基于纳滤膜基膜和表面二次反应技术构建高通量抗污染复合反渗透膜

Reverse osmosis has become the key and important support technology for the alleviation of water shortage and solution of water pollution. However, membrane fouling and high energy consumption are the two key technical problems need to be solved urgently for the extensive application of reverse osmosis technology in wastewater treatment and reclamation. The objective of this proposal is to construct high-flux and anti-fouling multilayer composite reverse osmosis membranes based on the secondary interfacial reaction technique by using the nascent composite polyamide nanofiltration membrane as support membrane and polyvinyl alcohol or cellulose derivatives as the functional material. The function of reverse osmosis and property of high-flux of the constructed multilayer composite membrane will be achieved through depositing an ultrathin dense layer on the surface of the support membrane having nano-scale pore size and high permeability characteristic, and the antifouling property will be realized by forming a smooth, neutral and hydrophilic surface through taking the advantages of the smooth surface of the support membrane and the property of the selective surface layer. The formation process of the ultrathin dense active layer of the multilayer composite membrane will be investigated by using AFM, SEM and XPS, et al. to probe the mechanism and modulation method of the micro-structure of the skin layer, as well as the matching between the support membrane and skin dense layer. The mechanism and method for the structural construction of high-flux and anti-fouling composite reverse osmosis membrane will be clarified through studying the relationship between the membrane structure and functionality. The complement of this proposal will provide theoretical and technical guide for the design and preparation of novel membrane.

反渗透是当前缓解水资源短缺和解决水污染问题的重要支撑技术，而膜污染和高能耗则是目前反渗透膜在废水处理领域应用中迫切需要解决的关键科技问题。本项目拟以初生态聚哌嗪酰胺纳滤膜为基膜，以聚乙烯醇或纤维素衍生物为功能材料，采用表面二次反应技术，开展具有多层结构的高通量抗污染反渗透复合膜的构建及其性能研究。通过在具纳米孔结构和高渗透特性的纳滤膜表面均匀沉积超薄亲水致密分离层，实现复合膜的反渗透功能和高通量；利用基膜的光滑表面和分离层材料性质，构筑光滑、亲水和中性的膜表面，赋予复合膜抗污染性能。运用扫描电镜、原子力显微镜、光电子能谱等现代表征技术，研究超薄致密分离层的形成过程，探讨致密分离层微结构的形成机理和调控方法、纳滤膜基膜与致密分离层之间的匹配性；研究膜微结构与膜功能间的构效关系，探明高通量抗污染反渗透膜微结构构建方法和机理。项目实施将为新型分离膜的设计与制备提供理论与技术参考。

本项目紧紧围绕反渗透膜在应用中迫切需要解决的关键问题--膜污染和高能耗。以具多层结构的复合膜微结构与膜功能为研究对象，以膜微结构的功能化构建为核心，利用初生态聚哌嗪酰胺纳滤膜和表面二次反应技术对膜微结构进行构建和调控，通过在具纳米孔结构和高渗透特性的基膜上构建均匀、光滑、亲水的超薄致密复合分离层，获得高通量抗污染复合脱盐膜材料的制备方法。系统开展了具多层结构复合膜的制备方法、微结构形成机理及调控机制、微结构对分离性能和抗污染功能的影响规律等等方面的研究工作。揭示了以初生态纳滤膜为基膜构建具多层结构的高通量抗污染复合反渗透膜的机制，阐明了具有高通量特性与抗污染功能的复合脱盐膜材料的微结构本质，建立了具有多层结构复合膜微结构与分离性能和抗污染功能之间的构效关系，形成了基于纳滤膜基膜和表面二次反应技术构建具有多层结构的高通量抗污染复合膜的理论与方法，获得了分离性能优、抗污染性能好的复合脱盐膜材料，获得了易工业化的兼具高渗透选择性和抗污染功能的高性能复合脱盐膜的制备方法。. 项目研究成果将为基于纳滤膜和表面二次反应构建具多层结构的复合膜材料提供理论指导、为反渗透膜领域提供兼具高渗透选择性和抗污染功能的高性能膜材料、为解决反渗透膜应用过程中的污染和高能耗问题提供新思路和方法，对于推动我国膜科学技术的研究和进步具有重要意义。项目执行过程中发表SCI收录论文9篇，授权发明专利1件，申请发明专利5件，培养培养博士毕业研究生1名、硕士毕业研究生5。