Effect of precursor and hydrolysis conditions on drying shrinkage

Using a theory developed by Smith et al. [J. Non-Cryst. Solids 188 (1995) 191], the drying shrinkage of a gel can be predicted, given the density dependence of the bulk modulus and the characteristic pore size. The theory was tested for two types of silica gel made from tetramethoxysilane, and the agreement between measured and calculated densities was satisfactory. (C) 1997 Elsevier Science B.V.