Organic-inorganic Hybrid Gels of Diol-TEOS Type. Synthesis and Study on the Chemical Interaction.
Hybrid inorganic-organic materials, silica - diol, were prepared by the sol-gel process from mixtures of tetraethyl orthosilicate (TEOS) and two diols (1,2-propanediol and 1,4-butanediol), using different molar ratios TEOS: diol, in acidic catalysis. The resulted materials were studied by thermal analysis, FT-IR spectroscopy, 29Si-NMR and nitrogen adsorption measurements. The thermal analysis of the gels, in air and nitrogen, has clearly evidenced the chemical bonding of the studied diols with the Si-OH groups resulting from the hydrolysis of TEOS, forming hybrid gels. The mass loss registered on TG in the range 250-300 °C, corresponding to the burning of the organic chains from the hybrid network allowed us to calculate the fraction of the bonded diol. This fraction depends on the initial molar ratio TEOS:diol and on the diol's nature. By annealing the hybrid gels at 600 °C we have obtained silica matrices with different textural parameters.
Oana
O
Stefanescu
Marcela
M
Stoia
Mirela
M
Barbu
Mircea
M
Stefanescu