Synthesis of poly(vinyl pyrrolidone) nanohydrogels by the template-assisted ionizing radiation

Poly(vinyl pyrrolidone), PVP nanohydrogels were successfully synthesized by a nanotemplate-assisted ionizing radiation method. Steady-state ionizing radiation (γ-ray) was used to generate the gel-forming chemical crosslinking bonds on polymer molecules confined in the highly ordered cylindrical capillary well structure of the nanoporous membrane. The inter-molecular separation of PVP molecules by the capillary well promoted the inter- and intra-molecular carbon-centered PVP radical recombination reaction only within the same capillary pore upon irradiation and produced the nano-sized hydrogels. It was observed that size of the synthesized PVP nanohydrogel particles was determined by the diameter of nanocapillary pore.