Surface Antifouling Modification on Polyethylene Filtration Membranes by Plasma Polymerization

Surface modification on microporous polyethylene (PE) membranes was facilitated by plasma polymerizing with two hydrophilic precursors: ethylene oxide vinyl ether (EO1V) and diethylene oxide vinyl ether (EO2V) to effectively improve the fouling against mammalian cells (Chinese hamster ovary, CHO cells) and proteins (bovine serum albumin, BSA). The plasma polymerization procedure incorporated uniform and pin-hole free ethylene oxide-containing moieties on the filtration membrane in a dry single-step process. The successful deposition of the plasma polymers was verified by Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) analyses. Water contact angle measurements and permeation experiments using cell and protein solutions were conducted to evaluate the change in hydrophilicity and fouling resistance for filtrating biomolecules. The EO1V and EO2V plasma deposited PE membranes showed about 1.45 fold higher filtration performance than the pristine membrane. Moreover, the flux recovery reached 80% and 90% by using deionized (DI) water and sodium hydroxide (NaOH) solution, indicating the efficacy of the modification and the good reusability of the modified PE membranes.