Sintese e propriedades de alumoxanos : modificações de superficie e aplicações / Synthesis and properties of alumoxanes : surface modifications and applications

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Alumoxanes are materials which their cores are identical to alumina´s core, consisting of an Al-O-Al backbone with a variety of pendant groups, such as alkyl, aryl, halides or any functional groups bonded with aluminum atoms. The first synthesis of these compounds had been made by reacting organoaluminum and water or other compounds cointaining oxygen. In this mastering work, alumoxanes were synthesized by reactions between solid surfaces from aluminum oxides or aluminum oxihydroxide and solutions which solutes originated pendant groups. The alumoxanes made from this kind of synthesis and which reactants were carboxylic acids are named carboxylatoalumoxanes. This reaction causes drastic changes in chemical properties of an aluminum oxide, such as alumina, but keeps its mechanical properties. In this work, benzoatoalumoxane, oxalatoalumoxane, vinil-acetatoalumoxane, succinatoalumoxane and adipatoalumoxane were synthesized. After the successful synthesis of these materials, some applications involving alumoxanes were investigated. For example: the benzoatoalumoxane surface energy, studied by contact angle experiments and the biocompatibility of alumoxanes from dicarboxylic acids. The alumina´s surface modified by reaction with benzoic acid, resulting in benzoatealumoxane, showed an expressive rise about its hydrofobicity. This fact was supported by the contact angle around 70o between benzoatealumoxane surface and a drop of water. The alumina´s surface which were modified by reaction with dicarboxylic acids, resulting in oxalatoalumoxane, succinatoalumoxane and adipatoalumoxane, were analyzed by SBF test, about using them as biocompatible bioceramics. Among these materials, only oxalatoalumoxane had shown good results because a lot of calcium phosphate crystals had been formed on its surface. Supported by this result, this material could be tested in cell adhesion and in vivo tests. Their results agreed with SBF test, showing a considerable possibility of using oxalatoalumoxane as a biomaterial

ASSUNTO(S)

superfície biocompatibilidade alumoxanes alumina surface biocompatibility alumoxanos alumina

ACESSO AO ARTIGO

Documentos Relacionados