Poly(vinyl alcohol)–graphene oxide nanohybrid “pore-filling” membrane for pervaporation of toluene/n-heptane mixtures

The stability of the membrane for pervaporation separation of aromatic/aliphatic mixtures is critical for industrial applications. To improve the stability of the membrane, a “pore-filling” membrane was prepared by dynamic pressure-driven assembly of a poly(vinyl alcohol)–graphene oxide (PVA–GO) nanohybrid layer onto an asymmetric polyacrylonitrile ultrafiltration membrane. The results of the swelling experiment suggest that the pore-filling structure could effectively reduce swelling of the nanohybrid membrane. Assembly of the nanohybrid membrane by molecular-level dispersion of GO in PVA led to enhanced affinity of the membrane to aromatic compounds and thus improved performance in the pervaporation of toluene/n-heptane mixtures. Moreover, the dynamic assembly process could easily be used to adjust the separation performance by controlling the pressure, filtration time, polymer, and GO concentration.