Hollow microcapsules with a complex polyelectrolyte shell structure fabricated by polymerization of 4-vinylpyridine in the presence of poly(sodium 4-styrenesulfonate) and silica particles

Abstract

Hollow microcapsules having shells of polyelectrolyte complexes were fabricated by polymerization of 4-vinylpyridine hydrochloride in a solution containing surface-modified silica particles and poly(sodium 4-styrenesulfonate), and followed by a core removal with HF. Here both the PSS molecules and the silica particles function as templates to guide the alignment of VPy monomers and support the deposition of the PSS/PVPy complexes, respectively. The continuous shells with a thickness of 5–15 nm on the silica particles are created by covalent linking of the PSS/PVPy complexes. The hollow and intact microcapsules in both wet and dry states were characterized and confirmed by transmission electron microscopy, scanning electron microscopy, and confocal laser scanning microscopy. The chemical compositions of the microcapsules were determined and confirmed by elemental analysis and FTIR spectroscopy.