Cellulose Amorphization by Swelling in Ionic Liquid/Water Mixtures: A Combined Macroscopic and Second-Harmonic Microscopy Study

Amorphization of cellulose by swelling in ionic liquid (IL)/water mixtures at room temperature is a suitable alternative to the dissolution–precipitation pretreatment known to facilitate enzymatic digestion. When soaking microcrystalline cellulose in the IL 1-ethyl-3-methylimidazolium acetate containing 20 wt% water, the crystallinity of the cellulose sample is strongly reduced. As less than 4% of the cellulose dissolves in this mixture, this swelling method makes a precipitation step and subsequent energy-intensive IL purification redundant. Second harmonic generation (SHG) microscopy is used as a structure sensitive technique for in situ monitoring of the changes in cellulose crystallinity. Combined optical and SHG observations confirm that in the pure IL complete dissolution takes place, while swelling without dissolution in the optimal IL/water mixture yields a solid cellulose with a significantly reduced crystallinity in a single step.

Jaar van publicatie:2015

BOF-keylabel:ja

IOF-keylabel:ja

BOF-publication weight:3

CSS-citation score:1

Authors from:Higher Education

Toegankelijkheid:Closed