Synthesis And Properties Of Anti-bacterial Amphiphilic Copolymers P(HMBA- PEGMA-HEA) And Applied In Modification Of PES Membrane

Surface fouling including dense surface fouling and porous membrane fouling is of great concern in various applied fields. Surface hydrophobility is the main reason which causes the fouling of materials, so that improving surface hydrophilicity is an effective way to prevent fouling. Poly(ethylene glycol)(PEG) is one of the most commonly used materials to impart protein resistance to a surface in aquatic environments. The PEG chains can form hydration layer by hydrogen bonding among water and be attached to substrate surface, which effectively resists fouling due to proteins or cells. In addition, microbial infection on the surface from bacteria or fungi is another problem to overcome. It has been well known that introducing the antibacterial groups into the copolymer chains can endow the materials further application in various antifouling fields.This work is focus on designing a kind of antifouling coating with the anti-bacterial and protein-resistant properties. The amphiphilic random copolymers were prepared combining well-known protein repellency characteristics of hydrophilic monomer poly(ethylene glycol) methyl ether methacrylate(PEGMA), natural anti-bacterial capsaicin-mimic N-(4-hydroxy-3-methoxy benzyl) acrylamide (HMBA) with 2-hydroxyethyl acrylate (HEA) by free radical polymerization. And the copolymer structures were characterized by FT-IR,’H-NMR and GPC. Then the polyurethane copolymer coatings with the copolymer were prepared by crosslinking with polymeric phenyl methane-diisocyanate (PAPI). The characterization of surface contact angle, X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM) were used to study the surface wettability property, surface composition and surface morphology. Finally, we investigated the anti-bacterial performance with plate count method and the protein adsorption resistance of the coating with Ultraviolet spectrophotometer. The results showed that the bactericidal rate of the coatings to E.coli was higher than 90% and protein-resistance rate of 97%, which demonstrated that the polyurethane coating is a potential environmentally friendly materials for anti-fouling application.To further reveal the role of the amphiphilic copolymers in anti-fouling fields, they were used as additives in the preparation of PES porous membranes by immersion precipitation. Two series of blend membranes with different additive contents and composition were investigated. The surface chemical composition of the prepared blend membranes were analyzed using X-ray photoelectron spectroscopy(XPS), while the surface and section morphology of the blend membranes was observed by SEM. In addition, the membrane hydrophilicity and water permeation, anti-bacterial and protein-resistant properties were evaluated in detail. It was found that the modified membranes showed significantly improved hydrophilicity with the lowest water contact angle 37° and the permeation flux increased to 186.9 L/m2h. Moreover, the membranes showed significant bactericidal rate to E.coli with 80% and protein-resistant property. In a word, the membranes had excellent anti-fouling performance compared to the control PES membrane.