当前位置: X-MOL 学术J. Membr. Sci. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Hierarchical Janus membrane with superior fouling and wetting resistance for efficient water recovery from challenging wastewater via membrane distillation
Journal of Membrane Science ( IF 9.5 ) Pub Date : 2021-01-01 , DOI: 10.1016/j.memsci.2020.118676
Shanshan Zhao , Zhu Tao , Muqiao Han , Yu-xi Huang , Bin Zhao , Liang Wang , Xuelin Tian , Fangang Meng

Abstract Conventional hydrophobic membranes are susceptible to membrane fouling and pore wetting, impeding the applications of membrane distillation (MD) processes for water recovery from complex wastewater. To address these challenges, we herein developed a novel Janus membrane by a hybrid plant-derived polyphenols coating and polyelectrolytes layer-by-layer assembly strategy. Through alternative deposition of catechol/chitosan and polyethylenimine (PEI) on top of a hydrophobic polyvinylidene fluoride (PVDF) substrate, a Janus membrane with a superhydrophilic and defect-free top layer was achieved. The synergistic effects of covalent bonding, non-covalent interactions, and electrostatic interactions between neighboring coatings endowed the membrane with robust chemical stability in the pH range of 2–12. In comparison with the pristine PVDF membrane, the Janus membrane exhibited remarkably stable water vapor flux and high quality of effluent during long-term treatments of non-ionic/cationic surfactants and Tween® 20-stabilized oil-in-water (O/W) emulsion in the bench-scale direct contact membrane distillation (DCMD) experiments. The excellent anti-fouling and anti-wetting properties of the Janus membrane were attributed to its hierarchical structured superhydrophilic surface, in which a strong hydration layer was formed and served as an energetic barrier to prevent adsorption of surfactants and oil droplets. Moreover, the electrostatic repulsion between the protonated amino groups on the membrane surface and cationic surfactant molecules also contributed to the robust long-term performance (nearly one-week operation) of the Janus membrane in the treatment of saline water containing cationic surfactant. Our findings reveal the significant role of surface functionality in fouling and wetting resistance of MD membranes and the as-developed Janus membrane shows great potential for water recovery from saline wastewater containing challenging contaminants via DCMD.

中文翻译:

分层 Janus 膜具有优异的抗污染性和抗湿性,可通过膜蒸馏从具有挑战性的废水中有效回收水

摘要 传统的疏水膜易受膜污染和孔隙润湿的影响,阻碍了膜蒸馏 (MD) 工艺从复杂废水中回收水的应用。为了应对这些挑战,我们在此通过混合植物来源的多酚涂层和聚电解质逐层组装策略开发了一种新型 Janus 膜。通过在疏水性聚偏二氟乙烯 (PVDF) 基材上交替沉积儿茶酚/壳聚糖和聚乙烯亚胺 (PEI),实现了具有超亲水性和无缺陷顶层的 Janus 膜。相邻涂层之间的共价键、非共价相互作用和静电相互作用的协同作用使膜在 2-12 的 pH 范围内具有强大的化学稳定性。与原始 PVDF 膜相比,Janus 膜在长期处理非离子/阳离子表面活性剂和 Tween® 20 稳定的水包油 (O/W) 期间表现出非常稳定的水蒸气通量和高质量的出水实验室规模直接接触膜蒸馏 (DCMD) 实验中的乳液。Janus 膜优异的防污和抗润湿性能归功于其分层结构的超亲水表面,其中形成了强大的水合层,并作为能量屏障防止表面活性剂和油滴的吸附。而且,膜表面质子化氨基与阳离子表面活性剂分子之间的静电排斥也有助于 Janus 膜在处理含有阳离子表面活性剂的盐水中具有强劲的长期性能(近一周运行)。我们的研究结果揭示了表面功能在 MD 膜的污垢和抗湿性方面的重要作用,并且开发的 Janus 膜显示出通过 DCMD 从含有挑战性污染物的含盐废水中回收水的巨大潜力。
更新日期:2021-01-01
down
wechat
bug