Synthesis of Porous Zirconia Spheres-Mechanism and Prospects for Multistep Processing

We have previously reported the polymerization-induced colloid aggregation process (1, 2) to synthesize monodisperse, porous zirconia particles. One drawback is that it is difficult to simultaneously achieve a larger particle size and a higher zirconia yield. In this paper, we develop strategies to achieve these dual goals. We elucidate the interplay between the polymerization reaction and the various polymer-colloid interactions which result in the formation of the monodisperse particles. We explain the role of the polymer and the colloid in the process and suggest reasons for the limitations observed with a single-step process in achieving the dual goals of larger particle size and increased zirconia yield. Finally, we demonstrate a multistep process to overcome these limitations and achieve these dual goals. Copyright 1999 Academic Press.