Fluffy-like amphiphilic graphene oxide (f-GO) and its effects on improving the antifouling of PAN-based composite membranes

Membrane fouling remains a significant restriction for the long-time operation. In this paper, fluffy-like amphiphilic graphene oxide (f-GO) was prepared by simple grafting silane coupling agent (KH-570) onto the graphene oxide matrix, and thus featured with good dispersion behavior in organic solution. The f-GO was further incorporated into the PAN-based (poly(acrylonitrile-methyl acrylate), P(AN-MA)) copolymer during the phase inversion process. Compared with the P(AN-MA) membrane, the resistance of the f-GO/P(AN-MA) composite membrane reduced from 4.49 x 10(-12) m(-1) to 1.78 x 10(-12) m(-1). The pure water flux increased from 200 to 326 L/m(2)h, while the water contact angle declined from 92.8 degrees to 68.3 degrees. It is worthy to note that the fouling mode changed from irreversible fouling to reversible fouling, with the total fouling rate showing a half decay. The fouling recovery rate reached 98.16% and the BSA rejection rate increased from 70.59% to 99.33% as 0.5 wt % f-GO was incorporated. The f-GO is easily scaled up and can be widely applied in other polymer matrices, showing potential application prospects in the membrane separation and purification area. The f-GO/P(AN-MA) composite membranes with excellent water flux, BSA rejection and FRR, are candidates for further employment in wastewater purification applications.

Automated summary

A modified graphene oxide composite membrane with good dispersion behavior was prepared, which reduced resistance, increased pure water flux, decreased water contact angle, and achieved reversible fouling. It shows potential for application in wastewater purification.