Abstract We report here the fabrication of a membrane with dual wettability capable of desalinating oily saline water using membrane distillation (MD). The fabrication process involves modification of electrospun PVDF-HFP (PH) using a nanozeolite-cellulose surface coating followed by stacking unto unmodified electrospun PH to form a dual-layered membrane. Cross-sectional EDS mapping of the modified PH membranes indicates that as the concentration of nanoparticles in the coating solution increases, they become less uniformly distributed across the membrane thickness. Direct contact membrane distillation (DCMD) of oily saline feed tests show that the membrane performance is optimized when 1 wt % of nanoparticles is embedded in the cellulose coating. The composite membrane with 1 wt % nanosized zeolite loading maintains a flux 38% higher than that of the dual-layered membrane without zeolite due to the increase in the feed side membrane porosity from 41.59% to 49.71%. This study concludes that the incorporation of an optimum amount of nanosized Linde type L (LTL) zeolite into the cellulose surface coating can alter the characteristics of the PH membrane enabling achievement of higher flux in MD without compromising the oil and salt rejection.

中文翻译：

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在双层 PVDF-HFP/纤维素膜中加入纳米级 LTL 沸石以提高膜蒸馏性能

摘要 我们在此报告了一种具有双重润湿性的膜的制造，该膜能够使用膜蒸馏 (MD) 对含油盐水进行脱盐。制造过程包括使用纳米沸石-纤维素表面涂层对电纺 PVDF-HFP (PH) 进行改性，然后堆叠到未改性的电纺 PH 以形成双层膜。改性 PH 膜的横截面 EDS 映射表明，随着涂层溶液中纳米粒子浓度的增加，它们在整个膜厚度上的分布变得越来越不均匀。油性盐水进料测试的直接接触膜蒸馏 (DCMD) 表明，当 1 wt% 的纳米颗粒嵌入纤维素涂层时，膜性能得到优化。由于进料侧膜孔隙率从 41.59% 增加到 49.71%，具有 1 wt% 纳米沸石负载的复合膜保持的通量比没有沸石的双层膜高 38%。该研究得出的结论是，将最佳量的纳米级林德 L 型 (LTL) 沸石掺入纤维素表面涂层可以改变 PH 膜的特性，从而在不影响油和盐截留率的情况下实现更高的 MD 通量。