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Hybrid Materials (hybrid + material)
Kinds of Hybrid Materials Selected AbstractsMultiwalled Carbon Nanotubes Encased in Ruthenium Oxide Film as a Hybrid Material for Neurotransmitters SensorELECTROANALYSIS, Issue 16 2009Chien-Chieh Ti Abstract A hybrid film (MWCNTs-RuOx,nH2O) which contains multiwalled carbon nanotubes (MWCNTs) along with the incorporation of ruthenium oxide (RuOx,nH2O) has been synthesized on glassy carbon electrode (GCE), gold (Au), indium tin oxide (ITO) and screen printed carbon electrode (SPCE) by potentiostatic methods. The presence of MWCNTs in the hybrid film enhances surface coverage concentration (,) of RuOx,nH2O to ,2100%. The surface morphology of the hybrid film deposited on ITO has been studied using scanning electron microscopy and atomic force microscopy. These two techniques reveal that the RuOx,nH2O incorporated on MWCNTs. Electrochemical quartz crystal microbalance study too reveals the incorporation of MWCNTs and RuOx,nH2O. The MWCNTs-RuOx,nH2O hybrid film exhibits promising enhanced electrocatalytic activity towards the biochemical compounds such as epinephrine and norepinephrine. The electrocatalytic responses of these analytes at RuOx,nH2O, MWCNTs and MWCNTs-RuOx,nH2O hybrid films have been measured using cyclic voltammetry. The obtained sensitivity values from electrocatalysis studies of analytes for MWCNTs-RuOx,nH2O hybrid film are higher than the RuOx,nH2O and MWCNTs films. Finally, the flow injection analysis has been used for the amperometric studies of analytes at MWCNTs-RuOx,nH2O hybrid film modified SPCEs. [source] Metal-Containing Carbon Nitride Compounds: A New Functional Organic,Metal Hybrid MaterialADVANCED MATERIALS, Issue 16 2009Xinchen Wang The electronic and optical functions of polymeric C3N4 can be easily modified by the inclusion of metal species such as Fe in its structure. The metal species lowers the bandgap and expands the light absorption of the material further into the visible region of the electromagnetic spectrum, while keeping a sufficient overpotential for carrying out oxidation reactions. [source] Titanosilsesquioxanes Embedded in Synthetic Clay as a Hybrid Material for Polymer Science,ANGEWANDTE CHEMIE, Issue 33 2009Fabio Carniato Dr. Zwischen den Schichten: Ein neuartiges Hybridmaterial (siehe Bild) wurde durch die Interkalation eines difunktionellen Titanosilsesquioxans in synthetisches Natriumsaponit erhalten. Ein Nanokomposit aus einer Polystyrolmatrix und dem Hybrid als Additiv weist verbesserte thermooxidative Eigenschaften auf. [source] Efficient Removal of Anionic Surfactants Using Mesoporous Functionalised Hybrid MaterialsEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 25 2009Carmen Coll Abstract A new hybrid system for surfactant removal from water has been developed using mesoporous material (MCM-41) functionalised with suitable binding groups. Solid S1, S2 and S3 were prepared by reaction of the mesoporous material with N -methyl- N, -(propyltrimethoxysilyl)imidazolium chloride, (3-aminopropyl)trimethoxysilane or 4-[(triethoxysilylpropylthio)methyl]pyridine, respectively. The functionalised materials were characterised following standard solid-state techniques. The final prepared solids consist of a siliceous MCM-41-type mesoporous support with the surface decorated by imidazolium, amine and pyridine binding groups suitable for anion coordination. Equilibrium adsorption studies of linear alkylbenzenesulfonate (LAS) using S1, S2 and S3 in water have been carried out. The obtained adsorption data were correlated with a Langmuir isotherm model that gives an acceptable description of the experimental data. The maximum surfactant uptake/binding site (mol,mol,1) and the surfactant adsorption capacity (mmol,g,1) for materials S1, S2 and S3 were calculated. S1 shows a positive-charged functionalised surface that is independent of the pH of the solution, whereas S2 and S3 are functionalised with neutral groups that need to be protonated in order to display electrostatic binding interactions with the anionic surfactants. Therefore, whereas the adsorption capacity of S1 is pH-independent, S2 and S3 display larger LAS adsorption at acidic pH. The adsorption ability at a certain pH follows the order S1 >> S3 > S2. A remarkable maximum surfactant adsorption of 1.5 mmol per gram of material was observed for S1 at neutral pH. S2 and S3 behave as poorer adsorbents and show maximum surfactant adsorption of 0.197 and 0.335 mmol per gram of material, respectively, at pH 2.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Crystal Structure, Solid-State NMR Spectroscopic and Photoluminescence Studies of Organic-Inorganic Hybrid Materials (HL)6[Ge6(OH)6(hedp)6]·2(L)·nH2O, L = hqn or phen,EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2006Luís Mafra Abstract Two germanium,hedp4, solids with heteroaromatic amines 8-hydroxyquinoline (hqn) and 1,10-phenanthroline (phen), (HL)6[Ge6(OH)6(hedp)6]·2(L)·nH2O (L = hqn or phen), in I and II respectively, have been prepared and characterised by single-crystal XRD, thermogravimetry, FTIR and UV/Vis spectroscopy. The complex hydrogen-bond networks, particularly in compound I, have been studied by advanced high-resolution solid-state NMR spectroscopy that combines homonuclear recoupling techniques (two-dimensional 1H- 1H DQF and 1H- 1H RFDR MAS NMR) and combined rotation and multiple-pulse spectroscopy (two-dimensional 1H- 1H FS-LG, 1H- 31P FS-LG). The fine details of the crystal structure of I have been elucidated, mainly those involving the ,,, stacking of 8-hydroxyquinoline and the relative orientation of adjacent such molecules. Compound II exhibits an emission from the lowest triplet-state energy (,,,* 0-phonon transition) of the aromatic rings at 320 nm (31250 cm,1) from 14 K to room temperature. In contrast, the triplet emission of I at 530 nm (18868 cm,1) is only detected at low temperature, because of thermally activated non-radiative mechanisms. The emission spectra of I and II display a lower-energy component with a larger life time, which results from the formation of an excimer state that originated from the ,,, phenanthroline and hydroxyquinoline interactions, respectively. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source] Synthesis and Physicochemical Characterization of meso -Functionalized Corroles: Precursors of Organic,Inorganic Hybrid MaterialsEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 21 2005Jean-Michel Barbe Abstract Cobalt(III) corroles exhibit an infinite selectivity for the coordination of carbon monoxide towards dioxygen and dinitrogen. This peculiar property thus allows their use as sensing devices for CO detection. Here are described the syntheses and physico-chemical characterization of meso mono-, bis- and tris(triethoxysilyl)-functionalized corroles, precursors of organic,inorganic materials. The corrole ring formation was achieved in every case using the "2+1" method involving the reaction of two equivalents of an encumbered dipyrromethane with one equivalent of an aromatic aldehyde in the presence of a catalytic amount of trifluoroacetic acid. The functionalization of the corrole by triethoxysilyl chains was carried out by a condensation reaction of an isocyanate, bearing a triethoxysilyl termination, either on an amino or hydroxy group. Each final compound and intermediate were characterized by various physico-chemical techniques such as 1H NMR, UV/Vis, MALDI/TOF or EI mass spectrometry and elemental analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source] Rewritable Holographic Structures Formed in Organic,Inorganic Hybrid Materials by Photothermal ProcessingADVANCED FUNCTIONAL MATERIALS, Issue 16 2009Hiroshi Kakiuchida Abstract Holographic and direct-written structures are fabricated in tin-doped silicophosphite thin plates containing rhodamine 6G dye by a photothermal process based on the principle of glass softening/frozen-in behavior. To be highly processable by photothermal treatment and stable at room temperature after processing, the intrinsic viscoelastic property is improved by increasing the crosslinking density of the network structure, and the photothermal conditions for efficient transfer of the irradiated photons to thermal phonons are explored. Then, the excellent rewritability and reliability of the fine processed structure are found by examining the writing/erasing repetition. Furthermore, the origins of the changes in refractive index due to photothermal treatment are classified into density change and photobleaching, and the dynamics of the formation process of holographic gratings are studied by measuring refractive index changes as functions of irradiation time and wavelength. As a result, it is found that the holographic structure consists of spatial modulation of the refractive index and the refractive index change results primarily from the change in the frozen structure, although there is a slight influence by photobleaching. [source] Ligand-Driven Wavelength-Tunable and Ultra-Broadband Infrared Luminescence in Single-Ion-Doped Transparent Hybrid MaterialsADVANCED FUNCTIONAL MATERIALS, Issue 13 2009Shifeng Zhou Abstract Here, tuning of the optical properties of emission centers by tailoring the ligand fields is investigated. Experimentally, it is demonstrated that Ni2+ can act as a single emission species in multiple octahedral local environments. Nanocrystal-embedded hybrid materials are employed as hosts in order to take advantage of their convenience in local environment design for practical applications. Novel composite gain materials with high transparence are successfully made, and show interesting wavelength-tunable and ultra-broadband infrared luminescence covering the whole near-infrared region from 1,100 to 1,800,nm. The infrared luminescence peak positions can be finely tuned from 1,300 to 1,450 and to 1,570,nm, with the largest full width at half maximum being about 400,nm and covering the telecommunication bands at 1,200,1,500,nm. According to the results of characterization, the unusual luminescence, interestingly, originates from Ni2+ in nanocrystals and the doping efficiency of Ni2+ is surprisingly high. The results demonstrate that the method presented may be an effective way to fabricate multifunctional light sources with various fundamental multifunctional applications from efficient broadband optical amplifiers to bio-imaging. [source] Effect of SWNT Defects on the Electron Transfer Properties in P3HT/SWNT Hybrid Materials,ADVANCED FUNCTIONAL MATERIALS, Issue 18 2008Jianxin Geng Abstract Poly(3-hexylthiophene) (P3HT) hybrids with single-walled carbon nanotubes (SWNTs) were prepared using a series of SWNTs with various defect contents on their surfaces. The hybrids were synthesized by exploiting the ,,, interaction between P3HT and the SWNTs, resulting in efficient dispersion of the carbon nanotubes in the P3HT solution. UV-visible and photoluminescence (PL) spectra showed that the carbon nanotubes quench the PL of P3HT in the hybrids, indicating that electron transfer occurs from photo-excited P3HT to the SWNTs. This electron transfer from P3HT to carbon nanotubes was disrupted by the presence of defects on the SWNT surfaces. However, the PL lifetime of P3HT in the hybrids was found to be the same as that of pure P3HT in solution, indicating the formation of a ground-state non-fluorescent complex of P3HT/SWNTs. [source] Synthetic Strategies for Hybrid Materials to Improve Properties for Optoelectronic Applications,ADVANCED FUNCTIONAL MATERIALS, Issue 14 2008Olga García Abstract We report, for the first time to the best of our knowledge, a systematic study to relate the laser action from BODIPY dyes, doped into monolithic hybrid matrices, with the synthetic protocols of the final materials prepared via sol-gel. To this aim, the influence of both the hydrolysis time, increased in a controlled way, and the nature of the neutralization agent (pyridine, 3-amino-propyltriethoxy-silane (APS), N -[3-(trimethoxysilyl)propyl]-ethylene diamine (TSPDA), and N1 -[3-(trimethoxysilyl)propyl]- diethylene triamine (TSPTA) on the laser action of PM567, incorporated into hybrid matrices based on copolymers of methyl methacrylate (MMA) and 2-hydroxyethyl methacrylate (HEMA), with methyltriethoxysilane (TRIEOS) as inorganic precursor, was analyzed. The presence of the amine-modified silane TSPDA as neutralization agent, which is able at the same time to be anchored to the inorganic network enhancing the inorganic-organic compatibility through the matrix interphase, and utilization of hydrolysis times lower than 10 minutes, increased significantly the lasing efficiency and photostability of dye. The extension of this study to the laser behavior of BODIPY dyes embedded in other different hybrid materials based on hydrolyzed-condensed copolymers of MMA with 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) in a 1/1 volumetric proportion, validates the generalization of the above conclusions, which provide guides for the optimization of the synthesis of organic-inorganic hybrid materials with optoelectronic innovative applications independently of their composition. [source] Ionic/Electronic Hybrid Materials Integrated in a Synaptic Transistor with Signal Processing and Learning FunctionsADVANCED MATERIALS, Issue 22 2010Qianxi Lai A synaptic transistor is fabricated by integrating ionic/electronic hybrid materials to emulate biological synapses with spike signal processing, learning, and memory functions. A potential spike generates transient ionic fluxes in a polymer layer in the transistor gate, triggering an excitatory postsynaptic current in the transistor drain. Temporally correlated pre- and post-synaptic spikes modify ions stored in the polymer, resulting in the nonvolatile modification of the transistor with spike-timing-dependent plasticity. [source] Two Photon Polymerization of Polymer,Ceramic Hybrid Materials for Transdermal Drug DeliveryINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 1 2007A. Ovsianikov Three-dimensional microneedle devices were created by femtosecond laser two photon polymerization (2PP) of organically modified ceramic (Ormocer®) hybrid materials. Arrays of in-plane and out-of-plane hollow microneedles (microneedle length=800 ,m, microneedle base diameter=150,300 ,m) with various aspect ratios were fabricated. The fracture and penetration properties of the microneedle arrays were examined using compression load testing. In these studies, the microneedle arrays penetrated cadaveric porcine adipose tissue without fracture. Human epidermal keratinocyte viability on the Ormocer® surfaces polymerized using 2PP was similar to that on control surfaces. These results suggest that 2PP is able to create microneedle structures for transdermal drug delivery with a larger range of geometries than conventional microfabrication techniques. [source] Book Review: Functional Hybrid Materials.ADVANCED MATERIALS, Issue 17 2004By Pedro Gómez-Romero, Clément Sanchez (Eds.). No abstract is available for this article. [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] Novel High-Performance Talc/Poly[(butylene adipate)- co -terephthalate] Hybrid MaterialsMACROMOLECULAR MATERIALS & ENGINEERING, Issue 4 2008Jean Marie Raquez Abstract New talc/PBAT hybrid materials were prepared through reactive extrusion. First, PBAT was free-radically grafted with MA to improve the interfacial adhesion between PBAT and talc. Then, the resulting MA- g -PBAT was reactively melt-blended with talc through esterification reactions of MA moieties with the silanol functions from talc. Sn(Oct)2 and DMAP were used as catalysts. Interestingly, the tensile properties for these compatibilized composites were improved due to a better interfacial adhesion between both partners. XPS showed the formation of covalent ester bonds between the silanol functions from talc particles, and the MA moieties grafted onto the polyester backbones. [source] Preparation and Characterization of Trialkoxysilane-Containing Acrylic Resin/Alumina Hybrid MaterialsMACROMOLECULAR MATERIALS & ENGINEERING, Issue 8 2006Mingqi Li Abstract Summary: In the present study (3-methacryloxypropyl)trimethoxysilane (MPMS) containing acrylic resin/alumina hybrid materials with various alumina contents were prepared. The effects of ethylacetoacetate (EAA) content, catalyst type, and water content during sol,gel process for alumina sols on the microstructure and properties of the hybrid materials were investigated by SAXS, AFM, DSC, TGA, and nano-indentation tester, respectively. It was found that the hybrid materials exhibited a homogeneity and the alumina phase of the hybrids had mass fractal dimension and open structure. The thermal and mechanical properties of the hybrid materials were obviously improved when alumina was incorporated. The EAA contents, catalyst type, and water content during sol,gel process for alumina sols had obvious effects on the microstructure and properties of the hybrid materials. Typical load,displacement curves of the pure acrylic resin and hybrid materials with increasing alumina content. [source] Preparation of a Transparent Spherical Polymer Matrix Containing TiO2/SiO2 Hybrid MaterialsCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 4 2008D.-H. Zhang Abstract A transparent spherical polymer matrix containing TiO2/SiO2 hybrid materials is prepared from the copolymerization reaction between TiO2/SiO2 hybrid materials containing vinyl groups and methyl methacrylate (MMA). Transparent TiO2/SiO2 hybrid materials are prepared from the reaction between nucleophilic agents and tetrabutyl titanate (TBT). Three reaction mechanisms leading to the formation of nanometer TiO2/SiO2 hybrid materials, including the single group coordination reaction mechanism (SGCRM), double group chelation reaction mechanism (DGCRM) and bridge coordination reaction mechanism (BCRM) are discussed in detail and confirmed by FT-IR spectroscopy. The sizes of the TiO2/SiO2 hybrid material nanoparticles are also characterized and calculated by TEM and range from 20,40,nm. The diameter of the particles in the transparent spherical polymer matrix is ca. 100,200,nm and their shape is a regular spherical structure from TEM observations. The transparent spherical polymer matrix containing TiO2/SiO2 hybrid materials could be used as holographic anti-counterfeiting materials. [source] ChemInform Abstract: Organic,Inorganic Hybrid Materials for Enantioselective Organocatalysis.CHEMINFORM, Issue 51 2009Vivek Srivastava Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Hydrothermal Syntheses and Crystal Structures of Two Hybrid Materials Constructed from Polyoxometalate Clusters and Metal,Dipyridine Complexes.CHEMINFORM, Issue 25 2008Guangzhe Li Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] A Highly Efficient Three-Component Coupling of Aldehyde, Terminal Alkyne, and Amine via C,H Activation Catalyzed by Reusable Immobilized Copper in Organic,Inorganic Hybrid Materials under Solvent-Free Reaction Conditions.CHEMINFORM, Issue 40 2007Pinhua Li Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Synthesis and Optical Properties of Europium-Complex-Doped Inorganic/Organic Hybrid Materials Built from Oxo,Hydroxo Organotin Nano Building BlocksCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2010Wei-Qiang Fan Dr. Abstract Hybrid materials doped with novel europium complexes were synthesized using PMMA- co -Sn12Clusters (copolymers from oxohydroxo-organotin dimethacrylate and methylmethacrylate) as the matrix material. Two types of hybrid materials were obtained: the physically doped product, PMMA- co -Sn12Cluster/Eu(TTA)3phen, and the grafted product, PMMA- co -Sn12Cluster- co -[EuAA(TTA)2phen] (TTA=2-thenoyltrifluoroacetone, phen=phenanthroline and AA=acrylic acid). The hybrid materials exhibited characteristic luminescence of the Eu3+ ions, and also showed relative especial optical properties compared with samples just using PMMA as the matrix material. The PMMA- co -Sn12Cluster matrix exhibited a high physical doping quantity of [Eu(TTA)3phen], which can be attributed to the special structure of this kind of hybrid material. GPC (gel-permeation chromatography), TGA (thermogravimetric analysis), SEM, 1H,NMR, ICP (inductively coupled plasma), 119Sn,NMR, FTIR, and diffuse reflectance techniques were employed to characterize the structures and properties of these hybrid materials. [source] "Breathing" in Adsorbate-Responsive Metal Tetraphosphonate Hybrid MaterialsCHEMISTRY - A EUROPEAN JOURNAL, Issue 27 2009Rosario M. Abstract Breathe easy: Reversible H2O and NH3 gas uptake by 2D calcium tetraphosphonates (see figure) is accompanied by framework structural changes similar to those previously reported for some carboxylate-based hybrids. This breathing mechanism is accompanied by a volume increase of 55,%, while maintaining the topology and crystallinity of the material. The structures of various layered calcium tetraphosphonates (CaH6DTMP; H8DTMP=hexamethylenediamine tetrakis(methylenephosphonic acid)), have been determined. Starting from CaH6DTMP,2H2O, thermal treatment and subsequent exposure to NH3 and/or H2O vapors led to four new compounds that showed high storage capacity of guest species between the layers (up to ten H2O/NH3 molecules) and a maximum volume increase of 55,%. The basic building block for these phosphonates consists of an eight-membered ring chelating Ca2+ through two phoshonate groups, and the organic ligand is located within the layers, which are held together by hydrogen bonds. The structural analysis revealed that the uptake/removal of guest species (H2O and NH3) induces significant changes in the framework not only by changing the interlayer distances but also through important conformational changes of the organic ligand. An anisotropic breathing motion could be quantified by the changes of the unit-cell dimensions and ligand arrangements in four crystalline derivatives. Complete characterization revealed the existence of interconversion reactions between the different phases upon gas uptake and release. The observed behavior represents, to the best of our knowledge, the first example of a breathing-like mechanism in metal phosphonates that possess a 2D topology. [source] Constitutional Self-Organization of Adenine,Uracil-Derived Hybrid MaterialsCHEMISTRY - A EUROPEAN JOURNAL, Issue 24 2007Carole Arnal-Hérault Dr. Abstract The alkoxysilane nucleobase adenine (A) and uracil (U) precursors described in this paper generate in solution a complex library of hydrogen-bonded aggregates, which can be expressed in the solid state as discrete higher oligomers. The different interconverting outputs that nucleobases may form by oligomerization define a dynamic polyfunctional diversity that may be "extracted selectively" in solid state by sol,gel transcription, under the intrinsic stability of the system. After the sol,gel process, unique constitutional preference for specific geometries in hybrid materials is consistent with a preferential arrangement of nucleobase systems, favoring the self-assembly by the Hoogsteen geometry. FTIR and NMR spectroscopy and X-ray powder diffraction experiments demonstrate the formation of self-organized hybrid supramolecular materials. Electron microscopy reveals the micrometric platelike morphology of the hybrid materials. The MA,U hybrid material is nanostructured in ordered circular domains of 5,nm in diameter of alternative light and dark rows with an one-dimensional periodicity of 3.5,Å. [source] Sol,Gel Derived Nanocomposites for Optical ApplicationsADVANCED ENGINEERING MATERIALS, Issue 5 2010Peter W. de Oliveira This paper provides a selective description of the development of nanostructured materials and the fabrication of the devices for optical applications. Examples are interference coatings, refractive and diffractive lenses, and macro- and micro-GRIN (graded refractive index) optical elements. Hybrid materials containing nanoparticles are of particular interest for the production of optical elements because, by exploiting the intrinsic solid state properties of the nanoparticles, nanocomposites can be tailored to exhibit the desired properties. A particular advantage of wet chemical processing lies in its great flexibility for depositing functional coatings. [source] Energy-Absorbing Hybrid Composites Based on Alternate Carbon-Nanotube and Inorganic LayersADVANCED MATERIALS, Issue 28 2009Qiang Zhang Hybrid materials with aligned carbon nanotubes intercalating naturally layered compounds (see upper figures) are fabricated using general metal-ion intercalation and in situ growth. As indicated by SEM images (lower figures), they exhibit periodic and hierarchical structures. The ability to control their composition resulted in some samples possessing excellent mechanical properties, such as high energy absorption during compression. [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] One-step preparation of hybrid materials of polyacrylamide networks and gold nanoparticlesMICROSCOPY RESEARCH AND TECHNIQUE, Issue 6 2008Yonghai Song Abstract Hybrid materials of polyacrylamide networks and gold nanoparticles were prepared by directly heating an aqueous solution containing HAuCl4, acrylamide, N,N,-methylenebis-acrylamide, and sodium sulfite (Na2SO3). Acrylamide, N,N,-methylenebis-acrylamide, and Na2SO3 were used as monomers, crosslinking agent, and initiator, respectively. In the process of polyacrylamide network synthesis, HAuCl4 was reduced by acrylamide and Na2SO3 into gold nanoparticles and adsorbed on the produced polyacrylamide networks. Transmission electron microscopy proved that the size of gold nanoparticles was in the range of 3,10 nm. Atomic force microscopy showed that the gold nanoparticles homogeneously dispersed into the polyacrylamide networks matrix. The hybrid materials as absorbents may be useful in healthcare, communication technology, building industry, chromatography, water purification, and agriculture. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc. [source] Coloured inorganic-organic films on glassPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3 2007K. Cholewa-Kowalska Abstract Two kinds of inorganic-organic hybrid materials (A and B class) were obtained in the form of thin films on glass. As starting materials were used: PhTES + TEOS (A class); PhTES + GPTMS + TBA (B class). Hybrid materials were coloured using ORASOL type dyes. The coloured coatings were put on glass by dip-coating technique. The structure of hybrid matrix was examined by spectroscopic methods: FTIR, 29Si MAS NMR, 27Al MAS NMR. On this base structural units of hybrid were identified. UV/VIS spectra of thin films were measured directly after obtainment as well as after thermal and chemical treatment of samples. It has been found that UV/VIS spectra originate from electron transitions between ligands and transition metal ions. The coloured centres in hybrid matrix show good thermal and chemical resistance. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Photonic circuits writing with UV pulsed laserPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 1 2007K. R. Kribich Abstract Photonics technology is employed in a growing number of applications. Biological and chemical sensors (E. Udd, Fiber Optic Sensors: An Introduction for Engineers and Scientists, Wiley, New York, 1991 [1]) for health and environment demand an adaptable technology. Network development towards the end-user requires more interconnecting components. Vision, lighting, data processing in hostile environment (spatial, military) need specific technologies. A flexible and low-cost process using good quality material is necessary. The sol-gel process is a chemical method to fabricate glasses at ambient pressure and moderate temperature. Hybrid materials (H.K. Schmidt et al., Proc. SPIE 3136, 220 (1997) [2]), mixing organic and inorganic parts, offer the advantages of polymer-like materials and glasses. We report on a new hybrid sol-gel technology to overcome the drawbacks of the formerly presented one (H. Krug, F. Teillantes, P.W. Oliviers, and H. Schmidt, Proc. SPIE 1758, 448 (1992) [3]). We present the material synthesis, an accurate and flexible fabrication process based on a pulsed UV laser lithography system and the characterisation of the optical waveguides and photonic circuits realised. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Preparation and properties investigation of PMMA/silica composites derived from silicic acidPOLYMERS FOR ADVANCED TECHNOLOGIES, Issue 2 2009H. P. Fu Abstract Hybrid materials based on silicic acid and polymethyl methacrylate (PMMA) were prepared by in situ bulk polymerization of a silicic acid sol and MMA mixture. Silicic acid sol was obtained by tetrahydrofuran (THF) extraction of silicic acid from water. Silicic acid was prepared by hydrolysis and condensation of sodium silicate in the presence of 3.6,M HCl. As a comparative study, PMMA composites filled by silica particles, which were derived from calcining the silicic acid gel, were prepared by a comparable in situ polymerization. Each set of PMMA/silica composites was subjected to thermal and mechanical studies. Residual THF in PMMA/silicic acid composites impacted the properties of the polymer composites. With increase in silica content, the PMMA composites filled with silica particles showed improved thermal and mechanical properties, whereas a decrease in thermal stability and mechanical strength was found for PMMA composites filled with silicic acid dissolved in THF. With a better compatibility with polymer matrix, silicic acid sol shows better reinforcement than silica particles in PMMA films prepared via blending of the corresponding THF solutions. Copyright © 2008 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||