Superparamagnetic ZnFe2O4 Nanoparticles-Reduced Graphene Oxide-Polyurethane Resin Based Nanocomposites for Electromagnetic Interference Shielding Application

Abstract

Superparamagnetic ZnFe2O4 spinel ferrite nanoparticles were prepared by the sonochemical synthesis method at different ultra-sonication times of 25 min (ZS25), 50 min (ZS50), and 100 min (ZS100). The structural properties of ZnFe2O4 spinel ferrite nanoparticles were controlled via sonochemical synthesis time. The average crystallite size increases from 3.0 nm to 4.0 nm with a rise of sonication time from 25 min to 100 min. The change of physical properties of ZnFe2O4 nanoparticles with the increase of sonication time was observed. The prepared ZnFe2O4 nanoparticles show superparamagnetic behavior. The prepared ZnFe2O4 nanoparticles (ZS25, ZS50, and ZS100) and reduced graphene oxide (RGO) were embedded in a polyurethane resin (PUR) matrix as a shield against electromagnetic pollution. The ultra-sonication method has been used for the preparation of nanocomposites. The total shielding effectiveness (SET) value for the prepared nanocomposites was studied at a thickness of 1 mm in the range of 8.2–12.4 GHz. The high attenuation constant (α) value of the prepared ZS100-RGO-PUR nanocomposite as compared with other samples recommended high absorption of electromagnetic waves. The existence of electric-magnetic nanofillers in the resin matrix delivered the inclusive acts of magnetic loss, dielectric loss, appropriate attenuation constant, and effective impedance matching. The synergistic effect of ZnFe2O4 and RGO in the PUR matrix led to high interfacial polarization and, consequently, significant absorption of the electromagnetic waves. The outcomes and methods also assure an inventive and competent approach to develop lightweight and flexible polyurethane resin matrix-based nanocomposites, consisting of superparamagnetic zinc ferrite nanoparticles and reduced graphene oxide as a shield against electromagnetic pollution.

Effect of different molecular coatings on the heating properties of maghemite nanoparticles

“…Also, other authors observed a nonlinear behavior of the susceptibility imaginary part with the frequency that can cause the nonconstant response of the ILP. 93–95 For all samples except Fe_SA-P188, the maximum ILP is reached at the maximum frequency. For Fe_SA-P188, in contrast, 639 kHz is the most efficient frequency.…”

Lightweight, Flexible and High-Performance Nanocomposites based on Reduced Graphene Oxide and Spinel Ferrite (ZnFe2O4 / CoFe2O4) Nanoparticles in Thermoplastic Polyurethane Matrix for Electromagnetic Interference Shielding Applications

“…The distinctive XRD peaks assigned to crystalline planes (220), (311), (400), ( 422), ( 511), (440), and (533) which confirmed the cubic spinel structure with the Fd3m space group symmetry for both ZnFe2O4 and CoFe2O4 nanoparticles [9]. Moreover, the crystallite size was calculated by debye Scherrer's formula [7], which was found to be 3.45 nm and 11.13 nm for ZnFe2O4 and CoFe2O4 nanoparticles, respectively. Further, The XRD investigation of ZnFe2O4 -rGO-TPU and CoFe2O4 -rGO-TPU nanocomposites displayed in Figure 1 (b), which reveals the presence of the diffraction planes (220), (311), (400), (422), (511), and (440) associated with the face-centered cubic structure of spinel ferrites.…”

“…Further, the value of coercivity Hc ≈ 36.17 Oe and remanent magnetization Mr 3.37emu/g, for CoFe2O4 nanoparticles revealing its ferromagnetic behavior. However, the value of coercivity Hc ≈ 0 Oe and remanent magnetization Mr ≈ 0 emu/g for ZnFe2O4 nanoparticles, proves superparamagnetic characteristics [7]. (a-c) displays the SET, SEA, and SER of ZnFe2O4 -rGO-TPU and CoFe2O4 -rGO-TPU nanocomposites with a thickness of 0.80 mm in the frequency range of 8.2 to 12.4 GHz.…”

“…(a-c) displays the SET, SEA, and SER of ZnFe2O4 -rGO-TPU and CoFe2O4 -rGO-TPU nanocomposites with a thickness of 0.80 mm in the frequency range of 8.2 to 12.4 GHz. The value of SET, which is a sum of the magnitude of SEA and SER, is found to be 48.39 dB for ZnFe2O4 -rGO-TPU and 50.76 dB for CoFe2O4 -rGO-TPU nanocomposites [7]. It can be noticed from Figure 3(b) that the maximum value of SEA for ZnFe2O4 -rGO-TPU is 26.19 dB.…”

“…CoFe2O4 and ZnFe2O4 nanoparticles were synthesized using the sonochemical method reported in the previous literature [7] using an ultrasonic homogenizer (UZ SONOPULS HD 2070) with a frequency of 20 kHz and power of 70 W for 60 min. Graphene oxide (GO) was synthesized by the modified hummer's method [8].…”