title: Understanding changes in cellulose crystalline structure of lignocellulosic biomass during ionic liquid pretreatment by XRD.
abstract: X-ray diffraction (XRD) was used to understand the interactions of cellulose in lignocellulosic biomass with ionic liquids (ILs). The experiment was designed in such a way that the process of swelling and solubilization of crystalline cellulose in plant cell walls was followed by XRD. Three different feedstocks, switchgrass, corn stover and rice husk, were pretreated using 1-butyl-3-methylimidazolium acetate ([C4mim][OAc]) at temperatures of 50-130°C for 6h. At a 5 wt.% biomass loading, increasing pretreatment temperature led to a drop in biomass crystallinity index (CrI), which was due to swelling of crystalline cellulose. After most of the crystalline cellulose was swollen with IL molecules, a low-order structure was found in the pretreated samples. Upon further increasing temperature, cellulose II structure started to form in the pretreated biomass samples as a result of solubilization of cellulose in [C4mim][OAc] and subsequent regeneration.
authors.affiliation: College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, China.
authors.forename: Jiafu
authors.initials: J
authors.lastname: Zhang
authors.forename: Yixun
authors.initials: Y
authors.lastname: Wang
authors.forename: Liye
authors.initials: L
authors.lastname: Zhang
authors.forename: Ruihong
authors.initials: R
authors.lastname: Zhang
authors.forename: Guangqing
authors.initials: G
authors.lastname: Liu
authors.forename: Gang
authors.initials: G
authors.lastname: Cheng
mesh_terms: D018533:Biomass; D002482:Cellulose / Q000737:chemistry*; D003460:Crystallization; D007093:Imidazoles / Q000494:pharmacology*; D052578:Ionic Liquids / Q000494:pharmacology*; D008031:Lignin / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: C525963:1-butyl-3-methylimidazolium; D007093:Imidazoles; D052578:Ionic Liquids; C036909:lignocellulose; D002482:Cellulose; D008031:Lignin
keywords: Biomass; Crystallinity; Ionic liquid; XRD