NF membranes with high permeability and excellent antifouling performance based on enhanced steric hindrance and the introduction of polyquaternium-10

In this study, NF membranes (DP NF membranes) with high permeability and excellent antifouling performance were fabricated by 3,5-diaminobenzoic acid (DABA) with steric hindrance through interfacial polymerization and grafting quaternized cationic cellulose derivative polyquaternium-10 (PQ10). The incorporating of DABA and PQ10 was verified through XPS and FTIR characterization. Smoothness of membrane surface was revealed through SEM and AFM. The modified membranes showed a remarkable increase in hydrophilicity, as evidenced by a reduction in water contact angle from 67.07° for PVDF to 30.70° for DP NF membranes. The water flux of the DP NF membrane reached 33.7 L·m −2 ·h −1 . MgSO 4 and Na 2 SO 4 rejection rates of DP NF membranes were 96.4 % and 94.1 %, respectively. DP NF membranes demonstrated high flux recovery ratios, achieving 97.6 % for bovine albumin, 96.8 % for humic acid, 96.4 % for sodium alginate, and 95.4 % for oil/water emulsion. After three fouling cycles, a slight decline was observed to DP NF membranes. Besides, rejection rates and water flux values exhibited no substantial alterations following long-term fouling tests that lasted for 100 h. These findings indicated that the membranes possessed high permeability and excellent antifouling performance, offering a facile and effective method for creating NF membranes for advanced water treatment applications.