A Novel PVDF Ultrafiltration Membrane Modified by C₆₀(OH)_n-Ag

Ultrafiltration membranes in the fields of water treatment and biomedicine should have high permeability as well as antibacterial and antifouling capabilities. In this study, based on the hydrophilicity of fullerol (C₆₀(OH)_n) and the bacteriostatic properties of silver (Ag), a fullerol-silver (C₆₀(OH)_n-Ag) complex was prepared as a multifunctional additive. A polyvinylidene fluoride (PVDF)-composited C₆₀(OH)_n-Ag ultrafiltration membrane (C₆₀(OH)_n-Ag/PVDF) was prepared by immersion precipitation phase transformation. Addition of the C₆₀(OH)_n-Ag complex improved the permeability and retention of the traditional PVDF membrane. Compared with the traditional PVDF membrane, the surface water contact angle of the modified PVDF and C₆₀(OH)_n-Ag ultrafiltration membrane was reduced from 75.05° to 34.50°, its pure water flux increased from 224.11 L·m^-2·h^-1 to 804.05 L·m^-2·h^-1, the retention rate on bovine serum protein was increased from 75.00% to 96.44% and the flux recovery rate increased from 64.91% to 79.08%. The C₆₀(OH)_n-Ag/PVDF ultrafiltration membrane had good inhibitory effects on Escherichia coli and Staphylococcus aureus, while the PVDF ultrafiltration membrane had no obvious inhibitory effects.