Production of chitosan nanofibers using the HFIP/acetic acid mixture as electrospinning solvent

Chitosan nanofiber mats are of interest for biotechnological purposes owing to its physical and chemical properties, nonetheless, the production of pristine chitosan nanofibrous mats is challenging due to some of these traits restrict its solubility in most common solvents, thus limiting its electrospun processability. This work presents the production of pristine chitosan electrospun nanofibers using the 1,1,1,3,3,3-Hexafluoro-2-propanol/acetic acid binary mixture as solvent. This binary solvent improves pristine chitosan spinnability and facilitates the one-step fabrication of highly stable nanofiber mats insoluble in water and aqueous media without the need for crosslinking and neutralization, which implies no need for further washing steps, no waste production, less energy consumption, reagents saving and a significant impact on reducing total processing time compared with previously reported methodologies. Moreover, the aqueous adsorption capacity of methyl orange is improved by the microarchitecture of chitosan as-spun nanofibers produced in this work compared with chitosan powder and film, confirming an essential role of the microstructure and highlighting its potential as bioadsorbent for dye removal.