(725c) Self-Assembly of Graphene Oxide and Polymer Nanohybrid Membranes for Separation Application

Organic-inorganic nanohybrids are believed to be one of the most promising membrane materials for separation applications. Graphenen oxide could be integrated with other functional materials at a molecular/nanometer scale to create multifunctional GO-based composites because of its numerous oxygen-containing functional groups. In this study, nanohybrid membranes were prepared by incorporating graphene oxide (GO) into polymer for nanofiltration and pervaporation. Firstly, the PEI-modified GO and polyacrylic acid was sequentially assembled onto hydrolyzed polyacrylonitrile (PAN) ultrafiltration supporting membrane. It was found that the resulting membranes had excellent dye removal capacity and separation performance of monovalent and divalent ions. Additionally, it was demonstrated that this GO/PECs nanohybrid membrane is also a good candidate for the pervaporation dehydration of different solvent-water mixtures. In the second part, GO could be doped into poly(vinyl alcohol) (PVA) solutions to form nanohybrids. The PVA-GO nanohybrid could be assembled onto PAN membrane to form “pore-filling” membrane by dynamic pressure-driven assembly. The composite membrane could be used for separating toluene/n-heptane mixtures. With respect to the separation factor of pure PVA membrane, an improvement in the separation factor in the pervaporation of toluene/n-heptane mixture was observed after doping of PVA with GO. The “pore-filling” structure could effectively reduce swelling of the nanohybrid membrane. Furthermore, with the doping of GO, the thermal and mechanical properties of organic-inorganic nanohybrid membrane significantly improved. These results strongly suggest that GO has much potential in applications for preparing organic-inorganic nanohybrid membrane.