Biocompatible electrically conducting chitosan-based films filled with single-wall carbon nanotubes were obtained. Atomic force microscopic studies of the free surface topography revealed a change in the morphology of chitosan films filled with single-wall carbon nanotubes. Introducing 0.5 wt.% of single-wall carbon nanotubes into chitosan results in an increase in tensile strength of the films (up to ~180 MPa); the tensile strain values also rise up to ~60%. It was demonstrated that chitosan films containing 0.1–3.0 wt.% of single-wall carbon nanotubes have higher conductivity (10 S/m) than pure chitosan films (10⁻¹¹ S/m). The investigation of electrical stimulation of human dermal fibroblasts on chitosan/single-wall carbon nanotubes film scaffolds showed that the biological effect of cell electrical stimulation depends on the content of single-walled carbon nanotubes in the chitosan matrix.

Bioactive biodegradable chitosan films containing chitin nanofibrils have been developed for use as face masks in cosmetology. It was found that thermal modification of chitosan films promotes the transformation of the polymer into insoluble form without the use of alkali or aldehydes. The structure and properties of the films were studied by IT spectroscopy, atomic force microscopy, thermogravimetric analysis, and X-ray structural analysis. Analysis of infrared (IR) spectra showed that the addition of nanofibrils accelerates the process of thermal transformation in the composite films. This is apparent from the observed increase in the intensity ratio of 1030 cm⁻¹\1580 cm⁻¹ peaks in the spectrum of the thermally treated film (as compared to the spectrum of the initial sample and the spectrum of a chitosan film without chitin nanofibrils). The prepared composite films containing chitin nanofibrils possess improved mechanical characteristics: tensile strength 99 MPa and tensile strain 14%. The tetrazolium bromide (MTT) test revealed good viability of human dermal fibroblasts cultivated in the presence of the conditioned medium obtained after incubation of all types of films in the nutrient medium. The used process of thermal modification of chitosan and composite films (which is efficient and environmentally safe) allows one to prepare bioactive materials for applications in medicine and cosmetology.

Chitosan and composite fibers containing chitin nanofibrils have been developed for use in cosmetology. The tensile strength of the chitosan multifilaments is 160.6 ± 19.0 MPa, and of the composite multifilaments containing chitin, nanofibrils are 198.0 ± 18.4 MPa. Chitin nanofibrils introduced into the chitosan solution contribute to the creation of a new spatial arrangement of chitosan chains and their denser packing. The studies carried out by optical, scanning electron, and atomic force microscopy has shown that the serum, consisting of a mixture of lactic acid and sodium lactate, contains extended oriented structures—“liquid filaments”. It has been also shown that a mixture of serum and composite fibers based on chitosan and chitin nanofibrils has mucoadhesive, film-forming properties. The introduction of composite fibers containing chitin nanofibrils into the serum promotes the reinforcing effect of liquid filaments, the lifting effect of the film. The obtained composition can be used in cosmetology as a skin care product.

The effect that implantation of argon and oxygen ions (both individually and in combination) has on the physicochemical structure of the surface of 14Cr17Ni2 steel and its corrosion and electrochemical behavior is studied by linear sweep voltammetry (polarization curve measurements), atomic force microscopy, and X-ray photoelectron spectroscopy. Treatment with Ar⁺ ions results is enrichment of the surface in Cr atoms and a reduction in the total corrosion losses of steel samples, but it essentially has no effect on localized corrosion. In terms of reduction in localized and general corrosion, treatment with O⁺ ions produces optimal results. With this treatment, the surface undergoes extensive oxidation to a depth of more than 20 nm. The physicochemical properties (i.e., microhardness) of surface layers of the steel are not significantly affected by ion implantation.

The effect of oxygen ion implantation on the physicochemical structure of the surface and the corrosion-electrochemical behavior of high-chromium Fe13Cr steel has been examined by potentiometry, atomic force microscopy, X-ray photoelectron spectroscopy, and microhardness measurements. Ion implantation leads to a significant reduction in corrosion losses. Optimal from the point of surface passivation and, consequently, reduction of corrosion losses of the material is the regime of steel treatment with oxygen ions with a dose of D = 5 × 10¹⁶ cm^–2, after which the sample demonstrates the most stable behavior during local and general corrosion. It has been shown that the increase in the corrosion resistance of steel is due to the redistribution of elements in the surface layers caused by ion implantation and the intense formation of spinels of variable composition consisting of iron and chromium oxides with different oxidation states. In this case, the microhardness of the surface layers of the steel after ion implantation does not change significantly.

The effect of implantation of argon, oxygen, and nitrogen ions on the physicochemical structure of the surface and the corrosion and electrochemical behavior of chromium-nickel steel 03Cr18Ni11 has been studied. Methods of electrochemical polarization (EP), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) were used. Ion implantation of argon, oxygen, and nitrogen leads to an increase in the corrosion resistance of steel 03Cr18Ni11 both in a neutral environment and in the presence of a corrosion activator (chloride anions), while irradiation with argon ions is most effective. It is found that, after implantation of argon ions, a partial etching of the steel surface occurs, i.e., an increase in the true surface. This, in turn, facilitates the onset of the passive state. At the same time, the use of oxygen and nitrogen ions leads to smoothing of the surface. AFM data indicate that the studied steel treated with argon ions exhibits the greatest resistance to local corrosion. The implantation of oxygen and argon ions reduces the overall corrosion to the greatest extent. It is important to note that deep craters and traces of pitting corrosion do not form on the surface of the steel. The XPS data show that after ion implantation, there is a change in the concentration of the elements that make up the steel in the near-surface layers of the material in the depth of the implanted layer compared with the unirradiated sample. It is established that the surface layers of steel are enriched in chromium atoms during ion implantation. This process occurs most intensively when samples are treated with argon ions. In this case, mixed chromium and iron oxides are formed, contributing to the passivation of the steel surface. Also, the process of ion implantation is accompanied by oxidation of the surface of the steel under study. This is confirmed by an increase in the oxygen content in the surface layers. To the greatest extent, this process occurs during the implantation of oxygen ions. After corrosion tests, an increased chromium content is also observed on the surface of steel treated with Ar⁺ ions, which confirms the formation in this case of stable chromium oxides that remain on the surface during the corrosion of steel. The analysis of the fine structure of the XPS spectra showed that, under the action of argon ions, the oxygen of surface oxides is redistributed in favor of chromium atoms and the formation of stable mixed iron and chromium oxides of the spinel type, including Fe²⁺, Fe³⁺, Cr³⁺, and Cr⁶⁺ compounds. It is important to note that, although chromium oxides are also formed during oxygen implantation and in the same quantities as during argon implantation, the protective properties of the resulting compounds are noticeably lower. Therefore, not only the chemical composition but also the structure of the resulting layers are important. It can be assumed that the high kinetic energy of heavy argon ions affects both the formation of developed surface relief and the formation of stable mixed iron and chromium oxides of the spinel type.