State Key Laboratory of Urban Water Resource and Environment (SKLUWRE), School of Environment, Harbin Institute of Technology, Harbin 150090, China.
Key Laboratory of New Membrane Materials, Ministry of Industry and Information Technology, School of Environment and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Environ Sci Technol. 2021 Aug 17;55(16):11308-11317. doi: 10.1021/acs.est.1c02687. Epub 2021 Jul 28.
Membrane distillation (MD) is a promising technology for treating the concentrated seawater discharged from the desalination process. Interconnected porous membranes, fabricated by additive manufacturing, have received significant attention for MD technology because of their excellent permeability. However, their poor hydrophobic durability induced by the deformation of pores constrains their water desalination performance. Herein, an in situ three-dimensional (3D) welding approach involving emulsion electrospinning is reported for fabricating robust nanofibrous membranes. The reported method is simple and effective for welding nanofibers at their intersections, and the reinforced membrane pores are uniform in the 3D space. The results show that the in situ 3D welded nanofibrous membrane, with a stability of 170 h and water recovery of 76.9%, exhibits better desalination performance than the nonwelded (superhydrophobic) nanofibrous membrane and the postwelded (superhydrophobic) nanofibrous membrane. Furthermore, the stability mechanism of the in situ 3D welded nanofibrous membrane and the two different wetting mechanisms of the nonwelded and postwelded nanofibrous membranes were investigated in the current work. More significantly, the in situ 3D welded nanofibrous membrane can further concentrate the actual concentrated seawater (121°E, 37°N) to crystallization, demonstrating its potential applications for the desalination of challenging concentrated seawater.
膜蒸馏（MD）是一种很有前途的技术，可用于处理海水淡化过程中排放的浓缩海水。通过增材制造制造的相互连接的多孔膜因其优异的渗透性而受到 MD 技术的广泛关注。然而，由于孔的变形导致其疏水性耐久性差，限制了其水淡化性能。本文报道了一种涉及乳液静电纺丝的原位三维（3D）焊接方法，用于制造坚固的纳米纤维膜。所报道的方法简单有效，可以在纳米纤维的交点处进行焊接，并且增强后的膜孔在 3D 空间中均匀。结果表明，原位 3D 焊接纳米纤维膜的稳定性为 170 h，水回收率为 76.9%，其淡化性能优于未焊接（超疏水）纳米纤维膜和后焊接（超疏水）纳米纤维膜。此外，本文还研究了原位 3D 焊接纳米纤维膜的稳定性机制以及未焊接和后焊接纳米纤维膜的两种不同润湿机制。更重要的是，原位 3D 焊接纳米纤维膜可以进一步浓缩实际的浓缩海水（121°E，37°N）至结晶，表明其在处理具有挑战性的浓缩海水中具有潜在的应用前景。
