Journal
MICROPOROUS AND MESOPOROUS MATERIALS
Volume 130, Issue 1-3, Pages 295-302Publisher
ELSEVIER
DOI: 10.1016/j.micromeso.2009.11.024
Keywords
Aerogel; Monolith; Silylation; Springback; Ambient-drying
Categories
Funding
- Ministry of Commerce, Industry and Energy, Korea Energy Management Corporation
Ask authors/readers for more resources
For the successful preparation of crack-free silica aerogel monoliths (disk and tile) at ambient pressure, the effect of surface modification conditions on the hydrophobicity of aerogels was investigated. Aqueous colloidal silica hydrosol obtained from the ion-exchange of an industrial waterglass was used as an inexpensive stating material. After gelation and aging, the pore liquid (H2O) of silica hydrogel was sequentially exchanged with n-Hexane by multiple solvent exchanges using acetone as an intermediate exchanging solvent. Surface modification (i.e. silylation) of the gel surface was controlled using trimethylchlorosilane with isopropyl alcohol. Surface-modified gel monoliths were carefully dried at atmospheric pressure and were then transformed to aerogels by the 'springback' effect during the drying process. Finally, most of the wet monolith samples were successfully transformed to aerogel monoliths without visible cracks. The resulting aerogel monoliths have a well-developed mesoporous structure (mean pore size of similar to 15 nm) with low density (similar to 0.13 g/cm(3)) and a high specific surface area (similar to 730 m(2)/g). (C) 2009 Elsevier Inc. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available