Fabrication of Polyacrylonitrile‐Based Composite Fiber Membranes via Ultraviolet‐Curing‐Electrospinning Combined Technology and Their Adsorption Performance for Methylene Blue

ABSTRACT To tackle low adsorption capacity and eco‐unfriendly preparation of methylene blue adsorbents, this study fabricated three polyacrylonitrile (PAN)‐based composite fiber membranes via a novel ultraviolet curing‐electrospinning method, namely Type I (PAN/acrylic acid (AA)‐hydroxypropyl acrylate (HPA)), Type II (PAN/AA‐ethylene glycol (EG)), and Type III (PAN/(AA‐polyacrylamide)‐EG). After 5 cycles at an initial methylene blue concentration of 520 mg/L, the membranes retain over 80% of initial adsorption capacity, demonstrating excellent reusability. Material properties were characterized, and key adsorption‐affecting parameters were studied. Results indicated the Type III membrane with 8% PAN + 9% prepolymer had the best comprehensive performance, achieving a maximum methylene blue adsorption capacity of 1420.84 mg/g, much higher than Type I (958.13 mg/g) and Type II (1159.35 mg/g). Type III membrane has continuous, uniform fibers without beaded defects and excellent thermal stability. The adsorption process is highly consistent with the pseudo‐second‐order kinetic model and Langmuir model, belonging to chemisorption. The mechanism is dominated by electrostatic attraction between carboxyl groups and methylene blue cation, supplemented by hydrogen bonding of amide groups, combined with a flexible cross‐linked network structure. This verifies the “multi‐functional group synergy‐microstructure optimization” design strategy for high‐performance adsorbents, providing a new scheme for the green preparation of efficient MB adsorbents.