纳米纤维支撑结构渗透汽化复合膜的制备及其脱盐性能研究

Pervaporation composite membranes have potential advantages in salty water desalination, but present available pervaporation composite membranes are low in desalination efficiency. In this study, in order to meet the potential needs of high-performance pervaporation composite membranes, we started from changing the conventional structure of pervaporationmembrane, first we chose suitable polymer material to prepare nanofiber support layer with special structure and high porosity by electrospinning method, and selected hydrophilic polymer material to prepare ultra-thin skin layer with controllable thickness and surface microstructure by electrospraying on the surface of nanofiber support layer, then controlled the chemical structure and free volume of the ultra-thin skin layer by controlling the cross-linking process to give it good separation performance, and eventually obtained pervaporation composite membranes with high flux and high desalination efficiency. The desalination performance was characterized, and the desalination mechanism was investigated.

由于渗透汽化复合膜在盐水淡化领域脱盐具有潜在的优势，但是当前渗透汽化复合膜脱盐效率普遍较低，本课题结合对高性能渗透汽化复合膜的潜在需求，从改变渗透汽化膜的常规结构出发，首先选取合适的聚合物材料，通过静电纺丝法制备出具有特殊结构及高孔隙率的纳米纤维支撑层，并且选取亲水性较好的聚合物材料在纳米纤维支撑层表面利用静电喷涂技术制备厚度及表面微结构可控的超薄皮层，然后通过不同的交联方法对已得到的超薄皮层的化学结构和自由体积进行控制，使之具有优良的分离性能，最终得到高通量的、具有高脱盐效率的渗透汽化复合膜，并对渗透汽化复合膜的脱盐性能和脱盐机理分别进行表征和深入研究。

制备并完善了以电纺丝PAN为支撑膜，PVA为涂层的渗透汽化复合膜。开发了GO/PAN高性能渗透汽化脱盐复合膜,在分离90°C 35000 ppm盐水溶液时水通量高达65.1 LMH 。分别以PMDA和SPTA做交联剂，制备了交联PVA/PAN渗透汽化脱盐膜，膜水通量高达46kg/L m2,脱盐率高于99.8%。以商业化DAIS膜为基础，制备了平板渗透汽化膜中试装置。：在处理3.5wt% NaCl盐水时，产水量可达到80 L/d。为渗透汽化脱盐的工业应用和开发奠定了基础。同时采用分子模拟，建立了磺酸基团促进水分子传质的分子模型。为新一代SPTA交联的PVA渗透汽化脱盐膜的高性能做出了理论解释。项目执行4年间，发表SCI论文12篇，核心论文5篇，申请专利2项，圆满完成项目计划。