Development and characterization of dual functional weak-strong acidic ion exchange nanofiber membranes for efficient...

In this study, polyacrylonitrile (PAN) nanofiber membranes with a polyethylene terephthalate (PET) support and dual-layer PAN structure were modified into ion exchange membranes through carboxylation and subsequent sulfonation, yielding AEA-COOH-AMS membranes with both weak and strong acidic functional groups. These membranes were thoroughly characterized in terms of structure, morphology, and adsorption performance. Lysozyme adsorption experiments using purified solutions demonstrated a high binding capacity of 629.16 mg/g at 318 K, with thermodynamic analysis confirming spontaneous and endothermic adsorption. Kinetic studies identified the Avrami model as the best fit, with increasing adsorption rates at higher temperatures. Moreover, complete lysozyme desorption using 0.4 mol/L NaCl validated the membrane's regeneration potential. This study evaluated membrane performance using pure lysozyme solutions under controlled conditions, establishing a foundation for future application in protein separation from complex food matrices. The AEA-COOH-AMS nanofiber membrane system demonstrates strong potential as a reusable platform for selective protein adsorption, with promising prospects for integration into food biotechnology and bioproduct recovery processes.