Home About us Contact
|
Home About us Contact | ||
|
|
||
Hybrid Films (hybrid + film)
Selected AbstractsReagentless Biosensor for Hydrogen Peroxide Based on the Immobilization of Hemoglobin in Platinum Nanoparticles Enhanced Poly(chloromethyl thiirane) Cross-linked Chitosan Hybrid FilmELECTROANALYSIS, Issue 12 2009Shanshan Jia Abstract An unmediated hydrogen peroxide (H2O2) biosensor was prepared by co-immobilizing hemoglobin (Hb) with platinum nanoparticles enhanced poly(chloromethyl thiirane) cross-linked chitosan (CCCS-PNs) hybrid film. CCCS could provide a biocompatible microenvironment for Hb and PNs could accelerate the electron transfer between Hb and the electrode. Spectroscopic analysis indicated that the immobilized Hb could maintain its native structure in the CCCS-PNs hybrid film. Entrapped Hb exhibited direct electrochemistry for its heme Fe(III)/Fe(II) redox couples at ,0.396,V in the CCCS-PNs hybrid film, as well as peroxidase-like activity to the reduction of hydrogen peroxide without the aid of an electron mediator. [source] Characterization of Quantum Dot/Conducting Polymer Hybrid Films and Their Application to Light-Emitting DiodesADVANCED MATERIALS, Issue 48 2009Jeonghun Kwak Quantum dot/conducting polymer hybrid films are used to prepare light-emitting diodes (LEDs). The hybrid films (CdSe@ZnS quantum dots excellently dispersed in a conducting polymer matrix, see figure) are readily prepared by various solution-based processes and are also easily micropatterned. The LEDs exhibit a turn-on voltage of 4,V, an external quantum efficiency greater than 1.5%, and almost pure-green quantum-dot electroluminescence. [source] Advanced Calcium Copper Titanate/Polyimide Functional Hybrid Films with High Dielectric PermittivityADVANCED MATERIALS, Issue 20 2009Zhi-Min Dang A functional hybrid film with high dielectric permittivity and good thermal stability is obtained using calcium copper titanate as filler in a polyimide polymer matrix. The giant dielectric permittivity of the filler and its semiconducting characteristics impart good dielectric properties to the hybrid films. A dielectric permittivity high as 49 is achieved at a 40,vol% filler concentration at 102,Hz. [source] Self-Organized Nanocrystalline Organosilicates in Organic-Inorganic Hybrid FilmsADVANCED MATERIALS, Issue 17 2009Masahide Takahashi Organic-inorganic hybrid films containing layered organosilica nanocrystals are obtained by an alcohol-free hydrolytic sol-gel process from a mono-functionalized organically modified alkoxide. Kinetically controlled self-organization is used to design the hybrid nanocomposite films. The layered nanocrystals are shown to be oriented within the films, which exhibited optical anisotropy (,n,>,10,3); the hybrid nanocomposite material is shown to be suitable for microfabrication by soft lithography. [source] Highly Conductive Carbon-Nanotube/Graphite-Oxide Hybrid Films,ADVANCED MATERIALS, Issue 9 2008Dongyu Cai Conductive hybrid carbon nanotube (CNT( films are prepared by a new and simple method. Thee graphite oxide nanoplatelet/carbon-nanotube hybrid films exhibit an extremely low square resistance. The SEM image shows the surface morphology, and reveals that one-dimensional carbon nanotubes form a conductive percolated network by covering the two-dimensional graphite oxide nanoplatelets. [source] Preparation of Molybdenum, Vanadium, and Tungsten Oxide Thin Films from Self-Assembly Deposited Polyoxometalate,Alkylamine-Layered Hybrid FilmsJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 2 2007Tetsuya Kida A novel, simple, and efficient route for preparing MoO3, V2O5, and WO3 films has been developed from layered polyoxometallate (POM)-alkylamine hybrid films by calcination. The highly ordered hybrid films were self-assembly deposited in a one-step process using clear precursor POM solutions, prepared by reacting layered MoO3, V2O5, and WO3·H2O powders with hexylamine in the presence of water. The morphology of the resulting films can be tuned by removing the intercalated hexylamine molecules from the as-prepared hybrid films through UV irradiation before calcination. [source] Biologically Inspired, Strong, Transparent, and Functional Layered Organic,Inorganic Hybrid Films,ANGEWANDTE CHEMIE, Issue 12 2010Hong-Bin Yao Wie Mutter Natur: Biologisch inspirierte organisch-anorganische Hybridfilme, in denen Schichten aus Chitosan und Mikro- und Nanoplättchen aus Doppelhydroxiden mit Schichtstruktur abwechseln, ahmen die einzigartigen Mikroschichtstrukturen von Perlmutt nach (siehe Bild) und weisen eine hohe Reißfestigkeit auf. Zudem können die Hybridfilme mit den optischen Eigenschaften der Plättchen versehen werden. [source] Electroanalysis of Bisphenol A at a Multiwalled Carbon Nanotubes-gold Nanoparticles Modified Glassy Carbon ElectrodeELECTROANALYSIS, Issue 22 2009Xinman Tu Abstract A sensitive electrochemical method was developed for the determination of bisphenol A (BPA) at a glassy carbon electrode (GCE) modified with a multiwalled carbon nanotubes (MWCNTs)-gold nanoparticles (GNPs) hybrid film, which was prepared based on the electrostatic interaction between positively charged cetyltrimethylammonium bromide (CTAB) and negatively charged MWCNTs and GNPs. The MWCNT-GNPs/GCE exhibited an enhanced electroactivity for BPA oxidation versus unmodified GCE and MWCNTs/GCE. The experimental parameters, including the amounts of modified MWCNTs and GNPs, the pH of the supporting electrolyte, scan rate and accumulation time, were examined and optimized. Under the optimal conditions, the differential pulse voltammetric anodic peak current of BPA was linear with the BPA concentration from 2.0×10,8 to 2×10,5 mol L,1, with a limit of detection of 7.5,nmol L,1. The proposed procedure was applied to determine BPA leached from real plastic samples with satisfactory results. [source] Multiwalled 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] Reagentless Biosensor for Hydrogen Peroxide Based on the Immobilization of Hemoglobin in Platinum Nanoparticles Enhanced Poly(chloromethyl thiirane) Cross-linked Chitosan Hybrid FilmELECTROANALYSIS, Issue 12 2009Shanshan Jia Abstract An unmediated hydrogen peroxide (H2O2) biosensor was prepared by co-immobilizing hemoglobin (Hb) with platinum nanoparticles enhanced poly(chloromethyl thiirane) cross-linked chitosan (CCCS-PNs) hybrid film. CCCS could provide a biocompatible microenvironment for Hb and PNs could accelerate the electron transfer between Hb and the electrode. Spectroscopic analysis indicated that the immobilized Hb could maintain its native structure in the CCCS-PNs hybrid film. Entrapped Hb exhibited direct electrochemistry for its heme Fe(III)/Fe(II) redox couples at ,0.396,V in the CCCS-PNs hybrid film, as well as peroxidase-like activity to the reduction of hydrogen peroxide without the aid of an electron mediator. [source] Zinc Oxide/Zinc Hexacyanoferrate Hybrid Film-Modified Electrodes for Guanine DetectionELECTROANALYSIS, Issue 18 2007Hung-Wei Chu Abstract An electroactive polynuclear hybrid films of zinc oxide and zinc hexacyanoferrate (ZnO/ZnHCF) have been deposited on electrode surfaces from H2SO4 solution containing Zn(NO3)2 and K3[Fe(CN)6] by repetitive potential cycling method. Simultaneous cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM) measurements demonstrate the steady growth of hybrid film. There are two redox couples present in the voltammograms of hybrid film and it is obvious in the case of pH,2. Surface morphology of hybrid film was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Energy dispersive spectrometer (EDS) data confirm existence of zinc oxide in the hybrid film. The effect of type of monovalent cations on the redox behavior of resulting film was investigated. In pure supporting electrolyte, electrochemical responses of modified electrode resemble with that of a surface immobilized redox couple. The electrocatalytic activity of ZnO/ZnHCF hybrid film was investigated towards guanine using cyclic voltammetry and rotating disc electrode (RDE) techniques. Finally, feasibility of using ZnO/ZnHCF hybrid film-coated electrodes for guanine estimation in flow injection analysis (FIA) was also investigated. [source] Electrocatalysis and Amperometric Detection of the Reduced Form of Nicotinamide Adenine Dinucleotide at Toluidine Blue/Zinc Oxide Coated ElectrodesELECTROANALYSIS, Issue 18 2007Ashok Kumar Abstract Thin toluidine blue (TBO) and zinc oxide (ZnO) hybrid films have been grown on glassy carbon electrode (GCE) and indium tin oxide coated (SnO2) glass electrodes by using cyclic voltammetry (CV). Scanning electron microscopy (SEM) images revealed spherical and beads-like shape of highly oriented TBO/ZnO hybrid films. Energy dispersive spectrometry (EDS) results declared that the films composed mainly of Zn and O. Moreover, TBO/ZnO hybrid films modified electrode is electrochemically active, dye molecules were not easily leached out from the ZnO matrix and the hybrid films can be considered for potential applications as sensor for amperometric determination of reduced nicotinamide adenine dinucleotide (NADH) at 0.0,V. A linear correlation between electrocatalytic current and NADH concentration was found to be in the range between 25,,M and 100,,M in phosphate buffer. In addition, we observed that dopamine, ascorbic acid and uric acid are not interference in amperometric detection of NADH in this proposed method. In addition, TBO/ZnO hybrid film modified electrode was highly stable and its response to the NADH also remained relentless. [source] Surface-Modified Mesoporous SiO2 Containers for Corrosion ProtectionADVANCED FUNCTIONAL MATERIALS, Issue 15 2009Ekaterina V. Skorb Abstract The development of active corrosion protection systems for metallic substrates is an issue of prime importance for many industrial applications. The present work shows a new contribution to the design of a new protective system based on surface modified mesoporous silica containers. Incorporation of silica-based containers into special sol,gel matrix allows for a self-healing effect to be achieved during the corrosion process. The self-healing ability occurs due to release of entrapped corrosion inhibitors in response to pH changes caused by the corrosion process. A silica,zirconia-based hybrid film is used in this work as a coating matrix deposited on AA2024 aluminum alloy. Mesoporous silica nano-particles are covered layer-by-layer with polyelectrolyte layers and loaded with inhibitor [2-(benzothiazol-2-ylsulfanyl)-succinic acid]. The hybrid film with nanocontainers reveals enhanced long-term corrosion protection in comparison with the individual sol,gel films. The scanning vibrating electrode technique also shows an effective healing ability of containers to cure the corrosion defects. This effect is due to the release of the corrosion inhibitor triggered by the corrosion processes started in the cavities. The approach described herein can be used in many applications where active corrosion protection of materials is required. [source] Application of Inhibitor-Loaded Halloysite Nanotubes in Active Anti-Corrosive CoatingsADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Dmitri Fix Abstract Halloysite particles are aluminum-silicate hollow cylinders with a length of 0.5,1,µm, an outer diameter of ca. 50,nm and a lumen of 15,nm. These nanotubes are used for loading and sustained release of corrosion inhibitors. The inhibitor is kept inside the particles infinitely long under dry conditions. Here, halloysite nanotubes filled with anticorrosive agents are embedded into a SiOx,ZrOx hybrid film. An aluminum plate is dip-coated and immersed into 0.1,M sodium chloride aqueous solution for corrosion tests. A defect in the sol,gel coating induces pitting corrosion on the metal accompanied by a strong anodic activity. The inhibitor is released within one hour from halloysite nanotubes at corrosion spots and suppresses the corrosion process. The anodic activity is successfully restrained and the protection remains for a long time period of immersion in NaCl water solution. The self-healing effect of the sol,gel coating doped with inhibitor-loaded halloysite nanotubes is demonstrated in situ via scanning vibrating electrode technique measurements. [source] Advanced Calcium Copper Titanate/Polyimide Functional Hybrid Films with High Dielectric PermittivityADVANCED MATERIALS, Issue 20 2009Zhi-Min Dang A functional hybrid film with high dielectric permittivity and good thermal stability is obtained using calcium copper titanate as filler in a polyimide polymer matrix. The giant dielectric permittivity of the filler and its semiconducting characteristics impart good dielectric properties to the hybrid films. A dielectric permittivity high as 49 is achieved at a 40,vol% filler concentration at 102,Hz. [source] Colorless polyimide nanocomposite films: Thermomechanical properties, morphology, and optical transparencyJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Hyo-Seong Jin Abstract Polyimide (PI)/organoclay hybrid films were prepared by the solution intercalation method, using dodecyltriphenylphosphonium-mica (C12PPh-Mica) as the organoclay. The variations with organoclay content of the thermomechanical properties, morphology, and optical transparency of the hybrids were examined for concentrations from 0 to 1.0 wt %. For low clay contents (, 0.5 wt %), the clay particles are better dispersed in the matrix polymer, without the formation of large agglomerates of particles, than they are for high clay contents. However, agglomerated structures form and become denser in the PI matrix for clay contents , 0.75 wt %. This is in agreement with the observed trends in the thermomechanical properties and the optical transparency, which worsen drastically when the clay content of the C12PPh-Mica/PI hybrids reaches 0.75 wt %. However, when the amount of organoclay in the hybrid is 0.75 wt %, the initial modulus of the hybrid film is at its maximum value. The PI hybrid films were found to exhibit excellent optical transparencies and to be almost colorless. It was found, however, that the transparency decreases slightly with increases in the organoclay content because of agglomeration of the clay particles. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Preparation and Fluorescent and Magnetic Properties of Polyurethane/Eu(MA)3 FilmsMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 24 2007Shuxue Zhou Abstract Europium(III) (Eu3+)-doped polyurethane films were prepared by mixing Eu-methacrylic acid complex (Eu(MA)3) with aliphatic polyurethane oligomer and subsequently curing under UV irradiation. Transmission electron microscopy photos and the appearance of the resulting hybrid films showed that phase separation occurred only at an Eu(MA)3 content above 20 wt.-%. Fluorescence spectra indicated that the fluorescence of Eu3+ was barely influenced by the polyurethane matrix and its intensity increased with an Eu(MA)3 content in the range of approximately 0 to 10 wt.-%. An obvious applied external-field-dependent magnetization (M) of polyurethane/Eu(MA)3 films, namely, an increasing M at low field and a decreasing M at high field, was observed at room temperature from the hysteresis loops, which was influenced by both the Eu(MA)3 content and the ultrasonication imposed on the coatings before curing. It seems that ultrasonication leads to a thermodynamically-unstable structure of Eu3+ in hybrid films, which can be fixed by UV curing but gradually rearranges to its original form during the thermal-curing process, and enhances the diamagnetic part of the hybrid film. Thus, the magnetic property of Eu3+ -doped polyurethane film at room temperature can be adjusted by simply changing the preparation method and the Eu(MA)3 content instead of the type of Eu3+ -organic complex. [source] Hybrid Nonlinear Optical Materials Containing Imidazole Chromophore through the Sol-Gel ProcessMACROMOLECULAR RAPID COMMUNICATIONS, Issue 20 2007Yuanjing Cui Abstract A new sol-gel hybrid film based on heterocyclic chromophore, namely 2-[4,-(N -ethyl- N -hydroxyethyl)amino phenyl azo]-4,5-dicyanoimidazole (IZ), has been synthesized and characterized. The hybrid system possesses a high chromophore loading density up to 65 wt.-% without observing a phase separation. The initial decomposition temperatures of the chromophore and hybrid material were determined to be 260 and 272,°C, respectively. Poled films show a fairly high and stable nonlinear optical (NLO) response, even at an elevated temperature. [source] Stabilized dispersions of titania nanoparticles via a sol,gel process and applications in UV-curable hybrid systemsPOLYMER INTERNATIONAL, Issue 4 2006Xiahong Zhang Abstract Organic,inorganic hybrid UV-curable coatings were synthesized through blending UV-curable components and stabilized titania sol prepared via a sol,gel process of tetrabutyl titanate (TBT) with three different stabilizers, acetylacetone (Acac), isopropyl tri(dioctyl)pyrophosphato titanate coupling agent (TTPO) and a polymerizable organic phosphoric acid (MAP). The size and the dispersion of titania particle in the UV-cured organic matrix were dominated by the properties of these stabilizers. A cured hybrid film with titania particle size around 20 nm was obtained when TTPO was utilized as protection agent for the sol. It is interesting that the hardness and flexibility of the photocured hybrid films were improved simultaneously, in contrast to results with neat organic UV-curable formulations. Copyright © 2006 Society of Chemical Industry [source] Multiwalled 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] Zinc Oxide/Zinc Hexacyanoferrate Hybrid Film-Modified Electrodes for Guanine DetectionELECTROANALYSIS, Issue 18 2007Hung-Wei Chu Abstract An electroactive polynuclear hybrid films of zinc oxide and zinc hexacyanoferrate (ZnO/ZnHCF) have been deposited on electrode surfaces from H2SO4 solution containing Zn(NO3)2 and K3[Fe(CN)6] by repetitive potential cycling method. Simultaneous cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM) measurements demonstrate the steady growth of hybrid film. There are two redox couples present in the voltammograms of hybrid film and it is obvious in the case of pH,2. Surface morphology of hybrid film was investigated using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Energy dispersive spectrometer (EDS) data confirm existence of zinc oxide in the hybrid film. The effect of type of monovalent cations on the redox behavior of resulting film was investigated. In pure supporting electrolyte, electrochemical responses of modified electrode resemble with that of a surface immobilized redox couple. The electrocatalytic activity of ZnO/ZnHCF hybrid film was investigated towards guanine using cyclic voltammetry and rotating disc electrode (RDE) techniques. Finally, feasibility of using ZnO/ZnHCF hybrid film-coated electrodes for guanine estimation in flow injection analysis (FIA) was also investigated. [source] Electrocatalysis and Amperometric Detection of the Reduced Form of Nicotinamide Adenine Dinucleotide at Toluidine Blue/Zinc Oxide Coated ElectrodesELECTROANALYSIS, Issue 18 2007Ashok Kumar Abstract Thin toluidine blue (TBO) and zinc oxide (ZnO) hybrid films have been grown on glassy carbon electrode (GCE) and indium tin oxide coated (SnO2) glass electrodes by using cyclic voltammetry (CV). Scanning electron microscopy (SEM) images revealed spherical and beads-like shape of highly oriented TBO/ZnO hybrid films. Energy dispersive spectrometry (EDS) results declared that the films composed mainly of Zn and O. Moreover, TBO/ZnO hybrid films modified electrode is electrochemically active, dye molecules were not easily leached out from the ZnO matrix and the hybrid films can be considered for potential applications as sensor for amperometric determination of reduced nicotinamide adenine dinucleotide (NADH) at 0.0,V. A linear correlation between electrocatalytic current and NADH concentration was found to be in the range between 25,,M and 100,,M in phosphate buffer. In addition, we observed that dopamine, ascorbic acid and uric acid are not interference in amperometric detection of NADH in this proposed method. In addition, TBO/ZnO hybrid film modified electrode was highly stable and its response to the NADH also remained relentless. [source] Highly Fluorescent Mesostructured Films that consist of Oligo(phenylenevinylene),Silica Hybrid Frameworks,ADVANCED FUNCTIONAL MATERIALS, Issue 22 2008Norihiro Mizoshita Abstract Highly fluorescent and visible-light-responsive mesostructured organosilica films are successfully obtained by acidic sol,gel polycondensation of oligo(phenylenevinylene) (OPV)-bridged organosilane and tetraethoxysilane precursors in the presence of a template surfactant. The OPV-bridged organosilane precursors with different lateral alkoxy substituents, hexyloxy and 2-ethylhexyloxy, and no substituent, are synthesized by Rh-catalyzed silylation of corresponding aromatic iodides. From the organosilane precursors, three kinds of mesostructured OPV,silica hybrid films are prepared by spin-casting using evaporation-induced self-assembly. UV-vis absorption and fluorescence behavior of the OPV,silica hybrid films show that the optical properties and intermolecular interactions of the OPV moieties embedded within the organosilica frameworks strongly depend on the lateral alkoxy substituents in the precursors. The hexyloxy and 2-ethylhexyloxy substituents prevent aggregation of the OPV units in the organosilica frameworks; this result leads to high fluorescence quantum yields of 0.48,0.61 and 0.63,0.66, respectively, while non-substitution leads to lower fluorescence quantum yields of 0.25,0.34. Fluorescence decay profiles of the organosilica hybrid films also confirm a suppression of the aggregation of OPV moieties by the lateral substituents. These mesostructured organosilica films with significant optical properties in the visible-light region are promising as a new class of phosphor materials. [source] Characterization of Quantum Dot/Conducting Polymer Hybrid Films and Their Application to Light-Emitting DiodesADVANCED MATERIALS, Issue 48 2009Jeonghun Kwak Quantum dot/conducting polymer hybrid films are used to prepare light-emitting diodes (LEDs). The hybrid films (CdSe@ZnS quantum dots excellently dispersed in a conducting polymer matrix, see figure) are readily prepared by various solution-based processes and are also easily micropatterned. The LEDs exhibit a turn-on voltage of 4,V, an external quantum efficiency greater than 1.5%, and almost pure-green quantum-dot electroluminescence. [source] Advanced Calcium Copper Titanate/Polyimide Functional Hybrid Films with High Dielectric PermittivityADVANCED MATERIALS, Issue 20 2009Zhi-Min Dang A functional hybrid film with high dielectric permittivity and good thermal stability is obtained using calcium copper titanate as filler in a polyimide polymer matrix. The giant dielectric permittivity of the filler and its semiconducting characteristics impart good dielectric properties to the hybrid films. A dielectric permittivity high as 49 is achieved at a 40,vol% filler concentration at 102,Hz. [source] Self-Organized Nanocrystalline Organosilicates in Organic-Inorganic Hybrid FilmsADVANCED MATERIALS, Issue 17 2009Masahide Takahashi Organic-inorganic hybrid films containing layered organosilica nanocrystals are obtained by an alcohol-free hydrolytic sol-gel process from a mono-functionalized organically modified alkoxide. Kinetically controlled self-organization is used to design the hybrid nanocomposite films. The layered nanocrystals are shown to be oriented within the films, which exhibited optical anisotropy (,n,>,10,3); the hybrid nanocomposite material is shown to be suitable for microfabrication by soft lithography. [source] Highly Conductive Carbon-Nanotube/Graphite-Oxide Hybrid Films,ADVANCED MATERIALS, Issue 9 2008Dongyu Cai Conductive hybrid carbon nanotube (CNT( films are prepared by a new and simple method. Thee graphite oxide nanoplatelet/carbon-nanotube hybrid films exhibit an extremely low square resistance. The SEM image shows the surface morphology, and reveals that one-dimensional carbon nanotubes form a conductive percolated network by covering the two-dimensional graphite oxide nanoplatelets. [source] Colorless polyimide nanocomposite films: Thermomechanical properties, morphology, and optical transparencyJOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008Hyo-Seong Jin Abstract Polyimide (PI)/organoclay hybrid films were prepared by the solution intercalation method, using dodecyltriphenylphosphonium-mica (C12PPh-Mica) as the organoclay. The variations with organoclay content of the thermomechanical properties, morphology, and optical transparency of the hybrids were examined for concentrations from 0 to 1.0 wt %. For low clay contents (, 0.5 wt %), the clay particles are better dispersed in the matrix polymer, without the formation of large agglomerates of particles, than they are for high clay contents. However, agglomerated structures form and become denser in the PI matrix for clay contents , 0.75 wt %. This is in agreement with the observed trends in the thermomechanical properties and the optical transparency, which worsen drastically when the clay content of the C12PPh-Mica/PI hybrids reaches 0.75 wt %. However, when the amount of organoclay in the hybrid is 0.75 wt %, the initial modulus of the hybrid film is at its maximum value. The PI hybrid films were found to exhibit excellent optical transparencies and to be almost colorless. It was found, however, that the transparency decreases slightly with increases in the organoclay content because of agglomeration of the clay particles. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Flexible nanocrystalline-titania/polyimide hybrids with high refractive index and excellent thermal dimensional stabilityJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 6 2010Guey-Sheng Liou Abstract In this study, a novel synthetic route was developed to prepare polyimide,nanocrystalline,titania hybrid optical films with a relatively high titania content (up to 50 wt %) and thickness (20,30 ,m) from soluble polyimides containing hydroxyl groups. Two series of newly soluble polyimides were synthesized from the hydroxy-substituted diamines with various commercial tetracarboxylic dianhydrides. The hydroxyl groups on the backbone of the polyimides could provide the organic,inorganic bonding and resulted in homogeneous hybrid solutions by controlling the mole ratio of titanium butoxide/hydroxyl group. AFM, SEM, TEM, and XRD results indicated the formation of well-dispersed nanocrystalline-titania. The flexible hybrid films could be successfully obtained and revealed relatively good surface planarity, thermal dimensional stability, tunable refractive index, and high optical transparency. A three-layer antireflection coating based on the hybrid films was prepared and showed a reflectance of less than 0.5% in the visible range indicated its potential optical applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1433,1440, 2010 [source] Infrared stealth and anticorrosion performances of organically modified silicate-NiZn ferrite/polyaniline hybrid coatingsJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 3 2008K. H. Wu Abstract Hybrid coatings based on organically modified silicate-Ni0.5Zn0.5Fe2O4/polyaniline were synthesized through a sol,gel technique with different NiZn ferrite/polyaniline weight ratio (1/1, 1/2, 1/5). These hybrid films were deposited via spin coating onto an aluminum alloy to improve the corrosion protection and to act as infrared stealth coatings. The effects induced by the NiZn ferrite/polyaniline hybrids on the chain dynamic, ferromagnetic behavior, infrared stealth, and anticorrosion performances of the coated samples were investigated. The rotating-frame spin-lattice relaxation times and scale of the spin-diffusion path length indicated that the configuration of the hybrid films was highly cross-linked and dense. The thermal extinction of the hybrid coatings increased with the increase in the polyaniline content. Potentio-dynamic and salt-spray analysis revealed that the hybrid films provided an exceptional barrier and corrosion protection in comparison with untreated aluminum alloy substrates. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 926,935, 2008 [source] | ||||||||||||||||||||||||||||