Hollow Capsules Fabricated by Template Polymerization of N-Vinylcaprolactam

We report the facile fabrication of polymer capsules based on the template polymerization of N-vinylcaprolactam (VCL) at the surface of silica particles. The modification of silica surfaces with methacrylate groups favors the polymerization of VCL leading to the formation of a homogenous PVCL layer. PVCL capsules approximately 200 nm in diameter were obtained after removal of the silica template. In contrast to most of other polymer capsules, the hollow morphology was maintained even in the dried state. The PVCL capsules, which possess smart properties based on thermal stimuli, should have wide potential applications in biological therapy.