Electrospinning of cellulose nanofibers from ionic liquids: The effect of different cosolvents

Abstract

Cellulose was electrospun with various concentrations of ionic liquid and cosolvent. Three different cosolvents were used in this study; dimethylacetamide (DMAc), dimethyl formamide (DMF), and dimethyl sulfoxide (DMSO). The cosolvents were added to modify the viscosity, electrical conductivity, and surface tension of the solutions. The solubility of cellulose in ionic liquids is highly affected by changes in solvent properties on the molecular level in the binary solvent systems. The difference in molecular structure of the cosolvents and the interactions between cosolvent and ionic liquid can explain the difference in dissolution power of the cosolvents. Scanning electron microscope (SEM) was used to characterize electrospun cellulose fibers. For the systems tested the importance of having a rather high viscosity and high surface tension, and some degree of shear thinning to produce fibers is shown. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Ionic Liquid as Reaction Media for the Production of Cellulose-Derived Polymers from Cellulosic Biomass

“…Although, cellulose/IL/DMSO solutions behave as Newtonian fluids at very low cellulose concentration (<0.80 wt %), the solution viscosity increases with cellulose concentration and exhibits a shear-thinning behavior at higher shear rates [118]. Additionally, shear thinning behavior can be detected, as well with dimethylacetamide (DMAc) and dimethylformamide (DMF), at high fractions of IL [119]. As an alternative to water or organic solvents, viscosity reduction can be provided by carbon dioxide (CO 2 ) [120].…”

Antimicrobial activity of cellulose-based nanofibers with different Ag phases

“…Among the nanostructured celluloses, cellulose-based nanofibers are very interesting, due to relatively easy fabrication via the electrospinning process. Several solvents that directly dissolve cellulose have been used for electrospinning, including N-methyl-morpholine N-oxide/water (NMMO/ water), dimethylacetamide/lithium chloride (DMAc/LiCl), and ionic liquids [5][6][7][8]. However, these solvents have low volatility, and thus cannot completely evaporate during the electrospinning process.…”

Effect of methylimidazole on cellulose/ionic liquid solutions and regenerated material therefrom

“…It has been suggested that appropriate cosolvents can be found by measuring solvatochromic parameters [20], which has been reported for e.g., N-methylimidazole (MIM) [21]. Dimethylsulfoxide (DMSO), N,N-dimethylacetamide (DMAc), and dimethylformamide (DMF) have been used together with BMIMCl and other ILs to increase reactivity and/or processability of cellulose in solution [22,23]. Cosolvents can be used to facilitate derivatization, e.g., molecular bases such as pyridine used as catalysts in tosylation reactions [21] and for viscosity modification [24].…”