writer：Yongyan Wu, Yingbo Chen*, Yongxiang Shi, Yutong Qin, Haowei Bai
keywords：Loose nanofiltration; Aniline activation; Dye separation
source：期刊
specific source：Separation and Purification Technology 405 (2026) 139002
Issue time：2026年

Separation and Purification Technology 405 (2026) 139002

DOI: 10.1016/j.seppur.2026.139002

Growing demand for acidic dye wastewater treatment drives development of acid-resistant nanofiltration (NF) separation layers to expand NF applications. However, acid-resistant materials often yield hydrophobic membranes with low flux and poor rejection. This work developed a poly(amide-sulfonamide) (PASA) NF membrane via interfacial polymerization (IP) using trimesoyl chloride (TMC) and 3-aminobenzenesulfonamide (ABSA). The PASA layer was activated and modified with aniline. Results demonstrated that the polar amino groups of aniline molecules interact with the PASA through hydrogen bonds or dipole interactions, exposing more hydrophilic groups and enhancing surface hydrophilicity. The increase in permeability is largely attributed to the swelling of the selective layer in the aniline solution and the dissolution/washing away of loose oligomers. Additionally, the aniline molecules reacting with residual sulfonyl acyl moderately may further contribute to the swelling or increase the free volume (fractional free volume), expanded the effective pore size, and significantly improved dye solution flux while maintaining a high dye rejection. For Congo Red (CR) and Direct Red 23 (DR23), the membrane maintained 100% rejection with a 26-fold flux increase from 3 to 78.2 L·m?2·h?1·bar?1. For Amaranth (AMA), rejection remained above 90% with a 29-fold flux increase from 3 to 88 L·m?2·h?1·bar?1. After 15 days in 20 wt% H?SO?, dye rejection remained unchanged. The membrane exhibited excellent acid resistance, chlorine resistance, hydrophilicity, and antifouling properties, demonstrating strong potential for acidic dye wastewater treatment.