Mechanistic study on the cellulose dissolution in ionic liquids by density functional theory  

用密度泛函理论研究离子液体中的纤维素溶解机理（英文）

作　　者：姚莹莹 李垚 刘晓敏 张晓春 王键吉 姚晓倩 张锁江 

机构地区：[1]Beijing Key Laboratory of Ionic Liquids Clean Process,Key Laboratory of Green Process and Engineering Institute of Process Engineering,Chinese Academy of Sciences [2]School of Chemistry and Chemical Engineering,University of Chinese Academy of Sciences [3]Key Laboratory of Green Chemical Media and Reactions,Ministry of Education,School of Chemistry and Environmental Science,Henan Normal University

出　　处：《Chinese Journal of Chemical Engineering》2015年第11期1894-1906,共13页中国化学工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China(21210006,21276255,21406230,91434111);the Natural Science Foundation of Beijing of China(2131005,2142029)

摘　　要：Ionic liquids （ILs） have attracted many attentions in the dissolution of cellulose due to their unique physicochemical properties as green solvents. However, the mechanism of dissolution is still under debate. In this work, computational investigation for the mechanisms of dissolution of cellulose in [Bmim]Cl, [Emim]C1 and [Emim]OAc ILs was performed, and it was focused on the process of breakage of cellulose chain and ring opening using cellobiose as a model molecule. The detailed mechanism and reaction energy barriers were computed for various possible pathways by density functional theoretical method. The key finding was that 1Ls catalyze the dissolution process by synergistic effect of anion and cation, which led to the cleavage of cellulose chain and formation of derivatives of cellulose. The investigation on ring opening process ofcellobiose suggested that carbene formed in ILs played an important role in the side reaction of cellulose, and it facilitated the formation of a covalent bond between cellulose and imidazolium core. These computation results may provide new perspective to understand and apply ILs for pretreatment of cellulose.Ionic liquids(ILs) have attracted many attentions in the dissolution of cellulose due to their unique physicochemical properties as green solvents.However,the mechanism of dissolution is still under debate.In this work,computational investigation for the mechanisms of dissolution of cellulose in[Bmim]Cl,[Emim]Cl and[Emim]OAc ILs was performed,and it was focused on the process of breakage of cellulose chain and ring opening using cellobiose as a model molecule.The detailed mechanism and reaction energy barriers were computed for various possible pathways by density functional theoretical method.The key finding was that ILs catalyze the dissolution process by synergistic effect of anion and cation,which led to the cleavage of cellulose chain and formation of derivatives of cellulose.The investigation on ring opening process of cellobiose suggested that carbene formed in ILs played an important role in the side reaction of cellulose,and it facilitated the formation of a covalent bond between cellulose and imidazolium core.These computation results may provide new perspective to understand and apply ILs for pretreatment of cellulose.

关 键 词：Ionic liquidsCelluloseDissolution mechanism 

分 类 号：O636.11[理学—高分子化学] O613.4[理学—化学]