Xiong Zhu, He Zijun, Mahmud Sakil, Yang Yang, Zhou Li, Hu Chun, Zhao Shuaifei
Institute of Environmental Research at Greater Bay Area, Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, Guangzhou University, Guangzhou 510006, P. R. China.
Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, P. R. China.
ACS Appl Mater Interfaces. 2020 Oct 14;12(41):47018-47028. doi: 10.1021/acsami.0c13508. Epub 2020 Sep 29.
Long-term efficient separation of highly emulsified oily wastewater is challenging. Reported herein is the preparation of a reinforced superhydrophilic, underwater superoleophobic membrane with demulsification properties using active iron nanoparticles in situ generated on a polydopamine (PDA)/polyethylenimine (PEI)-modified polyvinylidene fluoride (PVDF) membrane surface. A stable zwitterionic structure is fabricated on the membrane surface and provides it with an excellent capability of binding a hydration layer, leading to enhanced superhydrophilic/underwater superoleophobic properties. The interaction between the membrane surface and water is quantified using the relaxation time of water. After iron nanoparticles in situ anchoring, the superhydrophilic, underwater superoleophobic PDA/PEI modified PVDF membrane shows more stable flux behaviors, higher oil separation efficiency, demulsification, and excellent antioil-fouling properties for various anionic, nonionic, and cationic surfactant-stabilized oil-in-water emulsions in a crossflow filtration system. The reinforced hydration layer and the amphoteric charged demusification properties of the membrane play important roles in enhancing the membrane separation performance. The reinforced membrane also exhibits excellent cleaning and reusability performance in long-term operations. The outstanding separation performance, as well as the simple and cost-effective fabrication process of the membrane with various favorable properties, highlight its promise in practical emulsified oily water applications.
长期高效分离高度乳化的含油废水具有挑战性。本文报道了一种具有破乳性能的增强型超亲水、水下超疏油膜的制备方法，该膜是通过在聚多巴胺（PDA）/聚乙烯亚胺（PEI）改性的聚偏氟乙烯（PVDF）膜表面原位生成活性铁纳米颗粒而制备的。在膜表面构建了稳定的两性离子结构，使其具有优异的结合水化层的能力，从而增强了超亲水/水下超疏油性能。利用水的弛豫时间对膜表面与水之间的相互作用进行了量化。原位锚定铁纳米颗粒后，超亲水、水下超疏油的PDA/PEI改性PVDF膜在错流过滤系统中对各种阴离子、非离子和阳离子表面活性剂稳定的水包油乳液表现出更稳定的通量行为、更高的油分离效率、破乳性能以及优异的抗油污染性能。增强的水化层和膜的两性带电破乳性能在提高膜分离性能方面发挥着重要作用。增强后的膜在长期运行中还表现出优异 的清洗和可重复使用性能。该膜出色的分离性能以及具有各种良好性能的简单且经济高效的制备工艺，突出了其在实际含油乳化水应用中的前景。
