Gel Systems Basedon Tetraethoxysilane with Organic Additives: I. Sols
T. G. Movchan*, N. B. Ur’ev*, T. V. Khamova**, E. V. Tarasyuk**, A. N. Potapov*,
O. A. Shilova**, N. S. Klimenko***, and V. V. Shevchenko***
* Institute of Physical Chemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119991 Russia
** Grebenshchikov Institute of Silicate Chemistry, Russian Academy of Sciences,
ul. Odoevskogo 24/2, St. Petersburg, 199155 Russia
*** Institute of Macromolecular Chemistry, National Academy of Sciences of Ukraine,
Kharkovskoe sh. 48, Kiev, 02160 Ukraine
Received June 28, 2004
Abstract—This paper reports on the results of rheological investigations into the kinetics of gelation of the sol–
gel systems based on a water–alcohol solution of tetraethoxysilane (TEOS) modified by a number of metal salts
and organic polyhydroxyl compounds, such as glycerol, poly(ethylene glycol) (PEG-300), and hyperbranched
aliphatic complex polyol polyethers (HBP-49, HBP-64). It is demonstrated that, at a dispersed phase concen-
tration of approximately 10 wt %, water–ethanol sol–gel systems containing 2–4 g/l of high-molecular additives
possess a shear strength and are characterized by anomalous properties in their flow. The gelation time of sols
in the presence of organic additives is affected by the ratio between the numbers of OH– hydrophilic and CH3
hydrophobic groups in the polymer molecule, the concentration of the introduced additive, and the electrolyte
multivalence. The presence of metal salts enhances the structuring effect of polymers.
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