Abstract The present study reports on the kinetics of borided AISI D3 steel. Boriding thermochemical treatment was carried out in a solid medium consisting of B4C, SiC and KBF4 powders mixture at 1123, 1173 and 1223 K for 2, 4 and 6 h, respectively. The boride layer was characterized by optical microscopy, X-ray diffraction technique and micro-Vickers hardness tester. X-ray diffraction analysis of

Abstract The synthesis of porous carbon materials was carried out by mechanochemical dehydrochlorination of polyvinyl chloride in the presence of alkalis (KOH, LiOH) using a high-energy planetary mill and the subsequent two-stage heat treatment of the obtained polyvinylenes (polymers with a conjugated double bond system)—carbonization to 400°C and carbon dioxide at 850°C or alkaline activation and

Abstract The study of ion sorption of Cu2+ on fungi isolated from mycelium Aspergillus niger chitin- and chitosanglucan complexes showed that these biopolymers have a fairly high sorption ability. As a result of mathematical modeling found that the theoretical models of Langmuir, Freundlich and Temkin are adequate, with a high coefficient of determination (R2 = 0.97–0.99) describe equilibrium sorption

Abstract Technologies for producing liquid-phase polymer composites of carbon nanofibers and their modifications are presented: carboxylated carbon nanotubes, polyaniline-modified nanotubes, supercondensate of multiwalled carbon nanotubes in epoxy phenol–formaldehyde resins. Polymeric composites with microwave absorption capabilities are considered.

Abstract The corrosion inhibition of mild steel by a drug substance, namely piroxicam, in HCl (1 M) solution was investigated. The Electrochemical Impedance Spectroscopy (EIS) and potentiodynamic polarization technique were used. EIS measurements showed larger capacitive loops in the presence of piroxicam. The inhibition efficiency was found to be dependent on the piroxicam concentration. From the

Abstract The resistance of different TiB2 powders to oxidative degradation is studied by synchronous thermal analysis. The temperature dependence of oxidation rate of the powders is determined by the size and morphology of their constituting particles. Our findings can be used to establish the structural and morphological properties of powdered titanium diboride that are optimal for its use in wettable

Abstract To extend the service time of #45 steel, Ni–Fe–Co–P alloy coatings were prepared on workpieces. CeO2 nanoparticles were also added and a heat treatment was carried out. Both the addition of CeO2 nanoparticles and the heat treatment had a positive influence on the dispersion strengthening, the fine grain strengthening, and the pinning effect. The surface topography and the chemical composition

Abstract Using the methods of positron annihilation and optical spectroscopy, the effect of gamma (Co60) and electron irradiation (Cockcroft–Walton accelerator) on NaCl single crystals, followed by annealing at various temperatures. It was found that electron color centers are effective traps of positrons diffusing in the lattice. At the same time, hole centers do not capture positrons. It was shown

Abstract To improve the mechanical and biological properties and also to increase the lifetime and performance of Ti–6Al–4V dental implants they were coated by hydroxyapatite nanoparticles using a modified mechanical coating technique. A novel milling vial was developed to simultaneously coat hydroxyapatite nanoparticles on the Ti–6Al–4V substrates. The modified dimensions of the milling vial and optimized

Abstract Corrosion is a phenomenon that directly related to the environment. The surface protection by potential inhibitors is one of the possible solutions to combat metal/or metallic alloy corrosion. Here, we are reporting two 1,2,4-triazole-5-thione derivatives – 4-amino-3-(N-phthallimidomethyl)-1,2,4-triazole-5-thione (Tz-1) and 3-(N-phthalimidomethyl)-4-(4-pyridine)amino-1,2,4-triazole-5-thione

Abstract The isotherms of absolute methane adsorption in an Fe–BDC metal–organic porous structure after long-term storage were measured at a pressure as high as 40 MPa and the temperatures of 303, 313, 323, and 333 K. The dependences of differential molar isosteric heats of adsorption and entropies of adsorption on methane uptake were calculated. It was shown that taking into account the nonideality

Abstract Polyacrylate latex contained monobutyl itaconate (MBI) and N,N-diethylacrylamide (DEA) was successfully prepared by semi-continuous seeded emulsion polymerization with a green mixed emulsifier of sodium dodecyl benzene sulfonate (SDBS) anion surfactant and tetradecyl hydroxypropyl decyl betaine (THDB) amphoteric emulsifier, the mixed monomers of methyl methacrylate (MMA), butyl acrylate (BA)

Abstract The implants used as cardio stents, orthopedic and dental implant may be subjected to biological corrosion. Uncoated implants can be corroded in various parts of the body due to acidic erosion and oxidation. This paper presents the findings of a coating technique for the deposition of hydroxyapatite (HAP) coatings on Ti, Ti6Al4V and AISI 316L stainless steel substrates (316L SS). HAP synthesized

Abstract Corrosion inhibition properties of benzotriazole were studied in 0.1 M hydrochloric acid solution for copper samples with different roughness levels using open-circuit potential, potentiodynamic polarization, electrochemical impedance, and weight loss measurements. According to the results, inhibition properties were improved because of an increase in surface roughness leading to an increase

Abstract The nanocrystalline tantalum alloys were investigated in terms of mechanical properties. The materials were obtained by powder metallurgy techniques—mechanical alloying (MA) and hot pressing (pulse plasma sintering mode). Pure powders of niobium, molybdenum, and tungsten were used for tantalum as an additive element in the concentration of 5, 10, 20, and 40 wt %. The analysis of XRD (Williamson–Hall

Abstract The active layer of a lithium-oxygen battery (LOB) cathode must have a complex structure consisting of two types of pores (macropores and mesopores). For successful operation of the cathode active layer during the LOB discharge, attempts are being made to create two types of pore clusters: a macropore cluster that provides the transport of oxygen to a zone, where the final product, lithium

Abstract The results of the creation of an electrically conductive layer of polyaniline (PANI) on the surface of a polyethylene (PE) film modified by postradiation chemical grafting polymerization of styrene followed by the sulfonation of the grafted polystyrene (PS) chains are presented in this work. The distribution of sulfonated PS through the thickness of the PE film when varying both the degree

Abstract When accelerated electrons were irradiated with aqueous solutions of cadmium and lead salts containing methyl alcohol, metal precipitates with densities of 1.17 and 1.1 g/cm3 were obtained and porosities of 86.5 and 90.3%, respectively, and greater surface area. The process of metal deposition was studied and the radiation–chemical yields were calculated, which amounted to (1.7 ± 0.2) × 10–2

Abstract The passivating properties of various polymer matrices have been studied for a metal-polymer composite prepared by intensive plastic deformation of “iron powder–polymer” mixtures, as well as the processes of their thermal decomposition in the presence of a filler (active iron particles) and processes of subsequent iron depassivation and oxidation. For this purpose, the initial mixtures of

Abstract Austenitic stainless steels (ASSs) offer many advantages over carbon and/or graphite composites for bipolar plates of proton exchange membrane fuel cells (PEMFCs). However, its corrosion resistance in PEMFCs operating conditions is lower. A low temperature (450°C) salt bath nitriding technique for different durations (3, 6 and 12 h) was employed to modify the surface of 316L ASS to enhance

AbstractPolyurethane bentone coatings were prepared using high shear homogenizer (HSH@4000rpm, a high shear instrument), mixer (M@40rpm) along with ultrasonicator bath(USB), to visualize the impact of the processing instruments on the structure, properties, performance of polyurethane/bentone 38 coatings. We also alter the sequencing of the instruments i.e. parallel and series sequencing of USB and

AbstractChemical polishing of metals using nanostructured media—reverse microemulsions has been studied using the example of aluminum. It has been shown that the surface roughness of aluminum foil reduced after the treatment with reverse microemulsion of sodium bis-(2-ethylhexyi)phosphate in kerosene containing an aqueous solution of hydrochloric acid with a concentration of 0.11 mol/L inside the drops

AbstractIn this study, Hardox450 + FeW alloys were coated on AISI1020 substrate material by using plasma transferred arc welding (PTAW) technique. The ratios of the coating materials were chosen as 5, 10, 15, 20 and 25 wt % FeW. The coating process was carried out as the current density (130 A), shielding gas (pure argon), shielding gas flow rate (25 L min–1), plasma gas flow rate (0.8 l min–1), welding

AbstractThe effect of diatomite introduced as an active filler in nickel 2(+) and sodium (+) ionic forms on the adhesion resistance of bitumen–diatomite protective systems during their cathodic polarization is studied. A significant effect of the introduced diatomite clay, the method of its activation, its ionic form on the cathodic exfoliation, and, as a result, the adhesive durability of bitumen–polymer

AbstractSingle NbSi2 and duplex NbSi2/Nb5Si3 coatings were successfully applied on Nb substrates using halide activated pack cementation (HAPC) method at 1100 and 1300°C, respectively. Duplex NbSi2/Nb5Si3 coating with Nb5Si3 inner barrier layer, higher thickness, and lesser micro-cracks considerably decreased the infiltration of simulated body fluid (SBF) solution. This deduction was pertained to the

AbstractThe effect of various methods of abrasive impact (filing with standard and impregnated abrasive tools) on the surface layer of 12X18H10T austenitic stainless steel has been investigated, which included the analysis of the interrelation of the measured properties obtained by the methods of direct indentation, Kelvin probe, micro-X-ray spectral analysis, and raster microscopy. The results of

AbstractThe reaction of osmium(II) tetra-15-crown-5-porphyrin (Os(II)TCP) with molecular iodine in high yield yielded the corresponding osmium(IV) porphyrin containing iodide ions in the axial positions of the osmium(IV) atom and possessing paramagnetic properties according to 1H NMR. The iodine anions in the complex create an additional heavy atom effect in addition to such an effect from the osmium(IV)

AbstractThe relationship between the effective (real) specific surface area of the nanofiller and the elastic modulus for polymer/graphene nanocomposites is studied. The process of aggregation of a graphene 2D nanofiller (the formation of its tactoids) leads to a decrease in its effective specific surface area, since the surface of graphene plates inside the tactoid, which does not interact with the

AbstractThe fractal characteristics of individual macromolecular tangles of block and random copolymers are investigated. It was found that the dependence of the mass of macromolecules on the radius of inertia of a statistically significant sample is well described by the de Gennes equation with a fractal dimension of 5/3. It was established that the fine structure of the polymer coil also has a fractal

AbstractThis paper studies the effect of preliminary magnetohydrodynamic activation of a trilonate electrolyte for the deposition of Co–Bi alloys on some of its physicochemical characteristics (surface tension, wetting, and electrical conductivity) and the quality of the coatings obtained. At the same time, an increase in the deposition rate of the Co–Bi alloy and an increase in the range of working

AbstractOrgano-inorganic film materials based on polystyrene were obtained. The films are characterized by optical microscopy and X-ray diffraction analysis. Thermal behavior was investigated using differential scanning calorimetry. It was found that, with increasing concentration of the modifying additive, the glass transition temperature of the composite increases.

AbstractProtective oxide coatings are developed on aluminum substrate through plasma electrolytic oxidation using a pulsed current and within the alkaline electrolyte. The morphology and corrosion resistance of the oxide layer established under a pulsed current condition have been previously carried out. Since the frequency is one of the main characteristics of the pulse current, the results were performed

AbstractCorrosion inhibition effects of water-soluble peripheral substituted cobalt, copper and zinc metallophthalocyanines (CoPc (1), CuPc (2) and ZnPc (3)) on the copper metal in 0.1 N HCl were investigated by using gravimetric, electrochemical, SEM-EDS analysis and quantum chemical calculations. On the electrochemical investigations and gravimetric analysis the highest inhibitor efficiency was obtained

AbstractThe electrochemical behavior of a combined iron–titanium electrode in aqueous halide solutions has been studied. The distribution of the potential on the surface of metals of the combined anode under external polarization is shown. The possibility of changing the rate of anodic dissolution of titanium and iron component of the combined electrode with a change in the current density and ratio

AbstractIn this study, AISI 5140 steel samples were borided in an electrical furnace at a temperature of 950°C for 4, 6 and 8 h. Structural examinations, hardness measurement and corrosion tests were performed to determine the effect of the boriding time on the microstructure, hardness and corrosion resistance of the steel surface. It was observed that 4 h of boriding treatment resulted in the forming

AbstractElectroactive composite coatings (CCs) are prepared on the basis of 3,6-di(3-aminophenylene)amino-2,5-dichloro-1,4-benzoquinone (DAPADCB) and its polymerization product poly-DAPADCB. We use two types of carbon substrates: (1) with a smooth surface, which are represented by glassy carbon (GC) and Graflex commercial graphite foil (GF), and (2) with a rough surface, which is represented by activated

AbstractThe technology of pulsed cathode-arc evaporation (P-CAE) has been successfully applied for coating deposition in the Cr–B–C–N system. The coatings had a structure typical for arc coatings with a significant fraction of the condensed droplet phase, but the formation of an adverse columnar morphology has been eliminated. The coatings contained crystallites of the h-CrB2 and с-CrN phases along

AbstractIn this study, the possibility of powder-pack boriding of the In-738LC superalloy at 900°C for two different short times of 30 and 60 min was explored. Boriding caused to formation of aluminium borate and a superficial metallic boride layer at top surface. It was found that the boride coating was consists of three layers: Al18B4O33 and Ti rich boride; Cr rich borides; and W, V and Mo rich borides

AbstractThe study described the preparation and characterization of thiophene/pyrazine Schiff base, (E)-N-{(thiophene-2-yl)methylene}pyrazine-2-carboxamide (HL) using melting point and micro (CHN) analysis; vibrational, nuclear magnetic resonance (1H- and 13C-NMR) and electronic (UV–Vis) spectroscopies. HL was also studied for adsorption and corrosion properties. The spectral data were consistent with

AbstractThe kinetic regularities of the electrodeposition process of alloyed zinc–nickel coatings from an ammonium-chloride electrolyte solution have been studied. The effect of the addition of aminoacetic acid on the mechanism of the electrodeposition process, current efficiency, surface morphology, chemical and phase composition of the synthesized coatings has been established. The process of electrochemical

AbstractThe conditions of chemical modification of the surface of synthetic magnetic iron oxides (magnetite Fe3O4, maghemite γ-Fe2O3) by phosphonic complexones (PBTC, HEDP, HEIDPH, NTMP, EDTMP) are studied. It is shown that the maximum concentration of grafted groups is observed upon treating iron oxides with aqueous solutions of complexones containing two or three phosphonic groups at pH 2–3 and temperature

AbstractThe morphology and composition of an oxide layer on the surface of iron chipping cuts obtained using metal-working under conditions of intense plastic shear deformation and subsequent thermal oxidation have been investigated by scanning electron microscopy with an X-ray probe, Raman spectroscopy, and thermogravimetry. It is shown that agglomerations of metal–oxide nanoparticles and nanostructures

AbstractThe morphology, composition, and chemical state of coating elements based on titanium nitride (TiN) formed by the method of condensation with ion bombardment at different modes on Hadfield steel substrates (110G13L grade) have been studied by the methods of SEM, EDX, and XPS. It has been established that, in the formed coatings, the highest titanium content was in the composition of nitride

AbstractIn this paper, a small molecular complex {[Cu(2,3-Hpyza)] · 2(H2O)} (compound 1) was synthesized by solvothermal method from pyrazine dicarboxylic acid and Cu(H3COOH)2 · H2O. A metal organic framework (MOF) compound {[Nd2(2,3-Hpyza)3] · 4(H2O)}n (compound 2) was synthesized by solvothermal method from pyrazine dicarboxylic acid and Nd(NO3)3 · nH2O. Weight loss method, electrochemical measurement

AbstractA method for quantitation of exogenous cis fatty acids in the presence of exogenous cis and trans fatty acids that does not require time-consuming and tedious chromatographic separation is described. In it, we use an inhibitor that blocks Elovl6, an enzyme involved in fatty acid synthesis in vivo. Samples prepared in the absence or presence of the inhibitor are sequentially analyzed by liquid

AbstractThe main objective of this research was to examine the effect adding B at 0, 100, 170 ppm had on the mechanical properties, wear and corrosion behaviour (in two different corrosive media) of cast 304 stainless steels. The microstructures, wear surface and corrosion morphologies were examined by optical microscopy, X-ray diffraction analyses and scanning electron microscopy (SEM). The cast 304

AbstractThe stability constants of zinc and nickel(II) complexes with taurine have been determined at 25°C and ionic strength values of 0.5; 1.0; and 1.5 (KNO3). The values of thermodynamic stability constants have been calculated. The processes of electrodeposition of zinc–nickel alloys on the 08KP-grade steel from electrolytes with taurine additive and physicochemical properties of coatings have

AbstractNickel-based composite electrochemical coatings (CECs) modified with graphite nitrate have been obtained. Their microstructure and functional properties (sliding friction coefficient and protective ability) have been studied. It has been found that when a dispersion of graphite nitrate is introduced into a sulfate–chloride electrolyte for nickel plating, the sliding friction coefficient of

AbstractThe present work was devoted to a study of the effect of the electrolyte composition on the anodic behavior of stainless steel. Morphology and X-ray phase composition of oxide coatings formed in Al- and Ti-containing electrolytes have been investigated. Electrical conductivity and defects of the coatings have been studied by the method of impedance spectroscopy. It has been established that

AbstractIn this work, Cu–Sn–TiO2 composite coatings have been deposited from an oxalic acid electrolyte additionally containing 4 g/dm3 TiO2. Using energy-dispersive X-ray spectroscopy and X-ray fluorescence analysis, the influence of ultrasonic treatment and current load on the inclusion and distribution of the dispersed TiO2 phase in the Cu–Sn metal matrix has been established. Scanning electron

AbstractBased on the concept of collective vibrations of ions in the bulk of metal systems, the frequency of vibrations of an oxygen molecule on the aluminum–cerium alloy surface has been evaluated. Numerical estimation of the physical adsorption isobar has been carried out in accordance with the Henry law using these data and the heats of oxygen adsorption on the surface of this alloy in amorphous

AbstractSwelling of synthesized N-vinylpyrrolidone-based polymer sorbents in aqueous solutions with different pH has been studied. The initial rate and degree of swelling, their dependence on the ratio of functional monomer and cross-linking agents in the polymer samples synthesized in various solvents have been found. It has been shown that the sorption of nitrophenols depends on the swelling of the

AbstractThe regularities of the effect of the duration of coatings' galvanostatic formation in Zr(SO4)2 electrolyte on their composition, structure, surface contact angle with water, and the time of emergence of electrostimulated pitting when samples are in contact with an aqueous NaCl solution have been studied. It has been shown that coatings formed on titanium in the range of transition from the

Abstract—The processes of the pulsed magnetron sputtering (PMS) of multicomponent ceramic targets are studied upon deposition of functional coatings of various purposes. The regularities of changes in the structural characteristics, as well as mechanical and tribological properties, under increasing magnetron power frequency are studied. Summarizing the results obtained using the PMS technology upon

Abstract—The electrochemical properties of Ti–Al–Mo–Ni–N coatings with a molybdenum content of 20 and 25 at % fabricated by cathodic arc deposition (Arc-PVD) are studied. Series 2 coatings are characterized by the presence of Mo in both a chemically bound (Mo2N, as with series 1 coatings) and free states (i.e., metallic phase). Considering the multilayer architecture of coatings based on the mixed

AbstractThis work is aimed at obtaining mixed cluster ions of amino acids with copper salts using soft ionization methods. We have shown that amino acid molecules are capable of forming aggregates stabilized by d-metals. In particular, such clusters can form in the presence of silver salts. In the present work, it is revealed that the largest cluster ions can be obtained using the electrospray ionization

AbstractThe structural organization of the surface (active) layer and the state of water in composite ultrafiltration membranes have been investigated by means of the methods of vibrational IR spectroscopy and differential scanning calorimetry (DSC). Analysis of the shape of the absorption band of stretching vibrations of hydroxyl groups at ν = 3366.2 cm–1 with an asymmetry coefficient of ~1 and the

AbstractA method for constructing the spectral dependence of near-field maximum efficiency \(Q_{{nf}}^{{{\text{max}}}}\) on the surface of a spherical nanoparticle has been suggested. It has been shown that, for preset wavelength λ and a selected refractive index of the environment n, the dependences of near-field efficiency Qnf on particle radius a had the form of smooth curves with a maximum. Therefore

AbstractSilver nanoparticles (Ag NPs) have been synthesized in various media using chemical reduction of silver ions with tannin and absorption spectra have been recorded during synthesis of organosol, organohydrosol, and hydrosol. Analysis of the spectra has provided the concentration of Ne conduction electrons, volume fraction of particles NV, and damping coefficient of plasma oscillations γ, which

AbstractThe properties of a cobalt-modified nanoporous alumina formed by two-stage oxidation were investigated by electrochemical impedance spectroscopy. States corresponding to the different distribution of cobalt in the pores are considered. Equivalent circuits were selected that adequately correspond to the obtained impedance spectra, allowing the results of surface modification and its change to