Department of Desalination and Water Treatment, Zuckerberg Institute for Water Research, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, Sede Boqer Campus 84990, Israel.
Biomacromolecules. 2011 Apr 11;12(4):1169-77. doi: 10.1021/bm101470y. Epub 2011 Mar 1.
Microbial biofilms and their components present a major obstacle for ensuring the long-term effectiveness of membrane processes. Graft polymerization on membrane surfaces, in general, and grafting with oppositely charged monomers, have been shown to reduce biofouling significantly. In this study, surface forces and macromolecular properties of graft copolymers that possess oppositely charged groups were related to their potent antibiofouling behavior. Graft polymerization was performed using the negatively charged 3-sulphopropyl methacrylate (SPM) and positively charged [2-(methacryloyloxy)ethyl]-trimethylammonium (MOETMA) monomers to yield a copolymer layer on polyvinylidene fluoride (PVDF) surface. Quartz crystal microbalance with dissipation monitoring (QCM-D) technology was used to monitor the reduced adsorption of extracellular polymeric substances (EPS) extracted from a membrane bioreactor (MBR) wastewater treatment facility. Complemented measurements of attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy provided evaluation of the antifouling properties of the surface. Increase in water content in grafted layer exposed to 100 mM aqueous NaCl solution was observed by QCM-D. Therefore, the grafted copolymer layer is swelled in the presence of 100 mM NaCl because of reversing of polymer self-association by counterions. Force measurements by atomic force microscopy (AFM) showed an increased repulsion between a carboxylate-modified latex (CML) particle probe and a modified PVDF surface, especially in the presence of 100 mM NaCl. The hydration and swelling of the grafted polymer layer are shown to repel EPS and reduce their adsorption. Delineating the surface properties of antifouling grafted layers may lead to the design of novel antifouling surfaces.
微生物生物膜及其组成部分是确保膜过程长期有效性的主要障碍。一般来说，在膜表面进行接枝聚合，以及接枝带相反电荷的单体，已被证明可以显著减少生物污垢。在这项研究中，具有相反电荷基团的接枝共聚物的表面力和高分子性质与其有效的抗生物污垢行为有关。使用带负电荷的 3-磺丙基甲基丙烯酸酯（SPM）和带正电荷的[2-（甲基丙烯酰氧基）乙基]三甲基氯化铵（MOETMA）单体在聚偏二氟乙烯（PVDF）表面进行接枝聚合，生成共聚物层。石英晶体微天平耗散监测（QCM-D）技术用于监测从膜生物反应器（MBR）废水处理设施中提取的细胞外聚合物（EPS）的吸附减少情况。衰减全反射傅里叶变换红外（ATR-FTIR）光谱学的补充测量提供了对表面抗污染性能的评估。通过 QCM-D 观察到暴露于 100 mM 水溶液中的接枝层中水含量增加。因此，由于反离子的逆转聚合物自组装，在存在 100 mM NaCl 的情况下，接枝共聚物层会溶胀。原子力显微镜（AFM）的力测量显示，在存在 100 mM NaCl 的情况下，羧基改性乳胶（CML）颗粒探针与改性 PVDF 表面之间的排斥力增加。接枝聚合物层的水合和溶胀被证明可以排斥 EPS 并减少其吸附。描绘抗生物污垢接枝层的表面性质可能会导致新型抗生物污垢表面的设计。
