Antifouling, antibacterial and non-cytotoxic transparent cellulose membrane with grafted zwitterion and quaternary ammonium copolymers

Copolymer brushes with different ratios of sulfobetaine methacrylate (SBMA) and [2-(Acryloyloxy)ethyl] trimethylammonium chloride (DAC) were grafted from transparent cellulose membrane (CM) via surface-initiated atom transfer radical polymerization (SI-ATRP) method for improving its antifouling and antibacterial performance. Surface concentrated copolymer grafting on the cellulose membranes can be obtained without significantly sacrificing the transparency and mechanical properties. The zwitterionic PSBMA chains of the copolymers can lead to an extremely hydrophilic surface with significantly reduced non-specific protein adsorption and bacterial attachment, therefore, leading to satisfying antifouling and antibacterial property. While the PDAC chains of the copolymers improved antibacterial performance against both Gram-positive and Gram-negative bacteria due to the presence of quaternary ammonium groups, the PDAC modified CM (CM-1) possessed best antibacterial performance, reaching to 95.1 % against S. aureus and 90.5 % against E. coli, respectively. More importantly, the biocompatibility of all grafted CM was retained, leading to over 100 % cell viability.