Materiais híbridos orgânico-inorgânicos: preparação e algumas aplicações=Hybrid organic-inorganic materials: preparation and some applications

The preparation and application of organic-inorganic hybrid materials are under fast development and constitute an interesting research topic on account of the versatility and wide range of applications offered by these materials. These properties can be achieved due to the mixture of the components at the molecular level. The present review covers the state of the art, the most useful preparation routes and the potential applications of these materials

Surface modification of alumina nanoparticles with silane coupling agents

In the present paper we describe the surface modification of alumina nanoparticles using epoxy-containing alkoxysilanes (silane coupling agents, SCA). The materials were characterized using infrared spectroscopy and solid-state nuclear magnetic resonance. Whereas, neat alumina nanoparticles could be expectedly modified with the afore mentioned SCA, as evidenced by 13C CPMAS NMR, the presence of arylsulphonates at the surface of alumina caused the ringopening polymerization of the epoxide. This polymerization reaction facilitated the surface modification of alumina by the SCA. X-ray powder diffraction and 27Al MAS NMR clearly demonstrated that in spite of the SCA polymerization, there were neither structural changes nor phase transitions in the alumina after the surface modification. The surface modification decreased the thermal stability of alumina, in comparison to pristine alumina nanoparticles. © 2010 Sociedade Brasileira de Química

Synthesis and characterization of aliphatic polyesters from glycerol, by-product of biodiesel production, and adipic acid

In the present work, polyesters were prepared from the polycondensation between glycerol and adipic acid using dibutyltin dilaurate as catalyst. Three glycerol: adipic acid molar ratio were used for the bulk polymerization namely: 2:2; 2:3 and 2:4. FTIR confirmed the esterification of glycerol by the acid for all the polymers, DSC and XRD indicated no crystallinity for all the polymers. The morphology of the material are characterized by globular structure, which may suggest compositional fluctuations throughout the samples.Fundação de Amparo à Pesquisa do Estado da Bahia (FAPESB