Abstract
A kinetic scheme is proposed for the processes of hydrolysis of alkoxysilanes and polycondensation of the hydrolysis products represented as monomers, dimers, trimers, oligomers, and polymers. A kinetic model that makes it possible to evaluate the weight fractions of silica associates at different instants of time after the beginning of the hydrolysis and to determine the kinetic characteristics of these processes is constructed. The evolution of silica associates at different pH values and dilutions at the early stages of the hydrolytic polycondensation of silicon alkoxides is analyzed. It is noted that the structuring of silica in the case of tetraethoxysilane differs from the structuring for tetramethoxysilane.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Rakhimov, V.I., Rakhimova, O.V., and Syomov, M.P., Kinetics of the Early Stages of the Sol-Gel Process: II. Distribution of Silica over Molecular Species, Fiz. Khim. Stekla, 2008, vol. 34, no. 2, pp. 207–214 [Glass Phys. Chem. (Engl. transl.), 2008, vol. 34, no. 2, pp. 160–165].
Rakhimov, V.I., Rakhimova, O.V., Syomov, M.P., and Shil’nikova, M.A., Kinetics of Interaction of Silicon Alkoxides with Ammonium Molybdate, Dokl. Akad. Nauk, 1998, vol. 360, no. 2, pp. 220–223 [Dokl. Phys. Chem. (Engl. transl.), 1998, vol. 360, nos. 1–3, pp. 161–164].
Rakhimov, V.I., Rakhimova, O.V., Syomov, M.P., Khimich, N.N., and Shil’nikova, M.A., Kinetics of the Early Stages of the Sol-Gel Process: I. Method of Studying Hydrolysis Kinetics of Silicon Alkoxides, Fiz. Khim. Stekla, 1999, vol. 25, no. 2, pp. 113–121 [Glass Phys. Chem. (Engl. trans.), 1999, vol. 25, no. 2, pp. 176–182].
Coudurier, M., Baudru, B., and Donnet, J.-B., Étude de la polycondensation de l’acide disilicique, Bull. Soc. Chim. Fr., 1971, no. 9, pp. 3147–3165.
Iler, R.K., The Chemistry of Silica, New York: Wiley, 1979, part 1. Translated under the title Khimiya kremnezema, Moscow: Mir, 1979, Ch. 1.
Brinker, C.J. and Scherer, G.W., Sol-Gel Science: the Physics and Chemistry of Sol-Gel Processing, San Diego, CA: Academic, 1990.
Alexander, G.B., The Polymerization of Monosilicic Acid, J. Am. Chem. Soc., 1954, vol. 76, no. 8, pp. 2094–2096.
Stade, H., Die Umsetzung von Monokieselsäure mit Molybdänsäure, Z. Anorg. Allg. Chem., 1978, vol. 441, pp. 29–38.
Stade, H., Die Umsetzung von kondensierten Kieselsäuren mit Molybdänsäure, Z. Anorg. Allg. Chem., 1978, vol. 446, pp. 5–16.
Egorova, E.N., Metody vydeleniya kremnevoi kisloty i analiticheskogo opredeleniya kremnezema (Methods for Separation of Silicic Acid and Analytical Determination of Silica), Moscow: Akad. Nauk SSSR, 1959 [in Russian].
Author information
Authors and Affiliations
Corresponding author
Additional information
Original Russian Text © V.I. Rakhimov, O.V. Rakhimova, M.P. Syomov, 2009, published in Fizika i Khimiya Stekla.
Rights and permissions
About this article
Cite this article
Rakhimov, V.I., Rakhimova, O.V. & Syomov, M.P. Kinetics of the early stages of the sol-gel process: III. Evolution of silica associates. Glass Phys Chem 35, 163–169 (2009). https://doi.org/10.1134/S1087659609020072
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1134/S1087659609020072