A Reliable Cyclic Voltammetry Technique for the Degradation of Salicylaldehyde: Electrode Kinetics

Salicylaldehyde (SA) is used in numerous biological, pharmaceutical, and industrial applications. Releasing effluents from these industries contaminates water. So the degradation of salicylaldehyde is necessitated. The electrochemical degradation of salicylaldehyde in buffered media was studied using the eco-friendly cyclic voltammetry (CV) technique on a platinum electrode at different scan rates. Kinetic and electrochemical parameters were evaluated for the reaction such as standard heterogeneous rate constant (k0,2.468×103 s-1 ), anodic electron transfer rate constant (kox,2.507×103 s-1), electron transfer coefficient of reaction (?,0.673), and formal potential (E0, 1.0937) under the influence of scan rate. The nature of the reaction is found to be diffusion controlled. The concentration study in the range of 1 mM to 4 mM was calibrated. The limit of detection and the limit of quantification were calculated to be 0.0031 mM and 0.0103 mM respectively.

Red Wine Oxidation Characterization by Accelerated Ageing Tests and Cyclic Voltammetry

In order to obtain information on the oxidative behavior of red wines, oxygen consumption rates and electrochemical changes (cyclic voltammetry) were measured for nine red wines subject to three different accelerated ageing tests: chemical (with hydrogen peroxide), enzymatic (with laccase from Trametes versicolor), and temperature (at 60 °C). Oxidative behavior depended both on the wine sample and accelerated ageing test type. A good correlation was observed between electrochemical parameters of charges for reference/non-oxidized wines, in accordance with their antioxidant capacity, and the variation of charges after enzymatic and temperature tests, meaning that cyclic voltammetry could be used in order to predict these two oxidation tests and reflect the wine sensitivity towards respective oxidation targets. However, it was not possible to predict wine chemical oxidation test based on hydrogen peroxide from the electrochemical measurements.

Melanin’s Semiconductor Nature and His Polymer Structure Successfully Modifies Sulfur Cathode and Increases Efficiency on Li-S Batteries

Dynamics of change in impedance spectra and electrochemical parameters of the Li-S rechargeable batteries with non-aqueous liquid electrolyte 0.7 M LiIm, 0.25 M LiNO3, DME: DOL (2:1) during storage after assembly and cycling have been shown. For modification of the Sulfur cathode, we used the different types of melanin. Our results confirm that melanin can be used as a promising component of sulfur-based electrodes

The Use of Mathematical Modelling Methods in the Creation of Composite Materials Based on Carbon Fibre Materials

The report provides data on the electrochemical modification of carbon-graphite fibers as the basis for the creation of composite materials. The results of studies of the electrodeposition of metals on pre-electrochemically modified carbon fiber materials (CFM) in order to obtain composite materials based on them are presented. The use of CFM for the creation of composite materials is associated with the possibility of deposition of metals, alloys or their compounds on the surface of their constituent fibers. Electrochemical treatment in aqueous solutions of electrolytes is a promising method for modifying the surface properties of carbon materials, including in order to improve their adhesive properties. Preliminary electrochemical modification of carbon fiber materials in indifferent solutions of electrolytes made it possible to obtain composite and nanocomposite materials with good adhesion of the electrodeposited metal to the surface of the fibers of carbon materials.When metals are deposited on carbon fiber materials, it is necessary to solve the problem of applying a uniform metal deposit or with a certain profile in the thickness of the material. In this case, it is effective to use methods of mathematical modeling of metal deposition processes in a flowing three-dimensional electrode. Depending on the selected modes of deposition of metal sediment on the CFM, some electrochemical parameters of the process and system may be dependent on both the time of the process and the thickness coordinate of the electrode. This is especially true for the value of the resistivity of the solid phase of the system, that is, carbon-graphite fibrous material. Other electrochemical parameters, such as the specific electrode surface, the exchange current and the transfer coefficient of the electrochemical reaction, the porosity of the material, etc., can also change during the electrodeposition of the metal on the CFM. It is proposed to take into account the change in the characteristic properties of modified carbon fiber materials in the mathematical modeling of the processes of electrodeposition of metals on carbon fiber materials in order to determine the technological parameters to improve the efficiency of the properties of composite materials. In order to implement mathematical models used in the calculation of electrochemical processes in the volume and on the surface of carbon fiber materials, a set of programs based on modern computational methods and programming languages has been developed.

Experimental Study Regarding the Behavior at Different pH of Two Types of Co-Cr Alloys Used for Prosthetic Restorations

Cobalt-chromium (Co-Cr) alloys are widely utilized in dentistry. The salivary pH is a significant factor, which affects the characteristics and the behavior of dental alloys through corrosion. This study aimed to evaluate the corrosion behavior in artificial saliva with different pH values (3, 5.7, and 7.6) of two commercial Co-Cr dental alloys manufactured by casting and by milling. Corrosion resistance was determined by the polarization resistance technique, and the tests were carried out at 37 ± 1 °C, in Carter Brugirard artificial saliva. After the electrochemical parameters, it can be stated that the cast Co-Cr alloy has the lowest corrosion current density, the highest polarization resistance, and the lowest speed of corrosion in artificial saliva with pH = 7.6. In the case of milled Co-Cr alloy, the same behavior was observed, but in artificial saliva with pH = 5.7, it recorded the most electropositive values of open circuit potential and corrosion potential. Although both cast and milled Co-Cr alloys presented a poorer corrosion resistance in artificial saliva with a more acidic pH value, the milled Co-Cr alloy had better corrosion behavior, making this alloy a better option for the prosthetic treatment of patients suffering from GERD.