(587z) An Investigation of Dissolution and Resistance to Dissolution in Cellulose: Or, What Makes a Solvent Good?

Despite the abundant supply of natural cellulose, it still remains a major untapped renewable, energy-rich resource.
This is largely a result of its resistance to dissolution as a result of its strong hydrogen-bonded network. Though a handful of good solvents have been identified, as well as a number of ionic liquids, the underlying processes leading to dissolution remain ill-understood. A better understanding of the key mechanisms leading to this breakup could aid in the search for new and better solvents and pretreatment methods that could facilitate the adoption of large-scale, cost-effective biorefineries.

We examine the breakup of microcrystalline bundles of cellulose in a variety of different imidazolium-based ionic liquids (ILs) via molecular dynamics. We investigate many ILs that have been proven to be effective in dissolving cellulose and other, similar solvents that have not. Using these results alongside single-strand studies we examine how interaction energies, hydrogen bonding, solvent structure, and the presence of certain functional groups aid or inhibit the breakup of the strong hydrogen-bonding network in cellulose. In doing so, we present a clearer picture of the complex interactions between cellulose and solvent and aim to answer what makes a solvent "good."