Abstract:

In order to improve the structural stability and water resistance of chitosan-based nanofiber membranes, the glutaraldehyde cross-linking modification to the chitosan/polyoxyethylene nanofiber membranes prepared by electrospinning was carried out. Then,the nanofiber membranes of different crossing-linking time were immersed into phosphate buffer saline simulating body fluid environment in order to characterize its microstructure, chemical and crystalline structure, and the water resistance and mechanical properties was measured. The experimental results show that after glutaraldehyde cross-linking modification, the stability of the fiber structure is improved after soaking in the buffer for 24 h,and the water absorption ratio of nanofiber membranes in phosphate buffer saline gradually increases with the cross-linking time and the dissolution ratio gradually decreases, revealing that the cross-linking treatment has a positive effect on the structural stability and water resistance of the fiber membrane. It is also found that the cross-linking modification causes a strong interaction between the molecules, and changes the inherent crystalline structure of chitosan macromolecules, resulting in an increase in the initial modulus of the fiber membrane. In addition, the research shows that the mechanical strength of the nanofiber membranes increases first and then decreases with the extension of the cross-linking time. The cross-linking treatment increases both the strength and brittleness of the fiber membranes.

Key words: chitosan, polyoxyethylene, electrospinning, cross-linking modification, wound care, mechanical property