Control of the morphology of cellulose acetate nanofibers via electrospinning

The morphologies of cellulose acetate (CA) nanofibers were studied in relation to various factors, i.e., the composition of the solvent; the concentration of the polymer; and the solubility of the solvent and the polymer. Also, we incorporated polyvinylpyrrolidone (PVP) in the CA nanofibers to modulate the morphology to some extent. We used mixtures of the solvents dimethylformamide (DMF) and acetone at volume ratios of 6:4, 4:6 and 2:8, and we also used mixtures of the solvents dichloromethane (DCM) and acetone at the volume ratio of 3:1. The mixture of DMF/acetone can be used to fabricate very smooth, bead-free CA nanofibers in the proper concentration of polymer. It was remarkable that the higher volume ratios of the good solvent (DMF) required higher polymer concentrations for the successful fabrication of nanofibers. This result implies that the quality of the solvent affects the formation of the nanofibers. In addition, porous CA nanofibers can be fabricated with the DCM/acetone solvent mixture through electrospinning. In this case, the surface roughness of the fabricated nanofibers could be adjusted by varying the concentration of the polymer. Hot water treatment of the CA nanofibers with PVP incorporated can be used to control the morphology of the nanofibers. These results confirmed that these methods are straightforward and facile and that it can be used to control the morphology of CA nanofibers, thereby broadening the application of CA nanofibers.