Functional polyaspartic acid fibers hydrogel membrane with enhanced mechanical performance prepared by coaxial electrospinning

Coaxial electrospinning is a practical technique to combine the advantages of different materials. In this work, polyaspartic acid (PASP) fibers hydrogel membrane (FHM) was enhanced by thermoplastic polyurethane (TPU) via coaxial electrospinning. Firstly, polysuccinimide (PSI) served as the intermediate of PASP was employed for coaxial electrospining with TPU. TPU/PSI core-shell fiber possessed cracked shell on core, uniform core-shell structure, dumbbell-shape and beaded-on-string morphology according to parameters adjustment. Then TPU/PASP-FHM was produced by the crosslinking and hydrolysis treatment of TPU/PSI fibers membrane. TPU with excellent mechanical properties improved the tensile strength of TPU/PASP-FHM. Owing to the Cu²⁺ absorption capability of PASP hydrogel shell, TPU/PASP-FHM was successfully used to detect 1 mg L⁻¹ Cu²⁺ with color change from white to blue, which was able to be observed by naked-eye. Moreover, TPU/PASP-FHM after Cu²⁺ detection returned to its original color with acid elution, and it was able to be used repeatedly for Cu²⁺ detection. (paper)