Influence of ionic liquid (IL) treatment conditions in the regeneration of cellulose with different crystallinity

Abstract

In this study, we treated microcrystalline cellulose (MCC) with the ionic liquid (IL) 1-butyl-3-methylimmidazolium chloride (BMIMCl) to elucidate the effects that IL treatment conditions have on the properties of amorphized cellulose (AC). Analysis of X-ray diffractograms confirmed that after 20 min of IL treatment AC crystallinity was reduced from 77.7 to 57.1%. After 10 h of IL treatment, AC crystallinity decreased to 29.6%. Chemical and morphological changes in the regenerated AC were determined via FT-IR and SEM studies. The rapid transformation of crystalline cellulose domains into amorphous domains is linked to the small MCC particle size (20 μm) and the presence of a moisture-free condition during IL treatment. Thermal stability of the treated cellulose, as determined by TGA and DSC profiling, decreased as the crystallinity index decreased. The high tunability of cellulose crystallinity by IL treatment provides a facile way for designing more efficient hybrid bioactive materials for biomedical applications. Graphical abstract: [Figure not available: see fulltext.].