Articles
  • Electrical and rheological properties of colloidal alumina suspensions
  • Xu Hong Wang* and Yoshihiro Hirarta
  • Department of Applied Chemistry and Chemical Engineering, Kagoshima University, 1-21-40 Korimoto, Kagoshima 890-0065, Japan
Abstract
The valence (Z) of positively and negatively charged alumina particles in the dilute suspensions was analyzed with the electrical conductivity of the suspensions. The mobility of negative particles was lower than that of positive particles at a similar Z value because of the stronger effect of chemical bonding over the hydrated particle surfaces. The apparent viscosity of acidic suspensions of 1-40 vol% solid was lower than that of basic suspensions. This result was discussed based on the three important effects of the valence, concentration and nature of hydrated surface of alumina particles. The density of alumina compacts consolidated by filtration through gypsum molds became lower for the basic suspensions than for the acidic suspensions. This result was correlated to the properties of the colloidal alumina suspensions.

Keywords: Valence, Electrohoretic mobility, Alumina suspension, Rheology, Viscosity, Chemical bonding, Green compact

This Article

  • 2000; 1(1): 64-68

    Published on Jun 30, 2000