The surface physicochemical properties of materials-based on polylactic acid modified by flows of low-temperature glow discharge plasma were studied. A mixture of argon and air acted as a plasma-forming gas, and diethylamine vapor was injected into the plasma as a precursor of amino groups. The elemental composition and chemical state of the surface were studied using X-ray photoelectron spectroscopy. The attachment of nitrogen atoms to the polylactic acid surface and the formation of a bond between the surface carbon and the penetrated nitrogen have been established. It was shown that the hydrophilicity of the plasma modified polylactic acid surface was significantly increased. The obtained polylactic acid-based materials with the argon/air/diethylamine plasma modified surface may have prospects for use in biomedicine due to improved hydrophilicity and the presence of reactive oxygen- and nitrogen-containing functional groups on the surface.

The regenerator plays a dominant role in the overall energy-economic performance of liquid desiccant systems. Nevertheless, very few studies have been reported on falling film liquid desiccant regenerators. Most of the previous studies targeted experimental/numerical modelling needs of regeneration process under design conditions. In the current research workexperimental investigation of regeneration process is carried out to study the coupled heat and mass transfer process for adiabatic regeneration of LiCl liquid desiccant over outer surface of vertical Plain and Modified polypropylene cylindrical surfaces under design (complete wetting) and part load (partial wetting) operating conditions. Modified cylindrical surfaces are developed to compensate the poor wetting of the plastic surfaces. New generalised one-dimensional numerical philosophy is proposed to accommodate the need of part load operating conditions by inclusion of actual wetting of the working surface as well as convective heat transfer happening from dry patches of solid surface to the flowing air. The heat and mass transfer coefficients are determined by solving the governing coupled heat and mass balance non-linear differential equation using the numerical finite difference method. It is found that the Modified surface offered an average improvement of 35.8% in the mass transfer coefficient under partial wetting conditions. New Sh and Nu number correlations are proposed by incorporating heat and mass transfer driving potentials and new parameter wetting factor. The developed correlations predicted the change in humidity and temperature across the regenerator with an average error of 6.2% and 7.5%, whereas from the existing two correlations found in the literature, the first one predicted the same experimental observations with an average error of 54.6% and 36.2%, while second one predicted with an average error of 77.3% and 22.0%, respectively. The results highlighted that the assumption of complete wetting of working surface under part load operating conditions leads to significant error in prediction of air outlet conditions. The proposed correlations will be helpful for numerical modelling and simulation of falling film regenerators under wide range of liquid loading conditions.

In this work, composite materials were obtained for the first time using various methods and the dependences of the resulting surface morphologies were investigated. This involves modifying the surface with cucurbit[n]urils, which are highly promising macrocyclic compounds. The process includes applying cucurbit[6]uril to the hydroxyapatite surface in water using different modification techniques. The first method involved precipitating a dispersion of CB[6] in undissolved form in water. The second method involved using fully dissolved CB[6] in deionized water, after which the composite materials were dried to constant weight. The third method involved several steps: first, CB[6] was dissolved in deionized water, then, upon heating, a dispersion of CB[6] was formed on the surface of HA. The fourth method involved using ultrasonic treatment. All four methods yielded materials with different surface morphologies, which were studied and characterized using techniques such as infrared (IR) spectroscopy and scanning electron microscopy (SEM). Based on these results, it is possible to vary the properties and surface morphology of the obtained materials. Depending on the method of applying CB[6] to the surface and inside the HA scaffold, it is possible to adjust the composition and structure of the target composite materials. The methods for applying CB[6] to the hydroxyapatite surface enhance its versatility and compatibility with the body’s environment, which is crucial for developing new functional composite materials. This includes leveraging supramolecular systems based on the CB[n] family. The obtained results can be used to model the processes of obtaining biocomposite materials, as well as to predict the properties of future materials with biological activity.

The effect of surface modification by an arc discharge plasma in a nitrogen flow with treatment durations of 5 and 10 min on the physicochemical properties and biocompatibility of the surface of composites based on polylactic acid and hydroxyapatite (PLA/HA) with different mass ratios (80/20, 70/30, 60/40) has been investigated. The aim of this work was to show the correlation between the changes of the physicochemical characteristics (chemical compound, morphology, wettability) of the surface layer of the PLA/HA composites and the cell viability (macrophages) in the presence of the plasma-modified materials. The dependence of alterations of the functional properties (wettability, biocompatibility) on the change in the chemical composition under the plasma exposure has been established. The chemical composition was studied using X-ray photoelectron spectroscopy (XPS), the surface morphology was researched with scanning electron microscopy (SEM), and the wettability of the composite's surface was analyzed by measuring the contact angle and surface energy calculation. In addition, the viability of macrophages was investigated when the macrophages from three donors interacted with a modified PLA/HA surface. It was found that the formation of the new functional groups, -C-N and N-C=O/C=O, improves the wettability of the surface of the composites and promotes the viability of macrophages in the presence of the composite materials. The fundamental principles for obtaining promising materials with the required properties for eliminating bone defects have been created.

The present work deals with the chemical constitution of coatings deposited by plasma activation of hexamethyldisiloxane in positive column plasma of a low-pressure DC glow discharge in an argon flow (mass flow rate 230 mg/min). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) are used to analyze deposit chemistry. The substance is complex and consists of many constitutional units forming branched and cross-linked irregular macromolecules. Chemical constitution depends on both discharge current (10-60 mA) and monomer flow rate (1-10 mg/min). Using the specific energy (SE) and Arrhenius-like approach, the threshold energy for the plasma polymerization of HMDSO has been estimated to be 12 +/- 1 eV. Two regimes of the plasma chemical system have been identified. At SE near the threshold energy (from 5 to 40 eV/molecule), polymethylsiloxane-like coatings are deposited and variation of SE practically does not lead to changes in chemical constitution, but significantly affects the mass yield of deposit. At specific energies much higher than threshold energy, polymethylhydroxysiloxane-like coatings are formed; the coating structure is strongly SE-dependent, while the mass yield of the deposit does not change.

Nowadays, due to the increasing number of diseases and injuries related to bone tissue, there is an acute problem of creating a material that could be incorporated into the bone tissue structure and contribute to accelerated bone regeneration. Such materials can be represented by a polymeric matrix that holds the material in the bone and an inorganic component that can be incorporated into the bone structure and promote accelerated bone regeneration. Therefore, in this work we investigated polyvinyl alcohol-based composite cryogels containing an in situ deposited inorganic filler, hydroxyapatite. The freezing temperature was varied during the synthesis process. The composition of the components was determined by infrared spectroscopy and the phase composition by X-ray phase analysis, from which it was found that the main phase of the composite is hydroxyapatite and that the particle size decreases with increasing freezing temperature. The elemental composition of the surface is dominated by carbon, oxygen, phosphorus and calcium; no impurities of other elements not typical for polyvinyl alcohol/ hydroxyapatite cryogels were found. Higher mechanical properties and melting points were observed at −15 °C. Cryogenic treatment parameters did not affect cell viability; however, cell viability was above 80% in all samples.

This study aimed to create new composite materials based on diatomite—a non-organic porous compound—through its surface modification with bioactive organic compounds, both synthetic and natural. Chloramphenicol, tetrahydroxymethylglycoluril and betulin were used as modifying substances. Composite materials were obtained by covering the diatomite surface with bioactive substance compounds as a solution and material dispersion in it. The materials were characterized by IR spectroscopy, SEM and X-ray photoelectron spectroscopy. For the biocomposites, the hemolytic effect, plasma proteins’ adsorption on the surface and the antibacterial activity of the obtained materials were studied. Results show that the obtained materials are promising for medicine and agriculture.

Palladium–bismuth nanomaterials are used in various chemical applications such detectors, electrodes, and catalysts. Pd-Bi catalysts are attracting widespread interest because these catalysts enable the production of valuable products quickly and efficiently, and are environmentally friendly. However, the composition of the catalyst can have a significant impact on its catalytic performance. In this work, we identified a correlation between the composition of the catalyst and its efficiency in converting glucose into sodium gluconate. It was found that the conversion decreases with increasing bismuth content. The most active catalyst was the 0.35Bi:Pd sample with a lower bismuth content (glucose conversion of 57%). TEM, SEM, EXAFS, and XANES methods were used to describe, in detail, the surface properties of the xBi:Pd/Al2O3 catalyst samples. The increase in particle size with increasing bismuth content, observed in the TEM micrographs, was associated with the low melting point of bismuth (271 °C). The SEM method showed that palladium and bismuth particles were uniformly distributed over the surface of the support in close proximity to each other, which allowed us to conclude that an alloy of non-stoichiometric composition was formed. The EXAFS and XANES methods established that bismuth was located on the surface of the nanoparticle predominantly in an oxidized state.

The structural and phase composition of TiZr50, AlZr50, TiAl49Zr2 composite materials obtained by the hydride technology was investigated. A model three-component phase diagram was constructed for Ti–Al–Zr at a temperature of 1150°C. The structural state of TiAl49Zr2 alloys was predicted based on reference lattices (USPEX code with VASP interface), quantum-chemical calculations of the energy of TiAl49Zr2 were carried out in the CASTEP code. Solid solutions dominate in TiAl49Zr2, in the composition of which the main elements are predominant: Al10–Ti9Al23–Ti8. Zr atoms can be introduced into the interstitial sites [– 0.257 0.042 0.2545] (St–Zr–27), [0.0053–0.0120–0.0765] (St–Zr–143), [–0.3251–0.3983 0.4880] (St–Zr– 75). The introduction of Zr into the specified lattice sites does not violate the stabilizing effect in the TiAl49Zr2 systems. All reference lattices are stable. In the TiAl49Zr2 alloy, the main phases are Al10Ti9Zr, Al23Ti8Zr, the contributions of which to the theoretical intensity are 78.57 and 21.43%. In the AlZr50 sample, the phases ZrAl, Zr2Al3, ZrAl2.

This study represents an advancement in the field of composite material engineering, focusing on the synthesis of composite materials derived from porous hydroxyapatite via surface modification employing cucurbit[n]urils, which are highly promising macrocyclic compounds. The surface modification procedure entailed the application of cucurbit[n]urils in an aqueous medium onto the hydroxyapatite surface. A comprehensive characterization of the resulting materials was undertaken, employing analytical techniques including infrared (IR) spectroscopy and scanning electron microscopy (SEM). Subsequently, the materials were subjected to rigorous evaluation for their hemolytic effect, anti-inflammatory properties, and cytotoxicity. Remarkably, the findings revealed a notable absence of typical hemolytic effects in materials incorporating surface-bound cucurbit[n]urils. This observation underscores the potential of these modified materials as biocompatible alternatives. Notably, this discovery presents a promising avenue for the fabrication of resilient and efficient biocomposites, offering a viable alternative to conventional approaches. Furthermore, these findings hint at the prospect of employing supramolecular strategies involving encapsulated cucurbit[n]urils in analogous processes. This suggests a novel direction for further research, potentially unlocking new frontiers in material engineering through the exploitation of supramolecular interactions.

The connection of Ti-H by ATAT, USPEX codes with QE and VASP interfaces is investigated in the work. Predictive estimates revealed a number of stable and geometrically optimized hydrides with different atomic compositions: Ti6H2, Ti5H3, Ti5H2, Ti4H3, Ti3H5 of a simple triclinic group and highly symmetrical TiH2, Ti2H2, Ti6H2, Ti3H5 alloys. The stability of hydrides was evaluated by first principles calculations and by the convex hull method. Model estimates of mechanical characteristics have shown that hydrides with low mass density are highstrength compounds. The detected hydrides can be included in the reference database of Ti-H compounds. The possibility of obtaining alloys based on Ti-Al with additions of Sc, Y, Dy, Ho by "Hydride technology" is considered. The formation of a lamellar structure upon the introduction of 2 at.% Sc, Y into Ti-50Al (at.%) was found. When 2 at.% Dy, Ho is added to Ti-50Al (at.%), isotype compounds Y6Ti4Al43, Dy6Ti4Al43, Ho6Ti4Al43 are formed. The values of microhardness and electrical resistance are given.

Imidazolium barbiturate (two polymorphs, 1 and 2) and imidazolium 2-thiobarbiturate (3) with an unusual geometry of HB motifs were synthesized. Interestingly, 2 was more soluble in water than 3, while initial barbituric acids showed inverse tendency.

Herein, we have revealed the regularities in Pd–Bi nanoparticle formation supported on alumina from an acetic acid solution of organometallic precursors.

Study of samples of three-layer material “chromium-containing steel Kh17N2/vanadium alloy/chromium-containing steel Kh17N2" obtained by laser growing is presented. The structural-phase state and strength properties of the vanadium alloy and three-layer alloy in the initial state, after heat treatment at 1200°C, and also after irradiation have been studied. The interaction zone of vanadium alloy and steel has been studied in detail.

In this present investigation, a novel series of composite materials based on porous inorganic compounds—hydroxyapatite and diatomite—have been innovatively formulated for the first time through surface modification employing the promising macromolecular compound, bambus[6]uril. The process entailed the application of a bambus[6]uril dispersion in water onto the surfaces of hydroxyapatite and diatomite. Extensive characterization was carried out, involving IR spectroscopy and SEM. The materials underwent assessment for hemolytic effects and plasma protein adsorption. The results revealed that materials containing surface-bound bambus[6]uril did not demonstrate inherent hemolytic effects, laying a robust groundwork for their use as biocompatible materials. These findings hold significant promise as an alternative pathway for the development of durable and efficient bio-composites, potentially unveiling supramolecular strategies incorporating encapsulated bambus[6]urils in analogous processes.

The primary purpose of the study, presented in this article, was to obtain a composite cement material intended for osteanagenesis. The β-tricalcium phosphate powder (β-TCP, β-Ca3(PO4)2) was obtained by the liquid-phase method. Setting and hardening of the cement system were achieved by adding calcium sulfate hemihydrate (CSH, CaSO4·1/2H2O). An aqueous solution of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and a PVA/PVP mixture were used as a polymer component. The methods of capillary viscometry and Fourier-transform infrared spectroscopy (FTIR) revealed the formation of intermolecular hydrogen bonds between polymer components, which determines the good miscibility of polymers. The physicochemical properties of the synthesized materials were characterized by X-ray diffraction (XRD) and FTIR methods, and the added amount of polymers does not significantly influence the processes of phase formation and crystallization of the system. The size of crystallites CSD remained in the range of 32–36 nm, regardless of the ratio of polymer components. The influence of the composition of composites on their solubility was investigated. In view of the lower solubility of pure β-TCP, as compared to calcium sulfate dihydrate (CSD, CaSO4·2H2O), the solubility of composite materials is determined to a greater degree by the CSD solubility. Complexometric titration showed that the interaction between PVA and PVP impeded the diffusion of calcium ions, and at a ratio of PVA to PVP of 1/1, the smallest exit of calcium ions from the system is observed. The cytotoxicity analysis results allowed us to establish the fact that the viability of human macrophages in the presence of the samples varied from 80% to 125% as compared to the control.

The structural and phase state of the surface layers of technically pure titanium (VT1-0 alloy) implanted with aluminum ions in three states (submicrocrystalline, ultrafine-grained, and fine-grained) obtained by multiple uniaxial pressing (abc pressing) followed by multipass rolling in groove rolls at room temperature and subsequent annealing at 573, 673, and 773 K for 1 h, respectively, has been studied by transmission electron microscopy and energy dispersive X-ray spectroscopy on foils cut perpendicular to the machined sample surface. Ion implantation has been performed for 8 h and 20 min at an irradiation dose of 10 × 1017 ions/cm2 and a temperature of 623 K. It has been found that the implantation led to the formation of a gradient structure consisting of five layers. For each layer, the thickness, phase composition, and shape and arrangement of second-phase particles have been determined and the α-Ti grain size and the size, distribution density, and volume fractions of separated particles have been measured. It has been established that the implantation causes the formation of Ti3Al and TiAl3 intermetallic phases. Ti3Al particles have a lamellar shape and are located inside parts of α-Ti grains, while TiAl3 particles have a rounded shape and are arranged randomly.

The effect of low-temperature arc discharge plasma treatment in a nitrogen atmosphere on the modification of the physicochemical properties of PLA-based scaffolds was studied. In addition, the cellular-mediated immune response when macrophages of three donors interact with the modified surfaces of PLA-based scaffolds was investigated. PLA surface carbonization, accompanied by a carbon atomic concentration increase, was revealed to occur because of plasma treatment. Nitrogen plasma significantly influenced the PLA wettability characteristics, namely, the hydrophilicity and lipophilicity were improved, as well as the surface energy being raised. The viability of cells in the presence of the plasma-modified PLA scaffolds was evaluated to be higher than that of the initial cells.

Compounds composed of [Cu(HIm, metIm)2–3L] ∙ nH2O (n = 0, 2) were obtained during the interaction of slightly soluble tartrate and copper(II) salicylate composed of CuL ∙ nH2O (n = 1–2, L2−—Tar2−, Sal2−) with imidazole (HIm) and 2-methylimidazole (metIm). Mono- and bi-ligand salts were analyzed; the process of their thermal decomposition was studied. The solubility constants KS of the CuC4H4O6 ∙ 2H2O tartrate and CuC7H4O3 ∙ H2O salicylate of copper(II) with at ionic strength of 0.3 were determined. The IR spectroscopy method showed the participation in complexation of the nitrogen atom N(3) of imidazole and the oxygen atoms of the carboxyl groups of oxyacids, as well as the hydroxyl group of salicylic acid in the mixed-ligand salts of copper(II). The compositions and stability of the imidazole-tartrate(salicylate) copper(II) complexes in an aqueous solution were determined by performing photometry and spectrophotometry and of the monoligand complexes [CuTar] and [CuSal] were determined by solubility and isomolar series methods.

During the interaction of aqueous-ethanol or ethanol solutions AgNO3, H[AuCl4], and CuCl2, as well as aqueous suspensions of slightly soluble copper(II) salts Cu(C6H4NO2)2·H2O, Cu(C7H5O2)2∙3H2O, and CuC7H4O3∙H2O with the ethanol solution of clotrimazole at pH of ~(5.0–5.5), the [Ag(C22H17ClN2)2]NO3·2H2O, [Au(C22H17ClN2)Cl3], [Cu(C22H17ClN2)2Cl2]·5H2O, Cu(C22H17ClN2)4(C6H4NO2)2, Cu(C22H17ClN2)4(C7H5O2)2, and Cu(C22H17ClN2)3(C7H4O3)·2H2O compounds are synthesised. They are characterised by elemental, thermal, thermogravimetric, and IR spectroscopic methods of analysis. The [Ag(C22H17ClN2)2]NO3·2H2O complex was shown to have a higher antimycotic activity against Saccharomyces cerevisiae fungi than that of AgNO3 and C22H17ClN2. Cocrystals/salts of the composition C22H17ClN2·C6H5NO2, C22H17ClN2·C7H6O2, 2C22H17ClN2·C7H6O3, and 2C22H17ClN2·C19H19O6N7·H2O are obtained from aqueous and aqueous ethanol suspensions containing nicotinic, benzoic, salicylic, and folic acids and clotrimazole (pH is 4.5–6.0). These cocrystals and salts were studied usin thermogravimetric, IR-spectroscopic methods. Diffraction patterns of the powders were obtained. The influence of the difference in the pKa components on the ability to form cocrystals/salts was assessed.