Porous glass powder, physical

The porous samples used in this study were plugs made up from fine glass powder of a few microns in diameter so as to give a non adsorptive, simply-structured medium. They were formed by compressing the powder with a small amount of moisture in a brass cylinder and leaving for several days at room temperature, after which they were dried under mild conditions. Final drying and desorption is carried out in a vacuum dessicator. The appropriate physical properties of a porous sample are given in Table 1. 

Liquid infiltration into dry porous materials occurs due to capillary action. The mechanism of infiltrating liquids into porous bodies has been studied by many researches in the fields of soil physics, chemistry, powder technology and powder metallurgy [Carman, 1956 Semlak Rhines, 1958]. However, the processes and kinetics of liquid infiltration into a powdered preform are rather complex and have not been completely understood. Based on Darcy s fundamental principle and the Kozeny-Carman equation, Semlak Rhines (1958) and Yokota et al. (1980) have developed infiltration rate equations for porous glass and metal bodies. These rate equations can be used to describe the kinetics of liquid infiltration in porous ceramics preforms, but... 

Silica gels, porous glasses, and silica powders were prepared by A. Kiselev, Nikitin, and co-workers (Moscow State University, Moscow) (2, 3, 26, 27, 74-81) Dzisko, Fenelonov, and co-workers (Institute of Catalysis, Siberian Division of the U.S.S.R. Academy of Sciences, Novosibirsk) (82, 83) Zhdanov and co-workers (Institute of Silicate Chemistry, the U.S.S.R. Academy of Sciences, Leningrad) (84-87) Belotserkovsky, Kolosentsev, and co-workers (Technological Institute, Leningrad) (59-61) Neimark, Sheinfain, and co-workers (Institute of Physical Chemistry, the Ukrainian S.S.R. Academy of Sciences, Kiev) (28, 29) Chuiko (Institute of Surface Chemistry, the Ukrainian S.S.R. Academy of Sciences, Kiev) (88) and others. 

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