Recently, designers of electronic equipment have paid special attention to the issue of electromagnetic compatibility (EMC) of devices with their own components and assemblies. This is due to the high sensitivity of semiconductor microcircuits to electromagnetic interference. This interference can be caused either by natural phenomena, such as lightning strikes, or by technical processes, such as transients in circuits during fast periodic or random switching. Either way, interference implies a sudden change in voltage or current in a circuit, which is undesirable, whether it propagates along a cable or is transmitted as an electromagnetic wave. The purpose of this article is to review the works devoted to the development, creation, and investigation of modern polymeric nanocomposite materials used for shielding electromagnetic radiation and their effective application for solving problems of electromagnetic compatibility. Additionally, the approach to design EMI shielding complex media with predetermined parameters based on investigation of various properties of possible components is shown. In the review, all polymer composites are classified according to the type of filler. The issues of the interaction of a polymer with conductive fillers, the influence of the concentration of fillers and their location inside the matrix, and the structure of the nanocomposite on the mechanisms of electromagnetic interaction are considered. Particular attention is paid to a new generation of nanocomposite materials with widely adjustable electrical and magnetic properties. A wide class of modern filled polymeric materials with dielectric and magneto-dielectric losses is considered. These materials make it possible to create effective absorbers of electromagnetic waves that provide a low level of reflection coefficient in the microwave range. The model mechanisms for shielding electromagnetic radiation are considered in the paper. A detailed review of the electro-physical properties of polymer nanocomposites is provided. Multilayer electrodynamic media containing combinations of layers of filled polymer composite materials with nanoparticles of different compositions and manufactured using a single technology will make it possible to create electrodynamic media and coatings with the required electro-physical characteristics of absorption, transmission, and reflection. Within the framework of the two-layer coating model, the difference in the effects of the interaction of electromagnetic radiation with conductive layers located on a dielectric and metal substrate is demonstrated. It is shown that in order to achieve optimal (maximum) values of reflection and absorption of electromagnetic radiation in the appropriate frequency range, it is necessary to fit the appropriate layer thicknesses, specific conductivity, and permittivity. Such approach allows designers to create new shielding materials that can effectively vary the shielding, absorbing, and matching characteristics of coatings over a wide frequency band. In general, it can be said that the development of innovative polymer composite materials for shielding electronic devices from electromagnetic interference and excessive electromagnetic background is still an important task. Its solution will ensure the safe and uninterrupted operation of modern digital electronics and can be used for other applications.

Iron-containing composites with nanoparticles are synthesized by the method of thermal decomposition of pentacarbonyl and iron formate in a polyethylene melt. The synthesized nanoparticles are characterized by transmission electron microscopy (TEM), X-ray phase analysis, and Mössbauer spectroscopy. The size of nanoparticles synthesized from iron pentacarbonyl and iron formate is 5.3 and 11.5 nm, respectively. It follows from the diffraction patterns that the particles have a complex composition. Composite materials are obtained based on iron nanoparticles and high-density polyethylene (HDPE). According to dynamic mechanical analysis, the elastic modulus of HDPE filled with particles obtained from iron pentacarbonyl is higher than for matrices containing iron formate. The biocidity test showed that the particle-modified matrix inhibits the growth of microorganisms more effectively than pure polyethylene.

Composite materials based on NiFe₂O₄ nanoparticles and polyethylene matrix have been synthesized by thermal decomposition to expand the application area of high-pressure polyethylene by filling it with nanoscale particles. The synthesized compositions were obtained in the form of a dark gray powder and compressed for further study According to TEM, the average particle size in composites was 2, 3, and 4 nm in samples with a filling of 10%, 20% and 30%. The concentration dependences of the specific electrical resistivity ρ_V, dielectric permittivity ε, saturation magnetization M_S and the parameters of reflection and attenuation of microwave power of the obtained composites were investigated. The threshold for percolation in such materials is found to be within a concentration range of 20…30%. The electronic and atomic structure of composites was studied by methods of Mössbauer spectroscopy, X-ray diffraction and X-ray absorption spectroscopy. The closest atomic environment of nickel and iron in nanoparticles is close to that of crystalline NiFe₂O₄. The dependence of the nanoparticles size as well as the dependence of the number of tetrahedral or octahedral iron positions in nickel ferrite nanoparticles to their content in polyethylene matrix is established. It is shown that composite materials based on NiFe₂O₄ nanoparticles and polyethylene matrix can be used as components of electromagnetic compatibility systems.

The paper presents the study of two types of composite materials containing copper micro- and nanoparticles in a polyethylene matrix. Two types of copper-containing fillers were used to prepare the composites: microparticles with an average size of 3.5 μm; nanoparticles of an average size of 13 nm with a core-shell structure. The study of the temperature dependence of the electrical conductivity of copper microparticles at fixed pressures showed that the shell formed on their surface, consisting of copper oxide, exhibits a semiconducting character. Additionally, the conductivity and static permittivity of polyethylene infused with copper nano- and microparticles were examined near the percolation threshold. Discrepancies emerged between experimental findings and predictions of the modern inhomogeneous systems theory at conductivity levels below a certain threshold. In the composites with copper nanoparticles located below the percolation threshold, an additional influence on both electrical conductivity and permittivity was observed. The reasons for this effect are discussed here simultaneously taking into account the spatial structure of the hierarchical model for composite materials proposed by the scientific group of I. Balberg.