Tufts University , Department of Chemical and Biological Engineering, 4 Colby Street, Medford, Massachusetts 02155, United States.
Tufts University , Department of Physics and Astronomy, 574 Boston Avenue, Medford, Massachusetts 02155, United States.
ACS Appl Mater Interfaces. 2017 Jun 21;9(24):20859-20872. doi: 10.1021/acsami.7b04884. Epub 2017 Jun 6.
Membranes with high flux, ∼1 nm pore size, and unprecedented protein fouling resistance were prepared by forming selective layers of self-assembling zwitterionic amphiphilic random copolymers on porous supports by a simple coating method. Random copolymers were prepared from the hydrophobic monomer 2,2,2-trifluoroethyl methacrylate (TFEMA) and four zwitterionic monomers (sulfobetaine methacrylate, sulfobetaine 2-vinylpyridine, sulfobutylbetaine 2-vinylpyridine, and 2-methacryloyloxyethyl phosphorylcholine) by free radical polymerization. All copolymers microphase separated to form bicontinuous ∼1.2 nm nanodomains with the zwitterionic domains acting as nanochannels for the permeation of water and solutes. The resultant membranes all had a ∼1 nm size cutoff independent of zwitterion chemistry. There were, however, significant differences in the hydrophilicity, water uptake, water flux, and fouling resistance among membranes prepared with different zwitterionic monomers. Membranes prepared from the copolymer with 2-methacryloyloxyethyl phosphorylcholine were the most hydrophilic and had the highest water permeance, higher than that of commercial membranes of similar pore size. Furthermore, these membranes showed unprecedented fouling resistance, exhibiting no measurable flux decline throughout a 24 h protein fouling experiment. The structure-property relationships gleaned from this survey of different zwitterion structures serves as a guideline to develop new zwitterionic materials for various applications such as membranes, drug delivery, and sensors.
通过简单的涂层方法，在多孔载体上形成自组装两性离子两亲性无规共聚物的选择性层，制备出具有高通量（1nm 孔径）和前所未有的抗蛋白质污染能力的膜。无规共聚物由疏水性单体 2,2,2-三氟乙基甲基丙烯酸酯（TFEMA）和四种两性离子单体（甲基丙烯酰氧乙基磷酸胆碱、2-乙烯基吡啶磺基甜菜碱、2-乙烯基吡啶磺基丁基甜菜碱和）通过自由基聚合制备。所有共聚物都微相分离，形成1.2nm 的双连续纳米区，其中两性离子区作为水和溶质渗透的纳米通道。所得膜的截留分子量均为~1nm，与两性离子化学无关。然而，用不同两性离子单体制备的膜在亲水性、水吸收、水通量和抗污染性方面存在显著差异。用甲基丙烯酰氧乙基磷酸胆碱制备的共聚物制备的膜具有最高的亲水性和最高的水通量，高于具有相似孔径的商业膜。此外，这些膜表现出前所未有的抗污染性，在 24 小时蛋白质污染实验中没有观察到通量下降。从不同两性离子结构的调查中得出的结构-性能关系为开发各种应用（如膜、药物输送和传感器）的新型两性离子材料提供了指导。
