This study was focused on the experimental investigations about mechanical characteristics and tribological mechanisms of nanometric zirconia dental ceramics. A universal mechanical testing machine was used to test the threepoint flexural strength and the fracture toughness. A microhardness tester was used to test the Vickers hardness of the test specimens. An MRH-3 digital-display high-speed r...

Background: Platelet-rich plasma (PRP) and bioceramics such as hydroxyapatite (HA) and zirconium oxide (ZrO2) are used to reconstruct mandibular defects. We sought to determine the synergistic effects of HA/ZrO2 and PRP and compare their osteogenic activity.Methods: ZrO2 scaffolds were constructed by the slurry method and were then coated with HA and impregnated by PRP/heparan sulfate (HS). Bil...

OBJECTIVE In orthopaedics, novel bioactive composites are largely needed to improve the synthetic achievement of the implants. In this work, semiconducting metal oxides such as SiO2, TiO2, and ZrO2 particles (Ps) were used individually and in different ratios to obtain different biphasic composites. The immunotoxicity of these composites was tested to inspect the potential toxicity prior to the...

A zirconia-based catalyst with controlled crystalline phases is synthesized through a simple thermal decomposition of parent UiO-66 single precursor. The introduction Ti(IV) and Hf(IV) cation into the Zr(IV) framework has been successfully obtained to tune photocatalytic activity over methyl orange (MO) solution. Their resulting phases, morphologies, elemental analysis, band gap values, surface...

X-ray absorption near-edge structure (XANES) depends on stereochemical features of coordination polyhedra around probe atoms. K-edge XANES of Y and Zr segregated in alumina grain boundaries has been obtained and analyzed using metallic Y and Zr, Y2O3, YAG, and monoclinic ZrO2 as standards. Grain-boundary-segregated Y and Zr show a positive chemical shift, and the magnitude of the shift, as comp...

In Pt/ZrO2 catalysts used for CO2/CH4 reforming to syngas, not all accessible Pt contributes equally to the activity of the catalyst. The catalytic activity is determined by the accessibility of Pt on the Pt-ZrO2 perimeter. This is explained in terms of the CO2 activation via carbonate species on the support which must be in the proximity of the Pt particles to react with the methane activated ...

Mixed-matrix membranes based on amorphous and semi-crystalline polyimides with zirconium dioxide (ZrO2) nanostars were synthesized. Amorphous poly(4,4′-oxydiphenylenepyromellitimide) and semi-crystalline polyimide prepared from 1,4-bis(4-aminophenoxy)benzene and 4,4’-oxydiphthalic anhydride were used. The effect of ZrO2 nanostars on the structure and morphology of nanocomposite membranes was st...

Bulk ZrO2 polymorphs generally have an extremely high amorphization tolerance upon low energy ion and swift heavy ion irradiation in which ballistic interaction and ionization radiation dominate the ion–solid interaction, respectively. However, under very high-energy irradiation by 1.33 GeV U-238, nanocrystalline (40–50 nm) monoclinic ZrO2 can be amorphized. A computational simulation based on ...

Vapor-phase naphthalene hydrogenation over various supported Pt catalysts was studied in a continuous fixed-bed microreactor. Experimental results indicated that the catalytic activity of the catalyst strongly depended on the nature of the support and the pre-reduction temperature. Reaction order was independent of the support as the reaction was pseudo-first-order with respect to naphthalene i...

In this report, we study the evolution of valence band (VB) structure during a controlled amorphous to tetragonal transformation of ZrO2 core−shell nanostructures fabricated from electrospun nanofiber template (at 130, 200, and 250 °C). Shell-ZrO2 was formed with atomic layer deposition. X-ray diffraction and transmission electron microscopy are employed to unveil the transformation of amorphou...