Structure of e-beam sculptured poly(N-vinylpyrrolidone) networks across different length-scales, from macro to nano

Study of macromolecular structure and dynamics of networks formed by pulsed electron-beam irradiationof poly(N-vinyl pyrrolidone) (PVP) aqueous solutions, at relatively low energy per pulse and acrossdifferent concentration regimes, provides the basis for the understanding of a new generation of functionalnanostructures. Networks are the result of the followeup reactions initiated by a continuous seriesof electron pulse-generated hydroxyl radicals, which may have a different fate at the variance of polymerconcentration. Different spectroscopic techniques, FT-IR, 13C {1H} CP-MAS NMR and Raman, applied tocharacterize the formed networks, describe a profound modification of the chemical structure whennetwork size is approaching the nanoscale. Static light scattering measurements provide further informationon the average weight molecular weight modification of PVP when forming nanogel particles.From the simultaneous control of network size and modification of chemical functionality stems also anintrinsic fluorescence of these nanogels never observed before. Altogether the obtained radiationsculpturednanogels exhibit interesting multifunctionality that, coupled with the already provenbiocompatibility, can be exploited in the biomedical field.