title: Formation of cellulose-carbene complex via depolymerization in ILs: Dependence of IL types on kinetics, conformation and dispersity.
abstract: This study focused on the influence of anion type on the depolymerization and its effect on the molecular state, dynamics and dispersity of cellulose. GPC and the van Gurp-Palmen plot showed that molar mass was more significantly decreased by 1-butyl-3-methylimidazolium chloride ([C4C1Im][Cl]) comparing to 1-butyl-3-methylimidazolium acetate ([C4C1Im][OAc]). Acid-catalyzed hydrolysis of cellulose in IL was proved using base titration which was monitored by conductivity and pH value. On the contrary to the depolymerization case, [C4C1Im][OAc] solution needed more base to be neutralized than [C4C1Im][Cl] solution. The generated carbene was combined with reducing ends of cellulose, which was facilitated in low molar mass consisting of a large number of reducing ends. The formation of cellulose-carbene substitution caused steric hindrance of cellulose chain, thus resulting in increased segmental friction with high molecular density. The cellulose particle combined with carbene can be dispersed stably in aqueous media.
authors.affiliation: Department of Material Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Ahn
authors.affiliation: Department of Organic and Nano System Engineering, Konkuk University, Seoul 05029, Republic of Korea.
authors.forename: Younghan
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Organic and Nano System Engineering, Konkuk University, Seoul 05029, Republic of Korea. Electronic address: iconclast67@hotmail.com.
authors.forename: Hyungsup
authors.initials: H
authors.lastname: Kim
authors.affiliation: Department of Material Science and Engineering, Seoul National University, Seoul 08826, Republic of Korea. Electronic address: sykwak@snu.ac.kr.
authors.forename: Seung-Yeop
authors.initials: SY
authors.lastname: Kwak
mesh_terms: D002482:Cellulose / Q000737:chemistry* / Q000378:metabolism; D006868:Hydrolysis; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D007700:Kinetics; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry; D008968:Molecular Conformation; D058105:Polymerization
chemical_list: D007093:Imidazoles; D052578:Ionic Liquids; C030011:carbene; D002482:Cellulose; D008697:Methane
keywords: Acid-catalyzed hydrolysis; Carbene; Cellulose; Dispersity; Ionic liquid