Potential water-responsive self-healing membrane modified by oppositely-charged polyethyleneimine (PEI)/poly(acrylic acid) (PAA) via layer-by-layer (LbL) method
Eng Cheong Wong, Woon Chan Chong, Ying Hui Ong, Yean Ling Pang, Woei Jye Lau
Abstract
Physical damage on the membrane is the common issues that cause the loss of membrane performance. Pinpointing the precise damage location is almost impossible, sparking increased interest among researchers to tackle this demanding task. Polyelectrolytes polyethyleneimine (PEI) and poly(acrylic acid) (PAA) have demonstrated successful healing ability in various applications, but their healing ability in membrane technology is still unclear. Herein, this research fabricates a water-responsive self-healing membrane by modifying polyethersulfone (PES) substrate surface using PEI and PAA via layer-by-layer (LbL) method. Surface functional groups, morphology analysis and elemental compositions of the fabricated membrane were examined. From the results, the best-performing membrane exhibited its highest self-healing effectiveness at 75.9% based on pure water flux (PWF) when employing a concentration of 5.0 mg/mL of PEI and PAA solutions, with a ratio of 1:1 in a single-bilayer configuration. Besides, the tartrazine rejection of the healed membrane at the aforementioned configuration successfully improved by 95.6% compared to the pristine PES membrane. These findings revealed the capability of PEI and PAA as potential healing agents in membrane technology for water filtration. However, further studies are suggested to improve the membrane performance and self-healing efficiency of the fabricated membrane by investigating various modifications.