两亲聚类肽分离功能膜设计、制备与性能的探索性研究

Polymeric membrane is the base of the membrane separation technology, while the design and synthesis of high performance material for membrane fabrication, especially the amphiphilic polymer, is the base of the polymeric membrane with high performance. In this project, amphiphilic polypeptoids are first proposed to fabricate the novel separation membrane with outstanding antifouling properties and excellent biocompatibility, via the combination of the self-assembly of amphiphilic polypeptoids and non-solvent induced phase separation (NIPS) process. Amphiphilic polypeptoids consist of polysarcosine as the hydrophilic segment and poly (N‑substituted glycine) (substituted groups: n-propyl, n-pentyl, n-octyl, or n-decyl) as the hydrophobic segment, which make it possible as one kind of independently macroscopically solid functional material with integrated structure and performance. The self-assembly of amphiphilic polypeptoids in the solution is regulated by the solubility of polymer segment in the solvent, which induces the functionalization of the surface/interface of separation membranes. Moreover, the pore structures of the separation membrane are regulated by the NIPS process via changing the types of non-solvent, etc. based on the self-assembly of amphiphilic polypeptoids. Finally, it is expected to find the relationship between the structures and compositions of amphiphilic polypeptiod and its self-assembly behavior, to interpret and grasp the mechanism for regulating the structures and performance of the separation membranes by the combination of the self-assembly of amphiphilic polypeptoids and NIPS process, and to analyze the relationship between the structures and performance of the separation membrane.

聚合物分离膜是实现膜分离技术的基础，而设计与合成高性能的分离膜用材料，特别膜用两亲高分子，是实现聚合物分离膜高性能化的基础。本课题创新性的提出利用两亲聚类肽自组装行为和溶液相分离过程，制备具有优异抗污性和生物相容性的新型分离功能膜。两亲聚类肽以水溶性聚肌氨酸为亲水组分，以聚（N取代甘氨酸）（取代基为正丙基、正戊基、正辛基或正癸基）为疏水链段，使其独立的作为结构和性能统一的宏观固体功能材料成为可能。通过改变高分子链段与溶剂的溶解能力，调控两亲聚类肽在溶液中的自组装行为，诱导分离功能膜表界面功能化；结合两亲聚类肽自组装，通过改变非溶剂等方式，调控溶液相分离过程，诱导分离功能膜多孔结构形成。最终通过研究，厘清两亲聚类肽结构与组成对两亲聚类肽自组装行为的影响规律，阐明和掌握两亲聚类肽自组装行为与溶液相分离过程对分离功能膜结构和性能调控的机理，解析新型分离功能膜的构效关系。

高性能分离膜在水处理和生物医用材料领域具有重要意义。设计与合成高性能膜用材料，特别是膜用两亲高分子，同时发展新型分离膜制备技术，是实现聚合物分离膜高性能化的重要手段。本项目研究内容主要包括新型两亲聚类肽共聚物的设计与合成、两亲聚类肽共聚物薄膜制备与性能、聚类肽基聚合物分离膜的制备与性能以及具有抗污染功能分离膜的研究。水溶性聚类肽（以肌氨酸为代表）是一种优异的抗污染和生物相容性材料，但其无法独立的作为固体功能材料使用。聚类肽两亲化是实现聚类肽材料功能化的重要途径。本项目合成的两亲聚类肽分子量在3万左右，聚肌氨酸占两亲聚类肽的比例可以调节。研究表明，该材料负载的分离膜，蛋白吸附和血小板吸附显著降低，同时溶血率和细胞毒性降低，表明分离膜显著改善的血液相容性及其在血液透析领域的潜在应用。本项目提出分别采用复合凝胶法、荷电调控法以及季铵化和热引发法制备具有高抗污染抗菌功能分离膜。研究表明，复合凝胶法较传统方法能显著改善抗污染性能并提高水的渗透性；同时，链缠结和静电相互作用能增强分离稳定性；该法为抗有机物吸附和高渗透分离膜的制备提供新思路。荷电调控法以及季铵化和热引发法则侧重于分离膜的抗菌和抗污染功能，实现分离膜在复杂水环境中持久耐污性能，研究季铵盐基团对分离膜抗菌和抗污染性能的影响。该项目研制的新型两亲聚类肽材料和新型抗菌抗污染分离膜的制备方法为高性能化分离膜提供新材料和新方法，在水处理和生物医用领域具有重要的应用价值。