Exploring the incorporation of nitrogen-doped carbon quantum dots (NCQDs) on polyethersulfone (PES) membrane with dual-responsive self-healing property for water filtration

In recent years, self-healing materials have been widely discussed in various applications. A water-responsive polyethersulfone (PES)/polyethyleneimine (PEI)/poly(acrylic acid) (PAA) membrane was successfully fabricated for water filtration and exhibited its self-healing ability, self-healing efficiency and filtration performance is not satisfactory and requires further investigation became the interest. This study aims to further improve the performance of the water-responsive self-healing membranes by incorporating amine-functionalized carbon quantum dots (NCQDs) and introducing a dual-responsive (water and heat) self-healing mechanism. The surface functional groups and morphology analysis of NCQDs were examined, and the surface analysis of the fabricated membranes was determined. In this study, the self-healing efficiency and tartrazine recovery of fabricated NCQDs membranes have improved to 91.1 % and 63.3 %, respectively when the damaged membrane was healed in a dual-responsive mechanism for 6 h. Nonetheless, the pure water flux (PWF) rose by 47.6 % to 33.8 L/m2.h and the tartrazine rejection improved from 71.9 % to 87.9 % when 0.6 vol% and 0.4 vol% of NCQDs were added separately into the PEI and PAA solutions. These findings suggest that adding NCQDs and involving a dual-responsive self-healing mechanism could improve the membrane healing capability and enhance its overall performance. © 2024 Elsevier Ltd