Abstract The industrialization of membrane distillation (MD) is hindered by lack of desirable membranes with high performance. Recently, the engineered electrospun nanofibrous membranes (ENMs), such as dual- or multi-layered ENMs, have displayed superior permeations in MD compared with traditional membranes. However, it is still far from satisfactory due to membrane delamination and performance loss after long-term operation. Herein, inspired by the structure of nest with interweaved branches, we fabricated the interweaving hierarchical fibrous composite (iHFC) membrane comprising the interconnected poly(vinylidene fluoride-co-hexafluoropropylene) (PH) nanofibers and polyethylene terephthalate (PET) microfibers via convectional electrospinning. The hydrophobic PH nanofibers provide an enhanced anti-wetting property and high salt rejection. The PET microfibers could significantly both lower the resistance of mass transfer and improve the heat insulation. Results show that the optimized iHFC membrane having the ratio of PH/PET 1.5/0.8 and membrane thickness 80 μm exhibits both high permeation flux of 65 LMH and stable high performance over 60 h when operated at 40 °C temperature difference. Moreover, the interweaving structure endows the iHFC membrane great mechanical strength and excellent long-term stability. It is believed that the strategy explored, and the unique membrane developed here could pave a path to boost the industrialization of MD membranes.

中文翻译：

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用于高通量和稳健的直接接触膜蒸馏的交织分层纤维复合 (iHFC) 膜的制造

摘要 由于缺乏理想的高性能膜，膜蒸馏（MD）的工业化受到阻碍。最近，与传统膜相比，工程电纺纳米纤维膜 (ENM)，例如双层或多层 ENM，在 MD 中显示出优异的渗透性。然而，由于长期运行后膜层分层和性能损失，仍远不能令人满意。在此，受具有交织分支的巢结构的启发，我们通过对流静电纺丝技术制造了由相互连接的聚（偏二氟乙烯-共-六氟丙烯）（PH）纳米纤维和聚对苯二甲酸乙二醇酯（PET）微纤维组成的交织分层纤维复合材料（iHFC）膜。疏水性 PH 纳米纤维提供增强的抗湿性和高脱盐率。PET 超细纤维可以显着降低传质阻力并提高隔热性能。结果表明，优化后的 iHFC 膜的 PH/PET 比为 1.5/0.8，膜厚为 80 μm，在 40 °C 温差下运行时，既表现出 65 LMH 的高渗透通量，又表现出稳定的高性能超过 60 h。此外，交织结构赋予iHFC膜很大的机械强度和优异的长期稳定性。相信所探索的策略以及这里开发的独特膜可以为促进MD膜的产业化铺平道路。当在 40°C 温差下运行时，8 和膜厚 80 μm 表现出 65 LMH 的高渗透通量和超过 60 小时的稳定高性能。此外，交织结构赋予iHFC膜很大的机械强度和优异的长期稳定性。相信所探索的策略以及这里开发的独特膜可以为促进MD膜的产业化铺平道路。当在 40°C 温差下运行时，8 和膜厚 80 μm 表现出 65 LMH 的高渗透通量和超过 60 小时的稳定高性能。此外，交织结构赋予iHFC膜很大的机械强度和优异的长期稳定性。相信所探索的策略以及这里开发的独特膜可以为促进MD膜的产业化铺平道路。