Irregular solution thermodynamics of wood pulp in the superbase ionic liquid [m-TBDH][AcO]

Knowledge of solution thermodynamics is fundamental for solution control and solvent selection processes. Herein, experimentally determined thermodynamic quantities for solutions of wood pulp (hardwood dissolving pulp, i.e. cellulose) in [m-TBDH][AcO] are presented. Model-free activities (a(i,j)) and associated mass fraction (w(i,j)) activity coefficients (Ω(i,j)), are determined to quantify inherent solution non-ideality. Access to the Gibbs energy of mixing, G(mix), in combination with associated partial molar thermodynamic quantities, reveal strong enthalpically favourable (exothermic) interactions due to solvent-j and solute-i contact-encounters. Onset of an entropy driven phase instability appears at increased temperatures as excess entropic contributions dominate solvation character of the irregular solutions formed.