Influence of NiFe Alloy Nanopowder on Electromagnetic and Microwave Absorption Properties of MWCNT/Epoxy Composite

Abstract

Nanocomposite absorbers based on dielectric/magnetic materials are prepared by in situ incorporation of MWCNTs and NiFe alloy nanopowder into epoxy matrix. SEM micrographs and EDAX studies of these nanocomposites clearly revealed the incorporation of MWCNTs/NiFe nanoparticles in the epoxy matrix. Dielectric measurement revealed that the real part of permittivity and permeability of NiFe-filled MWCNT composites increased with an increase in NiFe concentration. The consolidated loss tangent values revealed that the total losses were highest for 15% of NiFe alloy nanopowder, thus accounting for the highest absorption loss. The two-layer RAS composed of NiFe alloy nanopowder-filled MWCNTs/epoxy composite achieves a minimum reflection loss of À12 dB (95% of absorption) in the range of 8.2-9.8 GHz and a maximum peak of À19 dB at 8.2 GHz with a thickness of 4 mm for 15 wt% NiFe alloy nanopowder MWCNTs/epoxy composites. In addition, À10 dB absorption bandwidths of composite material are <2 GHz, i.e., 8.2-9.8 GHz. Microwave absorption was attributed to both the dielectric and magnetic nature of MWCNTs and NiFe alloy nanopowder. The frequency of microwave absorption complies with the quarter wavelength (k/4) matching model.

Microwave absorption performance enhancement using glass fiber-reinforced polymer nanocomposites containing dielectric fillers in X-band

“…3,10,12 The solution is then brought to a probe sonicator and sonication is done at 50 MHz for a 90-min time period. The sonication time is chosen based on previous research studies 3,10,12,15,22 which showed maximum graphene dispersion in the base fluid. The sonicated graphene/epoxy solution thus obtained is added to hardener.…”

“…The EM properties of single-layered composites filled with 0-2.5 wt% MWCNT have been measured experimentally in the previous studies. 22 Also, the fabricated graphene/epoxy single-layered structures were brought to measure EM properties using the waveguide measurement technique. Here, X-band waveguides were used to measure EM properties and the network analyzer was calibrated using the TRL technique.…”

“…It should be noted that this work is an extension of the authors' previous studies. [21][22][23][24] Higher wt% of filler material results in a reduction in the structure absorption performance because of intermolecular collisions among filler materials due to agglomeration phenomenon. 5,6,9 Multilayered RASs have shown broad bandwidth (which is more than 90% absorption in 2.1 GHz range) compared to the single-layered structure in the same X-band.…”

Preparation and properties of functional particle Fe3O4-rGO and its modified fiber/epoxy composite for high-performance microwave absorption structure

“…According to the transmission line theory, microwave absorption characteristics are highly dependent on the complex permittivity and complex permeability of materials. The electromagnetic parameters of functional particle Fe 3 O 4 -rGO are quite different from those of resin and fiber, while the electromagnetic parameters of resin/fiber composites can be improved to a certain extent by increasing its filling amounts [35,36], thereby obtaining better EMW absorbing abilities. The dielectric properties of GF/EP composites filled with different functional particle As is known to all, the real parts (ε′ and μ′) of electromagnetic parameters represent their storage capacities to electromagnetic energy, while the imaginary parts (ε″ and μ″) show their loss capacities to electromagnetic energy [37].…”

Preparation of Fe–Si–Al intermetallic alloy and their composite coating for EM absorbing application in 6–18 GHz

“…Iron based intermetallic alloy such as FeNi [1], FeCo [2,3], FeCr [4] and Fe-Si-Al [5][6][7] etc. have received extensive attention as EM absorbing functional filler materials due to their advantage of high permeability in GHz region and good thermal stability at higher temperature.…”