title: Enhancement of the antimicrobial properties of orthorhombic molybdenum trioxide by thermal induced fracturing of the hydrates.
abstract: The oxides of the transition metal molybdenum exhibit excellent antimicrobial properties. We present the preparation of molybdenum trioxide dihydrate (MoO3 × 2H2O) by an acidification method and demonstrate the thermal phase development and morphological evolution during and after calcination from 25 °C to 600 °C. The thermal dehydration of the material was found to proceed in two steps. Microbiological roll-on tests using Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa were performed and exceptional antimicrobial activities were determined for anhydrous samples with orthorhombic lattice symmetry and a large specific surface area. The increase in the specific surface area is due to crack formation and to the loss of the hydrate water after calcination at 300 °C. The results support the proposed antimicrobial mechanism for transition metal oxides, which based on a local acidity increase as a consequence of the augmented specific surface area.
authors.affiliation: Technische Universität München (TUM), Chair for Biogenic Polymers, Schulgasse 16, D-94315 Straubing, Germany.
authors.forename: Shahram
authors.initials: S
authors.lastname: Shafaei
authors.affiliation: Technische Universität München (TUM), Chair for Biogenic Polymers, Schulgasse 16, D-94315 Straubing, Germany.
authors.forename: Daniel
authors.initials: D
authors.lastname: Van Opdenbosch
authors.affiliation: Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Department of Materials Science and Engineering 3: Glass and Ceramics, Martensstraße 5, D-91058 Erlangen, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Fey
authors.affiliation: INM, Leibniz Institute for New Materials, Campus D2 2, D-66123 Saarbrücken, Germany.
authors.forename: Marcus
authors.initials: M
authors.lastname: Koch
authors.affiliation: INM, Leibniz Institute for New Materials, Campus D2 2, D-66123 Saarbrücken, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Kraus
authors.affiliation: AMiSTec GmbH & Co. KG, Leitweg 23, A-6345 Kössen, Austria.
authors.forename: Josef Peter
authors.initials: JP
authors.lastname: Guggenbichler
authors.affiliation: Technische Universität München (TUM), Chair for Biogenic Polymers, Schulgasse 16, D-94315 Straubing, Germany. Electronic address: cordt.zollfrank@tum.de.
authors.forename: Cordt
authors.initials: C
authors.lastname: Zollfrank
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000737:chemistry* / Q000494:pharmacology*; D001419:Bacteria / Q000187:drug effects*; D006358:Hot Temperature; D008826:Microbial Sensitivity Tests; D008982:Molybdenum / Q000737:chemistry* / Q000494:pharmacology*; D010087:Oxides / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D010087:Oxides; C082290:molybdenum trioxide; D008982:Molybdenum
keywords: Antimicrobial properties; Molybdenum trioxide; Transition metal oxide