This paper studied the effect of additives of 0.5–20 wt.% synthetic CaSiO₃ wollastonite on the thermodynamic, mechanical, and tribological characteristics and structure of polymer composite materials (PCM) based on ultra-high-molecular weight polyethylene (UHMWPE). Using thermogravimetric analysis, X-ray fluorescence, scanning electron microscope, and laser light diffraction methods, it was shown that autoclave synthesis in the multicomponent system CaSO₄·2H₂O–SiO₂·nH₂O–KOH–H₂O allows one to obtain neeindle-shaped nanosized CaSiO₃ particles. It was shown that synthetic wollastonite is an effective filler of UHMWPE, which can significantly increase the deformation-strength and tribological characteristics of PCM. The active participation of wollastonite in tribochemical reactions occurring during friction of PCM by infrared spectroscopy was detected: new peaks related to oxygen-containing functional groups (hydroxyl and carbonyl) appeared. The developed UHMWPE/CaSiO₃ materials have high wear resistance and can be used as triboengineering materials.

The application of titanium and its alloys under friction conditions is severely restricted, owing to their poor wear resistance. The paper presents the results of studies of the composition, microstructure, and tribological properties of Ti-TiC-based composite coatings formed on titanium alloys by the electroarc treatment in an aqueous electrolyte using a graphite anode. It has been found that TiC grains have a different stoichiometry and do not contain oxygen. The grain size varies from hundreds of nanometers to tens of micrometers, and the micro-hardness of the treated surface reached the value of 29.5 GPa. The wear resistance of the treated surface increased approximately 40-fold, and the friction coefficient with steel decreased to 0.08–0.3 depending on the friction conditions. The formation of a composite material based on Ti-TiC will contribute to the effective protection of titanium alloys from frictional loads in engineering.

A theoretical model is presented of the visible, near-infrared, and near-ultraviolet transmittance spectra of arbitrarily-shaped small-sized insulator particles embedded in an insulator in relation to the particle dimensions and the radiation frequency. The model is based on a number of assumptions. In the band gap of the nanoparticles, there are allowed energy bands produced by surface defects. Two-particle states (electron-hole pairs) are only slightly confined, and the size-quantized states of charge carriers are formed in the conduction band; the states depend on the shape and dimensions of the nanoparticles. By the example of Al₂O₃ nanoparticles introduced into a liquid matrix of a transparent insulator, the results of experimental studies are compared with the theoretical model.

The transmission of laser femtosecond pulses by spicules of marine glass sponges and monolithic amorphous nanocomposite silica biomaterials synthesized on the basis of natural polysaccharides has been experimentally investigated. The strong non-linear optical properties of these biominerals have been revealed in spectral characteristics of transmitted ultra-short pulses (USP). Comparative analysis of the transmission spectra of USP reveals that spicules exhibit much stronger non-linear optical properties than quartz optical fibers. Recently new monolithic nanocomposite silica biomaterials were synthesized on the basis of various natural polysaccharides and completely water-soluble Si-precursor. The shape of transmitted spectrums through both spicules and new nanocomposite biomaterials demonstrates major changes indicating the broadening with formation markedly strong anti-Stokes component in the output spectrum with generation of supercontinuum spectra. The carried out studies have showed that the nature combination of spongin protein with silicon dioxide extracted from seawater by silicatein protein in glass sponge spicules and monolithic nanocomposite silica biomaterials are biological and biomimetical nanocomposite materials with unique optical properties.