Valery V. Kaminsky

Bio: Valery V. Kaminsky is an academic researcher. The author has contributed to research in topics: Magnesium & Copper. The author has an hindex of 2, co-authored 6 publications receiving 43 citations.

Bactericidal Activity of Superhydrophobic and Superhydrophilic Copper in Bacterial Dispersions.

Abstract: A method based on nanosecond laser processing was used to design superhydrophilic and superhydrophobic copper substrates. Three different protocols were used to analyze the evolution of the bactericidal activity of the copper substrates with different wettability. Scanning electron microscopy was used to study the variation of cell morphology after the attachment to superhydrophilic and superhydrophobic surfaces. The dispersions of Escherichia coli K12 C600 and Klebsiella pneumoniae 811 in Luria Bertani broth in contact with the superhydrophilic copper surface showed enhanced bacterial inactivation, associated with toxic action of both hierarchically textured copper surface and high content of Cu2+ ions in the dispersion medium. In contrast, the bacterial dispersions in contact with the superhydrophobic copper substrates demonstrated an increase in cell concentration with time until the development of corrosion processes. The resistance of bacterial cells to contact the copper substrates is discussed on the basis of surface forces, determining the primary adhesion and of the protective action of a superhydrophobic state of the surface against electrochemical and biological corrosion.

Antimicrobial activity and degradation of superhydrophobic magnesium substrates in bacterial media

Abstract: The interest in magnesium-based materials is promoted by their biocompatibility, bioresorbability, and by their recently found antibacterial potential. Until now the widespread use of magnesium alloys in different corrosive environments was inhibited by their weakly controllable degradation rate and poorly understood microbiologically induced corrosion behavior. To better understand the degradation and usability of magnesium-based alloys, in this study we have fabricated the superhydrophobic coatings on top of magnesium-based alloy and analyzed the behavior of this alloy in bacterial dispersions of Pseudomonas aeruginosa and Klebsiella pneumoniae cells in phosphate buffered saline. It was shown that immersion of such coatings into bacterial dispersions causes notable changes in the morphology of the samples, dependent on the bacterial dispersion composition and the type of bacterial strain. The interaction of superhydrophobic coatings with the bacterial dispersion caused the formation of biofilms and sodium polyphosphate films, which provided enhanced barrier properties for magnesium dissolution and hence for dispersion medium alkalization, eventually leading to inhibition of magnesium substrate degradation. Electrochemical data obtained for superhydrophobic samples continuously contacted with the corrosive bacterial dispersions during 48 h indicated a high level of anti-corrosion protection.

Antimicrobial activity and degradation of superhydrophobic magnesium substrates in bacterial media

Abstract: The interest in magnesium-based materials is promoted by their biocompatibility, their bioresorbability, and their recently discovered antibacterial potential. Until now, the widespread use of magnesium alloys in different corrosive environments was inhibited by their weakly controllable degradation rate and poorly understood microbiologically induced corrosion behavior. To better understand the degradation and usability of magnesium-based alloys, in this study we have fabricated superhydrophobic coatings on a magnesium-based alloy, and analyzed the behavior of this alloy in bacterial dispersions of Pseudomonas aeruginosa and Klebsiella pneumoniae cells in phosphate-buffered saline. It was shown that the immersion of such coatings in bacterial dispersions causes notable changes in the morphology of the samples, dependent on the bacterial dispersion composition and the type of bacterial strain. The interaction of the superhydrophobic coatings with the bacterial dispersion caused the formation of biofilms and sodium polyphosphate films, which provided enhanced barrier properties in magnesium dissolution and hence in dispersion medium alkalization, eventually leading to the inhibition of magnesium substrate degradation. The electrochemical data obtained for superhydrophobic samples in continuous contact with corrosive bacterial dispersions for 48 h indicated a high level of anticorrosion protection.

The Mechanisms of Antibacterial Activity of Magnesium Alloys with Extreme Wettability

Abstract: In this study, we applied the method of nanosecond laser treatment for the fabrication of superhydrophobic and superhydrophilic magnesium-based surfaces with hierarchical roughness when the surface microrelief is evenly decorated by MgO nanoparticles. The comparative to the bare sample behavior of such surfaces with extreme wettability in contact with dispersions of bacteria cells Pseudomonas aeruginosa and Klebsiella pneumoniae in phosphate buffered saline (PBS) was studied. To characterize the bactericidal activity of magnesium samples with different wettability immersed into a bacterial dispersion, we determined the time variation of the planktonic bacterial titer in the dispersion. To explore the anti-bacterial mechanisms of the magnesium substrates, a set of experimental studies on the evolution of the magnesium ion concentration in liquid, pH of the dispersion medium, surface morphology, composition, and wettability was performed. The obtained data made it possible to reveal two mechanisms that, in combination, play a key role in the bacterial decontamination of the liquid. These are the alkalization of the dispersion medium and the collection of bacterial cells by microrods growing on the surface as a result of the interaction of magnesium with the components of the buffer solution.

Bioinspired surfaces with wettability for antifouling application

Abstract: Wettability is a special character found in nature, including the superhydrophobicity of lotus leaves, the underwater superoleophobicity of fish scales and the slipperiness of pitcher plants. These surfaces exhibit unique properties such as resistance to icing, corrosion, and the like. The antifouling properties of the material surface have important applications in a variety of areas, such as in hulls, in medical equipment, in water pipes and underwater equipment. However, the traditional anti-fouling surface is usually combined with toxic substances or its manufacturing process is complicated and expensive, which cannot meet the current antifouling demand. These wettable surfaces have always exhibited good anti-biofouling and self-cleaning properties, and their use as antifouling surfaces can well solve the problems of the above-mentioned traditional antifouling surfaces. Here, we divided the wettable surfaces into superhydrophobic surfaces, underwater superoleophobic surfaces and slippery surfaces, respectively, summarizing their development in the field of antifouling. Their research progress in antibacterial, antibiotic flocculation and antiplatelet adhesion is highlighted. Furthermore, we provide our own insights into the shortcomings and development prospects of wettable surface applications in the field of antifouling.

Superhydrophobic, superamphiphobic and SLIPS materials as anti-corrosion and anti-biofouling barriers

Abstract: Nature-inspired interfacial materials with special wettability have received considerable attention owing to their superior properties and promising multifunctional applications. Owing to the unique interfacial phase contacts and liquid–repellent property, the interfacial materials with special wettability provide a great potential for corrosion inhibition and biofouling suppression. Thus, this brief review and perspective study provides an overview about the characteristics, fabrication and recent advances of three types of interfacial materials with special wettability, namely superhydrophobic, superamphiphobic and slippery liquid-infused porous surface (SLIPS) toward anti-corrosion and anti-biofouling applications. The bottlenecks and future research priorities of the functional interfacial materials with special wettability were pointed out to accelerate the comprehensive understanding and the development of this research field.

The effects of an inorganic corrosion inhibitor on the electrochemical behavior of superhydrophobic micro-nano structured Ni films in 3.5% NaCl solution

Abstract: The application of hierarchically micro-nano structured superhydrophobic Ni films with increased surface roughness is known as an attractive corrosion protection strategy because the chemically modified film with a low surficial free energy is capable of keeping water molecules and aggressive species away from the coating/electrolyte interface by trapping air pockets within the micro-nano structured layer. Furthermore, corrosion inhibitors are widely used for corrosion mitigation in a broad range of industrial applications. This study tends to investigate the corrosion resistance of electrodeposited superhydrophobic Ni films in the presence of sodium molybdate (0 M, 0.03 M, 0.06 M, 0.1 M) as an inorganic corrosion inhibitor in a 3.5 wt% NaCl solution at 25 °C, up to 120 h. The micro-nano structured superhydrophobic Ni film with a mean thickness of 4 μm was electrodeposited on a Cu substrate via a two-step electrodeposition process at 60 °C including 8 min of electrodeposition at a constant current density of 20 mA/cm2, followed by 1 min of electrodeposition at a constant current density of 50 mA/cm2 and a subsequent chemical modification step in stearic acid solution. Investigation of surface topography of the film by atomic force microscopy technique (AFM) revealed that the root-mean-square of height and the skewness of the film were equal to 14.4 nm and 0.21, respectively. The morphology of the film consisted of micro-nano cones in the size range of 50 to 1000 nm. The superhydrophobic film demonstrated a passivation behavior and a pitting potential. The EIS study identified the Ni film as a non-ideal capacitor and an equivalent circuit model with two parallel time-constants fitted to the EIS data. Upon 120 h of immersion of the superhydrophobic film in the electrolyte in the presence of 0.1 M of sodium molybdate, the corrosion inhibitor efficiency of about 80% was achieved and the Ni film demonstrated the best passivation behavior and the lowest corrosion current density.