Abstract Pervaporation desalination has several advantages over competing desalination technologies, most notably an ability to select for or against volatile organic compounds and the ability to process high salinity feeds at a low transmembrane pressure. Pervaporation has not been commercialized for desalination applications because of its energy intensity. However, emerging processes such as hydraulic fracturing produce high total dissolved solids (>30–45 g L−1) byproduct streams that exceed the operational limits of traditional reverse osmosis and could be treated by pervaporation. Here, we demonstrate free-standing pervaporation membranes with excellent permeance and high salt removal based on a partially sulfonated pentablock terpolymer with the tradename Nexar™. Pervaporation membranes were easily cast from this material with desalination performances comparable or superior to commercially available membranes. We found that the polymer degree of sulfonation and casting solvent polarity had a significant impact on the membranes’ water uptake but only a modest impact on the pervaporation desalination performance. Membranes with a degree of sulfonation of 52% (2.0 meq g−1 IEC) and a casting solution composed of 50 wt% n-propanol and 50 wt% toluene achieved a water flux of 3.32 kg m−2 h−1 (permeance 135 kg m−2 h−1 bar−1) with 99.5% salt removal in pervaporation from a 32 g L−1 sodium chloride feed solution at room temperature. We demonstrated that dense, non-porous Nexar™ pervaporation membrane permeance and salt separation performance were superior to commercial pervaporation membranes and equivalent to commercial membrane distillation membranes, which have much larger pores. This study demonstrates that commercially available sulfonated pentablock terpolymers are excellent membranes for pervaporation desalination because of their ease of casting and excellent performance.

中文翻译：

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用于高通量渗透蒸发脱盐的独立自组装磺化五嵌段三元共聚物膜

摘要 渗透蒸发脱盐与竞争性脱盐技术相比具有几个优势，最显着的是能够选择或反对挥发性有机化合物，以及在低跨膜压力下处理高盐度进料的能力。由于其能源强度，渗透蒸发尚未商业化用于海水淡化应用。然而，水力压裂等新兴工艺会产生高总溶解固体 (>30–45 g L-1) 副产品流，这些副产品流超出了传统反渗透的操作限制，可以通过渗透蒸发进行处理。在这里，我们展示了基于商品名为 Nexar™ 的部分磺化五嵌段三元共聚物的具有优异渗透性和高脱盐率的独立式渗透蒸发膜。渗透蒸发膜很容易由这种材料浇铸而成，其脱盐性能与市售膜相当或更好。我们发现聚合物磺化度和浇铸溶剂极性对膜的吸水率有显着影响，但对渗透蒸发脱盐性能影响不大。磺化度为 52% (2.0 meq g-1 IEC) 的膜和由 50 wt% 正丙醇和 50 wt% 甲苯组成的浇铸溶液实现了 3.32 kg m-2 h-1 的水通量（渗透率为 135 kg m-2 h-1 bar-1)，在室温下从 32 g L-1 氯化钠进料溶液渗透蒸发去除 99.5% 的盐。我们证明了密集的，无孔 Nexar™ 渗透蒸发膜的渗透性和盐分离性能优于商业渗透蒸发膜，相当于具有更大孔径的商业膜蒸馏膜。该研究表明，市售的磺化五嵌段三元共聚物由于易于浇铸且性能优异，因此是用于渗透蒸发脱盐的出色膜。