THE ROLE OF GRAVITY IN SUPRAMOLECULAR CRYSTALLIZATION DURING FORMATION OF PRECIOUS OPAL

Abstract

Experimental studies have revealed a dependence of the rates of sedimentation and growth of supramolecular crystals on the degree of deionization of suspensions of monodisperse silica spheres. At low pH, the rate of crystallization is determined by sedimentation of structural units. The calculated energy of interaction of two particles shows a drastic predominance of electrostatic repulsive forces over molecular attractive ones. On crystallization during sedimentation, the repulsion of structural units is balanced out by gravitational forces, an equivalent of molecular attractive forces.