The kinetics of water desorption from porous glasses

Abstract

The kinetics of water desorption from porous glasses silica gel and porous aluminosilicates were followed through the TG and DTG methods. In all cases only one thermodesorption peak appeared. The kinetic parameters were determined by standard nonisothermal methods. The activation energy is constant and independent of the coverage degree and pore diameter in the system porous glass-water. The function E(θ) were determined for the silica gel and porous aluminosilicates E=E0+a exp (-bθ). The parameters E0, a and b depend on the SiO2/Al2O3 ratio and on the distribution of active centers on the surface. © 1987 Wiley Heyden Ltd., Chichester and Akadémiai Kiadó, Budapest.