Dielectric relaxation in porous glasses

Dielectric spectroscopy was applied to different types of porous silica glass materials, wherein the effect of water adsorption at the pored surface of the glasses on the dielectric response was examined over wide temperature (-100 to +300 degreesC) and frequency (20 Hz-1 MHz) ranges. The dielectric relaxation in the porous materials was analyzed in terms of non-Debye slow decay dynamics. The physical nature of different states of water in the porous glass materials is discussed. Analysis of the dielectric parameters enables us to characterize the fractal dimension and porosity of the porous glasses. In addition to dielectric spectroscopy, FT-IR spectroscopy and thermogravimetric analysis have also been applied. (C) 2002 Elsevier Science Inc. All rights reserved.