Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, College of Materials Science and Engineering, Nanjing Forestry University, No. 159 Longpan Road, Nanjing 210037, PR China.
School of Materials Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, PR China.
J Hazard Mater. 2023 Jan 5;441:129900. doi: 10.1016/j.jhazmat.2022.129900. Epub 2022 Sep 3.
Oily sewage discharged from indiscriminate industrial and frequent oil spills have become a serious global problem. There is an urgent need to separate stable oil/water emulsions by efficient and environmentally friendly methods. Membrane separation technology has the advantages of low energy consumption and low cost, thus is an effective solution to the problems of oily wastewater. However, the manufacture of multifunctional membranes with high efficiency, high flux and self-cleaning using renewable materials remains a challenge. Herein, three-dimensional (3D) smart membranes with switchable superhydrophobic-hydrophilic surfaces were prepared by grafting photo-responsive poly-spiropyran (PSP) on wood-based substrates via surface atom transfer radical polymerization. This novel membrane can efficiently separate stabilized water-in-oil and oil-in-water emulsions due to reversible hydrophilic-hydrophobic transition by switching UV and visible light irradiation. Remarkably, after immobilization, the PSP grafted on the wood substrate exhibited a faster photo response effect than the free spiropyran (SP). More importantly, the prepared 3D smart membranes showed exceptional high flux (4392 L•m•h) and efficiency (above 99.99 %), good cycle stability (99.99 % after 12 times) and durability (available for at least 60 days) for the separation of surfactant-stabilized water-in-oil emulsions. This work opens a new avenue for the design of functional biomass-derived membranes for efficient and sustainable oily wastewater treatment with high flux, easy scale-up, and green regeneration.
含油污水的排放和频繁的溢油已成为一个严重的全球性问题。因此，需要采用高效且环保的方法来分离稳定的油/水乳液。膜分离技术具有能耗低、成本低的优点，是解决含油废水问题的有效方法。然而，利用可再生材料制造具有高效、高通量和自清洁功能的多功能膜仍然是一个挑战。本文通过表面原子转移自由基聚合（ATRP），将光响应聚螺吡喃（PSP）接枝到基于木材的基底上，制备了具有可切换超亲水性/疏水性表面的三维（3D）智能膜。由于通过切换紫外光和可见光照射实现可逆的亲水-疏水转变，这种新型膜可以有效地分离稳定的油包水和水包油乳液。值得注意的是，固定化后，接枝在木材上的 PSP 比游离的螺吡喃（SP）具有更快的光响应效果。更重要的是，所制备的 3D 智能膜在分离表面活性剂稳定的油包水乳液时表现出优异的高通量（4392 L·m·h）和效率（超过 99.99%）、良好的循环稳定性（12 次后仍保持 99.99%）和耐用性（至少 60 天内有效）。这项工作为设计具有高效、可持续的含油污水处理功能的生物质衍生膜开辟了新途径，该膜具有高通量、易于放大和绿色再生等优点。
