聚醚胺基接枝聚偏氟乙烯多功能复合膜的制备及其作用机制模拟

It is still a crucial scientific problem to improve the salinity tolerance and oil repellent properties for membranes using in oil-in-seawater treatment. According to the high salinity tolerance and strong hydrophilic property of polyether/amidogen surfactants, the project is aimed to study the polyether-amidogen surfactant grafted poly(vinylidene fluoride) (PVDF) membrane through both experimental and simulated methods.. Surfactants are most used to modify membranes by coating because of the limit of surfactant structures, which may result in the instability of membranes. Therefore, polyether-amidogen surfactant with alkenyl in hydrophobic tail will be designed and synthesized. Then the surfactant will be grafted on PVDF through UV polymerization to produce better stability, salinity tolerance and hydrophilic membranes. The design of molecular structure, aggregated state structures of the polymers and microporous structures of composite membranes will be explored to study the effect factors, such as surfactant structure, grafting rate, microporous structure, on salinity tolerance and oil repellent. Molecular dynamic simulation will be used to study the adsorption of oil molecules and the configuration of electrolytes on the membrane surface. The diffusion process of water and electrolytes will also be simulated. The mechanism of interactions between water/oil/electrolytes and membrane will be explored as well. Above all, ultimate purpose is to achieve the control rules of various factors on membrane separation so as to obtain a high efficiency new type membrane which can be used in actual water treatment.

提高膜的耐盐抗油性一直是膜技术在高盐（海洋）含油污水处理领域面临的关键科学问题。基于聚醚及胺基类表面活性剂高耐盐、强亲水的特点，本项目拟采用实验与模拟相结合的方法对聚醚胺基表面活性剂-聚偏氟乙烯（PVDF）多功能复合膜进行研究。.由于结构的限制，表面活性剂对膜材料的改性多采用涂覆方法，难以保证膜稳定性。为此，本项目拟设计合成尾链为烯基的聚醚胺基表面活性剂，采用紫外光聚合反应接枝于PVDF上，以提高复合膜的稳定性、耐盐性及抗油性。通过合成分子的结构设计、接枝聚合物的可控制备以及复合膜微孔结构的调控，研究表面活性剂结构、接枝率、微孔结构等因素与耐盐截油抗污染性能的关系；模拟油分子在不同膜结构表面的吸附、电解质在膜表面的排布、水分子以及电解质在复合膜中的扩散过程，揭示水、油分子及电解质与膜相互作用机理。以期获得多因素对膜分离性能的影响规律，设计、制备出现场条件下的高效新型水处理膜。

在处理工业废水，特别是含有油和其它污染物的高盐废水的过程中，膜的抗污染性能尤为重要。本项目对带有胺基的3-(甲基丙烯酰氧基)乙基]二甲基(3-硫代丙基)氢氧化铵内盐(DMAPS)与盐溶液的相互作用进行研究。并采用紫外光聚合反应将其接枝于PVDF上，以提高复合膜的稳定性、耐盐性及抗油性。通过接枝聚合物的可控制备以及复合膜微孔结构的调控，研究表面活性剂结构、接枝率等因素与耐盐截油抗污染性能的关系；模拟表面活性剂在电解质下与油水的相互作用关系，污染物分子在不同膜结构表面的吸附、电解质在膜表面的排布、水分子以及电解质在复合膜中的扩散过程，揭示水、污染物分子及电解质与膜相互作用机理。这对于新型高效抗盐抗污染膜的合理设计和制备有着十分重要的意义。