Surface Functionalization by Grafting (2-Dimethylamino)ethyl Methacrylate Methyl Chloride Quaternary Salt (DMAEMAq) onto Hollow Fiber Polyethersulfone (PES) Membranes for Improvement of Antibiofouling Properties

Surface modification of hollow fiber polyethersulfone (PES) membranes by UV irradiation induced graft polymerization of (2-dimethylamino)ethyl methacrylate (DMAEMAq) was developed. The grafted layers of the DMAEMAq monomer on the PES membrane surfaces were characterized using attenuated total reflectance Fourier transform infrared analysis and X-ray photoelectron spectroscopy. The performances of the modified FES membranes (PES-g-DMAEMAq) were investigated in terms of both organic fouling and biofouling. Filtration of bovine serum albumin (BSA) as a model protein and Pseudomonas putida (P. putida) as a model bacteria were carried out to evaluate organic antifouling and antibiofouling performances, respectively. The results showed that the membranes surface functionalized with the DMAEMAq monomer showed higher organic antifouling than unmodified PES membranes. A shaking flask test using P. putida also revealed that a PES-g-DMAEMAq membrane with a grafting amount of 4.8 mg/cm(2) showed higher biofouling resistance. That is, almost 99.9% of bacteria were killed by contact with the PES-g-DMAEMAq membrane. Thus, surface functionalization of PES membranes with the DMAEMAq monomer was quite useful for improving antibiofouling and organic antifouling properties.