Novos agentes sililantes derivados de precursor epoxido na imobilização e sintese de silica mesoporosa

AUTOR(ES)

Jose Almir de Almeida Sales

DATA DE PUBLICAÇÃO

2003

RESUMO

The silylant precursor agent 3-glycidoxypropyltrimethoxisilane was covalently anchored onto the silica gel surface through homogeneous and heterogeneous routes. Ethylenediamine, 1,3-diaminepropane and 2-aminemethylpyridine molecules were incorporated on the epoxide group in order to explore the properties of these basic nitrogen atoms in coordinating some divalent cations from aqueous solution, which process was followed through calorimetric titration. From sol-gel procedure by co-condensing tetraethoxysilane with the commercial N-[3-(trimethoxysilyl)propyl]ethylenediamine and other new silylant agents synthesized in this thesis, the mesoporous silica was prepared. All these compounds were characterized through elemental analysis, infrared spectroscopy, X-ray diffraction, pore volume determination, C and Si NMR in solid state, surface area and thermogravimetry. The interactive processes monitored through calorimetric titration in aqueous solution presented exothermic enthalpic values, positive entropic data and was also favorable from the point of view of the positive free Gibbs energy values.

ASSUNTO(S)

silica

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