title: Ball-milling-induced amorphization of zeolitic imidazolate frameworks (ZIFs) for the irreversible trapping of iodine.
abstract: The I2-sorption and -retention properties of several existing zeolitic imidazolate frameworks (ZIF-4, -8, -69) and a novel framework, ZIF-mnIm ([Zn(mnIm)2 ]; mnIm=4-methyl-5-nitroimidazolate), have been characterised using microanalysis, thermogravimetric analysis and X-ray diffraction. The topologically identical ZIF-8 ([Zn(mIm)2]; mIm=2-methylimidazolate) and ZIF-mnIm display similar sorption abilities, though strikingly different guest-retention behaviour upon heating. We discover that this guest retention is greatly enhanced upon facile amorphisation by ball milling, particularly in the case of ZIF-mnIm, for which I2 loss is retarded by as much as 200 °C. It is anticipated that this general approach should be applicable to the wide range of available metal-organic framework-type materials for the permanent storage of harmful guest species.
authors.affiliation: Department of Materials Science and Metallurgy, The University of Cambridge, Cambridge, CB2 3QZ, UK.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Bennett
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Saines
authors.forename: David A
authors.initials: DA
authors.lastname: Keen
authors.forename: Jin-Chong
authors.initials: JC
authors.lastname: Tan
authors.forename: Anthony K
authors.initials: AK
authors.lastname: Cheetham