Mechanical Strength of Particulate Silica Gels

Mechanical strength of gels is an important factor in determining their drying conditions. Parameters affecting the strength and Young's modulus of wet and dry particulate silica gels are reviewed, and experimental data of the authors are presented. It is shown that the gel strength is a function of particle size of the powders composing the sol; the higher the surface area of the powder the higher the strength values of the both wet and dry gels. Aging of the wet gel in a mold has no effect upon strength. Effects of modes of preparation of the sols upon strength of the resulting gels are also discussed.