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In this work, a novel CrAlNiYN coating was prepared by filter cathode vacuum arc (FCVA) technique. The evolution of the microstructure and properties of the coatings with varying N 2 flow rates was systematically investigated. The results revealed that as the N 2 flow rate increased from 10 to 90 sccm, the N content in the coating increased from 2.54 to 46.20 at.%, while the Ni content significantly decreased from 67.54 to 31.15 at.%. Simultaneously, the phase structure transitioned from the intermetallic compound AlNi 3 to the solid solution Al(Cr)N. This transformation, along with solid solution strengthening and grain refinement, resulted an increase in hardness from 13.4 ± 0.4 to 26.6 ± 0.6 GPa. Moreover, the H/E, H3/E2 and W e values also displayed a gradually increasing trend, indicating improved resistance to plastic deformation. However, the adhesion strength presented a weakening trend from HF1 to HF3. Furthermore, the corrosion current density of coatings first increased and then slightly decreased with the increase of N 2 flow rate, while the polarization resistance had the opposite trend of change. Among them, the coating at 10 sccm exhibited the best corrosion resistance, with the lowest i corr of 0.150 μA cm−2 and the highest R p of 302.1 kΩ cm2. • High-quality CrAlNiYN coatings were deposited on 35CrMnSi steel by FCVA. • N 2 flow rate altered the structure, mechanical and electrochemical performance. • Grain refinement and solid solution strengthening improved the hardness and resistance to plastic deformation. • Coatings dominated by AlNi 3 phase possessed the better adhesion and corrosion resistance. [ABSTRACT FROM AUTHOR]

Ion-exchange membranes (IEMs) are increasingly used in dialysis and electrodialysis processes for the extraction, fractionation and concentration of valuable components, as well as reagent-free control of liquid media pH in the food industry. Fouling of IEMs is specific compared to that observed in the case of reverse or direct osmosis, ultrafiltration, microfiltration, and other membrane processes. This specificity is determined by the high concentration of fixed groups in IEMs, as well as by the phenomena inherent only in electromembrane processes, i.e., induced by an electric field. This review analyzes modern scientific publications on the effect of foulants (mainly typical for the dairy, wine and fruit juice industries) on the structural, transport, mass transfer, and electrochemical characteristics of cation-exchange and anion-exchange membranes. The relationship between the nature of the foulant and the structure, physicochemical, transport properties and behavior of ion-exchange membranes in an electric field is analyzed using experimental data (ion exchange capacity, water content, conductivity, diffusion permeability, limiting current density, water splitting, electroconvection, etc.) and modern mathematical models. The implications of traditional chemical cleaning are taken into account in this analysis and modern non-destructive membrane cleaning methods are discussed. Finally, challenges for the near future were identified.

Inadequate mechanical properties of pure hydroxyapatite (HA) coating layers make it an unsuitable candidate for many load-bearing orthopedic implants. In this study, Titania nanotubes (TNT) and HA were synthesized using Rapid Breakdown Adonization (RBA) and sol–gel methods, respectively. The sintering process at different temperatures was then conducted for the phase transformation of titanium. HA–TNT mixtures in different quantities and phases were prepared for coating on Co–Cr-based substrates. To optimize the coated HA–TNT composite layer in term of hardness, bonding strength and corrosion potential, empirical models based on Response Surface Methodology (RSM) were developed. The synthesized TNT and HA–TNT coated samples were characterized using X-ray diffraction (XRD), Field Emission Scanning Electron Microscope (FESEM) and Transmission Electron Microscopy (TEM). The predicted models generated by RSM were compared with the experimental results, and close agreement was observed. While the models demonstrate that TNT quantity is a more significant factor than sintering temperature in improving hardness ( H ), bonding strength ( P ) and the corrosion potential ( E corr ) of a coated substrate, sintering temperature still has a considerable effect on H and E corr . The optimum HA–TNT composite coating layer in terms of the mechanical and electrochemical properties were obtained with a TNT ratio of 1.07 (wt%) at a sintering temperature of 669.11 °C. [ABSTRACT FROM AUTHOR]

Ion-exchange membranes (IEMs) are increasingly used in dialysis and electrodialysis processes for the extraction, fractionation and concentration of valuable components, as well as reagent-free control of liquid media pH in the food industry. Fouling of IEMs is specific compared to that observed in the case of reverse or direct osmosis, ultrafiltration, microfiltration, and other membrane processes. This specificity is determined by the high concentration of fixed groups in IEMs, as well as by the phenomena inherent only in electromembrane processes, i.e., induced by an electric field. This review analyzes modern scientific publications on the effect of foulants (mainly typical for the dairy, wine and fruit juice industries) on the structural, transport, mass transfer, and electrochemical characteristics of cation-exchange and anion-exchange membranes. The relationship between the nature of the foulant and the structure, physicochemical, transport properties and behavior of ion-exchange membranes in an electric field is analyzed using experimental data (ion exchange capacity, water content, conductivity, diffusion permeability, limiting current density, water splitting, electroconvection, etc.) and modern mathematical models. The implications of traditional chemical cleaning are taken into account in this analysis and modern non-destructive membrane cleaning methods are discussed. Finally, challenges for the near future were identified. [ABSTRACT FROM AUTHOR]