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Physical mechanisms of Cassie-Wenzel wetting transitions are discussed. The origin of the potential barrier separating the Cassie and Wenzel wetting states is clarified. It may contain contributions originating from the filling of hydrophobic pores and displacement of the triple line along the smooth portions of the relief. One- and two-dimensional scenarios of wetting transitions are considered. We demonstrate that the contribution to the potential barrier because of the displacement of the triple line is not negligible in both cases.

Titanium alloys have advanced mechanical properties jointly with high biocompatibility that make them eminently suitable for biomedical applications such as dental and orthopedic implants. Improvement in their osseointegration with human bone can be achieved by the development of hydroxyapatite (HAp) on a Ti alloy surface using different methods of deposition. However, plasma electrolytic oxidation (PEO) treatment has been found to be one of the most promising techniques, due to the formation of high bonding between the bone and the Ti surface. Along with this high bonding, an antibacterial ability of the surface to prevent bacterial infection is also essential. Silver, which is a widely applicable antibacterial agent, was used in this work. First, a titanium oxide coating containing calcium and phosphorus and Ag nanoparticles was formed by PEO treatment. Then, Ti alloy was subjected to hydrothermal treatment to ensure a crystalline formation of HAp. Morphology and phase composition investigations detected the presence of HAp crystals in the coating along with antibacterial agents of silver nanoparticles. The biocompatibility and bioactivity of the created coating were examined by contact angle (CS) measurement and electrochemical impedance spectroscopy (EIS). It was shown that the coating was extensively grown after exposure of the alloy to simulated body fluid (SBF) solution for 7 days with no effect on the Ag nanoparticles. An antibacterial test using Staphylococcus aureus and Escherichia coli revealed that the coating containing Ag nanoparticles has more significant antibacterial effectiveness compared to a coating that does not contain silver.

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The diffusion coefficients of iron (II) ions depositing on solid tungsten electrodes in a molten chloride systems at about 700°C have been determined by electrochemical techniques. The deposition process occurs under diffusion control for all the iron concentrations and temperatures studied. Conventional cyclic voltammetry and convolution cyclic voltammetry methods were used. Diffusion coefficients of iron (II) were calculated according to Randles‐Sevcik and Berzins‐Delahay equations for the conventional cyclic voltammetry and also by the limiting convoluted current for the convolution cyclic voltammetry. Convolution cyclic voltammetry is believed to be superior to conventional cyclic voltammetry for the quantitative evaluation of diffusion coefficients. The values of the diffusion coefficients lay in the range 1‐40‐10−5 cm2/s for the temperature range of 700‐750°C. The Arrhenius temperature dependence of the diffusion coefficients is characterized by the value of Ea = 31.2 kJ/mol.