Structurization of Aerosil OX50 Dispersions

摘要

Structural and mechanical properties of aqueous dispersions of Aerosil OX50 were studied by rotary viscometry. The thixotropic properties of concentrated (20-50 wt%) Aerosil dispersions used in the sol-gel synthesis of quartz glass are due to structurization caused by appreciable overlapping of the electrical double layers of the particles. The particle interaction occurring in a limited volume is accompanied by formation of periodic colloidal structures of the second kind. The viscoplastic properties and extrema in the pH dependence of the viscosity are explained in terms of collective interaction of Aerosil particles according to the Deryagin-Landau-Verwey-Overbeek (DLVO) theory.