(587j) A Systematic Computational and Experimental Study of Cation/Anion Pairings of Ionic Liquids With Cellulose | AIChE

(587j) A Systematic Computational and Experimental Study of Cation/Anion Pairings of Ionic Liquids With Cellulose

Authors 

Rabideau, B. D. - Presenter, Laboratoire de Matériaux et des Structures du Génie Civil
Agarwal, A., RWTH Aachen University
Viell, J., RWTH Aachen University
Ismail, A. E., RWTH Aachen University



Ionic liquids (ILs) are currently being investigated as a viable solvent medium to dissolve cellulose. Many of their inherent properties make them desirable in environmentally-friendly processes converting cellulosic biomass into usable resources such as fuels, and plastics. However, many practical considerations still remain. One main obstacle is the lack of understanding surrounding the dissolution of cellulose. Though it has generally been accepted that the ability to dissolve cellulose rests with the hydrogen bond accepting ability of the anions, much less is known about the role of the cation. Interestingly, certain cations can render the anion ineffective, and it has also been reported that the imidazolium chlorides exhibit a peculiar "odd-even" effect with respect to the length of the alkyl tail attached to the imidazolium ring.

We systematically examine the pairings of three different anions with 4 imidazolium-based cations of differing tail length for a total of 12 different ILs. Using both molecular dynamics simulation and experiments we are able to demonstrate how the anions and cations work in unison to solvate cellulose. We find that the tail length affects the coupling of the anion with cellulose and ultimately the overall interaction energy. Further, this coupling of the anions with cellulose contorts the overall structure, facilitating the weaker interactions between the cations and cellulose. A deeper understanding of the interplay between the anions and cations could aid in the search for more effective cellulose solvents.