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http://dx.doi.org/10.4191/KCERS.2007.44.3.162

Fabrication and Network Strengthening of Monolithic Silica Aerogels Using Water Glass  

Han, In-Sub (Energy Materials Research Center, Korea Institute of Energy Research)
Park, Jong-Chul (Energy Materials Research Center, Korea Institute of Energy Research)
Kim, Se-Young (Energy Materials Research Center, Korea Institute of Energy Research)
Hong, Ki-Seog (Energy Materials Research Center, Korea Institute of Energy Research)
Hwang, Hae-Jin (Department of Materials Science and Engineering, Inha University)
Publication Information
Journal of the Korean Ceramic Society / v.44, no.3, 2007 , pp. 162-168 More about this Journal
Abstract
Silica wet gels were prepared ken water glass ($29\;wt%\;SiO_{2}$) by using Amberlite as a ion exchange resin. After washing in distilled water, the wet gels were further aged in a solution of TEOS/EtOH to strengthen of 3-dimensional network structure. As increase TEOS content in aging solution, BET surface area and porosity of the ambient dried silica aerogels were significantly decreased, and average pore diameter was also decreased 30 nm to -10 nm. Also, higher density and compressive strength were obtained in case of higher TEOS content. This is due to precipitation of $SiO_{2}$ nano particles by TEOS. Hence, TEOS addition plays an important role of both strengthening and stiffness of silica wet gel network. By adding over 30 vol% TEOS, a crack-free monolithic silica aerogel tiles were obtained and its density, compressive strength, and thermal conductivity were shown $0.232g/cm^{3}$, 7.3 MPa, and 0.029 W/mk, respectivly.
Keywords
Aerogel; Water glass; Wet gel; Network strengthening; Surface meodification;
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