The mechanical properties of wet Silica gels.

The mechanical properties of wet silica gels formed by polymerization of TEOS an by colloidal dispersion of Cabosil(TM) have been studied. Modulus of elasticity, modulus of rupture, stress relaxation and viscosity were measured on wet gel rods immediately following gelation. These measurements were made using a beam- bending apparatus designed specifically for accurate analysis of very low strength solids. Tests were made in ambient conditions or immersion in a liquid bath. In this study mechanical behavior of gels is found to be dependent on formation of technique and gel age. Knowledge of the properties of wet gels has led to a better understanding of gel microstructure and formation.