title: Thermally Triggered Phase Separation of Organic Electrolyte-Cellulose Solutions.
abstract: Organic electrolyte solutions (OES)-binary mixtures of an ionic liquid (IL) with a neutral polar aprotic co-solvent-are being recognized as excellent candidate solvents for the dissolution, derivatization, and sustainable processing of cellulose. These solutions exhibit the beneficially combined properties of rapid-to-instantaneous cellulose dissolution, raised thermal stability, and reduced viscosity, compared to cellulose solutions in the parent ILs. Herein, we report the reversible, thermally triggered phase separation of cellulose solutions in 1-ethyl-3-methylimidazolium acetate with 1,3-dimethyl-2-imidazolidinone. In these solutions, cellulose drives the process of phase separation, resulting in a lower, IL-rich layer in which the biopolymer is segregated. In turn, the upper phase is enriched in the neutral co-solvent. We show that the temperature of phase separation can be fine-tuned by modification of mole fractions of IL, co-solvent, and cellulose. This finding holds promise for the design of strategies for separation and solvent recycling in cellulose chemistry.
authors: Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim-an-der-Ruhr, Germany.
authors: Heitor F N
authors: HF
authors: de Oliveira
authors: Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470, Mülheim-an-der-Ruhr, Germany.
authors: Matthew T
authors: MT
authors: Clough
authors: Department of Chemical Engineering, Imperial College London, South Kensington Campus, London, SW7 2AZ, UK.
authors: Roberto
authors: http://orcid.org/0000-0002-7175-4972
authors: R
authors: Rinaldi
mesh_terms: D002482:Cellulose / Q000737:chemistry* / Q000302:isolation & purification; D007093:Imidazoles; D052578:Ionic Liquids / Q000737:chemistry; D059027:Recycling; D012995:Solubility; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry*; D013696:Temperature
chemical_list: D007093:Imidazoles; D052578:Ionic Liquids; D012996:Solutions; D012997:Solvents; C583574:1,3-dimethyl-2-imidazolidinone; D002482:Cellulose; C518739:1-ethyl-3-methylimidazolium
keywords: cellulose; ionic liquids; organic electrolytes; phase separation; thermodynamics