Coatings

The presence and development of pathogens in the human body remains a serious problem. The existence of microorganisms is primarily related to their ability to adhere to various surfaces. The aim of this study was to evaluate the ability of Si(C,N) coatings on a nickel-chromium alloy surface to reduce bacterial and fungal adhesion and to provide antimicrobial activity. This publication also focused on determining which coating variant is most effective in reducing microbial adhesion. Si(C,N) coatings were sputtered onto the surface of the prosthetic alloy using the magnetron sputtering method. Observation was performed using a fluorescence microscope and a flow cytometer. The number of adhered bacterial cells decreased compared to the samples without coating (sample series A) by approximately 84% in sample series B and by 29% in sample series F. In the case of adhesion of fungal cells, their number decreased compared to the samples without coating (sample series A) by approximately 76% in sample series B and by 47% in sample series F. The applied one-way analysis of variance test indicated a statistically significant effect of the tested factor at a level below 0.001. Based on the conducted research, it was noticed that the use of Si(C,N) layers on the surface of the prosthetic alloy limits the adhesion of bacteria and fungi.

The escalating demand for clean and sustainable energy, coupled with the need to mitigate climate change, has positioned electrocatalysis and energy storage as hot research topics [...]

High-entropy ceramic (HEC) thin films generally refer to multi-component solid solutions composed of multiple metallic and non-metallic elements, existing in forms such as carbides, nitrides, and borides. Benefiting from the high-entropy effect, lattice distortion, sluggish diffusion, and cocktail effect of high-entropy systems, HEC thin films form simple amorphous or nanocrystalline structures while exhibiting high hardness/elastic modulus, excellent tribological properties, and thermal stability. Although the mixing entropy increases with the number of elements in the system, a higher number of elements does not guarantee improved performance. In addition to system configuration, the regulation of preparation methods and processes is also a key factor in enhancing performance. Arc ion plating (AIP) has emerged as one of the mainstream techniques for fabricating high-entropy ceramic (HEC) thin films, which is attributed to its high ionization efficiency, flexible multi-target configuration, precise control over process parameters, and high deposition rate. Through rational design of the compositional system and optimization of key process parameters—such as the substrate bias voltage, gas flow rates, and arc current—HEC thin films with high hardness/toughness, wear resistance, high-temperature oxidation resistance, and electrochemical performance can be fabricated, and several of these properties can even be simultaneously achieved. Against the backdrop of AIP deposition, this review focuses on discussions grounded in the thermodynamic principles of high-entropy systems. It systematically discusses how process parameters influence the microstructure and, consequently, the mechanical, tribological, electrochemical, and high-temperature oxidation behaviors of HEC thin films under various complex service conditions. Finally, the review outlines prospective research directions for advancing the AIP-based synthesis of high-entropy ceramic coatings.