Improvement of pervaporation PVA membranes by the controlled incorporation of fullerenol nanoparticles

Abstract

This work focuses on the incorporation of fullerenol nanoparticles to get PVA-fullerenol mixed matrix membranes for alcohol dehydration by pervaporation. Cross-linked hybrid membranes based on composites of polyvinyl alcohol (PVA) and low-hydroxylated fullerenol C60(OH)12 have been prepared by two different procedures. To improve the dispersion of the functionalized fullerene in the PVA network, the hydrodynamic properties of PVA, fullerenol and PVA/fullerenol composites in dilute solutions were studied by viscometry and dynamic light scattering. It was shown that the aggregate sizes increased with the increase of fullerenol content in the PVA/fullerenol composite solutions. The effect of low-hydroxylated fullerenol on the structure and morphology of PVA membranes was investigated by small-angle X-ray scattering and atomic force microscopy. It was observed that the incorporation of 5wt.% fullerenol and cross-linking with maleic acid led to a more uniform distribution of the amorphous PVA phase. As a result, membrane transport characteristics were improved for the dehydration of n-butanol–water mixtures by pervaporation. The PVA membranes containing 35wt.% maleic acid and 5wt.% fullerenol exhibited the best transport properties.