Browsing by Author "Qiao, A."

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    ArticlePublicationOpen Access
    Flux melting of metal–organic frameworks
    (Royal Society of Chemistry, 2019-03-28) Longley, L.; Collins, S. M.; Li, S. C.; Smales, G. L.; Fındıkçı, İlknur Eruçar; Qiao, A.; Hou, J.; Doherty, C. M.; Thornton, A. W.; Hill, A. J.; Yu, X.; Terrill, N. J.; Smith, A. J.; Cohen, S. M.; Midgley, P. A.; Keen, D. A.; Telfer, S. G.; Bennett, T. D.; Mechanical Engineering; FINDIKÇI, Ilknur Eruçar
    Recent demonstrations of melting in the metal-organic framework (MOF) family have created interest in the interfacial domain between inorganic glasses and amorphous organic polymers. The chemical and physical behaviour of porous hybrid liquids and glasses is of particular interest, though opportunities are limited by the inaccessible melting temperatures of many MOFs. Here, we show that the processing technique of flux melting, borrowed' from the inorganic domain, may be applied in order to melt ZIF-8, a material which does not possess an accessible liquid state in the pure form. Effectively, we employ the high-temperature liquid state of one MOF as a solvent for a secondary, non-melting MOF component. Differential scanning calorimetry, small- and wide-angle X-ray scattering, electron microscopy and X-ray total scattering techniques are used to show the flux melting of the crystalline component within the liquid. Gas adsorption and positron annihilation lifetime spectroscopy measurements show that this results in enhanced, accessible porosity to a range of guest molecules in the resultant flux melted MOF glass.
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    ArticlePublicationOpen Access
    Metal-organic framework glasses with permanent accessible porosity
    (Nature Publishing Group, 2018-11-28) Zhou, C.; Longley, L.; Krajnc, A.; Smales, G. J.; Qiao, A.; Fındıkçı, İlknur Eruçar; Doherty, C. M.; Thornton, A. W.; Hill, A. J.; Ashling, C. W.; Qazvini, O. T.; Lee, S. J.; Chater, P. A.; Terrill, N. J.; Smith, A. J.; Yue, Y.; Mali, G.; Keen, D. A.; Telfer, S. G.; Bennett, T. D.; Mechanical Engineering; FINDIKÇI, Ilknur Eruçar
    To date, only several microporous, and even fewer nanoporous, glasses have been produced, always via post synthesis acid treatment of phase separated dense materials, e.g. Vycor glass. In contrast, high internal surface areas are readily achieved in crystalline materials, such as metal-organic frameworks (MOFs). It has recently been discovered that a new family of melt quenched glasses can be produced from MOFs, though they have thus far lacked the accessible and intrinsic porosity of their crystalline precursors. Here, we report the first glasses that are permanently and reversibly porous toward incoming gases, without post-synthetic treatment. We characterize the structure of these glasses using a range of experimental techniques, and demonstrate pores in the range of 4 – 8 Å. The discovery of MOF glasses with permanent accessible porosity reveals a new category of porous glass materials that are elevated beyond conventional inorganic and organic porous glasses by their diversity and tunability.