Icephobic and Anticorrosion Coatings Deposited by Electrospinning on Aluminum Alloys for Aerospace Applications

Anti-icing or passive strategies have undergone a remarkable growth in importance as a complement for the de-icing approaches or active methods. As a result, many efforts for developing icephobic surfaces have been mostly dedicated to apply superhydrophobic coatings. Recently, a different type of ice-repellent structure based on slippery liquid-infused porous surfaces (SLIPS) has attracted increasing attention for being a simple and effective passive ice protection in a wide range of application areas, especially for the prevention of ice formation on aircrafts. In this work, the electrospinning technique has been used for the deposition of PVDF-HFP coatings on samples of the aeronautical alloy AA7075 by using a thickness control system based on the identification of the proper combination of process parameters such as the flow rate and applied voltage. In addition, the influence of the experimental conditions on the nanofiber properties is evaluated in terms of surface morphology, wettability, corrosion resistance, and optical transmittance. The experimental results showed an improvement in the micro/nanoscale structure, which optimizes the superhydrophobic and anticorrosive behavior due to the air trapped inside the nanotextured surface. In addition, once the best coating was selected, centrifugal ice adhesion tests (CAT) were carried out for two types of icing conditions (glaze and rime) simulated in an ice wind tunnel (IWT) on both as-deposited and liquid-infused coatings (SLIPs). The liquid-infused coatings showed a low water adhesion (low contact angle hysteresis) and low ice adhesion strength, reducing the ice adhesion four times with respect to PTFE (a well-known low-ice-adhesion material used as a reference).

Quantitative Deterioration Evaluation of Heavy-Duty Anticorrosion Coating by Near-Infrared Spectral Characteristics

Heavy-duty anticorrosion coatings are applied on the surface of steel bridges for protecting against corrosion. By aging deterioration, the coating is worn from the surface year by year. Appropriate re-painting construction programs should be adopted for the maintenance of the bridges according to the evaluation of wear extent. Experimental studies were conducted with the aim of quantitative estimation of the degree of abrasion of the top coat thickness. It was found that there was a correlation between the top coat thickness and the observed infrared intensity and that this calibration relationship could be used to estimate the top coat thickness.

Low-Mass Liquid Crystalline Materials Blended in Recycled Thermoplastic Polyester Elastomer for Corrosion Inhibitor Application

In this work, the development and application of multicomponents obtained from recycled polyethylene terephthalate (r-PET) waste and monotropic liquid crystals as anticorrosion coatings are reported. The r-PET raw material was alcoholyzed and reproduced as a thermoplastic polyester elastomer (TPEE) with different amounts (n%, n = 0, 1, 3, and 5) of 1,6-hexanediamine (HDA). Then, a fluorine-containing liquid crystal (4-cyano-3-fluorophenyl 4-ethylbenzoate (4CFE)) was incorporated into the TPEE mixture via solvent blending to modify and enhance the water resistance. The adhesion behavior of the coating on glass and iron substrates was evaluated by cross-cut tests and immersion tests in aqueous NaCl. In the corrosion resistance measurements, all of the coating samples fabricated with 10 ± 1 mm thickness were less active toward electrochemical corrosion (PEF% > 99%) than the bare iron plate, indicating that our work provided better protection against corrosion of the iron plate.

Improving the Antimicrobial and Mechanical Properties of Epoxy Resins via Nanomodification: An Overview

The main purpose of this work is to provide a comprehensive overview on the preparation of multifunctional epoxies, with improved antimicrobial activity and enhanced mechanical properties through nanomodification. In the first section, we focus on the approaches to achieve antimicrobial activity, as well as on the methods used to evaluate their efficacy against bacteria and fungi. Relevant application examples are also discussed, with particular reference to antifouling and anticorrosion coatings for marine environments, dental applications, antimicrobial fibers and fabrics, and others. Subsequently, we discuss the mechanical behaviors of nanomodified epoxies with improved antimicrobial properties, analyzing the typical damage mechanisms leading to the significant toughening effect of nanomodification. Some examples of mechanical properties of nanomodified polymers are provided. Eventually, the possibility of achieving, at the same time, antimicrobial and mechanical improvement capabilities by nanomodification with nanoclay is discussed, with reference to both nanomodified epoxies and glass/epoxy composite laminates. According to the literature, a nanomodified epoxy can successfully exhibit antibacterial properties, while increasing its fracture toughness, even though its tensile strength may decrease. As for laminates—obtaining antibacterial properties is not followed by improved interlaminar properties.

ELECTRODEPOSITION OF METALS AND ALLOYS FROM AQUEOUS SOLUTIONS. REVIEW OF WORK OF EMPLOYEES FROM V.I. VERNADSKY NASU

The article examines in a historical perspective the issues that have been associated with the theory and practice of electrochemical deposition over the years of existence of the V.I. Vernadsky Institute of General and Inorganic Chemistry of NAS of Ukraine. Research in the field of electrochemistry of aqueous solutions, which was and is being carried out at the Institute, made a significant contribution to theoretical and applied electro­chemistry: the theory of electrode pro­cesses, electrochemistry of complex compounds, masstransfer, chemical power sources, electrocatalysis, electrochemical devices, theoretical and engineering electroplating, hydroelectro­metallurgy, electrochemical ecology and a number of other areas of modern chemistry. This article highlights issues related to research in the field of electrodeposition, namely: theo­retical research in the field of electrodeposition, electrodeposition of metals and alloys, hydroelectrometallurgy, corrosion and anticorrosion coatings. It is proved the effect of complexation leads to the formation of elect­rochemically active and inactive coordination ions, a mechanism for the discharge of ions during the formation of a film on the electrode surface is also proposed. The regularities leading to the formation of powders and black deposits of metals are analyzed. The conditions for a stable electrolysis regime were identified, the concept of the electrochemical resistance of the system was introduced, and the relationship between the kinetic parameters of elect­rolysis and the structure of the coatings was shown. The works in the field of hydroelectrometallurgy, corrosion-resistant and protective coatings are analyzed. It is noted that the scien­tific achievements of the Institute’s scientists are widely known around the world.