A Novel Cellulose/Ionic Liquid Complex Crystal

Controlling water vapor diffusion into cellulose–ionic liquid solution induced a novel cellulose complex crystal. Its unit cell consists of one glucopyranoside unit and one molecule of ionic liquid as an asymmetric unit, revealed by the results of ¹³C solid-state NMR spectroscopy. The complex crystals exhibited exceptionally large size as indicated by the narrow peak width of X-ray diffraction. This crystal reported in this work represents a new class of cellulose complexes after caustic alkali and amine complexes of cellulose. The present study is potentially significant in understanding the molecular interactions of cellulose and leads to possible applications.