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The study describes the successful development of a TiO2 ceramic substrate with a protective nano-Al2O3 coating using two different coating techniques: microwave combustion and polymeric methods. The coated ceramics demonstrate enhanced corrosion resistance compared to the uncoated substrate. The optimal TiO2 substrate was prepared by firing it at 1000 °C. This was done to give the desired physical properties of the TiO2 substrate for the coating procedures. Nano-Al2O3 powder was coated onto the surface of the TiO2 substrates. The TiO2 substrates with the Al2O3 coating were then calcined (heat-treated) at 800 and 1000 °C. The structures, morphology, phase composition, apparent porosity, bulk density, and compressive strength of the substrate and coated substrate were characterized. Upon firing at 1000 °C, it was discovered that the two phases of TiO2—rutile and anatase—combine in the substrate. Once the substrate has been coated with nano Al2O3 at 1000 °C, the anatase is transferred into rutile. When compared to the substrate, the coated substrate resulted in a decrease in porosity and an increase in strength. The efficiency of the ceramic metal nanoparticles Al2O3 as a good coating material to protect the TiO2 substrates against the effect of the corrosive medium 0.5 M solution of H2SO4 was measured by two methods: potentio-dynamic polarization (PDP) and the electrochemical impedance spectroscopy (EIS). The results indicated that the corrosion rate was decreased after the substrate coated with alumina from (67.71 to 16.30 C.R. mm/year) and the percentage of the inhibition efficiency recorded a high value reaching (78.56%). The surface morphology and composition after electrochemical measurements are investigated using SEM and EDX analysis. After conducting the corrosion tests and all the characterization, the results indicated that the coated TiO2 substrate prepared by the polymeric method at 800 °C displayed the best physical, mechanical, and corrosion-resistant behavior. [ABSTRACT FROM AUTHOR]

Novel organic nanoparticles (ONPs) of (E)-2-(4-(hydrazonomethyl)phenoxyl) acetohydrazide (H2) and N′((E)-benzylidene)-2-(4-((E)hydrazonomethyl)phenoxyl)acetohydrazide (H3) were prepared by the re-precipitation method. The ONPs were characterized using MS, 1H-NMR, 13C-NMR, FT-IR, DLS, TEM and XRD. Both nanoparticles revealed a hemispherical shape with a particle size of 3.0 nm and 2.0 nm for H2 and H3 nanoparticles, respectively. The protective effect of the ONPs on mild steel in 1.0 M HCl was monitored by polarization, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The obtained results revealed that the inhibition efficiency increased with an increase in inhibitor concentration. The maximum inhibition efficiencies at a constant concentration of 1 × 10−3 M were 88.2% and 96.7% for H2 and H3, respectively. The inhibition mechanism depended on the physical adsorption of the nanoparticles on the steel surface, which was confirmed by SEM, AFM and impedance results. These novel nanomaterials showed great anti-corrosion behavior and thus can be potentially used in industrial applications such as cooling water systems, pipes, and oil production units. [ABSTRACT FROM AUTHOR]