Electrochemical characteristics

Investigations into the surface modification of a Ti-15Mo alloy via plasma electrolytic oxidation are reported. The oxidation process was conducted in a solution containing Ca(H 2 PO 2 ) 2 , H 3 PO 4 , or (HCOO) 2 Ca. Anodisation was performed at voltages in the range of 100-400 V. The morphology of the sample surface did not change during alloy oxidation at lower voltages. Higher voltages led to the incorporation of calcium and phosphorus or of calcium only into the formed oxide layer and to significant modification of the surface morphology. Based on the SEM and EDX analysis results, a set of samples was selected for further investigations. To study the surface of the Ti-Mo alloy after anodic oxidation, we used scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thin-layer X-ray diffraction (TL-XRD), and X-ray photoelectron spectroscopy (XPS). The electrochemical characteristics of the modified alloy in Ringer's solution were determined. Anodisation results in a considerable increase in the corrosion resistance of the Ti-15Mo alloy.

Based on graphene nanoplatelets capability to build block composites, as well as well-47 known electrochemical characteristic of the manganese oxide materials, in the present research, 48 a nanocomposite, formed from graphene nanoplatelets (GNP) and manganese(IV)-oxide 49 (MnO2) nanoparticles, has been proposed as a novel and convenient support for enzyme 50 immobilization. Performance of screen printed carbon electrodes (SPCEs) was significantly 51 improved after their modification with GNP@MnO2 (SPCE/GNP@MnO2). The polyphenolic 52 index biosensor was prepared by applying the drop coating technique using laccase and 53 Nafion®. Developed biosensor shows a fast and reliable amperometric response toward caffeic 54 acid, as a model compound, at operating potential of +0.40 V (vs. Ag/AgCl), with a wide linear 55 range and detection limit of 1.9 µmol L -1 . Developed procedure was successfully applied for 56 the determination of polyphenolic indexes in wine samples. Recovery tests indicate excellent 57 accuracy and precision of the method, concluding that the biosensor can offer a fast, accurate, 58 reliable and precise determination of the polyphenolic index. More importantly, our results 59 suggest a great potential for the application in real samples.

The microstructure and the corrosion behaviour of ultrafine-grained interstitial free (IF) ferritic steel processed by equal channel angular pressing (ECAP) at room temperature following route C were investigated. Already after the first pass of ECAP, the microstructure was refined by a factor of approximately 200. On further passes, ECAP was found to lead to continuous grain refinement, while elongated grain structure produced in the first pass was retained throughout all processing cycles. After 8 passes, the microstructure comprised bands of elongated grains of average length of 500-1000 nm and average width of 200-300 nm. Corrosion characteristics of a non-deformed coarse grained specimen and an ultrafine-grained specimen that had undergone 8 passes of ECAP were investigated using electrochemical potentiodynamic tests. ECAP induced grain refinement does not appear to influence the electrochemical characteristics in neutral NaCl solutions. This encouraging finding demonstrates that ECAP, while enhancing mechanical characteristics, does not compromise corrosion resistance of IF steel. A protective oxidic layer is formed in alkaline NaCl solution, which reduces the corrosion rate significantly.

The nature of the bridging dithiolate has an important role on tuning the physical and electrochemical properties of the synthetic H-cluster mimics of [FeFe]-hydrogenase and still of significant concern to scientists. In this report we describe the synthetic models of the active site of [FeFe]-hydrogenase containing perylene monoimide of peri-substituted disulfides as bridging linker. The resulting complexes were characterized by 1 H and 13 C{ 1 H} NMR and IR spectroscopic techniques, mass spectrometry, and elemental analysis as well as X-ray analysis of complex 2a. The purpose of this work was to investigate the influence of the perylene-linker on the redox potentials of the complexes and their catalytic ability in the presence of acetic acid (AcOH) by applying cyclic voltammetry. Moreover, we compare these results with different diiron hexacarbonyl complexes previously reported in the literature. As a result, we have found that the presence of the rylene-linker provides further stability for the reduced species and shifted its reduction potentials to more positive values.

Transparent displays have been emerged as a class of cutting-edge electronics. Here, we propose user-customized, design-it-yourself (DIY) transparent displays based on electrochromic (EC) ion gels including viologens. To achieve multiple colors and enhance the functionality of EC displays (ECDs), the incorporation of several EC chromophores is inevitable. However, the issue related to the discrepancy of coloration voltages is inherent due to the different electrochemical characteristics of each material, causing unbalance of the color contrast. To overcome this problem without significantly affecting the performance of ECDs, we suggest a simple but effective strategy by adjusting the oxidation activity of electrolyte-soluble anodic species (i.e., ferrocene (Fc)-derivatives) by modifying pendant groups. We systematically investigated the effects of the employed Fc-derivatives on the EC behaviors of ECDs in terms of the coloration voltage, maximum transmittance contrast, device dynamics, coloration efficiency, and operational stability. We determine the conditions for implementing red-green-blue (RGB) colors with comparable intensities at similar voltages. Last, we draw images using RGB EC inks for conceptual demonstration of the DIY transparent displays. The fabricated ECDs exhibit highly transparent bleached states and user-customized images in the colored states. Overall, this result implies that the extremely simple DIY ECDs, which do not require conventional lithography or printing, have great potential as future transparent displays that can be easily customized.

Investigations into the surface modification of a Ti-15Mo alloy via plasma electrolytic oxidation are reported. The oxidation process was conducted in a solution containing Ca(H 2 PO 2) 2 , H 3 PO 4 , or (HCOO) 2 Ca. Anodisation was performed at voltages in the range of 100-400 V. The morphology of the sample surface did not change during alloy oxidation at lower voltages. Higher voltages led to the incorporation of calcium and phosphorus or of calcium only into the formed oxide layer and to significant modification of the surface morphology. Based on the SEM and EDX analysis results, a set of samples was selected for further investigations. To study the surface of the Ti-Mo alloy after anodic oxidation, we used scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thin-layer X-ray diffraction (TL-XRD), and X-ray photoelectron spectroscopy (XPS). The electrochemical characteristics of the modified alloy in Ringer's solution were determined. Anodisation results in a considerable increase in the corrosion resistance of the Ti-15Mo alloy.

Investigations into the surface modification of a Ti-15Mo alloy via plasma electrolytic oxidation are reported. The oxidation process was conducted in a solution containing Ca(H 2 PO 2) 2 , H 3 PO 4 , or (HCOO) 2 Ca. Anodisation was performed at voltages in the range of 100-400 V. The morphology of the sample surface did not change during alloy oxidation at lower voltages. Higher voltages led to the incorporation of calcium and phosphorus or of calcium only into the formed oxide layer and to significant modification of the surface morphology. Based on the SEM and EDX analysis results, a set of samples was selected for further investigations. To study the surface of the Ti-Mo alloy after anodic oxidation, we used scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), thin-layer X-ray diffraction (TL-XRD), and X-ray photoelectron spectroscopy (XPS). The electrochemical characteristics of the modified alloy in Ringer's solution were determined. Anodisation results in a considerable increase in the corrosion resistance of the Ti-15Mo alloy.