Enhancing the Antimicrobial and Anti-biofouling Properties of Polyamide Composite Membrane Grafted with Polyhexamethylene Guanidine (PHMG)

In this work, a thin-film composite polyamide membrane with antimicrobial polyhexamethylene guanidine (PHMG) was fabricated by the combination of photo-induced and chemical grafting to enhance the antifouling and anti-biofouling properties of the membrane. The surface properties of the membrane were evaluated using field-emission scanning electron microscopy (FE-SEM) images, attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), water contact angle (WCA) values, and antimicrobial activity of the membrane. The membrane separation performance was evaluated by the flux and the ability to retain Ca2+ ions in water. The antifouling and anti-biofouling properties were evaluated by the maintained flux ratios after 9 hour-filtration of humic acid and bovine serum albumin (BSA) solutions. The results showed that the grafted membrane’s surface became tighter (the retention increased from 97.3% to 98.6%), and no bacteria were observed on the surface of the grafted membrane. Meanwhile, the anti-fouling and anti-biofouling properties were also improved compared to the original membrane.