Effect of dispersant concentration on slip casting of cordierite-based glass ceramics

Cordierite-based glass ceramics have been prepared by slip casting from slu rries with different dispersant concentrations at a given solids loading (6 0 wt%). The amount of dispersant was found to have great influence on the r heological behavior of the cordierite-glass suspensions. At low dispersant concentrations the Bingham model could be used to describe the flow behavio r, which gradually changed to a Newtonian type when the optimal amount of d ispersant was added. Further additions of dispersing agent led to a shear-t hickening behavior that could be described by the Casson model. A maximum c overage of dispersant on the surfaces of the particles resulted in the opti mal dispersant concentration, which yielded a maximum value of the zeta pot ential, and thus the lowest viscosity values of the suspensions. (C) 2001 A cademic Press.