Dissolution, materialization and derivatization of chitin and chitosan in ionic liquids

Chitin and chitosan are renewable biomass resources with macromolecular structures. Due to the strong intra- and inter-molecular hydrogen bonds, chitin and chitosan cannot be dissolved in water or traditional organic solvents, which tremendously limit their applications in many fields. Ionic liquid, as a novel green solvent, provides excellent solubility to chitin and chitosan. In this paper, the research progress on dissolution performance and dissolution mechanism of chitin and chitosan in ionic liquids is reviewed. Materials including fibers, films and gels created from the homogeneous solutions are summarized; meanwhile, the chemical derivatization of chitin and chitosan in ionic liquids are also discussed. Finally, the challenges and future development of ionic liquids in chitin and chitosan chemistry are proposed.