Search results for "OXIDATION"
showing 10 items of 1913 documents
Biocompatibility and Antibacterial Properties of ZnO-Incorporated Anodic Oxide Coatings on TiZrNb Alloy
2020
In a present paper, we demonstrate novel approach to form ceramic coatings with incorporated ZnO nanoparticles (NPs) on low modulus TiZrNb alloy with enhanced biocompatibility and antibacterial parameters. Plasma Electrolytic Oxidation (PEO) was used to integrate ZnO nanoparticles (average size 12&ndash
Incorporation mechanism of colloidal TiO2 nanoparticles and their effect on properties of coatings grown on 7075 Al alloy from silicate-based solutio…
2021
Plasma electrolytic oxidation (PEO) was applied using a pulsed unipolar waveform to produce Al2O3-TiO2 composite coatings from sol electrolytic solutions containing colloidal TiO2 nanoparticles. The sol solutions were produced by dissolving 1, 3, and 5 g/L of potassium titanyl oxalate (PTO) in a silicate solution. Scanning electron microscopy, energy dispersive spectrometry, X-ray diffraction, and Raman spectroscopy were applied to characterizing the coatings. Corrosion behavior of the coatings was investigated using polarization and impedance techniques. The results indicated that TiO2 enters the coating through all types of micro-discharging and is doped into the alumina phase. The higher…
Effect of Molybdate on Corrosion Performance of Oxide Coating Produced on 7075 Al Alloy Using PEO
2022
In this research, plasma electrolytic oxidation (PEO) coatings were prepared on 7075 Al alloy in a silicate-based solution with Na2MoO4 additive using a unipolar waveform at constant current density. The coatings displayed micro-pores, micro-cracks, pancake-like and crater-like features, and also solidified molten oxide particles on the surface. The coatings were majorly composed of Al2O3 (γ, δ, and α), SiO2 (amorphous), and MoO3 phases, which confirms the incorporation of molybdenum in the case of additive-containing coatings. Molybdenum species were transported through cracks, channels, and micropores, as the ready access pathways into the coating and partly sealed the c…
The role of polaronic states in the enhancement of CO oxidation by single-atom Pt/CeO2
2023
Single Atom Catalysts (SACs) have shown that the miniaturization of the active site implies new phenomena like dynamic charge transfer between isolated metal atoms and the oxide. To obtain direct proof of this character is challenging, as many experimental techniques provide averaged properties or have limitations with poorly conductive materials, leaving kinetic measurements from catalytic testing as the only reliable reference. Here we present an integrated Density Functional Theory-Microkinetic model including ground and metastable states to address the reactivity of Pt1/CeO2 for CO oxidation. Our results agree with experimentally available kinetic data in the literature and show that CO…
Understanding selective reduction reactions with heterogeneous Pd and Pt : climbing out of the black box
2016
Pro-Degradant Activity of Naturally Occurring Compounds on Polyethylene in Accelerate Weathering Conditions
2019
In this work, naturally occurring compounds, such as Vitamin E (VE) and Ferulic Acid (FA), at high concentrations, have been considered as pro-degradant agents for Low Density Polyethylene (PE). However, all obtained results using the naturally occurring molecules as pro-oxidant agents for PE have been compared with the results achieved using a classical pro-oxidant agent, such as calcium stearate (Ca stearate) and with neat PE. The preliminary characterization, through rheological, mechanical and thermal analysis, of the PE-based systems highlights that the used naturally occurring molecules are able to exert a slight plasticizing action on PE and subsequently the PE rigidity and crystalli…
Comparative Investigation on the Soil Burial Degradation Behaviour of Polymer Films for Agriculture before and after Photo-Oxidation
2020
Polymer films based on biodegradable polymers, polyethylene (PE) and modified PE with oxo-degradable additive were prepared by film blowing. Carbon black (1%) was added to all the films. Commercial biodegradable Ecovio®
Influence of accelerated ageing conditions on the process of polyolefines degradation
2003
The process of polymers weathering and the methods of polymers weathering and accelerated ageing investigations were characterized. Accelerated ageing tests of polyethylene and polypropylene samples have been done in laboratory conditions. The ageing time (up to 400 h) influence, at various levels of ageing factors: UV radiation intensity (80—190 W/m2), temperature (35—55 °C) and humidity (30—90%), on the changes of the structures of polymers investigated (shares of carbonyl and olefinic groups from FT-IR spectra — Fig. 1, 2, 4 and 5), on the changes of polymers molecular weights (Fig. 3 and 6, Table 1) and on the changes of mechanical properties during tension (Table 1) has been investigat…