Abstract
Ceramic slurry involving multi-component powders is often used in a variety of ceramic fabrication processes. In this study, we investigated the hetero-coagulation behavior in a mixed slurry of alumina and silica particles that have different isoelectric points. TEM observation of the in situ solidified slurry with 10mass% solid concentration revealed the interesting change of coagulation with pH. At acidic region, silica particles were coagulated while alumina particles were fairly dispersed. A large scale of aggregation caused by attractive force between alumina and silica particles was observed at neutral region. Alumina particles were coagulated with increasing pH. Inversely, silica particles were dispersed at basic region. These features of coagulation were interpreted in conjunction with the results of zeta potential and viscosity.
