High water permeable free-standing cellulose triacetate/graphene oxide membrane with enhanced antibiofouling and mechanical properties for forward osmosis

Free-standing cellulose triacetate (F-CTA)/graphene oxide (GO) membranes for forward osmosis were fabricated by means of phase inversion. The membranes exhibited low water resistance and degree of internal concentration polarization (103). The improvement was attributed to the absence of support layer in the free standing membranes. Moreover, incorporation of GO further increased the hydrophilicity of the F-CTA membrane. The water flux significantly increased to 18.43 L per square meter per hour (LMH) when deionized (DI) water was feed solution (FS) and 0.5 M NaCl was draw solution (DS). Meanwhile, the specific salt flux was 0.22 g/L. According to the microorganism attachment test, F-CTA/GO membranes exhibited remarkable resistance to biofouling. The anti-biofouling capability increased with the increase of GO content. The thickness of the biofilm formed on the pristine F-CTA membrane was 18.5 mu m. It finally decreased to 4 mu m on the surface of the F-CTA/GO membrane. Tensile test revealed that strength and Young's modulus of the F-CTA/GO membrane substantially increased to 42.8 MPa and 1.18 GPa, corresponding to similar to 84% and similar to 136% increase, respectively, compared with the pristine F-CTA. The presence of GO enabled excellent mechanical stability of the free standing membranes. (C) 2016 Elsevier B.V. All rights reserved.