title: Metal Oxide Assisted Preparation of Core-Shell Beads with Dense Metal-Organic Framework Coatings for the Enhanced Extraction of Organic Pollutants.
abstract: Dense and homogeneous metal-organic framework (MOF) coatings on functional bead surfaces are easily prepared by using intermediate sacrificial metal oxide coatings containing the metal precursor of the MOF. Polystyrene (PS) beads are coated with a ZnO layer to give ZnO@PS core-shell beads. The ZnO@PS beads are reactive in the presence of 2-methylimidazole to transform part of the ZnO coating into a porous zeolitic imidazolate framework-8 (ZIF-8) external shell positioned above the internal ZnO precursor shell. The obtained ZIF-8@ZnO@PS beads can be easily packed in column format for flow-through applications, such as the solid-phase extraction of trace priority-listed environmental pollutants. The prepared material shows an excellent permeance to flow when packed as a column to give high enrichment factors, facile regeneration, and excellent reusability for the extraction of the pollutant bisphenol A. It also shows an outstanding performance for the simultaneous enrichment of mixtures of endocrine disrupting chemicals (bisphenol A, 4-tert-octylphenol and 4-n-nonylphenol), facilitating their analysis when present at very low levels (<1 μg L(-1) ) in drinking waters. For the extraction of the pollutant bisphenol A, the prepared ZIF-8@ZnO@PS beads also show a superior extraction and preconcentration capacity to that of the PS beads used as precursors and the composite materials obtained by the direct growth of ZIF-8 on the surface of the PS beads in the absence of metal oxide intermediate coatings.
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra. de Valldemossa, km 7.5, 07122, Palma de Mallorca, Spain.
authors.forename: Mateo
authors.initials: M
authors.lastname: Del Rio
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra. de Valldemossa, km 7.5, 07122, Palma de Mallorca, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Palomino Cabello
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra. de Valldemossa, km 7.5, 07122, Palma de Mallorca, Spain.
authors.forename: Veronica
authors.initials: V
authors.lastname: Gonzalez
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra. de Valldemossa, km 7.5, 07122, Palma de Mallorca, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Maya
authors.affiliation: Instituto Nacional del Carbón, INCAR-CSIC, P.O. 73, 33080, Oviedo, Spain.
authors.forename: Jose B
authors.initials: JB
authors.lastname: Parra
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra. de Valldemossa, km 7.5, 07122, Palma de Mallorca, Spain.
authors.forename: Victor
authors.initials: V
authors.lastname: Cerdà
authors.affiliation: Department of Chemistry, University of the Balearic Islands, Cra. de Valldemossa, km 7.5, 07122, Palma de Mallorca, Spain. g.turnes@uib.es.
authors.forename: Gemma
authors.initials: G
authors.lastname: Turnes Palomino
mesh_terms: D001559:Benzhydryl Compounds / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry*; D000073396:Metal-Organic Frameworks / Q000737:chemistry*; D010636:Phenols / Q000737:chemistry*; D052616:Solid Phase Extraction; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D017641:Zeolites; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D007093:Imidazoles; D000073396:Metal-Organic Frameworks; D010636:Phenols; D014874:Water Pollutants, Chemical; D017641:Zeolites; C041594:4-nonylphenol; C105260:4-tert-octylphenol; C006780:bisphenol A; D000098826:Bisphenol A Compounds; C032655:2-methylimidazole
keywords: core-shell spheres; metal-organic frameworks; solid-phase extraction; water analysis; zinc oxide