999 resultados para composite electrolytes


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We report a high molar extinction coefficient heteroleptic polypyridyl ruthenium sensitizer, featuring an electron-rich 3,4-ethylenedioxythiophene unit in its ancillary ligand. A nanocrystalline titania film stained with this sensitizer shows an improved optical absorption, which is highly desirable for practical dye-sensitized solar cells with a thin photoactive layer, facilitating the efficient charge collection.

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We report a high molar extinction coefficient metal-free sensitizer composed of a triarylamine donor in combination with the 2-(2,2'-bithiophen-5-yl)acrylonitrile conjugation unit and cyanoacrylic acid as an acceptor. In conjugation with a volatile acetonitrile-based electrolyte or a solvent-free ionic liquid electrolyte, we have fabricated efficient dye-sensitized solar cells showing a corresponding 7.5% or 6.1% efficiency measured under the air mass 1.5 global sunlight. The ionic liquid cell exhibits excellent stability during a 1000 h accelerated test under the light-soaking and thermal dual stress. Intensity-modulated photocurrent and photovolatge spectroscopies were employed along with the transient photoelectrical decay measurements to detail the electron transport in the mesoporous titania films filled with these two electrolytes.

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We systematically studied the temperature-dependent physicochemical properties, such as density, conductivity, and fluidity, of 1,3-dialkylimidazolium iodides. In combination with the amphiphilic Z907Na sensitizer, we have found that it is important to use low-viscosity iodide melts with small cations to achieve high-efficiency dye-sensitized solar cells. By employing high-fluidity eutectic-based melts the device efficiencies considerably increased compared to those for cells with the corresponding state of the art ionic liquid electrolytes.

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Multilayer film of laccase, poly-L-lysine (PLL) and multi-walled carbon nanotubes (MWNTs) were prepared by a layer-by-layer self-assembly technique. The results of the UV-vis spectroscopy and scanning electron microscopy studies demonstrated a uniform growth of the multilayer. The catalytic behavior of the modified electrode was investigated. The (MWNTs/PLL/laccase)(n) multilayer modified electrode catalyzed four-electron reduction of O-2 to water, without any mediator.

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Immersion in various media has different effect on the properties of dental composites, such as sorption, solubility, elution of unreacted monomers, flexural strength, and flexural elastic modulus. In the present work, the effect of immersion in various media and the relationship between the variation of these properties and the components of dental composite were investigated.

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A new kind of bismuth film modified electrode to sensitively detect trace metal ions based on incorporating highly conductive ionic liquids 1-butyl-3-methyl-imidazolium hexafluorophosphate (BMIMPF6) in solid matrices at glassy carbon (GC) was investigated. Poly(sodium 4-styrenesulfonate) (PSS), silica, and Nafion were selected as the solid matrices. The electrochemical properties of the mixed films modified GC were evaluated. The electron transfer rate of Fe(CN)(6)(4-)/Fe(CN)(6)(3-) can be effectively improved at the PSS-BMIMPF6 modified GC.

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The copolymer of acrylonitrile (AN), methyl methacrylate (MMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) is synthesized in 1-butyl-3-methylimidazolium tetrafluoroborate (BMImBF(4)). The dynamic mechanical properties of the resulting gel polymer electrolytes containing ionic liquid are measured.

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Noble metal composite nanoparticles, as attractive building blocks of advanced functional materials, have received enormous attentions due to their specific optical, electronic and catalytic properties that are distant from those of the corresponding monometal nanoparticles. Such materials have important applications in such areas as sensors, optical materials, catalysis and biology, and developed into an increasingly important research area in nanomaterials science. This article reviews the recent progress in the synthesis, properties, and applications of noble metal composite nanoparticles with core-shell, heterostructure, and alloy structure.

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A series of superabsorbent composites containing Montmorillonite (MMT), modified- Montmorillonite (OMMT) and sodium acrylate were synthesized by free-radical polymerization in aqueous solution. The structure of composites was characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM) and X-ray diffraction (XRD), and the results showed that the polymer chains were grafted onto the edge and the surface of MMT or OMMT. At the same time, the equilibrium swelling ratio of the composites was investigated as a function of the clay content and the results showed that the equilibrium swelling ratio of composites was improved by the introduction of clay.

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The unique electrochemiluminescence (ECL) behavior of tris(bipyridine) ruthenium(II) (Ru(bpy)(3)(2+) immobilized in a gold/Nafion/Ru(bpy)(3)(2+) composite material was investigated. In this composite, the Ru(bpy)(3)(2+) ECL was found mainly occurred at 0-0.4 V during the cathodic scan process and the ECL peak was at about 0.1 V, which was quite different to the reported Ru(bpy)(3)(2+) ECL. Similar to the generally observed Ru(bpy)(3)(2+) ECL, the present ECL also could be enhanced by tri-n-propylarnine (TPA). It is also unique that in the presence of TPA, another ECL peak at about 0.38 V occurred.

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A new class of polymeric amine, namely, sulfonated cardo poly(arylene ether sulfone) (SPES-NH2) was synthesized and used for the preparation of thin-film composite membrane. The TFC membranes were prepared on a polysulfone supporting film through interfacial polymerization with trimesoyl chloride (TMC) solutions and amine solutions containing SPES-NH2 and m-phenylenediamine (MPDA). The resultant membranes were characterized with water permeation performance, chemical structure, hydrophilicity of active layer and membrane morphology including top surface and cross-section.

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Three novel of isomeric tetra-functional biphenyl acid chloride: 3,3',5,5'-biphenyl tetraacyl chloride (mm-BTEC), 2,2',4,4'-biphenyl tetraacyl chloride (om-BTEC), and 2,2',5,5'-biphenyl tetraacyl chloride (op-BTEC) were synthesized, and used as new monomers for the preparation of the thin film composite (TFC) reverse osmosis (RO) membranes through interfacial polymerization with m-phenylenediamine (MPDA). The results of membrane performance test showed that membranes prepared from om-BTEC and op-BTEC had higher flux at the expanse of rejection compared with membranes prepared from mm-BTEC.

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A novel cemented carbides (W0.7Al0.3)C-0.65-Co with different cobalt contents were prepared by solid-state reaction and hot-pressing technique. Hot-pressing technique as a novel technique was performed to fabricate the bulk bodies of the hard alloys. The novel cemented carbides have superior mechanical properties compared with WC-Co. The density, operate cost of the novel material were lower than WC-Co system. The novel materials were easy to process nanoscale sintering and get the rounded particles in the bulk materials. There is almost no eta-phase in the (W0.7Al0.3)C-0.65-Co cemented carbides system although the carbon deficient get the astonished 35% value.

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A novel cemented carbides (W0.5Al0.5)C-0.8-Co with different cobalt contents were prepared by mechanical alloying and hot-pressing technique. Hot-pressing technique as a common technique was performed to fabricate the bulk bodies of the hard alloys. The novel cemented carbides have superior mechanical properties compared to WC-Co. The density, operating cost of the novel material were much lower than WC-Co. There is almost no eta-phase in the (W0.5Al0.5)C-0.8-Co cemented carbides system although the carbon deficient get the value of 20%, and successfully got the nanostructured rounded (W0.5Al0.5)C-0.8 particles.

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Novel cemented carbides (W0.4Al0.6)C-0.5-Co With different cobalt contents were prepared by mechanical alloying and hot-pressing technique. Hot-pressing technique as a common technique was performed to fabricate the bulk bodies of the hard alloys. The novel cemented carbides have good mechanical properties compared with WC-Co. The density and operation cost of the novel material were much lower than the WC-Co system. It was easy to process submicroscale sintering with the novel materials and obtain the rounded particles in the bulk materials. There is almost no eta-phase in the (W0.4Al0.6)C-0.5-CO cemented carbides system although the carbon deficient obtains the astonishing value of 50%.