Cellulose electrospinning from ionic liquids: The effects of ionic liquid removal on the fiber morphology

The importance of the cellulose cycle has been increasing during the last decade along the ambitious targets of bioeconomy, however many novel fabrication processes yet lack of technological robustness. We present the optimization process for the fabrication of cellulose fibrous matrix by wet electrospinning via the controlled removal of the ionic liquids in order to avoid the formation of film-like structures. Fibers were produced on a bespoke wet-type electrospinning rig from cotton cellulose solutions of 3% in different types of ionic liquids (BMIMAc/C10MIMCl/EMIMAc). Three stage elution with a range of elution ratios using deionized water were applied to coagulate cellulose and remove residuals of ionic liquid. A variety of fibrous morphologies has been obtained. In case of a high water/IL ratio, the median fiber width across all ionic liquids was 0.4 μm, with the porosity at 92.3% and the pore diameter at 155 μm. The increasing elution ratio positively affected separate cellulose fiber formation, crystallinity, and mechanical strength of formed structures.