Catalisadores nanoestruturados contendo ligas de 'PT' e 'TI''O IND.2' para a oxidação eletroquímica de etanol

Pós-graduação em Química - IQ

Nanopartículas magnéticas de 'FE''CO'@'AU': preparação, caracterização e funcionalização com complexo de 'RU'(II) luminescente

Pós-graduação em Química - IQ

Síntese, caracterização estrutural, espectroscópica e análise do potencial fotocatalítico do aluminato de cobalto e potencial catalítico na preparação do biodiesel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Síntese e caracterização do compósito SnO2/TiO2 nanoestruturado

Pós-graduação em Ciência e Tecnologia de Materiais - FC

Oxidação de carboidratos via catálise metálica não enzimática para aplicação em sensores

This work has main aim of is to propose the synthesis and characterization of nanostructured materials for oxidation of carbohydrates such as glucose, with non-enzymatic catalysis. The proposed pathway of synthesis of metal catalysts is the polyol method and techniques of physical characterization proposals for analysis of prepared catalyst pass through diffraction technique of ray-x (DRX), scanning electron microscopy (SEM) and Energy Dispersive Spectroscopy ray-x (EDX). Technical proposals for the electrochemical characterization of the synthesized catalysts are Cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The prospects of this work are compared by the catalytic activity of the sensor designed with non-enzymatic sensors and biosensors also known in the literature

Síntese, Caracterização Estrutural e Análise do Potencial Catalítico, para a Preparação de Biodiesel, de Niobatos Não Estequiométricos com Estrutura Tungstênio Bronze

Pós-graduação em Química - IBILCE

Preparação pelo método poliol modificado, caracterização estrutural e espectroscópia de nanopós de niobato de potássio e neodímio e de suas condições sólidas dopadas em európio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Morphological characterization by SEM, TEM and AFM of nanoparticles and functional nanocomposites based on natural rubber filled with oxide nanopowders

Nanocomposites were prepared from mixture of different concentrations of ferroelectric nanoparticles in an elastomeric matrix based on the vulcanized natural rubber. The morphological characterization of nanocomposites was carried out using Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Atomic force microscopy (AFM). The nanocrystalline ferroelectric oxide is potassium strontium niobate (KSN) with stoichiometry KSr2Nb5O15, and was synthesized by the chemical route using a modified polyol method, obtaining particle size and microstrain equal to 20 nm and 0.32, respectively. These ferroelectric nanoparticles were added into the natural rubber in concentrations equal to 1, 3, 5, 10, 20 and 50 phr (parts per hundred of rubber) forming ferroelectric nanocomposites (NR/KSN). Using morphological characterization, we identified the maximum value of surface roughness at low concentrations, in particular, sample with 3 phr of nanoparticles and factors such as encapsulation and uniformity in the distribution of nanoparticles into the natural rubber matrix are investigated and discussed.

Nanostructured TiO2-based composites for light absorption

Metal oxidenanocomposites were prepared by two different routes: polyol and sol-gel. Characterization by X ray diffraction showed that the first processproducesdirectly a two-phase material, while the sol-gelpowder never showed second phase below 600 degrees C. Light spectroscopy of the treated powders indicated similarities for the processed materials. Although the overall material compositions are about the same, different structural characteristics are found for each processing. With the exception of Ti-Zn materials, all the double metal oxide powders showed higher absorbance than either TiO2 powder.

Synthesis and characterization of nanostructured TiO2-SnO2 composite

Nanostructured composites based on titanium dioxide have been studied in order to improve optical and photo-catalytic properties, as well as their performance in gas sensors. In this work, titanium and tin dioxides were simultaneously synthesized by the polyol method resulting in TiO2 platelet coated with SnO2 nanoparticles as was observed by scanning electron microscopy. The thermal analysis showed that the combined synthesis promotes more easily the crystallization of the TiO2 rutile phase. The composite obtained after heat treatment at 500 degrees C showed to be formed of almost only rutile phases of both oxides. The optical properties analyzed by UV-Vis spectroscopy showed that the combined oxides have higher absorbance, which reinforces a model found in the literature based on the flow of photo-generated electrons to the conduction band of SnO2 delaying the recombination of charges.

Synthesis and characterization of nanostructured TiO2-SnO2 composite

Nanostructured composites based on titanium dioxide have been studied in order to improve optical and photo-catalytic properties, as well as their performance in gas sensors. In this work, titanium and tin dioxides were simultaneously synthesized by the polyol method resulting in TiO2 platelet coated with SnO2 nanoparticles as was observed by scanning electron microscopy. The thermal analysis showed that the combined synthesis promotes more easily the crystallization of the TiO2 rutile phase. The composite obtained after heat treatment at 500 °C showed to be formed of almost only rutile phases of both oxides. The optical properties analyzed by UV-Vis spectroscopy showed that the combined oxides have higher absorbance, which reinforces a model found in the literature based on the flow of photo-generated electrons to the conduction band of SnO2 delaying the recombination of charges.

Filmes de Langmuir-Blodgett de nanopartículas de prata

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of polyol excess on the electrical property of vegetable-polyurethane film

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Polyol-mediated synthesis of ultrafine tin oxide nanoparticles for reversible Li-ion storage

A simple, cheap and versatile, polyol-mediated fabrication method has been extended to the synthesis of tin oxide nanoparticles on a large scale. Ultrafine SnO2 nanoparticles with crystallite sizes of less than 5 nm were realized by refluxing SnCl2 . 2H(2)O in ethylene glycol at 195 degrees C for 4 h under vigorous stirring in air. The as-prepared SnO2 nanoparticles exhibited enhanced Li-ion storage capability and cyclability, demonstrating a specific capacity of 400 mAh g(-1) beyond 100 cycles. (c) 2006 Elsevier B.V. All rights reserved.