25 Technology organic and inorganic substances 1. Introduction World scientific and technical development has led to the fact that there is a steady increase in the electromagnetic load on the industrial environment and the environment as a whole. This is due to an increase in the number and den- sity of the location of electrical and electronic equipment in production facilities, an increase in the load on power How to Cite: Glyva, V., Bakharev, V., Kasatkina, N., Levchenko, O., Levchenko, L., Burdeina, N., Guzii, S., Panova, O., Tykhen- ko, O., Biruk, Y. (2021). Design of liquid composite materials for screening electromagnetic fields. Eastern-European Journal of Enterprise Technologies, 3 (6 (111)), 25–31. doi: https://doi.org/10.15587/1729-4061.2021.231479 DESIGN OF LIQUID COMPOSITE MATERIALS FOR SHIELDING ELECTROMAGNETIC FIELDS V a l e n t y n G l y v a Doctor of Technical Sciences, Professor Department of Civil and Industrial Safety* V o l o d y m y r B a k h a r e v Doctor of Technical Science, Associate Professor, Dean Faculty of Natural Sciences Kremenchuk Mykhailo Ostrohradskyi National University Pershotravneva str., 20, Kremenchuk, Ukraine, 39600 N a t a l i a K a s a t k i n a Doctor of Technical Science, Head of Department Department of Doctoral and Postgraduate Studies National University of Food Technologies Volodymyrska str., 68, Kyiv, Ukraine, 01601 O l e g L e v c h e n k o Doctor of Technical Sciences, Professor, Head of Department Department of Labor protection, Industrial and Civil Safety** L a r y s a L e v c h e n k o Doctor of Technical Sciences, Associate Professor Department of Automation of Projection of Power Processes and Systems** N a t a i i a B u r d e i n a PhD, Associate Professor*** S e r g i i G u z i i PhD, Senior Researcher Department of Fire Prevention in Settlements National University of Civil Defence of Ukraine Chernyshevska str., 94, Kharkiv, Ukraine, 61023 O l e n a P a n o v a PhD, Associate Professor, Head of Department*** O k s a n a T y k h e n k o Corresponding author PhD, Associate Professor Department of Ecology* E-mail: okstih@ua.fm Y a n a B i r u k Assistant*** *National Aviation University Liubomyra Huzara ave., 1, Kyiv, Ukraine, 03058 **National Technical University of Ukraine "Igor Sikorsky Kyiv Polytechnic Institute" Peremohy ave., 37, Kyiv, Ukraine, 03056 ***Department of Physics Kyiv National University of Construction and Architecture Povitroflotsky ave., 31, Kyiv, Ukraine, 03037 This paper reports the principles of design and the examined protective properties of liquid materials for shielding the electric, magnetic, and electromagnetic fields over a wide frequency range. The materials were made on the basis of iron ore concentrate and a pigment additive, with water-dispersed and geopolymer paints used as a matrix. The tests of protective properties for the electrical and magnetic components of the electromagnetic field of industrial frequency showed that the electric field shielding coefficients at a concentration of the screening substance of 15−60 % (by weight) equaled 1.1−8.6; magnetic field – 1.2−5.3. The shielding coefficients of the material based on a water- dispersed paint are lower than those of a geopolymer one, which can be explained by the oxidation of an iron-containing component and a decrease in electrical conductivity. The shielding coefficients of the electromagnetic field with a frequency of 2.45 GHz are 1.2−7.9. The highest coefficients are inherent in the material with filler made of iron ore concentrate and titanium-containing pigment powder in a ratio of 1:1. To design materials with the required (predictable) protective properties, the relative magnetic, dielectric permeability of materials was calculated. It is shown that the obtained data are acceptably the same as the results from direct measurements of magnetic and dielectric permeability and could be used to calculate the wave resistance of the material and the predicted reflection coefficient of electromagnetic waves. Thus, there is reason to assert the need to build a database on the frequency dependence of effective magnetic and dielectric permeability in order to automate the design processes of composite materials with predefined protective properties Keywords: electromagnetic field, shielding coefficient, magnetic permeability, dielectric permeability, composite materials UDC 537.87:669.162.12(045) DOI: 10.15587/1729-4061.2021.231479 Received date: 01.04.2021 Accepted date: 13.05.2021 Published date: 18.06.2021 Copyright © 2021, Authors. This is an open access article under the Creative Commons CC BY license Eastern-European Journal of Enterprise Technologies ISSN 1729-3774 3/6 ( 111 ) 2021 26 structures. Study [3] identified the protective properties of a material made of polymer matrix and a metal filler made of ferrite of micro size. Recently, a significant part of studies addresses the development of compositions based on metal and metal-containing nanostructures. Article [4] describes a protective material based on nanocarbon with a matrix of complex hydrocarbon polymer. In [5], the matrix is made of common polypropylene, and filler – nanoparticles such as ferrite and graphene. These materials have higher, compared to composite materials with microparticles, screening coef- ficients. However, the issues related to manufacturing tech- nologies and high cost remained unresolved. Such material is difficult to clad the surfaces of a complex configuration. In many cases, there are problems with the adhesion of the polymer. More acceptable are liquid protective materials that could be applied on surfaces of any shape with the de- sired thickness. This approach was used in work [6], which shows the results of studies of the composition of the type of putty containing tungsten (70 %), nickel (18.6 %), and car- bon (11.4 %). However, such material is designed to protect against ionizing radiation and is designed to replace lead. Study [7] suggested a material based on carbon and aerogel. However, at acceptable protective properties, the mechanical properties of coatings are unsatisfactory. The technological advance reported in [8] and the above screening coefficients indicate the possibility of manufacturing protective putty and plasters by introducing magnetic and dielectric filler into them. However, their thickness is up to 10 mm, and the coat- ing is two-layer. This complicates practical application and increases the cost of work. Detailed studies [9, 10] have shown that the use of finely dispersed graphite and graphitized soot as a polymer matrix filler provides high screening coefficients over wide bands of frequencies. However, these fillers (espe- cially graphitized soot) are produced in small volumes and have a high cost. The polymer matrix does not always provide ease of facing surfaces of complex configuration. Paper [11] reports the results of studying the rheological and adsorption properties of water-dispersed and synthetic paints based on geopolymers. All this suggests that such paints could be used as the base of metal-containing compositions for shielding electromagnetic fields. It is also advisable to conduct research into their screening coefficients of electrical, magnetic, and electromagnetic fields of the most common frequencies. Our review allows us to conclude that most composite materials are designed for a narrow purpose. By functional- ity and cost, they are not adapted for facing surfaces of large areas and complex configurations. No fact-based data on the protective properties of liquid materials based on standard paint and varnishes are available. Known analytical ratios for determining the magnetic and electrophysical mixtures are not adapted to the forecasting of magnetic, electro- physical properties of liquid composite materials. Solving these problems would make it possible to devise the general principles of designing broadband electromagnetic screens on liquid media. 3. The aim and objectives of the study The aim of this study is to identify the protective prop- erties of materials based on paints with different content of a metal substance, to provide an estimation apparatus for the development of electromagnetic screens with controlled protective properties. electrical networks, and the development of wireless com- munication means. The transition to 5G mobile communi- cation standards with the use of extremely high-frequency electromagnetic radiation requires an increase in the number and density of the location of base stations to increase the maximum permissible levels of radiation. Therefore, much attention is paid to the study of this problem. Back in 1995, the World Health Organization (WHO) officially intro- duced the term “global electromagnetic pollution”. WHO included the problem of electromagnetic pollution in the list of humanity’s priority problems, and, in 1996, WHO created an international project to identify potential health risks associated with technologies that generate electromagnetic fields. WHO requires maximum reduction of field levels to a clear clarification of the limits of permissible exposure to electromagnetic fields, depending on frequencies and am- plitudes. Thus, the principle of maximum reduction under industrial conditions covers electromagnetic fields until reliable and unambiguous data on the maximum permissible levels are received. That is, this physical factor is covered by the principle of ALAR (as low as reasonably – as low as it is reasonably achievable). This principle is used even in developed countries in the variant of ALARP (as low as rea- sonably practicable), which implies establishing a reasonable level of danger as low as it could be achieved practically tak- ing into consideration social factors. This principle requires the employer to create conditions for maximum reduction of the risks of negative changes in the health of employees under the influence of the electromagnetic factor. At the same time, medical studies indicate the possibility of adverse health shifts under the influence of electromag- netic fields of low intensities [1, 2]. This requires justification and development of appropriate measures and means for pro- tecting people under industrial and household conditions. The most effective method of reducing the levels of elec- tromagnetic fields of the wide frequency range is shielding. Under the conditions of significant contribution to the elec- tromagnetic situation of electromagnetic fields of ultra-high and higher frequencies, the use of traditional metal shielding surfaces is not always acceptable due to high reflection coefficients. That predetermines the possible direction of reflected radiation in an undesirable direction. The most acceptable are composite screening materials, whose main advantage is the controllability of shielding coefficients by changing the concentration of the screening substance in the matrix. Disadvantages of the use of composite materials are the complexity of manufacturing technologies and high cost. However, most of them have large thicknesses, which makes it difficult to use them for facing surfaces of large areas, as well as high price. Therefore, it is important to de- sign highly efficient, broadband, and easy-to-use composite materials. To solve the task of shielding individual premises, parts of buildings, it is advisable to explore the possibility of production and application of shielding materials on liquid media. Such materials are more practical when applied to the surface of any shape with a minimum amount of waste and adjusting the thickness of the protective layer. 2. Literature review and problem statement Much attention is paid to the development and study of the protective properties of composite materials for shield- ing electromagnetic fields. Most of them are metal-polymer 27 Technology organic and inorganic substances To accomplish the aim, the following tasks have been set: – to investigate the shielding coefficients by liquid compos- ite materials of electrical, magnetic fields of industrial frequen- cy and ultra-high frequency electromagnetic fields; – to devise the principles of designing protective materi- als by predicting the magnetic and electrophysical properties of materials at different ratios of component content. 4. Materials and methods to study liquid composite materials for shielding electromagnetic fields For the convenience of applying a protective material on the surface, ready-made paints of two types were chosen as a matrix. The first is the acrylic water-dispersion paint VD˗AK˗22W (Belarus) (ρ=1.03 g/cm3), the second is the geopolymer paint MK 3/18˗9.20 (Ukraine) (ρ=1.15 g/cm3). Fine iron ore concentrate obtained by flotation at Polta- va Mining and Processing Plant (Ukraine) with a Fe con- tent of 68−72 %; Fe3O4, 20−22 % (ρ=6.24 g/cm3), was used as a screen filler. Also, the pigment mixture GreyX produced by “Ukrainian Mineral Company”, Kyiv (Ukraine), with the content of Al2O3 of 50 %; TiO2, 25 %; Fe2O3, 10 %, was used as a filler. It is known [12] that the effectiveness of shielding depends on the dispersion of the filler, so the granulo- metric analysis of mixtures by the standard method of sedimentation was performed. The average particle size of iron ore concentrate after grinding was 22−23 μm, GrayX mixture − 8−9 μm. Shielding mixtures were made by mixing the paint with the desired amount of filler in the laboratory dissolver. Three types of screen protective material were manufactured: ‒ a water-dispersion paint with the addition of iron ore concentrate in weights of 15, 30, 45, 60 % (material No. 1); ‒ a geopolymer paint with the addition of iron ore con- centrate in weights of 15, 30, 45, 60 % (material No. 2); ‒ a geopolymer paint with the addition of a mixture of iron ore concentrate and GreyX in a ratio of 1:1 in weights of 15, 30, 45, 60 % (material No. 3). All the materials were applied to the surface. After dry- ing, the thickness of the protective layer was 0.22−0.25. The intensity measure- ment of the electrical and mag- netic components of the elec- tromagnetic field of industrial frequency was carried out by the calibrated meter BE-meter, modifications “AT-004” and “50 Hz”, with a control unit “HTM-terminal”(Russian Fed- eration), according to the oper- ating instructions. The limit of permissible relative error of mea- surements of mean square values of electric and magnetic fields intensities was 15 %. To deter- mine the shielding coefficients of electromagnetic fields of ul- trahigh frequencies, we used the calibrated energy flux density meter PZ-31 (Russian Federa- tion) according to the operating instructions. The maximum basic error of measurement did not exceed 2.7 dB. The shielding coefficients were measured for geo- metrically closed screens of cubic shape, measuring 0.2×0.2×0.2 m, made of plasterboard, and covered with a protective mixture. The measuring antenna was placed inside the shielding structure through a technological hole, which was tightly closed during the measurement process. 5. Investigating the protective properties of liquid composite materials in terms of shielding of electromagnetic fields 5. 1. Studying the shielding coefficients of electric, mag- netic, and electromagnetic fields of a wide frequency range The results of measuring the shielding coefficients of the electric field of the industrial frequency with an intensity of 178−180 V/m by the developed materials are given in Table 1 and shown in Fig. 1. The sample of material No. 1 ‒ a water-dispersion paint with the addition of iron ore concentrate in weights of 15, 30, 45, 60 %. The sample of material No. 2 ‒ a geopolymer paint with the addition of iron ore concentrate in weights of 15, 30, 45, 60 %. The sample of material No. 3 ‒ a geopolymer paint with the addition of a mixture of iron ore concentrate and GreyX in a ratio of 1:1 in weights of 15, 30, 45, 60 %. Table 1 Shielding coefficients KS of the electric field of industrial frequency* Sample of material KS 15 % 30 % 45 % 60 % No. 1 1.1−1.2 1.3−1.4 1.6−1.7 2.8−2.9 No. 2 1.1−1.2 1.6−1.7 2.9−3.0 5.2−5.3 No. 3 1.3−1.4 1.8−1.9 4.2−4.3 8.5−8.6 Note: *Shielding factor KS=Ef/ES, where Ef is the intensity of the electric field of the source, ES is the intensity of the electric field in the shield-protected area y = 0,0011x2 - 0,0473x + 1,65 R² = 0,9816 y = 0,002x2 - 0,0593x + 1,6 R² = 0,9998 y = 0,0042x2 - 0,1567x + 2,75 R² = 1 0 1 2 3 4 5 6 7 8 9 10 10 20 30 40 50 60 70 80 Ks ρ, % Material No. 1 sample Material No. 2 sample Material No. 3 sample Fig. 1. Dependence of the shielding coefficients KS of the electric field of industrial frequency on the content of the screening substance Eastern-European Journal of Enterprise Technologies ISSN 1729-3774 3/6 ( 111 ) 2021 28 The results of measuring the shielding coefficients of the magnetic field of the industrial frequency with induction of 280−285 μT are given in Table 2 and shown in Fig. 2. Table 2 Shielding coefficients KS of the electric field of industrial frequency Sample of material KS 15 % 30 % 45 % 60 % No. 1 1.2−1.3 1.5−1.6 2.5−2.6 3.7−3.8 No. 2 1.4−1.5 1.9−2.0 3.8−3.9 7.7−7.8 No. 3 1.2−1.3 1.6−1.7 2.8−2.9 5.6−5.7 The results of measuring the shielding coefficients of the electromagnetic field with a frequency of 2.45 GHz with an energy flow density of 178−182 μW/cm2 are given in Table 3 and shown in Fig. 3. For high-frequency radiation, it is important to contrib- ute protection by reflecting electromagnetic waves into the overall shielding coefficient (the possibility of reflection in the undesirable direction). The reflection coefficients mea- sured by the procedure described in [12] are given in Table 4 and shown in Fig. 4. Table 3 Shielding coefficients KS of the electric field of ultra-high frequency Sample of material KS 15 % 30 % 45 % 60 % No. 1 1.2−1.3 1.3−1.4 1.8−1.9 4.0−4.1 No. 2 1.3−1.4 1.6−1.7 2.9−3.0 5.5−5.6 No. 3 1.7−1.8 2.3−2.4 4.0−4.1 7.8−7.9 The resulting correlation co- efficients indicate the reliability of our findings. The statistical treatment of experimental data has made it possible to derive an- alytical functions of the depen- dence of a shielding coefficient on the content of the screening material. These functions in the process of designing the protec- tive material make it possible to uniquely determine the con- tent of the screen filler in the dielectric matrix to obtain the required shielding coefficient of both low-frequency and high-fre- quency electromagnetic fields. Our results indicate that the developed materials are suitable for protecting people from elec- tromagnetic influences under industrial and household condi- tions, at least with a screen substance content above 45 % (by weight). The content of fillers by volume is much smaller due to significant differences in the density of metal-containing filler and paints used. Therefore, the filler does not significantly af- fect the adhesion of paint to the surface, which is important for the practical use of the obtained protective materials. y = 0,001x2 - 0,0183x + 1,275 R² = 0,9967 y = 0,0038x2 - 0,1447x + 2,8 R² = 0,9993 y = 0,0027x2 - 0,104x + 2,25 R² = 0,9973 0 1 2 3 4 5 6 7 8 9 10 10 20 30 40 50 60 70 80 Ks ρ, % Material No. 1 sample Material No. 2 sample Material No. 3 sample Fig. 2. Dependence of the shielding coefficients KS of the electric field of industrial frequency on the content of the screening substance y = 0,0023x2 - 0,1157x + 2,525 R² = 0,9836 y = 0,0026x2 - 0,099x + 2,275 R² = 0,9996 y = 0,0036x2 - 0,1333x + 3 R² = 0,9978 0 1 2 3 4 5 6 7 8 9 10 10 20 30 40 50 60 70 80 Ks ρ, % Material No. 1 sample Material No. 2 sample Material No. 3 sample Fig. 3. Dependence of the shielding coefficients KS of the electric field of ultra-high frequency on the content of the screening substance 29 Technology organic and inorganic substances Table 4 Shielding coefficients Kr of the electric field of ultra-high frequency * Sample of material Kr 15 % 30 % 45 % 60 % No. 1 ‒ – 0.10−0.15 0.22−0.23 No. 2 ‒ ‒ 0.15−0.18 0.28−0.29 No. 3 ‒ ‒ 0.22−0.24 0.32−0.34 Note: *Reflection effect for the filler concentrations of 15, 30 % is beyond the sensitivity of the measuring device 5. 2. Devising the principles of designing protective materials by predicting the magnetic and electrophysical properties of materials For calculations on the design of protective structures of the required efficiency, quantitative values of magnetic and electrophysical characteristics of materials are needed such as effective magnetic and dielectric permeability, as well as specific conductivity. However, these data are not available for composite materials. Therefore, it is advisable to calculate them based on the parameters of the com- position components and the ratio of their content in the material. Assume the filler particles are the same in size and shape and are distributed evenly into a dielectric matrix. We be- lieve that the volumetric coefficient of filling the matrix with shielding particles is small, that is, the particles do not affect each other. In this case, one can use a Lorentz ratio for the magnetic permeability of magnetodielectrics: ( ) ( ) 1 1 , 1 1 1 3 m m m m υ µ − µ = + − υ+ µ − (1) where μ is the effective magnetic permeability of the magne- todielectric, μm is the magnetic permeability of the filler, υm is the volume content of the filler in the material. In most cases, in the manufacture of a composition, it is convenient to change the weight content of the filler (includ- ing this work), which is due to its powdery state and high dispersion. For recalculation, one should use the following ratio: ,m d d m V k V ρ = ρ (2) where Vm, Vd are the filler and dielectric volumes; ρm, ρd are the filler and dielectric density; m d P k P = is the ratio of filler and dielectric weight. To determine the effective dielectric permeability of the composition ε, it is advisable to use the Maxwell-Garnet ratio, which holds for υm<1/3: , 2 2 d m d m d m d ε − ε ε − ε = υ ε + ε ε + ε (3) εd, εm are the dielectric permeability of the matrix and filler, υm is the volumetric share of the filler in a dielectric matrix. The materials of the matrix and filler are common, so their dielectric permea- bility is known. If necessary, these values could be measured by standard devices. In many cases, filler particles cannot be considered spherical, so, to determine the effective dielectric permeability of the composition, it is advisable to use the Odelevsky formula: ( ) ( ) 1 , 1 m m d d m m d d k F    υ ε − ε ε = ε +  υ − ε − ε + ε υ    (4) where εd, εm are the dielectric permeability of the matrix and filler, υm is the volume content of the filler, υk is the critical volume content of the filler at which the shielding particles are in contact with each other, F is the depolariza- tion coefficient 2 2 ln , l l F d d    =        (5) where l is the average particle length, d is the average diameter. ( ) ( ) 0,6 0,6 3 1 . 4 1 k F F F l d F l d  − υ =  + +  (6) The υk indicator is very important for the design of composite materials. As shown in [10], a sharp increase in the shielding coefficient is observed when the threshold of electric current leakage is achieved (conductivity circuits are formed by contact of filler particles). This is consistent with the positions of the electrodynamics of solid media. By calculating the effective values of magnetic and di- electric permeability, one could determine all the parameters that are necessary for the design of the protective material. Based on the following ratio ε = ε + ε′ ′′, (7) and considering that in the ultra-low and low-frequency range, the imaginary part of the complex dielectric permea- bility ε'' is much larger than ε' and could be neglected 4 '' , πσ ε = ε = ω (8) y = 0,0246e0,0362x R² = 1 y = 0,032e0,0364x R² = 1 y = 0,0779e0,0241x R² = 1 0,00 0,05 0,10 0,15 0,20 0,25 0,30 0,35 0,40 40 45 50 55 60 65 Kr ρ, % Material No. 1 sample Material No. 2 sample Material No. 3 sample Fig. 4. Dependence of the shielding coefficients Kr of the electric field of ultra- high frequency on the content of the screening substance Eastern-European Journal of Enterprise Technologies ISSN 1729-3774 3/6 ( 111 ) 2021 30 where σ is the specific conductivity of the material, ω is the circular frequency of the electromagnetic field. This ratio makes it possible to determine the specific conductivity of the material. Based on the obtained data, it is possible to determine the equivalent depth of field penetra- tion into the material (the depth at which the field is reduced by e=2.7 times). For example, for electromagnetic fields of ultra-high and higher frequencies, the equivalent penetration depth δ is defined as: 2 , a δ = ωµ σ (9) where μа is the absolute magnetic permeability, μа=μ0μ. If, for example, the field needs to be reduced by 10 times, the thickness of the protective screen should not be less than 2.3 δ. 6. Discussion of results of studying the protective properties of composite materials and determining ways to improve them The analysis of the measurement results given in Ta- bles 1−3 reveals that the general shielding coefficients for the filler content of 45 % and 60 % (by weight) are quite accept- able for the practical application of the developed mixtures. The lowest shielding coefficients of the material based on a water-dispersed paint could be explained by partial oxida- tion of the filler in the presence of water. This effect is not manifested at such concentrations of iron ore concentrate in a geopolymer paint. It is known that the protective prop- erties largely depend on the conductivity of the material. Therefore, in the presence of contact between individual par- ticles, the conductivity in mixtures No. 2 and No. 3 is greater due to the lack of oxidation and a greater conductivity of the GreyX material compared to ore concentrate. In addition, its dispersion is higher, which simplifies the formation of conductivity chains. The recalculation of the concentrations of the filler by weight into volumetric concentration according to the ratios given in section 6 indicates that the weight concentrations of 45 % and 60 % correspond to the volumetric concentrations of 15 % and 28 %. At such concentrations, the conductivity threshold is reached and there is a significant increase in shielding coefficients. To design protective materials, information about the magnetic and electrophysical properties of materials at cer- tain volume concentrations of filler is required. The calculat- ed values of the relative magnetic permeability of materials are 1.27−1.48. These data were compared to the results of di- rect measurements of relative magnetic permeability accord- ing to the procedure described in [13]. For example, for mix- ture No. 2, the relative magnetic permeability is 1.50−1.51, which is acceptable to match the calculated value (1.48). The calculated relative dielectric permeability values are 3.42−3.65, and the measured permeability values are 3.45−3.68. For example, for mixture No. 3, the relative di- electric permeability is maximum. The above predetermines the largest shielding factor of the magnetic component of the electromagnetic field of industrial frequency by material No. 2 and the electrical component – by material No. 3. At the same time, the calculated specific conductivity values are an order of 10-3 S/m, which is enough to ensure accept- able shielding coefficients. Increasing the conductivity of materials leads to an undesirable increase in reflection coef- ficients. This coefficient depends on the ratios of wave resis- tances Z of the distribution environment of electromagnetic waves (air) and protective material, which are determined from the following ratio: ,a a Z µ = ε (10) where μа is the absolute magnetic permeability of the materi- al, εа is the absolute dielectric permeability (60%). For material No. 1, the wave resistance is 249 Ω. Determination of the reflection coefficient is carried out by a known ratio: 1 2 1 2 ,S Z Z K Z Z − = + (11) where Z1 and Z2 are the wave resistances of the propagation medium of electromagnetic waves and the protective material. Given that the air wave resistance is 377 Ω, the reflection coefficient of the material KS=0.2, which acceptably coin- cides with the experimental data given in Table 4. The above indicates that in the presence of data on the electromagnetic situation under specific conditions and the necessary degrees of shielding (comparison with the maximum permissible values), a preliminary calculation assessment of the composition of the screen mixture for the manufacture of a protective screen is possible. The study reported here has certain limitations. Mea- surement of total shielding coefficients and the reflection coefficient of electromagnetic waves was performed for typ- ical frequencies and limited concentrations of the shielding substance in the dielectric matrix. The caveat of this study is the lack of data in reference sources on the magnetic and electrophysical properties of composite materials. However, in the future, this disadvan- tage could be eliminated by creating a reference database on the electrophysical properties of composite materials. Determining the effectiveness of the protective material, depending on the conditions of its use, is important for the introduction of the automated design of protective compos- ite materials. To automate the design processes of protective materials and structures of the required efficiency, it is ad- visable to perform a series of experimental and theoretical studies. Such research is due to the need to create a database on the actual values and frequency dependences of effective magnetic and dielectric permeability and their specific con- ductivities on the composition and physical characteristics of the components of composite materials. 7. Conclusions 1. For the manufacture of liquid compositions for shield- ing electrical, magnetic, and electromagnetic fields of the most common frequencies, it is advisable to use standard paints with the addition of iron ore concentrate and pigment metal-containing additives as a screening substance. The content of the screening substance up to 60 % (by weight) for the used fillers corresponds to the content by volume up to 28 % and does not significantly affect the adhesion of 31 Technology organic and inorganic substances the mixture to the surfaces on which composite materials are applied. The total shielding coefficients of the electro- magnetic field of industrial frequency of mixture layers 0.22−0.25 mm thick with the content of the shielding sub- stance of 15−60 % (by weight) for a water-dispersed paint are 1.1−2.9; for a geopolymer paint – 1.1−5.3. Adding 50 % of GreyX pigment metallic substance to the mixture increases shielding coefficients to 8.6. Magnetic field shielding coef- ficients also assume acceptable values. The shielding coef- ficients of ultra-high frequency electromagnetic field are up to 7.9. Low shielding coefficients of the material based on a water-dispersed paint could be explained by the oxidation of the metal filler and a decrease in the electrical conductivity of the material. In the presence of a filler up to 60 %, the reflection coefficient of an ultra-high frequency electromag- netic field does not exceed 0.23 for a water-dispersed paint and 0.34 for a geopolymer paint. This makes it possible to choose the formulation of the composition with the desired protective properties. 2. It has been shown that forecasting of protective prop- erties of materials is possible by calculating the magnetic and electrophysical properties of the material. Our assump- tions (point particles are evenly distributed in the body of the matrix) do not introduce a significant error to the result of relative calculations. 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