Thermotropic liquid-crystal/polymer microcapsules prepared by in situ suspension polymerization

In this study, thermotropic liquid-crystal/polymer microcapsules were produced via in situ suspension polymerization. The phase separation between cholesteryl liquid crystal (CLC) and poly(methyl methacrylate) (PMMA) in the droplets was induced by polymerization, resulting consequently in uniform liquid-crystal-containing polymer microcapsules. The phase behavior of the microcapsules was dependent on the loading amount of the liquid crystals and the degree of cross-linking of the polymer phase. Above 30% loading amount of CLC, the liquid crystals started to appear clearly. It was found that the spherical morphology of the microcapsules was achieved within a slight degree of cross-linking of the PMMA phase. At a high degree of cross-linking, nonspherical particles with a rough surface and deeper dents were obtained, which was due to the elastic-retractive force of the cross-linked network. The liquid-crystal/polymer microcapsules produced in this study could find great applicability in pharmaceutics and electronics as a smart drug carrier.