Spinodal decomposition in a sterically stabilized colloidal silica dispersion following from quench experiments

Abstract

Time-resolved light scattering at different quench depths is used to elucidate the kinetics of phase separation in a sterically stabilized colloidal dispersion with volume fractions up to 0.25 near the critical volume fraction and in the off-critical range. The early stage of spinodal decomposition is explicable in terms of the linearized Cahn-Hilliard theory. The late stage follows the power law relation with exponents close to 1 and - 1 3 predicted by the cluster theory of Binder and Stauffer. The trend of self-similarity is also observed in our experiments. The obtained spinodal curve following from the quench experiments are compared to the theory of adhesive hard spheres. The agreement between the experimental curve and the theoretical one is quite reasonable. Our contribution to this special issue of Advances in Colloid and Interface Science is dedicated to professor Overbeek on the occasion of his eightieth birthday in 1991. Stability (caused by electrostatic or steric interactions) in colloidal systems played a central part in his field of research. His enthusiasm and interest in a wide area of the physical chemistry of colloids and surfaces have stimulated many of us in our field of research. We hope that this paper will please him.