The paper presents the results of the morphological study of aerosol particles in the urban air of Moscow (Russia) in 2019–2022 by scanning electron microscopy (SEM). Our monitoring revealed mineral and anthropogenic particles, and also primary bioaerosols (PBA), such as pollen, spores, plant fibers, etc., typical for the urban environment. Moreover, in July 2021, brochosomes, lipid secretions of semi-hard-winged insects Cicadellidae (or leafhopper), were found in several aerosol samples. They are quasi-spherical hollow porous semi-regular polyhedra (truncated icosahedra) of 0.2–0.7 microns in size, consisting mainly of carbon and oxygen. Despite the prevalence and diversity of leafhoppers, identification of their secretions in atmospheric aerosols in situ is rather rare: single articles from South Korea, Spain, the Himalayas, and the United States. In this sense, the results obtained are interesting and novel. PBA particles cover a wide size range and have a complex and diverse shape, which determines the distance and efficiency of their atmospheric transport. Pollen and fungal spores have a high allergenic potential and can have harmful effects on human health. Any new information about PBA can be useful for studying the development and dynamics of ecosystems.

The supramolecular structure and tribological properties of filled polytetrafluoroethylene composites irradiated above the melting point of the crystalline phase of the polymer component and the phase transitions in them are investigated. In unirradiated composites, phase separation is observed, that is, the separation of the filler from the polymer matrix. The supramolecular structure of the polymer component does not depend on the nature and concentration of the filler, and it is characterized by the formation of lamellae during sintering and subsequent crystallization. Radiation exposure leads to the disappearance of the phase separation and the formation of axiolites with the radial orientation of fibrils, in the center of which the filler particles are located. Changes in the structure are explained by an increase in interfacial interactions through the radiation grafting of macromolecules (and low-molecular-weight products) to the surface of the filler particles. The linear wear rate of irradiated composites is 50 times lower relative to the unirradiated samples because of the transition from the delamination to abrasive wear mechanism.

The anatase nanoparticles are stabilized with titanium tetraisopropoxide Ti[OCH(CH₃)₂]₄ and isopropyl alcohol without surfactants suitable for biological studies. We showed that the hydrodynamic radii in suspensions depend on temperature and the duration of hydrolysis, whereas the composition (a mixture of anatase with brookite, anatase, brookite, and rutile) and the sizes of crystallites (X-ray), nanoparticles, and aggregates (SEM) in the dried state are mainly dependent on the pH of the environment. The nonphase of the samples stems from coherent intergrowth of unit cells of anatase and brookite via geometric and structural complementarity. We found that photocatalytic activity (PCA; Rhodamine 6G model dye under UV radiation) depends on OH/H₂O ratio (adsorbed), whereas antimicrobial activity (AMA) in the dark depends on an amount of free water on the surface of nanoparticles according to X-ray photoelectron spectroscopy (XPS). We revealed that samples with the smallest sizes of nanoparticles of all levels possess the highest PCA and AMA relative to Staphylococcus aureus and Escherichia coli.

The possibility of chemical metallization of the surface of poly(ethylene terephthalate) (lavsan) fibers in solutions using hydrazine sulfate as a reducing agent is shown. As a result, a conductive...

The influence of polytetrafluoroethylene (PTFE) processing in sc-CO₂ and sc-PFO above the melting point on the microstructure and characteristics of phase transitions is studied using high-resolution scanning electron microscopy and differential scanning calorimetry (DSC). It is shown that, depending on the crystallization conditions, after the processing of PTFE in the supercritical fluid, the formation of a microstructure with a radial orientation of fibrils atypical for this polymer is possible. The processing of PTFE in the supercritical fluid leads to an irreversible increase in the heat of melting and crystallization and, accordingly, to an increase in the degree of crystallinity by 1.5–2 times compared to the initial values. The growth in the crystallinity is explained by a change in the microstructure of the PTFE melt in the supercritical fluid: the release of a part of segments of macromolecules from physical knots during the process of swelling and plasticization of the polymer matrix. Disentanglement of such knots that limit molecular mobility contributes to an increase in the number of macromolecular units involved in the formation of crystalline domains and to an irreversible increase in the degree of crystallinity.