▎ 摘　　要

Polyethersulfone (PES) membranes containing cysteine-functionalized graphene oxide (CGO) were prepared to enhance the ultrafiltration performance such as water flux and antifouling property. The synthesis of CGO was achieved through a simple thiol-ene click reaction between graphene oxide and cysteine. Since CGO has a zwitterionic moiety, it was observed to improve the hydrophilicity and negative charge of the membranes. The results of the ultrafiltration test showed that the separation performance of the prepared CGO/PES nanocomposite membranes was much better than that of the pristine PES membrane. For example, the CGO/PES nanocomposite membrane with 0.5 wt.% CGO content has the pure water flux and BSA rejection values of 82.6 L m(2 )h(-1) and 99.8%, respectively, while the pristine PES membrane has these values of 51.7 L m(-2) h(-1) and 96.7%, respectively, indicating that the addition of CGO successfully improves the separation performance of PES-based membrane by overcoming the intrinsic trade-off relationship between permeability and selectivity. Furthermore, CGO/PES nanocomposite membranes also showed much better antifouling property than the pristine PES membrane. For example, the flux recovery ratio of the CGO/PES nanocomposite membrane with 0.5 wt.% CGO content is 92.1%, while that of the pristine PES membrane is only 47.5%. (C) 2020 The Korean Society of industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.