R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Jhong-Li, Taoyuan 320, Taiwan.
Langmuir. 2013 Aug 13;29(32):10183-93. doi: 10.1021/la401336y. Epub 2013 Aug 1.
Stable biofouling resistance is significant for general filtration requirements, especially for the improvement of membrane lifetime. A systematic group of hyper-brush PEGylated diblock copolymers containing poly(ethylene glycol) methacrylate (PEGMA) and polystyrene (PS) was synthesized using an atom transfer radical polymerization (ATRP) method and varying PEGMA lengths. This study demonstrates the antibiofouling membrane surfaces by self-assembled anchoring PEGylated diblock copolymers of PS-b-PEGMA on the microporous poly(vinylidene fluoride) (PVDF) membrane. Two types of copolymers are used to modify the PVDF surface, one with different PS/PEGMA molar ratios in a range from 0.3 to 2.7 but the same PS molecular weights (MWs, ∼5.7 kDa), the other with different copolymer MWs (∼11.4, 19.9, and 34.1 kDa) but the similar PS/PEGMA ratio (∼1.7 ± 0.2). It was found that the adsorption capacities of diblock copolymers on PVDF membranes decreased as molar mass ratios of PS/PEGMA ratio reduced or molecular weights of PS-b-PEGMA increased because of steric hindrance. The increase in styrene content in copolymer enhanced the stability of polymer anchoring on the membrane, and the increase in PEGMA content enhanced the protein resistance of membranes. The optimum PS/PEGMA ratio was found to be in the range between 1.5 and 2.0 with copolymer MWs above 20.0 kDa for the ultrastable resistance of protein adsorption on the PEGylated PVDF membranes. The PVDF membrane coated with such a diblock copolymer owned excellent biofouling resistance to proteins of BSA and lysozyme as well as bacterium of Escherichia coli and Staphylococcus epidermidis and high stable microfiltration operated with domestic wastewater solution in a membrane bioreactor.
稳定的抗生物污染能力对于一般的过滤要求非常重要，尤其是对于提高膜的寿命。通过原子转移自由基聚合（ATRP）方法合成了一系列含有聚甲基丙烯酸羟乙酯（PEGMA）和聚苯乙烯（PS）的超刷状 PEG 化两亲性嵌段共聚物，其通过改变 PEGMA 的长度来实现。本研究通过自组装将 PS-b-PEGMA 接枝的两亲性嵌段共聚物锚定在微孔聚偏二氟乙烯（PVDF）膜上，制备了具有抗生物污染的膜表面。使用两种类型的共聚物来修饰 PVDF 表面，一种共聚物的 PS/PEGMA 摩尔比在 0.3 到 2.7 范围内变化，但 PS 的分子量（MW，约 5.7 kDa）相同，另一种共聚物的 MW（约 11.4、19.9 和 34.1 kDa）不同，但 PS/PEGMA 比（约 1.7±0.2）相似。结果表明，由于空间位阻，两亲性嵌段共聚物在 PVDF 膜上的吸附容量随 PS/PEGMA 摩尔比的降低或 PS-b-PEGMA 的 MW 增加而降低。共聚物中苯乙烯含量的增加增强了聚合物在膜上的锚固稳定性，PEGMA 含量的增加增强了膜的抗蛋白质污染能力。发现当共聚物的 PS/PEGMA 比例在 1.5 到 2.0 之间且 MW 大于 20.0 kDa 时，PEG 化 PVDF 膜上蛋白质吸附的超稳定阻力最佳。在膜生物反应器中用生活污水运行时，用这种两亲性嵌段共聚物涂覆的 PVDF 膜对牛血清白蛋白和溶菌酶等蛋白质、大肠杆菌和表皮葡萄球菌等细菌具有优异的抗生物污染能力，并且具有很高的稳定微滤性能。
