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ZnO-Al(2)O(3) composites with different Zn/Al molar ratios (R) have been prepared using zinc-aluminium layered double hydroxides (LDHs) Zn( R )Al-CO(3) as precursor. The samples were characterized by XRD, ICP, EDX, EPR and FT-IR. The results show that ZnO is highly dispersed in all of the ZnO-Al(2)O(3) composites. Bactericidal experiments against Staphylococcus aureus ATCC 6538 and Bacillus subtilis var. niger ATCC 9372 were carried out by contacting the bacteria and spores with the ZnO-Al(2)O(3) composites. The composites all showed high bactericidal activity against Staphylococcus aureus ATCC 6538, and the bactericidal efficiency against Bacillus subtilis var. niger ATCC 9372 increased with increasing content of ZnO. The mechanism of bactericidal activity of ZnO-Al(2)O(3) has also been investigated. It is suggested that highly active O(2) (-) and *OH species generated on the surface of ZnO-Al(2)O(3) particles react with the peptide linkages in the cell walls of bacteria or spores resulting in their destruction.
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http://dx.doi.org/10.1007/s10856-008-3585-0 | DOI Listing |
Int J Biol Macromol
August 2025
Physics Department, College of Science, Taibah University, Medina, Saudi Arabia. Electronic address:
This study investigates the synergistic effects of zinc oxide (ZnO) nanorods and aluminium oxide (Al₂O₃) nanoparticles on the functional properties of chitosan/carboxymethyl cellulose (Cs/CMC) biopolymer blends. Cs/CMC/ZnO-Al₂O₃ nanocomposite samples were prepared using the solution casting method. SEM analysis revealed the nanoscale dispersion of ZnO nanorods and Al₂O₃ nanoparticles within the Cs/CMC matrix, while XRD spectra confirmed the crystalline nature of the nanofillers and their impact on reducing the crystallinity of the polymeric nanocomposites.
View Article and Find Full Text PDFMicrosc Microanal
August 2014
1Center for Electron Nanoscopy, Technical University of Denmark,Kgs. Lyngby DK-2800,Denmark.
Specimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking an environmental transmission electron microscope to an in situ X-ray diffractometer through a dedicated transmission electron microscope specimen transfer holder, capable of sealing the specimen in a gaseous environment at elevated temperatures. Two catalyst material systems have been investigated; Cu/ZnO/Al2O3 catalyst for methanol synthesis and a Co/Al2O3 catalyst for Fischer-Tropsch synthesis.
View Article and Find Full Text PDFACS Appl Mater Interfaces
May 2014
Department of Physics and Astronomy, University of Kansas, Lawrence, Kansas 66045, United States.
High-aspect-ratio, vertically aligned carbon nanofibers (VACNFs) were conformally coated with aluminum oxide (Al2O3) and aluminum-doped zinc oxide (AZO) using atomic layer deposition (ALD) in order to produce a three-dimensional array of metal-insulator-metal core-shell nanostructures. Prefunctionalization before ALD, as required for initiating covalent bonding on a carbon nanotube surface, was eliminated on VACNFs due to the graphitic edges along the surface of each CNF. The graphitic edges provided ideal nucleation sites under sequential exposures of H2O and trimethylaluminum to form an Al2O3 coating up to 20 nm in thickness.
View Article and Find Full Text PDFChemSusChem
May 2014
Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim a. d. Ruhr (Germany).
A series of polyols, carbohydrates, and cellulose were tested in the aqueous, CuO/ZnO/Al2O3-catalyzed hydrogenolysis reaction at 245 °C and 50 bar H2. The compositions of liquid-phase products were analyzed; based on these results a unified reaction mechanism is proposed that accounts for the observed product distribution. Elementary transformations such as dehydration, dehydrogenation/hydrogenation, Lobry de Bruyn-van Ekenstein isomerization and retro-aldol cleavage were identified as most important for controlling the selectivity of simple polyols and carbohydrates.
View Article and Find Full Text PDFNanostructured CuO-ZnO-Al2O3/HZSM-5 was synthesized from nitrate and acetate precursors using ultrasound assisted co-precipitation method under different irradiation powers. The CuO-ZnO-Al2O3/HZSM-5 nanocatalysts were characterized using XRD, FESEM, BET, FTIR and EDX Dot-mapping analyses. The results indicated precursor type and irradiation power have significant influences on phase structure, morphology, surface area and functional groups.
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