Organic−Inorganic Hybrid Membranes with Simultaneously Enhanced Flux and Selectivity

Tradeoff phenomenon is a sticky problem, which has been perplexing researchers in the polymeric membrane area for quite a long time. Since the inherent limitation of polymeric membrane and inorganic membrane, organic−inorganic hybrid membrane seems a feasible solution because it effectively combines the rigidity of inorganic moiety and the flexibility of polymer moiety. This study demonstrated such kind of hybrid organic−inorganic membrane composed of poly(vinyl alcohol) (PVA) and crystalline flake graphite and found that simultaneous increase of permeability and selectivity of the hybrid membranes in pervaporation separation of benzene and cyclohexane mixtures was achieved. More specifically, the hybrid membranes showed about 4-fold permeation flux and 6-fold separation factor increase in comparison to pure PVA membrane. In addition, it was found that pervaporation properties of the hybrid membranes were quite sensitive to both graphite particle size and content.