Search

The culprit of biofouling is the reproduction of viable microorganisms on the membrane surface. Recently, functionalization of membrane surface with natural antibacterial agents has drawn great attention. This work presents the fabrication of antibiofouling polyethersulfone (PES) ultrafiltration (UF) membranes by UV-assisted photo grafting of capsaicin derivative (N-(4-hydroxy-3-methoxy-benzyl)-acrylamide, HMBA) and itaconic acid (IA) on the surface of PES membrane. Results of FTIR-ATR, water static contact angle (WSCA) and atomic force microscopy (AFM) analysis confirmed the successful grafting of HMBA and IA on the membrane surface. We investigated the antifouling and antibacterial properties of these membranes using BSA and Escherichia coli as the test model, respectively. During a 150-min test, the modified membranes show much lower flux decline (42.7% for PES-g-1H0I, 22.2% for PES-g-1H1I and 7.7% for PES-g-1H5I) when compared with the pristine membrane (flux declined by 77%). The modified membranes exhibit excellent antibacterial activity (nearly 100%) when UV irradiation time was 6 min. The morphological study suggested that the E. coli on the pristine membrane showed a regular and smooth surface while that on the modified membrane was disrupted, which validated the antibacterial activity of the modified membranes. [ABSTRACT FROM AUTHOR]

Biofouling is a critical issue in membrane water and wastewater treatment. Herein, antibiofouling PSf membrane was prepared by UV-assisted graft polymerization of acrylic acid (AA) and a capsaicin derivative, N-(5-methyl-3-tert-butyl-2-hydroxy benzyl) acrylamide (MBHBA), on PSf membrane. AA and MBHBA were used as hydrophilic monomer and antibacterial monomer separately. The membranes were characterized by FTIR-ATR, contact angle, SEM, AFM, cross-flow filtration unit, antifouling and antibacterial measurements. Verification of MBHBA and AA that photo-chemically grafted onto the PSf membrane surface is confirmed by carbonyl stretching vibration at ∼1655 cm −1 and ∼1730 cm −1 , separately. The increasing AA concentration accelerates the graft-polymerization of MBHBA and resulted in a more hydrophilic surface. Consequently, antifouling property of the membranes was improved on a large level. The flux recovery rate can achieve 100% during the cyclic test, which may be attributed to the more hydrophilic and smooth surface, as well as the decreased membrane pore size. Most importantly, the presence of AA in graft co-polymer does not affect the antibacterial activity of MBHBA. That may be induced by the increasing chain length and flexibility of the grafted polymer chains. [ABSTRACT FROM AUTHOR]