Water responsive chitosan/polyacrylamide self-healable coating for polyethersulfone membrane

Membrane filtration has emerged as a promising technology for wastewater treatment systems. However, its application is restricted by the loss of membrane integrity due to physical damages, resulting in deterioration of deterioration of permeate quality. Herein, a self-healable composite membrane in dead-ended filtration system was developed by coating chitosan/polyacrylamide (CS/PAM) on polyethersulfone (PES), in which able to form dynamic hydrogen bonds that are essential for self-healing. The CS/PAM exploits the natural hydrogen-bonding capability of chitosan and the flexible network structure of polyacrylamide to achieve rapid repair of damaged sites. Upon fluxed with water, swelling of CS/PAM coating leads to the reconnection of fracture interfaces and provides mobility for the chains to form dynamic hydrogen bonding. From the findings, CS/PAM-coated PES membrane prepared by 2 h curing and coating condition of 1.2:1 CS to PAM mass ratio and 45 min coating time demonstrates high permeability flux (36.58 L/m 2 h), remarkable self-healing efficiency (100 %) of pure water flux and high tartrazine dye rejection (73.12 %). Besides, the results show that operating pressure exhibits negligible effect on self-healing efficiency. The result of this study presents a promising alternative by employing this self-healable CS/PAM-coated PES membrane in the application of realistic environment.