Caracterização de superfície, adesiva e mecânica de uma zircônia parcialmente estabilizada por ítria em função da partícula ou do momento do jateamento

Pós-graduação em Reabilitação Oral - FOAR

Structure and catalytic properties of sulfated zirconia foams

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

An investigation into the influence of zinc precursor on the microstructural, photoluminescence, and gas-sensing properties of ZnO nanoparticles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Synergistic electrocatalytic effect of nanostructured mixed films formed by functionalised gold nanoparticles and bisphthalocyanines

A synergistic electrocatalytic effect was observed in sensors where two electrocatalytic materials (functionalized gold nanoparticles and lutetium bisphthalocyanine) were co-deposited using the Langmuir-Blodgett technique. Films were prepared using a novel method where water soluble functionalised gold nanoparticles [(11-mercaptoundecyl)tetra(ethylene glycol)] (SAuNPs) were inserted in floating films of lutetium bisphthalocyanine (LuPc2) and dimethyldioctadecylammonium bromide (DODAB) as the amphiphilic matrix. The formation of stable and homogeneous mixed films was confirmed by pi-A isotherms, BAM, UV-vis and Raman spectroscopy, as well as by SEM and TEM microscopy. The synergistic effect towards hydroquinone of the electrodes modified with LuPc2:DODAB/SAuNP was characterised by an increase in the intensity of the redox peaks and a reduction of the overpotential. This synergistic electrocatalytic effect arose from the interaction between the SAuNPs and the phthalocyanines that occur in the Langmuir-Blodgett films and from the high surface area provided by the nanostructured films. The sensitivity increased with the amount of LuPc2 and SAuNPs inserted in the films and limits of detection in the range of 10(-7) mol L-1 were attained. (C) 2014 Elsevier B.V. All rights reserved.

Structure and properties of chemically synthesized BiFeO3. Influence of fuel and complexing agent

Perovskite, single multiferroic bismuth ferrite was prepared by two chemical methods: auto-combustion and soft chemical route. Influence of different fuels and complexing agents and thermal treatment on purity of bismuth ferrite powders and density of bismuth ferrite ceramics were investigated. X-ray diffraction technique (XRD) indicated that optimal temperatures and times for calcination and sintering are 600 degrees C for 2 h and 800 degrees C for 1 h with quenching, respectively. Scanning electron microscopy (SEM) analysis showed that soft route synthesized samples formed softer agglomerates and smaller grains with less secondary phases. Powders and pellets were characterized by Brunauer Emmett Teller (BET) specific surface area analysis, particle size distribution, Fourier transform infrared spectroscopy (FT-IR), dilatometry, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), dielectric and magnetic measurements. Resistivity and origin of electrical resistance were studied by means of impedance measurements. (C) 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Morphology and histochemistry of the digestive tract in carnivorous freshwater Hemisorubim platyrhynchos (Siluriformes: Pimelodidae)

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

The physicochemical characterization and in vivo response of micro/nanoporous bioactive ceramic particulate bone graft materials

In this study, the physicochemical characteristics of calcium phosphate based bioactive ceramics of different compositions and blends presenting similar micro/nanoporosity and micrometer scale surface texture were characterized and evaluated in an in vivo model. Prior to the animal experiment, the porosity, surface area, particle size distribution, phase quantification, and dissolution of the materials tested were evaluated. The bone regenerative properties of the materials were evaluated using a rabbit calvaria model. After 2, 4, and 8 weeks, the animals were sacrificed and all samples were subjected to histologic observation and histomorphometric analysis. The material characterization showed that all materials tested presented variation in particle size, porosity and composition with different degrees of HA/TCP/lower stoichiometry phase ratios. Histologically, the calvarial defects presented temporal bone filling suggesting that all material groups were biocompatible and osteoconductive. Among the different materials tested, there were significant differences found in the amount of bone formation as a function of time. At 8 weeks, the micro/nanoporous material presenting similar to 55,TCP:45%,HA composition ratio presented higher amounts of new bone regeneration relative to other blends and a decrease in the amount of soft tissue infiltration. (C) 2014 Elsevier B.V. All rights reserved.

Facile synthesis and characterization of ZrO2 nanoparticles prepared by the AOP/hydrothermal route

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