Journal of Materials Science, Vol.35, No.22, 5653-5659, 2000
Particle network re-structuring in highly-concentrated ceramic suspensions
In this study, the restructuring behavior of particle networks in highly-concentrated zirconia-wax suspensions as model suspensions is investigated in terms of temperature and solids concentration. The restructuring kinetics is analytically determined such that it can be formulated by a linear correlation between the relative viscosity (eta (r)) of the suspensions and the logarithmic time (t) of isothermal annealing. Upon restructuring, a gelling point t(g)el, defined as the time period of which the discrete particle networks in the pre-sheared suspensions are observed to start to form a continuous structure. Above t(g)el, a sharp increase in suspension viscosity is commonly observed. The t(g)el varies as a function of both temperature and solids concentration, The temperature effect provides valuable information for a better understanding of the restructuring behavior from an energy viewpoint. The influence of solids concentration, i.e., the t(g)el decreased linearly with increasing solid concentration, suggests a stronger interparticle attraction that further accelerates flocculation.