Title of Paper:A comparative study of drying techniques on the morphology of porous silica gels synthesized via sol-gel process

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Date of Publication:2011-08-01

Journal:Journal of Harbin Institute of Technology (New Series)

Included Journals:EI、Scopus

Volume:18

Issue:4

Page Number:71-76

ISSN No.:10059113

Abstract:The effect of drying techniques on the microstructure, morphology and pore structure of porous silica gels was studied in the paper. The gels were prepared by using sol-gel process and different drying routes: freeze-drying (FD), low pressure drying (LPD), high temperature drying (HTD) and chemical modification & ambient drying (CMD) techniques. Observation under pore distribution and structural properties showed that CMD technique leads to homogenous mesoporous silica material with specific surface area of 745 m2/g, and the average pore size around 20 nm, while LPD and HTD result in loosely packed particles with non-isotropic aggregation pattern. The specific surface areas of LPD and HTD samples are 419 and 513 m2/g respectively, and the pore size distribution of the samples are observed distributing widely in range of 10-100 nm. Freeze drying method is a new but prospective way to prepare mesoporous silica. The specific area of FD sample is around 500 m2/g. By the comparison for the properties of the gels, this paper wants to induce a further interest in finding a proper method to synthesize the porous silica gels for low price use.