Volume fraction effects in shear rheology and electroacoustic studies of concentrated alumina and kaolin suspensions

The electroacoustic and shear yield stress response of concentrated alumina and kaolin suspensions have been measured across a range of pH conditions and volume fractions. The inter-relationship between the surface properties as measured electrokinetically and the shear yield stress is shown to scale in a straight forward manner for alumina particles and a qualitative description has been developed from kaolin suspensions. The pair-wise interaction between particles over the range of volume fractions has been demonstrated to remain constant. The use of a semi-empirical electroacoustic volume fraction correction to the zeta potential, integral to the electroacoustic technique, appears reasonable on the basis of the results presented herein. (C) 1998 Elsevier Science B.V.