Miao Zhaohong, Zhou Jian
School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab for Green Chemical Product Technology, South China University of Technology, Guangzhou, Guangdong, 510640, P. R. China.
J Mater Chem B. 2024 Aug 22;12(33):8076-8086. doi: 10.1039/d4tb00899e.
The antifouling effects of a toothbrush-shaped photo-responsive polyzwitterionic membrane were studied dissipative particle dynamics simulations in this work. The results reveal that the membrane modified by spiropyran methacrylate brushes displays photo-switchable and antifouling capability due to the photo-induced ring-opening reaction. Namely, surface morphology and hydrophilicity change in response to visible or UV light irradiation, which can be observed visually by protein adsorption and desorption. Further study indicates that: (1) brush-modification density can influence the structure and properties of the membrane. With low modification density, systems cannot establish an intact selective layer, which hinders the antifouling ability; as the modification density increases, the intact selective layer can be formed, which is conducive to the expression of photo-responsiveness and antifouling capability. (2) Factors of toothbrush-hair length and grafting ratio can influence the establishment of a light-responsive surface: as the grafting ratio and toothbrush-hair length increase, the light-responsive surface is gradually formed, meanwhile, the antifouling ability can be continuously reinforced under UV light irradiation. (3) As the brushes switch into a zwitterionic merocyanine state under UV exposure, the selective layer swelling becomes stronger than that with a hydrophobic spiropyran state under visible exposure. This is owing to the enhanced interaction between zwitterionic brushes and water, which is the root of the antifouling effect. The present work is expected to provide some guidelines for the design and development of novel antifouling membrane surfaces.
在这项工作中，通过耗散粒子动力学模拟研究了牙刷形状的光响应性聚两性离子膜的防污效果。结果表明，由于光诱导的开环反应，由甲基丙烯酸螺吡喃刷修饰的膜具有光开关和防污能力。也就是说，表面形态和亲水性会响应可见光或紫外光照射而发生变化，这可以通过蛋白质吸附和解吸直观地观察到。进一步的研究表明：（1）刷修饰密度会影响膜的结构和性能。修饰密度较低时，体系无法建立完整的选择性层，这会阻碍防污能力；随着修饰密度的增加，可以形成完整的选择性层，这有利于光响应性和防污能力的表达。（2）牙刷刷毛长度和接枝率等因素会影响光响应表面的建立：随着接枝率和牙刷刷毛长度的增加，光响应表面逐渐形成，同时，在紫外光照射下防污能力可以不断增强。（3）由于在紫外光照射下刷转变为两性离子部花青状态，选择性层的溶胀比在可见光照射下处于疏水螺吡喃状态时更强。这是由于两性离子刷与水之间的相互作用增强，这是防污效果的根源。本工作有望为新型防污膜表面的设计和开发提供一些指导。
