Surface functionalization of metal-organic frameworks for improved moisture resistance
Castells Gil, Javier (Universitat de València. Instituto de Ciencia Molecular)
Novio Vázquez, Fernando (Institut Català de Nanociència i Nanotecnologia)
Padial, Natalia M. (Universitat de València. Instituto de Ciencia Molecular)
Tatay, Sergio (Universitat de València. Instituto de Ciencia Molecular)
Ruiz-Molina, Daniel (Institut Català de Nanociència i Nanotecnologia)
Martí Gastaldo, Carlos (Universitat de València. Instituto de Ciencia Molecular)

Date:	2018
Abstract:	Metal-organic frameworks (MOFs) are a class of porous inorganic materials with promising properties in gas storage and separation, catalysis and sensing. However, the main issue limiting their applicability is their poor stability in humid conditions. The common methods to overcome this problem involve the formation of strong metal-linker bonds by using highly charged metals, which is limited to a number of structures, the introduction of alkylic groups to the framework by post-synthetic modification (PSM) or chemical vapour deposition (CVD) to enhance overall hydrophobicity of the framework. These last two usually provoke a drastic reduction of the porosity of the material. These strategies do not permit to exploit the properties of the MOF already available and it is imperative to find new methods to enhance the stability of MOFs in water while keeping their properties intact. Herein, we report a novel method to enhance the water stability of MOF crystals featuring Cu(OC) paddlewheel units, such as HKUST (where HKUST stands for Hong Kong University of Science & Technology), with the catechols functionalized with alkyl and fluoro-alkyl chains. By taking advantage of the unsaturated metal sites and the catalytic catecholase-like activity of Cu ions, we are able to create robust hydrophobic coatings through the oxidation and subsequent polymerization of the catechol units on the surface of the crystals under anaerobic and water-free conditions without disrupting the underlying structure of the framework. This approach not only affords the material with improved water stability but also provides control over the function of the protective coating, which enables the development of functional coatings for the adsorption and separations of volatile organic compounds. We are confident that this approach could also be extended to other unstable MOFs featuring open metal sites.
Grants:	Ministerio de Economía y Competitividad CTQ2014-59209-P European Commission 714122 Ministerio de Economía y Competitividad MDM-2015-0538 Ministerio de Economía y Competitividad MAT2015-70615-R Ministerio de Economía y Competitividad SEV-2013-0295
Rights:	Tots els drets reservats.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Metal-organic frameworks ; Surface functionalization ; Water stability ; Catecholase biomimetics ; Hydrophobic coating ; Functionalized catechols
Published in:	Journal of visualized experiments, Núm. 139 (May 2018) , art. e58052, ISSN 1940-087X

DOI: 10.3791/58052
PMID: 30247466

6 p, 1.2 MB

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Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles