Xiaotong Wang,Yaxin Liu,Ming Zhang,Zhuo Luo,Dongzhi Yang
The development of switchable wettability membranes with high permeation fluxes is crucial for oily sewage treatment. A hierarchical beadlike porous PS fibrous membrane with pH-switchable wettability was precisely fabricated by nonsolvent-induced phase separation during electrospinning, followed by UV photografting copolymers of 2-(dimethylamino) ethyl acrylate (DMAEA) and 3,3,4,4,5,5,6,6,7,7,8,8,8-tridecafluorooctyl acrylate (TFOA). The designed unique structure notably increases the roughness of surface and enhances superwettability. Protonation of the amine groups on the fibers triggered by an acid solution (pH < 2) induces underwater superoleophobicity, which in turn causes superoleophilicity in a neutral or basic solution. The as-prepared fibrous membrane can effectively separate the hexane/water mixture with an oil flux of 10 186.8 L m–2 h–1 and a separation efficiency of 99.2% only driven by gravity. Especially, excellent separation performances (water fluxes) were also realized for other oil/water mixtures with higher viscosity by switching the wettability from superoleophilicity to hydrophilicity. Moreover, the as-prepared fibrous membrane can also be applied to a continuous T-shaped tube device delivering a high handling capacity of 6631.5 L m–2 h–1, which provides the oily sewage treatment with a facile strategy in practical application.
Yuhan Lin,Zhichuan Shen,Junqiao Huang,Junli Zhu,Shiyong Jiang,Shiying Zhan,Yu Xie,Jiahong Chen,Zhicong Shi
Gel polymer electrolytes (GPEs) play a crucial role in promoting the development of lithium metal batteries , as they combine the high ionic conductivity of liquid electrolytes with the enhanced safety provided by solid electrolytes . However, traditional polymer electrolytes are typically poured using non-in-situ methods, which results in poor electrode-electrolyte contact and compromises their performance. In this paper, in situ thermal polymerization is utilized to incorporate di-pentaerythritol pentaacrylate (DPPA) and 3,3,4,4,5,5,6,6,7,7,8,8-tridecafluorooctyl acrylate (TFOA) into PAN spinning porous membranes. Application of TFOA reduces the crystallinity of GPEs and thus enhancing the Li + transport capability, which enables the newly constructed GPEs to exhibit an ionic conductivity of 2.52 × 10 −3 S cm −1 and a lithium-ion transport number of 0.61 at 30 °C. Simultaneously, fluoro-containing groups actively contribute to the formation of a negative solid electrolyte interphase (SEI) film full of LiF, ensuring the stable operation of Li symmetrical batteries for over 2000 h at a current density of 0.40 mA cm −2 . The capacity retention rate of lithium metal batteries (LMBs) with commercial NCM811 cathodes reaches 88.2% after 300 cycles. We firmly believe that our newly designed gel polymer electrolytes (GPEs) can offer a viable solution for high-voltage and high-rate LMBs.
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