This study presents the fabrication of double-layer electrospun nanofibrous membranes (DL-ENMs) using polyvinylidene fluoride (PVDF) and polyether sulfone (PES) based polymers with different degrees of hydrophilicity (PES, sulfonated PES, and PES with hydroxyl terminals). A comparative analysis was carried out with single-layer electrospun nanofiber membranes (SL-ENM) with a total thickness of about 375 μm. Using feed solutions, including sodium chloride, sodium nitrate, and simulated nuclear wastewater (SNWW), the performance of DL-ENMs was evaluated for desalination and radionuclide decontamination by direct contact membrane distillation (DCMD) and air gap membrane distillation (AGMD) techniques. The results showed that DL-ENMs, especially those incorporating a sulfonated PES-based hydrophilic layer, exhibited superior permeate fluxes, reaching values of 72.72 kg/mh and 73.27 kg/mh in the DCMD using aqueous feed solutions of NaCl and NaNO, respectively, and 70.80 kg/mh and 41.96 kg/mh using aqueous feed solutions of SNWW in DCMD and AGMD, respectively. Both SL-ENMs and DL-ENMs exhibited high rejection efficiencies and decontamination factors for the feed solutions (>99.9%). In addition, the prepared ENMs were exposed to gamma radiation to evaluate their applicability in real-life applications. The result of irradiation revealed the negative impact of gamma radiation on the fluorine content of PVDF which could be a critical point in using PVDF as a hydrophobic material for decontaminating nuclear wastewater by membrane distillation.

中文翻译：

---

用于海水淡化和核废水处理的伽马辐照 Janus 电纺纳米纤维膜

本研究介绍了使用聚偏二氟乙烯（PVDF）和聚醚砜（PES）基具有不同亲水程度的聚合物（PES、磺化PES和带羟基末端的PES）制造双层电纺纳米纤维膜（DL-ENM）。对总厚度约为375μm的单层静电纺纳米纤维膜（SL-ENM）进行了对比分析。使用包括氯化钠、硝酸钠和模拟核废水 (SNWW) 在内的进料溶液，通过直接接触膜蒸馏 (DCMD) 和气隙膜蒸馏 (AGMD) 技术评估 DL-ENM 的海水淡化和放射性核素净化性能。结果表明，DL-ENM，特别是那些包含基于磺化 PES 的亲水层的 DL-ENM，表现出优异的渗透通量，在使用 NaCl 和 NaNO 水溶液的 DCMD 中分别达到 72.72 kg/mh 和 73.27 kg/mh 的值。使用SNWW在DCMD和AGMD中的水性进料溶液分别为70.80kg/mh和41.96kg/mh。 SL-ENM 和 DL-ENM 均对进料溶液表现出较高的截留效率和去污因子 (>99.9%)。此外，将制备的 ENM 暴露于伽马辐射下，以评估其在现实生活中的适用性。辐照结果揭示了伽马辐射对 PVDF 氟含量的负面影响，这可能是使用 PVDF 作为疏水材料通过膜蒸馏净化核废水的关键点。