Controlling submicron-particle template morphology: effect of solvent chemistry

Porous solids were obtained from self-assembled deposits of silica particles used as templates to form 3-D porous membranes. The effect of the solvent chemistry on the morphology of the deposits was investigated. The parameters of interest are surface tension and ionic strength of the solvent, as they impact electrostatic and capillary interactions. Deposits of particles of different sizes were obtained from a variety of conditions. The deposits were imaged by SEM and showed distinctive structures for each of the solvent chemistries. The phenomenon is qualitatively consistent with DLVO theory and calculations of capillary interaction energy as developed by Kralchevsky and co-workers.