Crosslinking degree of polyamide membranes: From determination to rational design
Xiaobei Lan, Yuan Liu, Xiangrong Chen, Shichao Feng, Yinhua Wan, Jianquan Luo
Abstract
Polyamide (PA) membranes produced through interfacial polymerization are widely used in desalination, wastewater treatment, solvent purification, and ion separation applications. Among their structural characteristics, the degree of crosslinking is a critical yet underexplored parameter that influences pore size, free volume, chargeability, permeability-selectivity balance, and long-term stability. However, achieving precise control over the degree and structure of crosslinking remains challenging, primarily due to the uncontrollable nature of interfacial polymerization reactions. This review is the first to systematically focus on the crosslinking of PA membranes, including quantitative characterization methods for crosslinking degree, the impact mechanism of crosslinking on membrane performance, and recent advances in strategies for regulating crosslinking degree. Finally, we discuss the challenges associated with accurately characterizing, precisely controlling, and scaling up the crosslinked structure of PA membranes, and propose the integration of emerging technologies such as in-situ probing, data-driven modeling, and intelligent manufacturing to aid in the design of PA membranes with precisely engineered network architectures. This review offers new insights into the development of next-generation PA membranes with enhanced efficiency and sustainability for separation processes.