Vol. 30, Issue 4, pp. 605-611 (2000)

Abstract

An original interferometric technique for investigating the influence of humidity on change in the linear dimensions of porous silica glasses is developed. The linear dimensions of a specimen are shown to change as a result of competition in the system of compressive capillary forces and expansion forces arising from the swelling of the residual silica gel present in pores. The possibility of selective inhibition of the capillary squeezing forces or the silica gel expansion forces by the pre-treatment of a porous material by a hydrophobized composition (hexamethyldisilazan - HMDS) or by annealing of carbon impregnated inside of the pores is shown experimentally.