Shape-memory behaviors of electrospun chitosan/poly(ethylene oxide) composite nanofibrous membranes

With aim of constructing a class of functional environmentally friendly materials, we electrospun chitosan (CS) blends with various contents of poly(ethylene oxide) (PEO) into a series of composite nanofibrous membranes exhibiting shape-memory behaviors. In the present composite system, CS and PEO served as hard and soft domains, respectively. The CS, presenting no thermal transition, and the PEO, with apparent melting-crystallization, were demonstrated by differential scanning calorimetry testing. Characterizations also revealed that the morphologies of the CS/PEO membranes were controlled by the mass ratios of CS/PEO. The composite fibrous membranes showed great mechanical performances and thermal stabilities as well. Moreover, CS/PEO possessed excellent shape-memory behaviors. Such fibrous membranes could complete their shape-recovery processes within 20 s at the temperature of 20°C above the melting transition temperature (T_m). Both the shape fixity and shape-recovery ratios were higher than 90%, even after five cycles. The CS/PEO fibrous membranes present significant potential applications in the field of biotechnology and tissue engineering, such as in scaffolds and smart tubes.