Biofouling resistance of polysulfobetaine coated reverse osmosis membranes

• The polymer brushes were successfully grafted from the surface of RO membranes. • The modification with pSBMA provides densely packed, regular length polymer chains. • Very stable hydration shell on the monomer segments within the polymer chain was formed. • Modified membranes showed a minimum of at least 4 times biofouling improvement. • Modified membranes still maintaining competitive permeation flux and rejection properties

Polysulfobetaine has been successfully grafted from the surface of commercially available TFC membranes using surface-initiated ARGET-ATRP. The reaction conditions were optimized to create stable covalently bound polyzwitterionic brushes generating hydrophilic, smooth surfaces. Microbial biofouling was reduced by at least 80% in aquaria experiments and hydrodynamic tests for polysulfobetaine coated RO desalination membranes compared to controls, while still maintaining competitive permeation flux. Acknowledgments This work was prepared with the support of the Australian Research Council Linkage Grant no. LP0669119, in conjunction with Wind Prospect and SA Water. The authors would also like to thank Dow FilmTec, GE Power & Water and NanoH2O for providing membrane samples used in this study. Dr Clare H. Worthley is thanked for assistance in performing the SEM analysis.