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In-situ generation of a nanodispersed conductive polymer within a polypropylene matrix has been pursued in order to obtain flexible, conductive films. Radiation grafting of acrylic acid to polypropylene (PP) has been applied to insert carboxyl functionalities on PP. The radiation-grafted films have been further derivatized with a variety of diamines and used as substrates for in-situ chemical oxidative polymerization of polyaniline (PANI). PANI grows as a thin skin from the surface of the film as well as an interpenetrated network in its interiors. Evidence of chemical attachment of PANI to PP has been sought by performing FTIR and XPS analyses after extraction of the unbound polymer. The influence of the nature of the substituent attached to PP on the optical and electrical properties of the films has been investigated. PANI-PP skin-core films have been also tested as flexible electrodes for further electrochemical growth of the conductive polymer.

Study of macromolecular structure and dynamics of networks formed by pulsed electron-beam irradiation of poly(N-vinyl pyrrolidone) (PVP) aqueous solutions, at relatively low energy per pulse and across different concentration regimes, provides the basis for the understanding of a new generation of functional nanostructures. Networks are the result of the follow–up reactions initiated by a continuous series of electron pulse-generated hydroxyl radicals, which may have a different fate at the variance of polymer concentration. Different spectroscopic techniques, FT-IR, 13 C { 1 H} CP-MAS NMR and Raman, applied to characterize the formed networks, describe a profound modification of the chemical structure when network size is approaching the nanoscale. Static light scattering measurements provide further information on 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 an intrinsic fluorescence of these nanogels never observed before. Altogether the obtained radiation-sculptured nanogels exhibit interesting multifunctionality that, coupled with the already proven biocompatibility, can be exploited in the biomedical field.

A novel electrically conductive composite material, consisting of polyaniline (PANI) nanoparticles dispersed in a polyvinyl pyrrolidone (PVP) hydrogel, was prepared ‘in situ’ by water dispersion polymerisation (DP) of aniline using PVP as steric stabiliser, followed by γ-irradiation induced crosslinking of the PVP component. Conversion yield of aniline into PANI particles was determined via HPLC and gas chromatography, while structural confirmation of the synthesised polymer was sought by FTIR. Morphology and dimensions of PANI particles into the coloured, optically transparent hydrogel was determined by electronic microscopy; moreover, swelling behaviour of composite hydrogels in different buffer solutions was investigated by gravimetric measurements and compared to that of pure PVP hydrogels. Cyclic voltammetry experiments were carried out both on these hydrogels and on the parent aqueous dispersions, at different pH values of the suspending/swelling medium, while conductivity of the composite hydrogels was derived from Impedance Spectroscopy; in both cases results were compared to those relative to hydrogels containing commercial-grade PANI particles.