A novel Janus sponge fabricated by a green strategy for simultaneous separation of oil/water emulsions and dye contaminants

• Published in: Journal of hazardous materials Vol. 424; no. Pt B; p. 127543
• Main Authors: Zeng, Xinjuan, Cai, Weicheng, Fu, Shuyi, Lin, Xiaomei, Lu, Qiaorou, Liao, Shuang, Hu, Huawen, Zhang, Min, Zhou, Cailong, Wen, Xiufang, Tan, Shaozao
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.02.2022
• Subjects: Adsorption; Coloring Agents; Dye removal; Eco-friendly fabrication; Emulsions; Janus sponge; Oil/water emulsion separation; Oils; Real industrial wastewater; Wettability; Oil/water emulsion separation; Dye removal; Real industrial wastewater; Janus sponge; Eco-friendly fabrication
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2021.127543

A novel Janus sponge with the ability to remove complex contaminants from water is reported. Firstly, a superhydrophilic sponge (PA@PEI-sponge) is prepared via synthesizing negatively charged phytic acid@polyethyleneimine (PA@PEI) nanoparticles and assembling them on the surface of polydopamine (PDA) and PEI-modified polyurethane (PU) sponge through electrostatic adsorption. The Janus sponge is generated by modifying one side of the PA@PEI-sponge with PDMS, which exhibits superior separation efficiency and high filtration flux toward both water-in-oil and oil-in-water emulsions due to its multiplex selective wettability and the interconnected and tortuous 3D porous channels. The numerous negatively charged active sites of PA@PEI nanoparticles and PDA layer impart the superhydrophilic PA@PEI-sponge with the removal efficiency of 39.95 ± 0.27% for malachite green (MG) via simple flow-through filtration, which can be improved to 99.92 ± 0.07% by Janus modification. More importantly, the Janus sponge exhibits an excellent treatment capacity for complex mixtures containing emulsified oil and dye, with the separation efficiency above 99.59%. The Janus sponge also demonstrates the effective separation of real industrial wastewater collected from an acrylic dyeing plant. Together with a facile and green preparation strategy, this Janus sponge shows excellent application potential for simultaneous dye removal and oil/water emulsion separation. [Display omitted] •An eco-friendly Janus sponge is prepared using a facile and green strategy.•The Janus sponge can separate both water-in-oil and oil-in-water emulsions.•The Janus modification promotes the dye removal efficiency from 39.95% to 99.92%.•The Janus sponge exhibits an excellent treatment capacity for complex wastewater.