Preparation and characterization of a high performance radiowave shielding material using fillers comprised of Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN-PT) (65/35), Zx+yFe9x–y+3O15x+4 (0 < (x, y) < 1) and ECM based on a polyamide matrix. (February 2022)

• Record Type: Journal Article
• Authors: Kadkhodayan, Hossein; Saidi, Majid; Alizadeh, Taher
• Is Part Of: Journal of physics and chemistry of solids. Volume 161(2022)
• Publication Date: 2022-02
• Subjects: Radiowave shielding -- Electric conductive materials -- Dielectric material -- Magnetic material -- Taguchi methodology; Solids -- Periodicals; Solides -- Périodiques; Solids; Periodicals; 530.41
• DOI: 10.1016/j.jpcs.2021.110439
• Languages: English
• ISSNs: 0022-3697

Abstract

Abstract: In the present study, a novel radiowave (RW) shielding material was successfully prepared based on polyamide (PA) using fillers including (i) electric conductive materials (ECMs) comprised of Cl-doped graphitic carbon nitrite (Cl-doped gC3 N4 ), reduced graphene oxide (RGO) and polypyrrole (PPy), (ii) dielectric material comprised of Pb(Mg1/3 Nb2/3 )O3 –PbTiO3 (PMN-PT) (65/35) and (iii) magnetic material comprised of Z x + y Fe 9x–y+3 O15 x +4 (0 &lt; ( x, y) &lt; 1) (Z = Mg, Co, Ni), x = 1, y = 0, Z = Mg hexaferrites (MgFe12 O19 ) and x = 0, y = 1, Z = Co and Ni spinel ferrite (NiFe2 O4 and CoFe2 O4 )). X-ray diffraction (XRD), scanning electron microscopy (SEM) and vibrating sample magnetometry (VSM) were utilized to characterize the crystal structures, morphologies and properties of the RW shielding material, respectively. The variables and their levels were optimized using Taguchi experimental design to achieve a shielding with higher RW absorption properties. The optimum conditions were determined as follows: 3 wt% PMN-PT, NiFe2 O4 as the magnetic material, PPy as the ECM and a shielding thickness of 1 mm. Finally, the optimized RW shielding material exhibited good RW absorbent properties including impedance (Z) in the range of 210–400 Ω, reflection loss (RL) &lt;–35 dB (absorption = 99.9%) and attenuation constant (α) of &gt;2000 dB/m at a shielding thickness of 1 mm in the RW frequency range. Graphical abstract: Magnetic materials with the general structure Z x + y Fe 9x–y+3 O15 x +4 (0 &lt; ( x, y) &lt; 1) can consume the magnetic-field energy of EM waves into heat energy. These magnetic materials have advantages, including high magnetic loss and good absorption bandwidth [8–10 ]. In the current work, three different types of magnetic material were used to create high magnetic losses due to their high saturation magnetization, excellent chemical stability and corrosion resistance. Finally, all of the prepared fillers were dispersed using a mechanical mixing method inside PA resin to provide a homogeneous and uniform mixture. Due to advantages of PA resin, which include good adhesion and excellent chemical and mechanical resistance, it was applied as a matrix. In this work, the RW absorption values of PMN-PT (composition: 65/35) (as a cubic perovskite) with some magnetic and electrically conductive materials are determined in the 8–12 GHz frequencies. The Taguchi method was applied to compare and optimize the effect of variables and their levels, such as the type of magnetic material, type of ECM and absorber thickness, on the RWs absorption properties. Highlights: Novel radar absorption coatings based on polyamide resin have been successfully synthesized. The structure of the synthesized nanoparticles were characterized using XRD, SEM and VSM. Taguchi methodology was applied to optimize the formulation and performance of absorber. The optimized radar absorber nanocomposite exhibits impedance in the range of 210–400 Ω. The optimized radar absorber nanocomposite exhibits an attenuation constant of &gt;2000 dB/m.