Core/shell and hollow polymeric capsules prepared from calcium carbonate whisker

Abstract

Polymeric capsules of a rod-like shape were prepared by depositing a poly(methyl methacrylate) or polystyrene thin layer onto the surface of calcium carbonate whisker via emulsion polymerization. The obtained core/ shell capsules were also converted to hollow capsules by dissolving the core material in a hydrochloric acid solution. The average thickness of the outer shell (polymer layer) ranged from 29 to 72 nm. The glass transition temperatures T g's of the outer shell were almost identical to those of the bulk both for the core/shell and hollow capsules in contrast to the results for ultrathin polymer films, which have been reported to show significantly different Tg from the bulk value.