High-Performance NiO/PANI/ZnNb₂O₆ Composites for EMI Shielding: Structural Insights and Microwave Shielding Effectiveness in the Sub-8 GHz Range

Abstract

The increasing demand for high-frequency applications and the widespread use of electromagnetic (EM) waves in communication systems necessitate the development of effective electromagnetic interference (EMI) shielding materials. This study investigates the structural and shielding effectiveness properties of novel polyaniline (PANI)-based NiO/ZnNb₂O₆ composites for sub-8 GHz applications. NiO and ZnNb₂O₆ were synthesized via conventional solid-state reactions and combined with PANI to form composites with varying compositions. X-ray diffraction (XRD) confirmed the successful formation of single-phase NiO and ZnNb₂O₆, while scanning electron microscopy (SEM) revealed well-defined microstructures, contributing to enhanced shielding efficiency. Shielding effectiveness (SE) measurements were performed across the 0–8 GHz frequency range using a vector network analyzer. Among the compositions tested, the epoxy-based NiO-ZnNb₂O₆ (75–25% by weight) with a 1:1 PANI ratio exhibited the highest SE value of −41.16 dB (decibels) at 6.24 GHz, demonstrating superior attenuation of EM waves. The observed shielding efficiency is attributed to multiple reflection effects, dipole interactions, and the conductive network formed by PANI. These findings highlight the potential of NiO/PANI/ZnNb₂O₆ composites as cost-effective, high-performance EMI shielding materials for next-generation microwave communication and electronic applications. Further optimization and hybridization approaches are recommended to enhance performance for broader frequency bands.

1. Introduction

Due to growing use of electronic devices and wireless satellite communication networks, the need for many high-frequency applications has increased accordingly. With the widespread use of electromagnetic waves in communication systems, an unexpected result is the large number of undesired electromagnetic waves forming. This phenomenon, characterized by the harmful spread of electromagnetic pollution, is generally called electromagnetic interference (EMI) [1]. The GHz frequency range is widely preferred and used in communication networks and most technological devices.

Another cause of pollution in the environment is currently thought to be the prevalent electromagnetic radiation brought on by the quick development of electronic equipment like GPS, wireless communication, and mobile phones [2].

Significant hazards to human health and the health of our environment are presented by this pervasive electromagnetic pollution phenomenon [3,4]. Electromagnetic radiation can damage the sensitivity and functionality of many electrical equipment, as well as have negative effects on various aspects of daily life. In the environment we live in, we are constantly exposed to wireless microwave signal networks that we are not aware of and that can harm us. Exposure to these electromagnetic waves at high intensity, which do not make sound and are invisible, can lead to a series of health problems and harmful effects that primarily occur through physiological changes [5,6,7].

Besides the electromagnetic interference (EMI) caused by regular electrical devices and environmental infrastructure, the idea of electromagnetic safety and security has gained significant attention. Shielding serves as an effective measure to protect against external EMI threats, including intentional electromagnetic interference (IEMI) attacks [8].

To stop and lessen exposure to electromagnetic waves, there are several control methods. The use of engineering methods, personal protective equipment (PPE), exposure duration limitation, and lowering exposure levels to safe levels are some of these [5]. It is essential to utilize EMI shielding materials to safeguard people and systems from this electromagnetic pollution. Because EMI shielding materials have systems that are intended to either absorb or reflect undesirable electromagnetic waves, they can offer protection against these waves.

From an environmental point of view, it is worth noting that the absorption mechanism is more preferred than reflection [9,10]. Reflection loss is one of the elements affecting EMI shielding. This element is predicated on how incoming electromagnetic waves interact with mobile charge carriers, such as electrons or holes. Absorption loss, which is influenced by the interaction of electric and magnetic dipoles with electromagnetic waves, is another important element. When the shielding material has broad surface or contact regions, the third mechanism, referred to as the multiple reflection effect, comes into effect and causes internal reflections [11,12].

Examples of EMI shielding include composite materials containing discontinuous conductive additives such as metallic wires, metal flakes, some particles and carbon fibers. These composite materials are composed of a blend of multiple microcomponents, each taking different forms and remaining insoluble in one another. Polymer matrix composites are more preferred because they offer a wide product range, and these composites can overcome the shortcomings of the new material [13]. Polyaniline (PANI) aniline monomer is used more widely than other conductive polymers because of its cheapness, high polymerization efficiency and conductivity, being unaffected by external conditions, excellent chemical stability and good thermal properties. In controlled environments, PANI can be produced by chemical oxidative polymerization of aniline. PANI can indeed be easily doped and shows sufficient stability. Polyaniline is the most preferred polymer among polymers due to its inherent conductivity. Inorganic materials combined with PANI can increase the mechanical and other properties of new composites formed, depending on the additives used [14].

The increasing advancements in microwave communication have generated a significant demand for microwave dielectric materials. ZnNb₂O₆ ceramics are gaining popularity due to their cost-effectiveness and the ability to sinter them at lower temperatures. The collimbit-structured ZnNb₂O₆ compound exhibits a dielectric constant of 25, a Qxf (quality factor and resonance frequency) of 83.700 GHz, and a temperature coefficient of the resonance frequency of −56 ppm/°C. This collimbit structure offers ZnNb₂O₆ (zinc niobates) as a low-loss dielectric material, boasting exceptional dielectric permeability, a higher quality factor, and a low-temperature resonance frequency coefficient. Furthermore, ZnNb₂O₆’s sintering temperature is relatively low, typically around 1200 °C. This attribute makes them particularly well-suited for use in microwave communication devices as dielectric resonators [15,16,17]. Nickel oxide (NiO) stands out as a promising electrochemical material, owing to its environmentally friendly composition, cost-effectiveness, and the wide range of synthesis possibilities it offers. This p-type semiconductor material possesses a substantial band gap, exceeding 3.5 eV. Its intriguing electrical transport characteristics, chemical resilience, and redox photoactivity render nickel oxide exceptionally well-suited for a diverse array of electrochemical applications, particularly in the realm of energy storage. Thin films of NiO exhibit electroactivity in solid-state environments, effectively serving as charge storage systems. The multifaceted utility of NiO necessitates the adoption of various preparation methods to cater to distinct application requirements. This demand for versatility has led to the availability of nickel oxide in a plethora of forms, morphologies, configurations, and even chemical compositions, enabling its adaptability across a wide spectrum of applications [18,19,20,21].

In prior research investigations, it was observed that 0.25% multi-walled carbon nanotube (MWCNT) composites achieved the highest electromagnetic shielding effect, registering at −39 dB at a frequency of 1.6 GHz [22]. Conversely, another study reported the lowest shielding efficiency for CuO/PANI/Colemanite composites, which measured at −50.84 dB when tested at a frequency of 6.66 GHz [3]. In a separate instance, Wollastonite/PANI/Colemanite composites exhibited a shielding effect of −41.65 at 6.26 GHz, with a thickness of 1.5 mm [8]. Shielding effectiveness quantifies how effectively incoming electromagnetic waves are attenuated. When an electromagnetic wave is reduced by 90%, and only 10% passes through the material, it yields a shielding efficiency value of −10 dB [23,24]. The extremely low SE values suggest that incoming electromagnetic waves are either reflected and absorbed, or solely reflected or absorbed within the material, necessitating separate measurements for precise determination.

In the current research, a new NiO/PANI/ZnNb₂O₆ composite was developed by investigating the optimum parameters for the first time, determining the ideal ratio, and carrying out shielding efficiency measurements.

The components were carefully mixed with epoxy powder in varying proportions to create these novel composites, and NiO/PANI/ZnNb₂O₆ composites, each 1.4 mm thick, were produced for SE measurements at various ratios using the hot-pressing method. The phase identification within the composites was carried out using an X-ray diffraction (XRD) instrument Bruker D2 Phaser (Karlsruhe, Germany) with CuKα radiation (λ = 1.5406 Å) and a monochromator to determine the phase composition of raw and sintered samples. The scan rate was 1°/min, and phase identification was performed using the ICDD database. The morphology of the internal structures was analyzed by scanning electron microscopy (SEM) measurements using a JEOL 5910LV instrument (Tokyo, Japan), (secondary electron mode). SEM observations were made of NiO and ZnNb₂O₆ to confirm the single-phase structure. Using a dispersive spectrometer (EDS) and an Oxford-Inca 7274 equipment, the chemical compositions were evaluated. Shielding effectiveness measurements of NiO/PANI/ZnNb₂O₆ composites were measured in a wide frequency range (0–8 GHz) including certain frequencies with a dual-port vector network analyzer (VNA) (R&S FSH-K42).

2. Experimental

2.1. Preparation of NiO/ZnNb₂O₆

NiO and ZnNb₂O₆ composites were synthesized through a series of carefully controlled processes involving the mixing of traditional oxides. Commercial NiO powders were acquired for the initial step. To prepare ZnNb₂O₆, high-purity ZnO (99.9% from Merc, Darmstadt, Germany) and Nb₂O₅ (99% from Sigma-Aldrich, St. Louis, MO, USA) powders were precisely weighed in specific proportions, and an oxide-mixing technique was employed. The ZnO and Nb₂O₅ starting powders were meticulously measured, combined in a plastic container with zirconium balls, and immersed in ethyl alcohol for 20 h within a milling apparatus. Ball milling was utilized for the initial powder blending. To prevent evaporative losses, the resulting slurry was subsequently dried in an oven at 100 °C for 20 h before undergoing calcination at 600 °C for 4 h within a sealed alumina crucible. The weight of the samples before and after calcination was carefully measured to evaluate the slurries. Following the initial calcination at 600 °C, the powders were ground into pellets in an agate mortar, resulting in the production of ZnNb₂O₆ powders that were sintered at 1150 °C for 4 h, using a heating and cooling rate of 300 °C/h. This process yielded single-phase ZnNb₂O₆.

2.2. Production of Polyaniline/(NiO-ZnNb₂O₆) Composites

NiO and ZnNb₂O₆ materials were finely tuned to varying weight ratios of 25–75%, 50–50%, and 75–25%, respectively. This adjustment was achieved by placing them together with zirconia balls within a sealed plastic container filled with ethanol, allowing them to intermingle for 20 h in a rotary mill. After this mixing process, separate slurries with different compositions were prepared and subsequently dried in an oven at 100 °C for a duration of 24 h. To create the PANI/(NiO-ZnNb₂O₆) composite powders, the NiO and ZnNb₂O₆ combinations, adjusted to the specified weight ratios (25–75%, 50–50%, and 75–25%), were combined with an equivalent amount of aniline (99.9% purity). These powder mixtures were then individually added to 1 mL of aniline within a 35 mL hydrochloric (HCL) acid solution (0.1 mol L⁻¹) and dispersed by mechanical mixing for thirty minutes. A 2.49 g sample of ammonium persulfate (APS) was dissolved with a magnetic stirrer in 15 mL of hydrochloric acid solution (1 mol L⁻¹) in a different solution. This APS solution was slowly introduced into the previously mentioned solution, specifically the one containing 1 mL of aniline and the NiO-ZnNb₂O₆ mixture, with a gradual drop-wise addition. The resulting blend was then stored in separate containers in an ice water bath, where polymerization occurred under freezing conditions at 0 °C for 12 h.

Each slurry obtained through the polymerization process was subsequently transferred to filter papers, filtered using distilled water and ethanol, and then subjected to vacuum drying at 60 °C for 24 h. This process yielded PANI/(NiO-ZnNb₂O₆) composite powders, with different weight ratios of Aniline/NiO-ZnNb₂O₆ (25–75% by weight), Aniline/NiO-ZnNb₂O₆ (50–50% by weight), and Aniline/NiO-ZnNb₂O₆ (75% by weight), each in a 1:1 ratio. These compositions were then fashioned into appropriately sized pellets through temperature hydraulic pressing, resulting in the production of PANI/(NiO-ZnNb₂O₆) compounds in pellet form.

2.3. Preparation of Epoxy-(PANI Based NiO-ZnNb₂O₆) Composites

The PANI/(NiO-ZnNb₂O₆) compound powders were shaped and solidified through combination with epoxy powder to form composite materials (Figure 1). The ratio of all mixed powders to epoxy was maintained at 5/1 by weight. The resulting pellets were shaped using a temperature-controlled hydraulic press under a consistent pressure of 5 MPa and at 100 °C for a duration of 1 h. These pellets, measuring 1.4 mm in thickness, were specifically crafted for conducting shielding effectiveness assessments. These novel composites, designed for microwave shielding efficiency, were crafted using epoxy while maintaining an Aniline/(NiO-ZnNb₂O₆) ratio of 1/1.

3. Results and Discussion

3.1. XRD Investigations of NiO-ZnNb₂O₆

To analyze the structure of NiO-ZnNb₂O₆ and polyaniline, X-ray diffraction (XRD) spectroscopy was conducted. NiO and ZnNb₂O₆ underwent sintering at 1100 °C for a duration of 4 h. As shown in Figure 2, the XRD analysis showed that both NiO and ZnNb₂O₆ formed singular-phase structures.

The major phases, which are NiO (PDF Card No: 00-047-1049), ZnNb₂O₆ (PDF Card No: 01-076-1827), and polyaniline (PANI) (PDF Card No: 00-053-1717), are clearly seen in the X-ray diffraction (XRD) patterns for NiO, ZnNb₂O₆ and polyaniline (Figure 2). The diffraction peaks for each component are consistent with their primary phases. By using the oxide mixture method, then appropriate calcination temperature and subsequent sintering, a single-phase structure was successfully obtained for NiO and ZnNb₂O₆, eliminating possible intermediate phases formed by calcination during the process. The XRD analysis confirmed the absence of secondary phases in PANI, sintered NiO and ZnNb₂O₆.

FullProf, Suite, a software package (https://www.ill.eu/sites/fullprof/) for Rietveld refinement, was utilized to refine the crystal structures and quantify phase compositions. Specifically, it was employed to generate the experimental lattice parameters and unit cell volume presented in

Table 1. Lattice characteristics of NiO, ZnNb₂O₆ specimens (sintered 4 h at 1100 °C) and PANI were calculated using FullProf.

Sample	a (Å)	b (Å)	c (Å)	Volume (Å3)	SYS
NiO	4.177	4.177	4.177	72.88	Cubic
ZnNb2O6	5.726	14.208	5.04	410.03	Orthorhombic
PANI	7.65	10.22	5.75	449.55	Orthorhombic

, while the XRD model was matched to the reference patterns of NiO, ZnNb₂O₆, and PANI [26,27].

3.2. SEM Analysis of NiO and ZnNb₂O₆

To delve into the microstructures and morphology of the NiO samples sintered at 1100 °C for 4 h and the ZnNb₂O₆ samples subjected to the same sintering conditions, scanning electron microscopy (SEM) analysis was performed. The SEM examination confirmed that the NiO samples revealed a single-phase cubic crystalline structure, supporting the results of the XRD investigation. Similarly, the ZnNb₂O₆ samples exhibited single-phase structures characterized by an orthorhombic crystal structure. Figure 3a,b show that there were no signals of secondary phases or microstructural impurities. It is worth noting that NiO possesses a centrosymmetric cubic crystal structure, while ZnNb₂O₆ adopts a centrosymmetric orthorhombic crystal structure.

The average EDS analysis of the NiO and ZnNb₂O₆ samples, presented in Figure 3c,d, confirms their elemental composition. NiO is primarily composed of nickel (Ni) and oxygen (O), while ZnNb₂O₆ consists mainly of niobium (Nb), zinc (Zn), and oxygen (O). These findings align well with the quantitative XRD measurements, further validating the phase composition of the samples.

The microstructure indicated a formation of complementary-morphology grains. As a result of internal reflections inside the material, the multiple reflection effect has a substantial impact on electromagnetic shielding. Large surface areas or interface zones in materials are frequently the sites of this phenomenon. Single-phase sintered NiO and ZnNb₂O₆, which have porous structures, probably have significant specific surface areas and multiple internal grain boundaries. These materials, which probably have a porous structure, have large specific surface area and large internal boundary grains (large number of internal grain boundaries), which further contribute to the shielding of electromagnetic waves.

3.3. Measurements of NiO/PANI/ZnNb₂O₆ Composite’s EMI Shielding Effect

The measurements of shielding effectiveness, denoted as SE (shielding effect), were conducted utilizing a flanged coaxial EMI SE tester (Figure 4).

The shielding effectiveness values of epoxy-based composites made of (NiO/PANI/ZnNb₂O₆) throughout the 0–8 GHz frequency range are demonstrated to vary with frequency in Figure 5. To guarantee precision, the measurements were made again using samples that were manufactured with a constant 1.4 mm thickness. The tester maintains a consistent 50 ohm impedance throughout its length. Initially, a reference measurement was taken without a sample. Subsequently, samples were inserted one by one, ensuring uniform pressure by pinching them at three points. The device transmitted output data to a computer, where the SE values were computed as the difference between measurements with and without the samples. The SE values of the composites were influenced by their geometry and orientation.

Table 2. Other results in the literature for the efficiency of microwave shielding.

Samples	Shielding Effectiveness Value	Frequency	Reference
NiFe1.7Cu0.3O3.85/Aniline: 1/3	−29.74 dB	6.82 GHz	[2]
% 25 MWCNT	−39 dB	1.6 GHz	[22]
Chopped strands/Ba(Zn1/3Nb2/3)O3 (at 20–80 wt. %)	−24.96 dB	6.22 GHz	[1]
Epoxy-(NiO/PANI/ZnNb2O6)	−41.16 dB	6.24 GHz	This work

lists the microwave shielding effectiveness measurements of different materials that have been reported in previous works.

Among the NiO/PANI/ZnNb₂O₆ composites, it is evident that the epoxy-based composition of NiO-/ZnNb₂O₆ (75–25% by weight) combined with Aniline at a 1/1 ratio exhibits superior microwave shielding effectiveness. According to Figure 5c, this particular composite produced the lowest recorded value of −41.16 dB at 6.24 GHz. For 1.27 GHz, 4.83 GHz, 6.86 GHz, and 7.51 GHz, it offered shielding effect values of −11.36 dB, −17.23 dB, −21.98 dB, and −24.68 dB, respectively. Additionally, it demonstrated a shielding effect of less than −10 dB throughout a broad spectrum, which included frequencies between 0 and 0.36 GHz, 3.16 and 4.43 GHz, 4.74 and 6.52 GHz, and 7.31 and 8 GHz. The shielding efficacy values of this composite material were consistently below −20 dB, for frequencies between 5.71 and 6.34 GHz.

On the other hand, the epoxy-based composition of NiO-ZnNb₂O₆ (50–50% by weight) combined with Aniline at a 1/1 ratio displayed the lowest shielding effectiveness value at −33.94 dB, occurring at a frequency of 5.64 GHz. Also, at 6.26 GHz, it obtained the second-lowest shielding efficacy rating, −31.91 dB. It recorded values below −10 dB in certain frequency bands, including 0 to 0.29 GHz, 4.74 to 6.52 GHz, 6.64 to 7.06 GHz, and 7.34 to 8 GHz (as shown in Figure 5b).

This composite material consistently maintained shielding effectiveness below −20 dB, for frequencies from 5.43 to 5.79 GHz. Lastly, the epoxy-based composition of NiO-ZnNb₂O₆ (25–75% by weight) combined with Aniline at a 1/1 ratio exhibited the lowest shielding efficiency value at −35.3 dB, occurring at 6.24 GHz. Additionally, it achieved shielding effectiveness values of −17.7 dB, −21.98 dB, and −23.57 dB at frequencies of 1.11 GHz, 6.85 GHz, and 7.5 GHz, respectively (as depicted in Figure 5a). This particular composite composition also demonstrated shielding effect values below −10 dB within specific frequency ranges, including the ranges 0 to 0.51 GHz, 0.78 to 1.81 GHz, 2.69 GHz to 3.8 GHz, 5.56 GHz to 6.51 GHz, 6.65 to 7.1 GHz, and 7.34 GHz to 8 GHz. Furthermore, it maintained shielding effectiveness below −20 dB, for the range from 6.11 to 6.32 GHz.

One of the conductive polymers, polyaniline, was particularly selected, and it played an important role in increasing the impedance matching and contributing to the shielding efficiency of the recently created composites in certain frequency ranges by selectively selecting frequencies. It is understood that the effective values of microwave shielding are closely related to the alignment of the irradiation impedance with the surface of the material. The presence of the conductive polymer PANI caused the emergence of distinct peaks in shielding efficiency together with the resonance effect. This conductive polymer not only contributes to these sharp peaks, but also strengthens them.

Significant value is added to the electromagnetic shielding composite material by the interface polarization between polyaniline and (NiO-ZnNb₂O₆). The interplay of the trap shape and the resonance effect of reflection is responsible for the observed peaks in shielding efficiency.

Additionally, the material’s electrical losses due to the conductive polymer PANI help to fine-tune the ZnNb₂O₆ structure’s dielectric shielding effect, increasing the electromagnetic shielding efficacy in the process.

The shielding efficacy values for epoxy-based (NiO/polyaniline/ZnNb₂O₆) composites across the GHz range are shown in

Table 3. Shielding effectiveness of the epoxy-(NiO/polyaniline/ZnNb₂O₆) composites across the frequency range.

Sample	SE (dB)	Frequency (GHz)
NiO:ZnNb2O6 (wt. % 25–75)/Anilin: 1/1	−35.3	6.24
	−20	6.11–6.32
	−10	0–0.51, 0.78–1.81, 2.69–3.8, 5.56–6.51, 6.65–7.1, 7.34–8
NiO:ZnNb2O6 (wt. % 50–50)/Anilin: 1/1	−33.94	5.64
	−20	5.43–5.79
	−10	0–0.29, 4.74–6.52, 6.64–7.06, 7.34–8
NiO:ZnNb2O6 (wt. % 25–75)/Anilin: 1/1	−41.16	6.24
	−20	5.71–6.34
	−10	0–0.36, 3.16–4.43, 4.74–6.52, 7.31–8

.

Microstructural Influence on Shielding Performance

The shielding effectiveness (SE) of NiO/PANI/ZnNb₂O₆ composites is closely linked to their microstructural characteristics, as revealed by SEM and XRD analyses. The NiO:ZnNb₂O₆ (25–75 wt. %)/PANI (1/1) composite exhibited moderate SE (−35.3 dB at 6.24 GHz), primarily due to its ZnNb₂O₆-rich phase, which enhanced dielectric polarization losses but had limited conductivity. Increasing the NiO content to a 50–50 ratio improved the conductive network and interfacial polarization, resulting in a slightly higher SE (−33.94 dB at 5.64 GHz). The best performance was observed in the NiO:ZnNb₂O₆ (75–25 wt. %)/PANI (1/1) composite, which achieved −41.16 dB at 6.24 GHz due to its well-connected NiO conductive pathways, improved impedance matching, and multiple scattering effects facilitated by PANI. The shielding mechanisms across all samples involved a combination of reflection, absorption, and internal scattering, with NiO enhancing conductivity and reflection, ZnNb₂O₆ contributing to dielectric loss, and PANI improving charge transport and absorption. These findings highlight that optimizing the NiO:ZnNb₂O₆ ratio is key to achieving superior EMI shielding performance, making these composites promising candidates for sub-8 GHz applications.

The proposed material offers a cost advantage due to the use of inexpensive raw materials, energy-efficient processing, and minimal maintenance compared to traditional metal-based shielding (the estimated price is USD 0.15/cm³). Additionally, its durability contributes to long-term cost savings.

In future research, the composite consisting of NiO/PANI/ZnNb₂O₆ can be subjected to more comprehensive studies at broad frequency bands, including with chopped fiber-like additives or different polymers. In addition, it is necessary to focus on multi-material hybridization, nanostructuring, geometric innovations, and specific frequency optimization to improve the microwave shielding efficiency of these composites. For researchers investigating higher frequencies, such studies will also allow them to comprehensively investigate shielding effectiveness and reflection loss in specific radar frequency bands and other frequency bands.

4. Conclusions

In this research, we conducted the first ever assessment of the microwave shielding efficiency properties of polyaniline-based NiO/ZnNb₂O₆ composites. NiO/ZnNb₂O₆ composites hold the potential to serve as cost-effective and straightforward solutions for microwave shielding applications. Among the compositions tested, the epoxy-based combination of NiO-ZnNb₂O₆ (75–25% by weight) with Aniline at a 1/1 ratio demonstrated the most remarkable microwave shielding efficiency. Notably, this composite material achieved an impressive low of −41.16 dB at a frequency of 6.24 GHz, all while maintaining robust shielding effectiveness across a broad frequency band, registering values below −10 dB from 0 to 0.36 GHz, 3.16 to 4.43 GHz, 4.74 to 6.52 GHz, and 7.31 to 8 GHz. These findings are particularly significant as they contribute to the advancement of innovative composite materials that have the ability to shield electromagnetic fields and are useful in a variety of applications.

Furthermore, there is potential for investigating the microwave shielding efficiency, reflection loss, and absorption efficiency of NiO/PANI/ZnNb₂O₆ composites when augmented with various additives, particularly at higher radar frequencies or in tandem with technological advancements in elevated frequency bands. Such composites can serve as valuable models for combating electromagnetic pollution, developing armor and shielding materials, and facilitating the comprehensive evaluation of diverse composite material attributes.