Enhanced pervaporation performance of polyamide membrane with synergistic effect of porous nanofibrous support and trace graphene oxide lamellae

Electrospun nanofibrous membrane as a supporting layer has attracted great interests in fabricating high performance composite membranes due to its interconnected porous structure. However, it's still a challenge to prepare an ultrathin and integrated skin layer on porous and undulating nanofibrous support, thereby restricting its application in pervaporation. Here, graphene oxide (GO) was introduced into amine aqueous phase to form an integrated and compact polyamide (PA) layer on nanofibrous substrate via interfacial polymerization (IP). Under the synergistic effect of high permeability of the nanofibrous scaffold and flexibility of GO lamellae, tiled GO lamellae acting as a skeleton got involved in the initial reaction for the construction of selective PA layer. By loading trace amount of GO in aqueous phase during IP, the selectivity of PA layer was enhanced significantly compared with that of pristine PA layer on nanofibrous scaffold. High permeate flux of 6593 g/m²h with a desirable separation factor of 1491 was achieved using the hybrid membrane with just 0.001 wt% of GO loading for pervaporation dehydrating 90 wt% isopropanol aqueous solution at 70 °C. These results indicated the feasibility of constructing a single homogeneous selective layer on nanofibrous support for high-performance pervaporation process.