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How xerogel carbonization conditions affect the reactivity of highly disperse SiO2–C composites in the sol–gel synthesis of nanocrystalline silicon carbideстатья
Информация о цитировании статьи получена из
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Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 февраля 2017 г.
- Авторы: Simonenko E.P.a, Simonenko N.P.a, Kopitsa G.P.b.c, Pipich V.d., Sevastyanov V.G.a, Kuznetsov N.T.a
- Журнал: Russian Journal of Inorganic Chemistry
- Том: 61
- Номер: 11
- Год издания: 2016
- Издательство: Maik Nauka/Interperiodica Publishing
- Местоположение издательства: Russian Federation
- Первая страница: 1347
- Последняя страница: 1360
- DOI: 10.1134/S0036023616110206
- Аннотация: A transparent silicon polymer gel was prepared by sol–gel technology to serve as the base in the preparation of highly disperse SiO2–C composites at various temperatures (400, 600, 800, and 1000°C) and various exposure times (1, 3, and 6 h) via pyrolysis under a dynamic vacuum (at residual pressures of 1 × 10–1 to 1 × 10–2 mmHg). These composites were X-ray amorphous; their thermal behavior in flowing air in the range 20–1200°C was studied. The encapsulation of nascent carbon, which kept it from oxidizing in air and reduced the reactivity of the system in SiC synthesis, was enhanced as the carbonization temperature and exposure time increased. How xerogel carbonization conditions affect the micro- and mesostructure of the xerogel was studied by ultra-small-angle neutron scattering (USANS). Both the carbonization temperature and the exposure time were found to considerably influence structure formation in highly disperse SiO2–C composites. Dynamic DSC/DTA/TG experiments in an inert gas flow showed that the increasing xerogel pyrolysis temperatures significantly reduced silicon carbide yields upon subsequent heating of SiO2–C systems to 1500°C, from 35–39 (400°C) to 10–21% (1000°C). © 2016, Pleiades Publishing, Ltd.
- Добавил в систему: Кузнецов Николай Тимофеевич