RESUMO
Density functional theory calculations and atoms in molecules theory were performed to investigate the mechanism of cellulose dissolution and regeneration in 1-ethyl-3-methylimidazolium acetate ([emim]Ac), and (1,4)-dimethoxy-ß-D-glucose (Glc) was chosen as the model for cellulose. The theoretical results show that the interaction of [emim]Ac with Glc is stronger than that of Glc with Glc. Further studies indicate that the anion acetate of [emim]Ac forms strong H-bonds with hydroxyl groups of Glc. It is also observed that the H-bonds between [emim]Ac and Glc are weakened or even destroyed by the addition of water. In addition, both the original and regenerated cellulose samples were characterized with FT-IR, XRD, TGA and SEM. The experimental results prove that cellulose can be readily reconstituted from the [emim]Ac-based cellulose solution by the addition of water and the crystalline structure of cellulose is converted to cellulose II from cellulose I in the original cellulose.