Photoinduced Grafting of Filtration Membranes: Principles and Applications

CTS-0094765Georges BelfortRensselaer理工学院过滤膜的光诱导接枝原理与应用摘要本工作的目标是确定聚醚砜(PES)膜的光诱导接枝改性的基本原理，并利用这一认识来修饰商业上可获得的PES膜的表面，使其在蛋白质溶液的超滤过程中表现出较少的污染。紫外光辅助的亲水单体接枝聚合是本研究选择的改性技术，因为它简单，易于工业化生产。选择PES超滤膜是因为它们在生物技术行业中得到了广泛的应用，但它们相对疏水，具有严重的蛋白质污染，并且具有内在的光活性。其具体目的是：1.研究PES的光诱导接枝机理，以期阐明光活性发色团(S)的特性，并确定最佳的辐照条件。2.评价一系列亲水性乙烯基单体替代目前研究最多的N-乙烯-2-吡咯烷酮(NVP)。我们推测，其他商业上可获得的亲水单体可以提供比NVP更好的优势。3.通过开发一种低蛋白质吸附和高阳离子交换能力的亲和膜，验证了我们新的表面改性技术的应用效果。4.评价最有前景的改性PES膜的化学、物理稳定性和使用寿命。生物技术、食品饮料和废水处理行业迫切需要更好、低生物污染的合成膜。目前使用最广泛的聚醚砜膜具有很高的非特异性蛋白质污染，需要更换。然而，为不同的膜过滤应用开发具有合适的表面或功能特性以及机械性能的新的聚合物材料需要付出巨大的努力和费用。因此，在过去的30年里，很少有聚合物被用于膜生产。在这项为期三年的综合研究计划中，提供了一条替代途径，即对商用PES膜进行简易改性。这种新方法提供了一种相对廉价、简单、可扩展和经过充分测试的改性方法，用于生产性能更好的聚芳基砜薄膜。

CTS-0094765Georges BelfortRensselaer Polytechnic InstitutePhoto-induced Grafting of Filtration Membranes: Principles and Applications ABSTRACT The goals of this work are to determine the underlying principles of photo-induced graft modification of poly(ether sulfone) (PES) membranes and to use this understanding to modify the surface of commercially available PES membranes so that they exhibit less fouling during ultrafiltration of protein solutions. Ultraviolet (UV)-assisted graft polymerization of hydrophilic monomers is the modification technique chosen for this study because it is simple and easy to scale industrially. PES ultrafiltration membranes are selected because they are widely used in the biotechnology industry, but they are relatively hydrophobic, exhibit severe protein fouling, and are intrinsically photoactive. The specific aims are: 1. To investigate the mechanism of the photo-induced grafting of PES with a view towards elucidating the identity of the photoactive chromophore(s) and to identify the optimal irradiation conditions. 2. To evaluate a series of hydrophilic vinyl monomers in lieu of N-vinyl-2-pyrrolidinone (NVP), the most well-studied monomer to date. We postulate that other commercially available hydrophilic monomers could offer advantages over NVP. 3. To demonstrate the efficacy of using our new surface-modification technology by developing an affinity membrane with low protein adsorption and high cation-exchange capacity. 4. To evaluate the chemical and physical stability and lifetime of the most promising modified PES membranes. There is an urgent need in the biotechnology, food and beverage, and wastewater- treatment industries for better, low-biofouling synthetic membranes. The current most widely used membrane, poly(ether sulfone), exhibits high non-specific protein fouling and needs to be replaced. However, developing new polymeric materials with appropriate surface or functional characteristics as well as mechanical properties for diverse membrane-filtration applications involves great effort and expense. As a result, over the past 30 years, few polymers have been used for membrane production. In this comprehensive three-year research program, an alternate route, i.e. the facile modification of commercial PES membranes, is offered. The new method proffers a relatively inexpensive, simple, scalable, and well-tested modification procedure for producing poly(aryl sulfone) membranes with improved properties.