title: Seawater Pervaporation through Zeolitic Imidazolate Framework Membranes: Atomistic Simulation Study.
abstract: An atomistic simulation study is reported for seawater pervaporation through five zeolitic imidazolate framework (ZIF) membranes including ZIF-8, -93, -95, -97, and -100. Salt rejection in the five ZIFs is predicted to be 100%. With the largest aperture, ZIF-100 possesses the highest water permeability of 5 × 10(-4) kg m/(m(2) h bar), which is substantially higher compared to commercial reverse osmosis membranes, as well as zeolite and graphene oxide pervaporation membranes. In ZIF-8, -93, -95, and -97 with similar aperture size, water flux is governed by framework hydrophobicity/hydrophilicity; in hydrophobic ZIF-8 and -95, water flux is higher than in hydrophilic ZIF-93 and -97. Furthermore, water molecules in ZIF-93 move slowly and remain in the membrane for a long time but undergo to-and-fro motion in ZIF-100. The lifetime of hydrogen bonds in ZIF-93 is found to be longer than in ZIF-100. This simulation study quantitatively elucidates the dynamic and structural properties of water in ZIF membranes, identifies the key governing factors (aperture size and framework hydrophobicity/hydrophilicity), and suggests that ZIF-100 is an intriguing membrane for seawater pervaporation.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , 117576, Singapore.
authors.forename: Krishna M
authors.initials: KM
authors.lastname: Gupta
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , 117576, Singapore.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Qiao
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , 117576, Singapore.
authors.forename: Kang
authors.initials: K
authors.lastname: Zhang
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore , 117576, Singapore.
authors.forename: Jianwen
authors.initials: J
authors.lastname: Jiang
keywords: ZIFs; atomistic simulation; permeability; pervaporation; salt rejection