Zuo Jihao, Zhou Yi, Chen Zehao, Zhao Ting, Tan Qing, Zhou Cailong, Zeng Xinjuan, Xu Shouping, Cheng Jiang, Wen Xiufang, Pi Pihui
School of Chemistry and Chemical Engineering, Guangdong Provincial Key Lab of Green Chemical Product Technology, Guangdong Engineering Technology Research Center of Advanced Insulating Coating, South China University of Technology, Guangzhou 510640, China.
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China.
J Hazard Mater. 2022 May 15;430:128378. doi: 10.1016/j.jhazmat.2022.128378. Epub 2022 Feb 10.
Design of charged materials for demulsification of ionic surfactant-stabilized oil-in-water emulsions is emerging in recent years. Herein, a superwetting stainless steel mesh with Janus surface charges (Janus SSM) was prepared by respectively brush-coating polyethyleneimine/aminated carbon nanotubes (PEI/CNTs-NH) coating and polyacrylic acid (PAA) coating on its two sides. Two demulsification mechanisms, i.e., electrostatic attraction-repulsion and electrostatic repulsion-attraction based on the synergism of two oppositely charged sides were proposed. Combined with the superwettability and optimized pore size, the Janus SSM can successfully be used to demulsify, coalesce and separate emulsions. In detail, the Janus SSM exhibited separation efficiencies of up to 99.29%, 97.12% for SDS- and DTAC-stabilized oil-in-water emulsions respectively under the electrostatic attraction-repulsion mechanism, and up to 97.10%, 98.57% under the electrostatic repulsion-attraction mechanism. The results indicated that the electrostatic attraction-repulsion mechanism proposed in this study is conductive to achieving higher efficiency in emulsion separation. Furthermore, excellent durability extend the operation life of Janus SSM. This Janus SSM, which combines opposite charges on its two sides, may advance the development of charged materials for emulsion separation.
近年来，用于离子表面活性剂稳定的水包油乳液破乳的带电材料设计不断涌现。在此，通过在其两侧分别刷涂聚乙烯亚胺/胺化碳纳米管（PEI/CNTs-NH）涂层和聚丙烯酸（PAA）涂层，制备了一种具有双面电荷的超疏水不锈钢网（双面SSM）。提出了两种破乳机制，即基于两个带相反电荷面协同作用的静电吸引-排斥和静电排斥-吸引。结合超疏水性和优化的孔径，双面SSM可成功用于乳液的破乳、聚结和分离。具体而言，在静电吸引-排斥机制下，双面SSM对SDS和DTAC稳定的水包油乳液的分离效率分别高达99.29%和97.12%，在静电排斥-吸引机制下分别高达97.10%和98.57%。结果表明，本研究提出的静电吸引-排斥机制有助于实现更高效率的乳液分离。此外，优异的耐久性延长了双面SSM的使用寿命。这种两侧带有相反电荷的双面SSM可能会推动用于乳液分离的带电材料的发展。
