title: Effect of chain topology of polyethylenimine on physisorption and chemisorption of carbon dioxide.
abstract: Polyethylenimine (PEI) is a promising candidate for CO2 capture. In this work, the physisorption and chemisorption of CO2 on various low-molecular-weight PEIs are investigated to identify the effect of chain architecture on sorption. The reliability of theoretical calculations are partially supported by our experimental measurements. Physisorption is calculated independently by the reference interaction-site model integral equation theory; chemisorption is distinguished from the total sorption given by the quantum density functional theory. It is shown that, as the chain length increases, both chemisorption and physisorption drop off nonlinearly, but the decay amplitude of chemisorption is more apparent. Conversely, as the amine group approaches the central triamine unit of each oligomer, the sorption capacity decreases, affecting the sorption equilibrium in a complex way. This arises from the cooperative contribution of an increased steric effect and renormalized electronic distribution.
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing (China).|The Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing (China).
authors.forename: Qiangli
authors.initials: Q
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing (China).
authors.forename: Quanyong
authors.initials: Q
authors.lastname: Wang
authors.affiliation: The Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing (China).
authors.forename: Chen
authors.initials: C
authors.lastname: Zhang
authors.affiliation: The Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing (China). duzj@mail.buct.edu.cn.
authors.forename: Zhongjie
authors.initials: Z
authors.lastname: Du
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing (China).
authors.forename: Ming
authors.initials: M
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, No. 15 Beisanhuan East Road, Chaoyang District, Beijing (China). mijg@mail.buct.edu.cn.
authors.forename: Jianguo
authors.initials: J
authors.lastname: Mi
keywords: density functional theory; electronic renormalization; reference interaction-site model; sorption efficiency; steric effects