Effect of Different Reaction Solvents on the Hydrophobic and Structural Properties of Silica Cryogels

Abstract:

The experimental results on the microstructural and physical properties of the TEOS-based silica cryogels have been reported. The cryogels were produced by two-step sol-gel process followed by vacuum freeze drying. The wet gels were synthesized via acid-base catalysis using tetraethoxysilane (TEOS) as a silica precursor, the different solvents containing ethanol (EtOH), methanol (MeOH) and tert-butanol (TBA), the molar ratio of TEOS / solvent were varied from 1:6 to 1:13. Further, the microstructure and specific surface area of the cryogels were analysed by Scanning Electron Microscopy (SEM) and nitrogen absorption/desorption isotherms. The hydrophobicity of the cryogels was studied by contact angle. It was found that the highest specific surface area (1040.17 m2 / g) was obtained with the solvent of MeOH. The lowest density (0.074 g/cm3) was acquired with the solvent of EtOH.

• Periodical: Materials Science Forum (Volumes 663-665)
• Pages: 1238-1241
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.663-665.1238
• Online since: November 2010
• Authors: Li Fen Su, Lei Miao, Sakae Tanemura, Gang Xu
• Keywords: Silica Cryogel, Solvent, Vacuum Freeze-Drying

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