Comparative analysis of the physicochemical characteristics of SiO2 aerogels prepared by drying under subcritical and supercritical conditions
- Authors: Lermontov S.A.1, Malkova A.N.1, Sipyagina N.A.1, Yorov K.E.2, Kopitsa G.P.3,4, Baranchikov A.E.2,5, Ivanov V.K.5,6, Pipich V.7, Szekely N.K.7
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Affiliations:
- Institute of Physiologically Active Compounds
- Moscow State University
- Konstantinov Institute of Nuclear Physics
- Grebenshchikov Institute of Silicate Chemistry
- Kurnakov Institute of General and Inorganic Chemistry
- National Research Tomsk State University
- Jülich Centre for Neutron Science Outstation at MLZ
- Issue: Vol 53, No 12 (2017)
- Pages: 1270-1278
- Section: Article
- URL: https://journals.rcsi.science/0020-1685/article/view/158337
- DOI: https://doi.org/10.1134/S002016851712007X
- ID: 158337
Cite item
Abstract
SiO2-based aerogels have been produced be removing a solvent (ethanol or hexafluoroisopropanol) from lyogels both above and below the critical temperature of the alcohols (in the range 210–260 and 160–220°C, respectively). The resultant materials have been characterized by low-temperature nitrogen adsorption measurements, X-ray diffraction, thermal analysis, scanning electron microscopy, X-ray microanalysis, and small-angle and ultrasmall-angle neutron scattering. The results demonstrate that removing the solvent 20–30°C below the critical temperature of the solvent yields silica that is characterized by higher specific porosity and has the same or a larger specific surface area in comparison with the aerogels produced by drying under supercritical conditions. The nature of the solvent used and the solvent removal temperature influence the size and aggregation behavior of primary clusters and the cluster aggregate size in the aerogels.
About the authors
S. A. Lermontov
Institute of Physiologically Active Compounds
Author for correspondence.
Email: lermon52@yandex.ru
Russian Federation, Severnyi proezd 1, Chernogolovka, Noginskii raion, Moscow oblast, 142432
A. N. Malkova
Institute of Physiologically Active Compounds
Email: lermon52@yandex.ru
Russian Federation, Severnyi proezd 1, Chernogolovka, Noginskii raion, Moscow oblast, 142432
N. A. Sipyagina
Institute of Physiologically Active Compounds
Email: lermon52@yandex.ru
Russian Federation, Severnyi proezd 1, Chernogolovka, Noginskii raion, Moscow oblast, 142432
Kh. E. Yorov
Moscow State University
Email: lermon52@yandex.ru
Russian Federation, Moscow, 119991
G. P. Kopitsa
Konstantinov Institute of Nuclear Physics; Grebenshchikov Institute of Silicate Chemistry
Email: lermon52@yandex.ru
Russian Federation, Orlova Roshcha 1, Gatchina, Leningrad oblast, 188300; nab. Makarova 2, St. Petersburg, 199034
A. E. Baranchikov
Moscow State University; Kurnakov Institute of General and Inorganic Chemistry
Email: lermon52@yandex.ru
Russian Federation, Moscow, 119991; Leninskii pr. 31, Moscow, 119991
V. K. Ivanov
Kurnakov Institute of General and Inorganic Chemistry; National Research Tomsk State University
Email: lermon52@yandex.ru
Russian Federation, Leninskii pr. 31, Moscow, 119991; pr. Lenina 36, Tomsk, 634050
V. Pipich
Jülich Centre for Neutron Science Outstation at MLZ
Email: lermon52@yandex.ru
Germany, Lichtenbergstrasse 1, Garching, 85747
N. K. Szekely
Jülich Centre for Neutron Science Outstation at MLZ
Email: lermon52@yandex.ru
Germany, Lichtenbergstrasse 1, Garching, 85747
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