The thesis is devoted to the problem of environmental protection against electromagnetic radiation. The timeliness of the work is determined by the need to optimize the technology of obtaining effective thin polymer composite coatings to protect people and equipment from electromagnetic radiation within the radio frequency range. The thesis is aimed at increasing the efficiency of shielding polymer compositions and reducing their cost. The thesis aims to improve the composition and optimize the technology of obtaining polymer composite coatings based on graphite and other functional components of different morphology (graphene, carbon nanotubes, graphitized carbon black, nano- and micromagnetite, etc.) for the effective protection of human and electronic equipment from EMR within the VHF frequency range (from 30 MHz to 30 GHz). The scientific novelty of the thesis lies in the theoretical and experimental grounding of choosing the hybrid fillers as a combination of micro- and nanostructured materials, as well as appropriate polymer matrices to develop technology for water-based and anhydrous composite coatings for protection against electromagnetic radiation.
The following have been established: the correlation between the shielding efficiency of the multi-component composite coating and its surface conductivity, which is a necessary but not sufficient condition for high shielding efficiency; additional factors are the high magnetic permeability of the coating, as well as a significant contribution to the synergistic interaction of carbon impurities of different structure and morphology; the feasibility of using scaly graphite of polymorphic composition with an average particle size of 130 μm as an electrically conductive filler in contrast to fine colloidal graphite in existing analogues, which increased the shielding efficiency by 63%; the efficiency of using magnetite obtained by natural oxidation of steel St3, as a filler to increase the level of absorption and shielding; the efficiency of using ultrasound both for dispersion of individual components of protective coatings (in particular, carbon black, graphite, magnetite) and for homogenization of a mixture of polymer with fillers as a whole.
The practical significance refers to: the compositions of polymer composite coatings based on graphite, carbon black, graphene, carbon nanotubes, nano- and micro-magnetite, etc. have been developed, and the scope of their application as shielding materials has been determined; the technological schemes and norms of a technological regime of obtaining polymeric protective composite water-based coatings and anhydrous polymer-based coatings have been streamlined; the developed polymer composite coating based on alcohol fully ensures electromagnetic compatibility of thermal imagers with other electronic equipment, in particular with the radio station, and also allows to partially reduce the "visibility" of equipment in the radio frequency range and has already found a practical application for producing more than 3600 sets of thermal imaging binoculars, optical sights of different types by ARCHER brand manufactured by Thermal Vision Technologies LLC (Kyiv) for the needs of the Armed Forces of Ukraine, the National Guard of Ukraine, the Border Guard Service and other law enforcement agencies; a broadband shielding composite material in the form of paint based on an aqueous emulsion of polymers has been developed with the use of the composite carbon nanomaterial "graphene nanotube", which can provide high shielding efficiency at -35… -40 dB in the frequency range from 30 MHz to at least 30 GHz.
