As the industry develops and energy demand increases, wind turbines are increasingly being used to generate electricity, resulting in an increasing number of obsolete turbine blades that need to be properly recycled or used as a secondary raw material in other industries. The authors of this work propose an innovative technology not yet studied in the literature, where the wind turbine blades are mechanically shredded and micrometric fibers are formed from the obtained powder using plasma technologies. As shown by SEM and EDS studies, the powder is composed of irregularly shaped microgranules and the carbon content in the obtained fiber is lower by up to seven times compared with the original powder. Meanwhile, the chromatographic studies show that no hazardous to the environment gases are formed during the fiber production. It is worth mentioning that this fiber formation technology can be one of the additional methods for recycling wind turbine blades, and the obtained fiber can be used as a secondary raw material in the production of catalysts, construction materials, etc.

The plasma-activated reactive evaporation technique was used for the formation of indium-tin-oxide (ITO) films. The ITO films were deposited on a heated (up to 350 °C) glass substrates using various mass ratios of indium and tin. The optical and electrical properties of the deposited ITO films were determined. The influence of the indium-to-tin mass ratio on the optical transmittance, bandgap, resistivity and resistance of ITO films was investigated. The bandgap of ITO films was increased from 3.18 to 3.37 eV, and the M_In/M_Sn ratio increased from 4.25 to 10.00. The average values of optical transmittance at the visible light wavelengths increased from ~43% to ~64% as tin mass was reduced. We demonstrated that ITO films with low resistivity ranging from 7.4 × 10⁻³ to 43.7 × 10⁻³ Ω·cm were obtained, and the M_In/M_Sn ratio changed from 4.25 to 10.00. The ITO film formed at the 9.25 M_In/M_Sn ratio demonstrated high transparency, a wide bandgap and optimal resistivity and resistance values. The heating characteristics indicated that the frozen ice on the ITO films was completely removed after 30 s when the applied voltage was 24 V.

The global coronavirus (COVID-19) pandemic in early 2020 caused the amount of medical waste, especially plastic waste, to increase. The pandemic exacerbated the plastic waste management problem, including the need to find more sustainable treatment methods. This study investigated the sustainable conversion of plastic waste (FFP2-type face masks) to syngas via pure CO₂ plasma gasification to recover energy and reduce environmental pollution. A direct current (DC) thermal arc plasma torch of 40.6–68.4 kW power generated the plasma stream. Carbon dioxide (CO₂), as a greenhouse gas (GHG), was used as the main plasma-forming gas and gasifying agent. The 140_thermal feedstock input plasma gasification system was used in the study. The effect of the CO₂-to-C ratio on the gasification performance efficiency was investigated. The best CO₂ plasma gasification process performance was obtained at a CO₂-to-C ratio of 2.34. In these conditions, the main syngas components (H₂ + CO) comprised 80.46 vol.% (H₂: 24.62 vol.% and CO: 55.84 vol.%) and the following values were seen for the heating value of the syngas (LHV_syngas: 13.88 MJ/Nm³), the syngas yield (3.13 Nm³/kg_FFP2), the tar content in the syngas (23.0 g/Nm³), the carbon conversion efficiency (CCE: 70.6%), and the cold gas efficiency (CGE: 47.8%). Additionally, the plasma gasification process mass and energy balance were evaluated. It was demonstrated that CO₂ plasma gasification could be a promising thermochemical treatment technology for sustainable plastic waste disposal and the simultaneous utilization of greenhouse gases, such as carbon dioxide.

In this study, Cr₂O₃, Cr₂O₃-SiO₂-TiO₂ and Cr₂O₃-SiO₂-TiO₂-graphite coatings were formed by atmospheric plasma spraying. The influence of SiO₂-TiO₂ and SiO₂-TiO₂-graphite reinforcements on the surface morphology, elemental composition, structure and tribological properties of chromia coatings was determined. The friction coefficients and specific wear rates were investigated by a ball-on-flat configuration using 1 N and 3 N loads under dry-lubrication conditions. The addition of SiO₂-TiO₂-graphite resulted in the lowest surface roughness and the most homogenous surface of the coatings. The X-ray diffraction (XRD) measurements demonstrated that all as-sprayed coatings consisted of an eskolaite chromium oxide phase. The results showed that the Cr₂O₃-SiO₂-TiO₂ coating demonstrated the lowest friction coefficient values. The SiO₂-TiO₂ and SiO₂-TiO₂-graphite additives reduced the specific wear rates of Cr₂O₃ coatings by 30% and 45%, respectively. Additionally, the wear resistance was improved almost 45 times in comparison to the steel substrate.

Cr-doped diamond-like carbon (DLC) films were formed on silicon and glass substrates by magnetron sputtering (MS). The surface morphology, elemental composition, bonding structure, and transparency of the as-deposited films were analyzed by atomic force microscopy (AFM), the energy-dispersive X-ray spectroscopy (EDS), multiwavelength micro-Raman spectrometer, and UV-VIS-NIR spectrophotometer. The study revealed that the oxygen concentration in the Cr-DLC films increased as the Cr content increased. The surface roughness of the films was slightly reduced when the Cr content was ~9.2 at.%, and further increase in the Cr content up to 13.1 at.% stimulated the growth of the highest-roughness Cr-DLC films. The micro-Raman analysis showed that the G peak position shifted to a higher wavenumber, and the sp² bond fraction increased as the Cr concentration in the DLC films rose. The optical transmittance of the Cr-DLC films was reduced by up to 30% compared to DLC coatings due to the increased graphitization process caused by chromium addition.

Cr₂O₃ and Cr₂O₃–SiO₂-TiO₂ coatings are deposited on P265GH steel using atmospheric plasma spraying. The influence of silicon oxide—titanium oxide addition on the surface morphology of the coatings, phase composition and tribological properties under non-lubricated sliding conditions are investigated. The addition of SiO₂-TiO₂ led to the formation of a more uniform surface morphology and reduce the surface roughness of the Cr₂O₃ coatings. The X-ray diffraction (XRD) studies indicated that both coatings are composed of an eskoloite Cr₂O₃ phase. The friction coefficients of the Cr₂O₃ coating are 0.504 and 0.431 when 1 N and 3 N loads were used, respectively. Meanwhile, the Cr₂O₃–SiO₂-TiO₂ coating demonstrated slightly lower values of friction coefficients under similar loads. The specific wear rate of the as-sprayed coating is reduced with the addition of SiO₂-TiO₂. It was found that the wear rates of the Cr₂O₃ and Cr₂O₃–SiO₂-TiO₂ coatings are up to 20 times lower compared to the steel substrate. This article is an expanded version of the “19th international conference on plasma physics and applications” conference