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Indexed by:期刊论文

Date of Publication:2014-07-01

Journal:RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A

Included Journals:SCIE、EI

Volume:88

Issue:7

Page Number:1196-1201

ISSN No.:0036-0244

Key Words:diatomite; silica aerogels; characterization; hydrophobic; ambient pressure drying

Abstract:The silica aerogels were successfully fabricated under ambient pressure from diatomite. The influence of different dilution ratios of diatomite filtrate on physical properties of aerogels were studied. The microstructure, surface functional groups, thermal stability, morphology and mechanical properties of silica aerogels based on diatomite were investigated by BET adsorption, FT-IR, DTA-TG, FESEM, TEM, and nanoindentation methods. The results indicate that the filtrate diluted with distilled water in a proportion of 1: 2 could give silica aerogels in the largest size with highest transparency. The obtained aerogels with density of 0.122-0.203 g/m(3) and specific surface area of 655.5-790.7 m(2)/g are crack free amorphous solids and exhibited a sponge-like structure. Moreover, the peak pore size resided at 9 nm. The initial aerogels were hydrophobic, when being heat-treated around 400A degrees C, the aerogels were transformed into hydrophilic ones. The obtained aerogel has good mechanical properties.