title: The dynamic process of atmospheric water sorption in [EMIM][Ac] and mixtures of [EMIM][Ac] with biopolymers and CO2 capture in these systems.
abstract: There are mainly three findings related to the dynamic process of atmospheric water sorption in the ionic liquid (IL) 1-ethyl-3-methlyl-imidazolium acetate ([EMIM][Ac]) and its mixtures with biopolymers (i.e., cellulose, chitin, and chitosan), and CO2 capture in these systems above. The analytical methods mainly include gravimetric hygroscopicity measurement and in situ infrared spectroscopy with the techniques of difference, derivative, deconvoluted attenuated total reflectance and two-dimensional correlation. These three findings are listed as below. (1) Pure [EMIM][Ac] only shows a two-regime pattern, while all the mixtures of [EMIM][Ac] with biopolymers (i.e., cellulose, chitin, and chitosan) present a three-regime tendency for the dynamic process of atmospheric water sorption. Specifically, the IL/chitosan mixture has a clear three-regime mode; the [EMIM][Ac]/chitin mixture has an unclear indiscernible regime 3; and the [EMIM][Ac]/cellulose mixture shows an indiscernible regime 2. (2) [EMIM][Ac] and its mixtures with biopolymers could physically absorb a trace amount of and chemically react with a much larger amount of CO2 from the air. The chemisorption capacity of CO2 in these pure and mixed systems is ordered as chitosan/[EMIM][Ac] mixture > chitin/[EMIM][Ac] mixture > cellulose/[EMIM][Ac] mixture > pure [EMIM][Ac] (ca. 0.09 mass ratio % g/g CO2/IL). (3) The CO2 solubility in [EMIM][Ac] decreases about 50% after being exposed to the atmospheric moist air for some specific time period.
authors.affiliation: Department of Chemistry, Renmin University of China , Beijing 100872, P. R. China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Xiaofu
authors.initials: X
authors.lastname: Sun
authors.forename: Chuanyu
authors.initials: C
authors.lastname: Yan
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Cao
authors.forename: Tiancheng
authors.initials: T
authors.lastname: Mu
mesh_terms: D000327:Adsorption; D001704:Biopolymers / Q000737:chemistry*; D002245:Carbon Dioxide / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry; D002686:Chitin / Q000737:chemistry; D048271:Chitosan / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D012995:Solubility; D013055:Spectrophotometry, Infrared; D014867:Water / Q000737:chemistry*; D017155:Wettability
chemical_list: D001704:Biopolymers; D007093:Imidazoles; D052578:Ionic Liquids; D014867:Water; D002686:Chitin; D002245:Carbon Dioxide; D002482:Cellulose; D048271:Chitosan; C518739:1-ethyl-3-methylimidazolium