Accession Number : AD0647303

Title :   THE DEHYDRATION OF POROUS GLASS.

Descriptive Note : Technical rept.,

Corporate Author : RUTGERS - THE STATE UNIV NEW BRUNSWICK N J SCHOOL OF CHEMISTRY

Personal Author(s) : Low,M. J. D. ; Ramasubramanian,N.

Report Date : 01 MAR 1967

Pagination or Media Count : 24

Abstract : A microbalance was used to follow the kinetics of dehydration of porous glass in vacuo at constant temperatures from 25C to 800C. The kinetics of water sorption and desorption by the degassed surfaces was measured. Infrared spectra of degassed specimens were obtained. Physically adsorbed water as well as some tightly-bound water could be removed at 25C. Degassing above 600C produces surfaces containing isolated hydroxyls. The amount of water retained after a sorption-desorption cycle is a maximum with samples degassed near 300C. It is proposed that geminal hydroxyls responsible for this maximum are destroyed. The percentage of the sorbed water which is retained increases with samples degassed above 600C. This effect is produced by boron migrating to the surface of the glass. (Author)

Descriptors :   (*GLASS, DEHYDRATION), REACTION KINETICS, POROUS MATERIALS, SURFACE PROPERTIES, SILICATES, BORON COMPOUNDS, INFRARED SPECTRA, WATER, SORPTION, VACUUM

Subject Categories : Ceramics, Refractories and Glass
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE