Ahmed Fayez U, Sharma Sushant, Purkayastha Debarun Dhar
Department of Physics, National Institute of Technology Nagaland, Chumukedima-797103, India.
LCPME, UMR 7564, Université de Lorraine -CNRS, 405 Rue de Vandoeuvre, 54600, Villers-lès-Nancy, France.
ACS Appl Mater Interfaces. 2024 Aug 14;16(32):42641-42659. doi: 10.1021/acsami.4c07900. Epub 2024 Aug 1.
The pressing need for effective methods to separate oil and water in oily wastewater has spurred the development of innovative solutions. This work presents the creation and evaluation of a Janus nanofibrous membrane, also known as the Liquid Diode, developed using electrospinning (e-spinning) and buoyancy-assisted hydrothermal techniques. The membrane features a unique structure: one side is composed of PVDF nanofibers embedded with a GO/TiO composite, exhibiting in-air superhydrophobic and superoleophilic properties, while the reverse side consists of PVDF nanofibers with a ZnO nanorod array, demonstrating in-air superhydrophilic and underwater (UW) superoleophobic properties. This distinct asymmetric wettability enables the membrane to effectively separate both water-in-oil (w-in-o) and oil-in-water (o-in-w) emulsions, achieving an impressive liquid flux and separation efficiency (SE). The in-air superhydrophobic side of the Janus nanofibrous membrane achieves a maximum oil flux () of 3506 ± 250 L m h, while the in-air superhydrophilic side achieves a maximum water flux () of 1837 ± 150 L m h, with SE exceeding 98% for both sides. Furthermore, the Janus nanofibrous membrane maintained reliable mechanical stability after 10 cycles of sandpaper abrasion test and demonstrated excellent chemical stability when subjected to acidic, alkaline, cold water and hot water conditions for 24 h. These properties, combined with its ability in breaking down of organic contaminants (98% ± 2% in 210 min) and pharmaceutical contaminants (97% ± 2% in 210 min) under visible light, highlight its photocatalytic potential. Additionally, the membrane's antifouling and antibacterial properties suggest long-term and sustainable use in wastewater treatment applications. The synergistic combination of these superior properties positions the Janus nanofibrous membrane as a promising solution for addressing complex challenges in wastewater treatment and environmental remediation.
对有效分离含油废水中油和水的方法的迫切需求推动了创新解决方案的发展。这项工作展示了一种采用静电纺丝（电纺丝）和浮力辅助水热技术开发的Janus纳米纤维膜（也称为液体二极管）的制备及评估。该膜具有独特的结构：一侧由嵌入GO/TiO复合材料的PVDF纳米纤维组成，具有空气中超疏水和超亲油性能，而另一侧由具有ZnO纳米棒阵列的PVDF纳米纤维组成，表现出空气中超亲水和水下超疏油性能。这种独特的不对称润湿性使该膜能够有效分离油包水（w-in-o）和水包油（o-in-w）乳液，实现令人印象深刻的液体通量和分离效率（SE）。Janus纳米纤维膜的空气中超疏水侧实现了3506±250 L m⁻² h⁻¹的最大油通量（），而空气中超亲水侧实现了1837±150 L m⁻² h⁻¹的最大水通量（），两侧的SE均超过98%。此外，Janus纳米纤维膜在经过10次砂纸磨损试验循环后保持了可靠的机械稳定性，并且在酸性、碱性、冷水和热水条件下处理24小时后表现出优异的化学稳定性。这些特性，再加上其在可见光下分解有机污染物（210分钟内98%±2%）和药物污染物（210分钟内97%±2%）的能力，突出了其光催化潜力。此外，该膜的抗污和抗菌性能表明其在废水处理应用中具有长期和可持续的使用潜力。这些优异性能的协同组合使Janus纳米纤维膜成为解决废水处理和环境修复中复杂挑战的有前途的解决方案。
