Multi-hierarchical structured PTFE membrane for liquid desiccant dewatering via membrane distillation
作者:Y Huang, G Y Zhang, Z J Xu , X T Zhao, W Q Xie, L Y Wang, Z Zhai, J Liu, S F Zhao, Y C Zhao
关键字:PTFE membrane; Hierarchical structure; MD; Desiccant regeneration
论文来源:期刊
具体来源:Journal of Membrane Science
发表时间:2024年
Poly (tetrafluoroethylene) (PTFE) can be used for robust separation membranes owing to its exceptional chemical and thermal stabilities. Simultaneously achieving construction of hierarchical pore structures and re-entrant surface microstructures during the fabrication of PTFE membrane holds significant importance in addressing the issues of low flux and membrane wetting in membrane distillation (MD). Herein, we proposed a flexible method for manufacturing hierarchically structured PTFE membrane by combining electrospinning/spraying with sintering/welding. The present approach facilitated the controlled fabrication of a superhydrophobic PTFE membrane with slippery surface (exhibiting a water contact angle of 153.5°, and an ultralow sliding angle of 7.5°) without using fluoride-based solvents or external nanoparticles. Moreover, the anti-wetting mechanism and performance stability of the PTFE membranes in MD were thoroughly investigated. In liquid desiccant regeneration experiments, the 20 wt% LiCl solution was successfully concentrated to 28.64 wt%. Furthermore, the PTFE membrane demonstrated a stable flux (>30 kg m?2 h?1) and relatively low permeate conductivity (<15 μs cm?1) during treating simulated seawater for 30 h. The present work offers a new approach to fabricate multi-hierarchical structured superhydrophobic membranes for desalination and regeneration of liquid desiccants.