Ethylene glycol-citric acid-silica hybrid organic-inorganic materials obtained by the sol-gel method
The combination of inorganic polymeric networks with organic molecules leads to hybrid materials. Tetraethoxysilane (TEOS) was used as the precursor for the inorganic component, covalently bonded to ethylene glycol (EG) and citric acid (CA) molecules, whose esterification provides the in situ water for hydrolysis of TEOS. Ethanol was added in various amounts to the TEOS-EG-CA mixtures in order to induce different molecular separations among the reacting molecules, thus modifying the molecular weight distributions of the resulting materials.
Characterization of these hybrid materials was performed by several techniques, with consistent results among them.
The materials obtained are thermoplastic systems which can be used as coatings, or as bulk materials. In particular, their rheological and thermal properties suggest their possible use as components of drilling fluids in the tertiary recovery of petroleum.
KeywordsORMOSILS rheology ethylene glycol citric acid
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