and nanometer spatial resolution. Recent developments in quantum dots (Qdots) surface coating and bio-conjugation schemes have made them most suitable probes for live cell applications. Here we review recent advancements in using quantum dots as SPT probes for live cell experiments. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Synthesis and characterization of a thiadiazole/benzoimidazole-based copolymer for solar cell applicationsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 20 2010Guan-yu Chen Abstract In this study, we synthesized a new polymer, PCTDBI, containing alternating carbazole and thiadiazole-benzoimidazole (TDBI) units. This polymer (number-average molecular weight = 25,600 g mol,1), which features a planar imidazole structure into the polymeric main chain, possesses reasonably good thermal properties (Tg = 105 °C; Td = 396 °C) and an optical band gap of 1.75 eV that matches the maximum photon flux of sunlight. Electrochemical measurements revealed an appropriate energy band offset between the polymer's lowest unoccupied molecular orbital and that of PCBM, thereby allowing efficient electron transfer between the two species. A solar cell device incorporating PCTDBI and PCBM at a blend ratio of 1:2 (w/w) exhibited a power conversion efficiency of 1.20%; the corresponding device incorporating PCTDBI and PC71BM (1:2, w/w) exhibited a PCE of 1.84%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 [source] Optimization of a Nanoporous Silicon Layer for Solar Cell ApplicationJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 12 2008Guk-Hwan An A pyramidal structure and an n/p junction-formed wafer were used for the porous silicon (PS) layer formation. The pyramidal structure was adopted to maximize the light confinement with the PS layer. Also, in order to apply the PS layer to the solar cell directly, the n/p junction was adopted. To optimize the PS layer on this new type of surface, three kinds of solutions, ethanol, N,N -dimethylformamide, and formamide (FA), were used with hydrofluoric acid as a base of electrolyte. Various current densities were applied for PS layer formation with various anodizing durations. The reflectance and the microstructure were used as criteria for the selection of the most suitable PS layer. Consequently, an effective reflectance of 2.4% was obtained with 50 mA/cm2 and 10 s under the FA-based electrolyte condition. The result was expected to be used as an antireflection coating for solar cell applications. [source] Physically and Chemically Cross-Linked Poly{[(maleic anhydride)- alt -styrene]- co -(2-acrylamido-2-methyl-1-propanesulfonic acid)}/Poly(ethylene glycol) Proton-Exchange MembranesMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 2 2007lser G. Devrim Abstract Novel proton exchange membranes were solvent-cast from DMF solutions of the terpolymers poly[(MA- alt -S)- co -AMPS], containing hydrophobic phenyl and reactive hydrophilic carboxylic and organo-sulfonic acid fragments with different compositions, and PEGs with different molecular weights and amounts. These membranes were formed as a result of physical (via H-bonding) and chemical (via PEG) cross-linking. The structures of membranes were confirmed by FT-IR and 1H- and 13C NMR spectroscopy. Mechanical and thermal properties, swellability, and proton conductivity of these membranes were significantly affected both by the chemical composition of the terpolymers (mainly the AMPS content) and also the cross-linker (PEG) molecular weight and content in the final form of the membranes. It was concluded that the membranes prepared by using the terpolymer with an AMPS content of 36.84 mol-% and PEG with a molecular weight of 1,450 and with an initial PEG content of 30 wt.-% are the most suitable ones for fuel cell applications. [source] Conducting Polymer Enzyme Alloys: Electromaterials Exhibiting Direct Electron TransferMACROMOLECULAR RAPID COMMUNICATIONS, Issue 14 2010Brianna C. Thompson Abstract Glucose oxidase (GOx) is an important enzyme with great potential application for enzymatic sensing of glucose, in implantable biofuel cells for powering of medical devices in vivo and for large-scale biofuel cells for distributed energy generation. For these applications, immobilisation of GOx and direct transfer of electrons from the enzyme to an electrode material is required. This paper describes synthesis of conducting polymer (CP) structures in which GOx has been entrained such that direct electron transfer is possible between GOx and the CP. CP/enzyme composites prepared by other means show no evidence of such "wiring". These materials therefore show promise for mediator-less electronic connection of GOx into easily produced electrodes for biosensing or biofuel cell applications. [source] RF sputtered HgCdTe films for tandem cell applicationsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 4 2004S. L. Wang Abstract Polycrystalline Hg1,xCdxTe films were investigated for their potential as bottom cells of a CdTe-based tandem solar cell. The films were deposited by RF sputtering from a cold pressed target containing 30% HgTe + 70% CdTe. The as-deposited films were highly resistive with (111) preferred orientation and a bandgap of ,1.0 eV. Various thermal treatment schemes were investigated under different conditions of ambient and temperature to reduce the resistivity. The film properties were analyzed using infrared transmission spectra, energy dispersive X-ray spectra and X-ray diffraction. N doped p-HgCdTe films were also prepared by reactive sputtering in a N2/Ar ambient. P-n junction solar cells were fabricated with CdS films as the heterojunction partner. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Proton conducting membranes based on poly(vinyl chloride) graft copolymer electrolytesPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 7 2008Jin Kyu Choi Abstract The direct preparation of proton conducting poly(vinyl chloride) (PVC) graft copolymer electrolyte membranes using atom transfer radical polymerization (ATRP) is demonstrated. Here, direct initiation of the secondary chlorines of PVC facilitates grafting of a sulfonated monomer. A series of proton conducting graft copolymer electrolyte membranes, i.e. poly(vinyl chloride)- g -poly(styrene sulfonic acid) (PVC- g -PSSA) were prepared by ATRP using direct initiation of the secondary chlorines of PVC. The successful syntheses of graft copolymers were confirmed by 1H-NMR and FT-IR spectroscopy. The images of transmission electron microscopy (TEM) presented the well-defined microphase-separated structure of the graft copolymer electrolyte membranes. All the properties of ion exchange capacity (IEC), water uptake, and proton conductivity for the membranes continuously increased with increasing PSSA contents. The characterization of the membranes by thermal gravimetric analysis (TGA) also demonstrated their high thermal stability up to 200°C. The membranes were further crosslinked using UV irradiation after converting chlorine atoms to azide groups, as revealed by FT-IR spectroscopy. After crosslinking, water uptake significantly decreased from 207% to 84% and the tensile strength increased from 45.2 to 71.5,MPa with a marginal change of proton conductivity from 0.093 to 0.083,S,cm,1, which indicates that the crosslinked PVC- g -PSSA membranes are promising candidates for proton conducting materials for fuel cell applications. Copyright © 2008 John Wiley & Sons, Ltd. [source] Breakthroughs in Hydrogen Storage,Formic Acid as a Sustainable Storage Material for HydrogenCHEMSUSCHEM CHEMISTRY AND SUSTAINABILITY, ENERGY & MATERIALS, Issue 10 2008Ferenc Joó Prof. A boost for fuel cells: Recent results suggest that formic acid is a convenient hydrogen-storage material: its decomposition yields CO-free hydrogen while the co-produced carbon dioxide can be hydrogenated back to formic acid. The hydrogen generated in this way is suitable for fuel cell applications. [source] Permeability and Conductivity Studies on Ionomer-Polysilsesquioxane Hybrid MaterialsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 3 2006Chedarampet S. Karthikeyan Abstract Summary: Hybrid materials based on sulphonated poly(ether ether ketone) (SPEEK, ionomer) and (RSiO1.5)n network (polysilsequioxane) were prepared by sol-gel process. Two different precursors namely aminopropyl trimethoxysilane (APTMS) and imidazoleglycidoxypropyl trimethoxysilane (IGPTMS) were utilized to generate (RSiO1.5)n in SPEEK matrix by sol-gel process. 29Si MAS NMR confirmed the formation of RSiO3/2 network structure inside the matrix. Characterisation of the hybrid materials showed lower methanol and water permeability compared to the plain SPEEK. They are therefore promising materials as membranes for direct methanol fuel cells applications. The hybrid material derived from amino group was more effective in decreasing the permeability than the material derived from imidazole group. However, the proton conductivity of the latter was higher than the material derived from amino group. The results indicate that hybrid material prepared from imidazole containing silane is more suitable as a membrane for direct methanol fuel cell than the one prepared from amino carrying silane because it fulfils the two main requirements, namely low methanol permeability and reasonably good proton conductivity. Figure shows a network of silica phase in SPEEK matrix. [source] Modulated surface textures using zinc-oxide films for solar cells applicationsPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 3 2010Olindo Isabella Abstract We present modulated surface textures on glass substrates for improved light trapping in thin-film silicon solar cells. The surface morphology, the roughness spectral distribution, and the scattering properties of the modulated surface-textured substrates were characterized. We deposited solar cells on the modulated surface-textured substrates and observed enhancement in the performance compared to a solar cell deposited on textured ZnO:Al (reference) substrates. [source] | ||||||||||||||||||||||||||||