The Dissolution Kinetics of SiO2 Aerogels in Aqueous NaOH Solutions | Sciact - CRIS-system of Boreskov Institute of Catalysis

The Dissolution Kinetics of SiO2 Aerogels in Aqueous NaOH Solutions Full article

Journal

Colloid Journal of the Russian Academy of Sciences: Kolloidnyi Zhurnal
ISSN: 1061-933X , E-ISSN: 1608-3067

Output data

Year: 1999, Volume: 61, Number: 3, Pages: 353-358 Pages count : 6

Tags

Alkalinity; Dissolution; Light scattering; Reaction kinetics; Silica; Solutions; X ray scattering; Density (specific gravity); Dispersions; Hydrolysis; Optical properties; Sodium compounds; Surface properties; Synthesis (chemical)

Authors

Okunev A.G. ¹ , Shaurman S.A. ¹ , Danilyuk A.F. ¹ , Shmakov A.N. ¹ , Aristov Y.I. ¹

Affiliations

1	Institute of Catalysis, Siberian Division, Russian Academy of Sciences, Novosibirsk, 630090, pr. Lavrent'eva 5, Russian Federation

The dissolution kinetics of SiO2 aerogels was investigated by three complementary experimental techniques-the kinetic method, static light scattering, and small-angle X-ray scattering. Four aerogel samples synthesized by the catalytic hydrolysis of alkoxides with the use of one- and two-stage procedures were investigated. The aerogels differed in their specific surface areas, densities, and optical properties. Regularities of the dissolution of the aerogels in 0.05-0.4 M NaOH aqueous solutions were studied in the kinetic- and diffusion-controlled regimes over the temperature range 15-56 °С. In spite of the different conditions of aerogel synthesis, the activation energies of their dissolution measured in the kinetic regime were identical and equal to 82 +/- 6 kJ/mol. Once the critical degree of dissolution for the aerogels was reached, the threshold disintegration of their secondary structure occurred, and silica clusters (SiO2),(ct) consisting of primary particles appeared in the solution. In situ registration of scattering showed that the disintegration of the aerogels resulted in 10-300 nm fragments. A correlation between the shape of peaks in light-scattering curves of the aerogel dispersions and their optical properties was found.

Okunev A.G. , Shaurman S.A. , Danilyuk A.F. , Shmakov A.N. , Aristov Y.I.
The Dissolution Kinetics of SiO2 Aerogels in Aqueous NaOH Solutions
Colloid Journal of the Russian Academy of Sciences: Kolloidnyi Zhurnal. 1999. V.61. N3. P.353-358. WOS Scopus РИНЦ ANCAN

Окунев А.Г. , Шаурман С.А. , Данилюк А.Ф. , Шмаков А.Н. , Аристов Ю.И.
Кинетика растворения аэрогелей SiO2 в водных растворах NaOH
Коллоидный журнал. 1999. Т.61. №3. С.383-388. РИНЦ

Published print:

May 1, 1999

Web of science:	WOS:000081114600016
Scopus:	2-s2.0-0032661494
Elibrary:	13308061
Chemical Abstracts:	1999:440342
Chemical Abstracts (print):	131:161963

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