Selective grafting polymerization of nanochannels in track-etched pet membranes initiated by remnant peroxides

Abstract

Track-etched PET membranes (TMs) are one of the first commercially available nanostructured materials. The number, size and shape of pores (or nanochannels) can be carefully tailored at industrial scale. Selective pore modification can be achieved using remnant radicals after the etching process; however, this technique has some limitations. In this work, a simple and straightforward procedure is described for selectively grafting glycidyl methacrylate (GMA) and acrylic acid into the nanochannel walls of track-etched PET membranes. Grafting polymerization was carried out at short and long post-etching time by thermal initiation. The ultra-low amounts of grafting modification were measured by fluorescence labelling and membrane hydrolysis. The presence/absence of polyGMA and polyacrylic acid was confirmed by FTIR spectroscopy and MS-ESI. Peroxide compounds were detected in track-etched membranes and attributed responsibility for the selective grafting polymerization in the nanochannel walls of TMs. This simple and quick procedure will enhance the development of novel functional materials based on this technology.