Effect of the balance between Co(II) and Co(0) oxidation states on the catalytic activity of cobalt catalysts for Ethanol Steam Reforming

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Europium-doped calcium titanate: Optical and structural evaluations

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Tuning the activity of alternative Ru-based initiators for ring-opening metathesis polymerization of norbornene and norbornadiene by the substituent in 4-CH2R-piperidine

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

Síntese e caracterização de copolímeros de polietilenoglicol monometil éter em quitosana cationizada para futuras aplicações em biotecnologia

Pós-graduação em Química - IQ

Síntese, caracterização e avaliação da citotoxicidade de complexos de Pd(II) contendo ligantes fosfínicos de N,S - quelantes

Pós-graduação em Química - IQ

Cinética de hidrólise de GPTS sob estimulação ultrassônica

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeito de nanopartículas de trimetafosfato de sódio associadas a dentifrício com concentração reduzida de fluoreto sobre a desmineralização do esmalte bovino: estudos in vitro e in situ

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Cerâmicas porosas a base de zircônia na forma de filmes suportados preparados a partir de emulsões

Pós-graduação em Química - IQ

Desenvolvimento de revestimentos siloxano-PMMA reforçados por nanotubos de carbono, óxido de grafite e óxido de grafite reduzido para aplicações anticorrosivas

Pós-graduação em Química - IQ

C-2, N-dimethylbenzylamine cyclopalladated compounds: evaluation of cytotoxic, mutagenic and antitubercular activities

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

Caracterização química dos géis produzidos pelas bactérias diazotróficas Rhizobium tropici e Mesorhizobium sp.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

alpha-SiAlON-SiC composites obtained by gas-pressure sintering and hot-pressing

The objective of this work was the obtaining in situ of alpha-SiAlON-SiC composite, using an alternative rare-earth oxide mixture, RE2O3, as sintering additive, by two different sintering processes. As sintering additive, 20 vol.% of AlN-RE2O3 in a molar ratio of 90: 10 was mixed to the alpha-Si3N4 powder. In the Si3N4-AlN-RE2O3 powder mixture, 0, 10, 15 and 20wt.% of SiC were added. The powder batches were milled, dried and compacted by cold isostatic pressing. Two different sintering processes were used: gas-pressure sintering at 1950 degrees C for 1 h under 1.5 MPa of N-2 atmosphere, or uniaxial hot-pressing at 1750 degrees C, for 30 min under pressure of 20 MPa. The sintered samples were characterized by X-ray diffraction, scanning electron microscopy and mechanical properties. XRD patterns indicate only alpha-SiAlON (alpha') and beta-SiC as crystalline phases. It was observed that the SiC addition did not influence the alpha-SiAlON formation, although the growth of elongated alpha'-grains is substantially decreased. The hot-pressed composites presented better mechanical properties, exhibiting fracture toughness of 5 MPa m(1/2) and hardness around 21.5 GPa. (c) 2007 Elsevier B.V. All rights reserved.

Online analysis of H2S and SO2 via advanced mid-Infrared gas sensors

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

Compostos de paládio(II) contendo ligantes sulfurados: síntese, caracterização e investigação da atividade biológica

This work deals with the synthesis, spectroscopic characterization of mono and polynuclear Pd(II) compounds obtained from the reaction between [PdCl2(MeCN)2] precursor and imidazolidine-2-thione (L1) and benzimidazoline-2-thione (L2). The interaction between [PdCl2(MeCN)2] and imidazolidine-2-thione, in the 1:2 molar ratio, using MeOH as solvent, yielded compound [Pd2Cl4(L1)4]Cl2 (1) whereas the complex [Pd2Br4(L1)4]Br2 (2) was obtained from the reaction between 1 and Br- ions. Binuclear compounds of general formulae [Pd2(L2)4]X23/2 MeOH {X= Cl-(3), Br-(4)} were synthesized using benzimidazoline-2-thione as ligand, employing the same procedure used in the synthesis of 1 and 2, respectively. The new complexes 1-4 are crystalline, air stable and soluble in methanol and dmso. The compounds were characterized by elemental analysis, IR spectroscopy, ESI/MS mass spectrometry and thermogravimetry. Coordination of the ligands L1 and L2 via sulphur atom was evidenced by the shift of the CS band (~499 cm-1, 1 and 2; ~620 cm-1, 3 and 4) to lower frequencies in comparison with those found in the free ligands (510 cm-1, L1; 660 cm-1, L2), indicating the weakening of the CS bom after coordination. ESI/EM mass spectra (positive mode) of the complexes 1-4 allowed atribute the molecular formulae [Pd2X4(L1)4]X2 {X= Cl-(1), Br-(2)} and [Pd2(L2)4]X2 {X= Cl-(3), Br-(4)} by the appearance of the peaks at m/z 794,61 [(1) + MeOH]+, m/z 836,77 [(2) - 2H - L1]+, m/z 810 [(3) - 2Cl]+, m/z 810 [(4) - 2Br]+. The TG-DTA curves showed that the complexes 1 and 2 are thermally stable up to 212 and 169º C, respectively, and further decompose to metallic palladium at 527º C (1, obt. 28,46 %; calcd. 27,88%) and 895º C (2, obt. 22,85 %; calcd. 22,62%). Compounds 3 and 4 exhibited an initial mass loss of ~5% between 25 -146º C related to the release of metanol molecules. The complexes 3...Fujimura Leite.

Propriedades elétricas de materiais híbridos de Sílica/orgânico à base de GPTS/TEOS preparados pelo método sol-gel

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)