A robust underwater superoleophobic aminated polyacrylonitrile membrane embedded with CNTs-COOH for durable oil/water and dyes/oil emulsions separation

• Published in: Chemosphere (Oxford) 2022-04, Vol.293, p.133535-133535, Article 133535
• Main Authors: Zhang, Liyun, He, Yi, Luo, Pingya, Ma, Lan, Li, Shuangshuang, Nie, Yiling, Yu, Jing, Guo, Xiao
• Format: Article
• Language: English
• Subjects: Acrylic Resins; Cassie–Baxter structure; Coloring Agents; Emulsions - chemistry; Nanofibrous membrane; Oil/dye purification; Oils - chemistry; Stability
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2022.133535

Considering the emulsified oil and water-soluble dyes in wastewater, the exploitation of easy-manufacturing, energy-saving and high-efficiency separation materials is urgently required. In this work, integrating the positively charged polyethyleneimine (PEI) with negatively charged CNTs-COOH constructed the superhydrophilic Cassie–Baxter structure onto the electrospun polyacrylonitrile (PAN) membrane surface by ultrasonic, electrostatic interaction and thermal treatment. Based on it, the PEN@CNTs membrane achieved efficient separation for surfactant-free, tween 80-stabilized, SDS-stabilized, and CTAB-stabilized emulsions (the fluxes reached 508–3158 L m−2 h−1, the separation efficiency reached 99.42%) by the splendid water-penetration and oil-repellency, electrostatic interaction, and “aperture sieve”. Moreover, because of the porosity and strong charged surface of PEN@CNTs membrane, the anionic dyes can be quickly removed by one-step filtrate method (∼403 L m−2 h−1). Meanwhile, the PEN@CNTs membrane also achieved synchronous and efficient remediation for oil/dye mixture emulsions after many cycles. More importantly, facing the complex physical and chemical environments, the combination of the stabilized PEN membrane, inactive CNTs-COOH layer, and the bond of embedding method between CNTs-COOH and PEN nanofibers made the PEN@CNTs membrane demonstrated robust stability and durable separation capability. [Display omitted] •Ultrasonic and electrostatic-assisted preparation of PEN@CNTs membrane.•PEN@CNTs demonstrated separation capability for oily emulsions.•PEN@CNTs achieved synchronously and efficiently remediation for oil/dye emulsions.•PEN@CNTs membrane maintained excellent stability in complex environment.