Electromagnetic Shielding Effectiveness of Glass Fiber/Epoxy Laminated Composites with Multi-Scale Reinforcements

Abstract

In this study, an experimental investigation has been performed to understand the electromagnetic interference-shielding effectiveness (EMI-SE) of glass fiber/epoxy laminated composites embedded with carbon nanotubes (CNTs) and Fe3O4 nanoparticles, reinforced with micro carbon fibers along the thickness direction. Micro carbon fibers were reinforced along the thickness direction between the laminates using an electro-flocking process and a vacuum infusion process used to fabricate the composites. The EMI-SE of the composites was measured in the X-band frequency range (8–12 GHz). The effect of carbon fibers of three different lengths (80 µm, 150 µm, and 350 µm) with two different fiber densities (1000 and 2000 fibers/mm2) and two different amounts of Fe3O4 nanoparticles (0.5 and 1 wt.%) on total SE, absorption, and reflection was investigated. Due to the synergetic effect of Fe3O4 nanoparticles, CNTs, and carbon fibers, the final EMI shielding of the composites was mainly dominated by the absorption process. The absorption was more pronounced in the composites of longer carbon fibers with improved electrical conductivity. The presence of Fe3O4 nanoparticles also enhanced total SE values with improved magnetic permeability. The composite with micro carbon fibers of 350 µm length and 2000 fibers/mm2 density with 1 wt.% of Fe3O4 nanoparticles showed the maximum value of total SE.

Airbrushing of carbon nanotubes on glass fibers for electromagnetic shielding epoxy composites

“…The electrical conductivity of the FCM containing 20 wt.% NCGF reached 6.68 x 10 -6 S/m, while the electromagnetic shielding properties exceeded 20 dB. Yesmin & Chalivendra [18] investigated the effect of CNT, micro-carbon fibers, and Fe 3 O 4 nanoparticles, deposited by paintbrushing on GF fabric, on electromagnetic shielding effectiveness of epoxy-matrix composites in the X-band frequency range and found that the nanoparticles had a major influence on the total shielding effectiveness as well as on the absorption. Airbrushing could thus be an efficient method for CNT deposition on GF to achieve a thin layer with high CNT concentration, since it is an easily controllable process and requires few devices to perform the deposition.…”

“…Decreasing the size of CNT clusters, the EMI SE of silicon rubber/CNT composites enhanced, due to the increase of interfacial contact area [10] . The use of CNT in nanocomposites with epoxy, other resins and glass fibers (GF) for EMI shielding has been reported by several authors [5,[11][12][13][14][15][16][17][18][19][20][21] . In one of the first works on this type of EMI material, Park et al [5] reported that epoxy resin/GF composites containing up to 5 wt% CNT have reached 20 dB (99% of effectiveness) in 300 MHz -1 GHz, with the highest value of electrical permittivity obtained for composites with 3% and 5 wt% CNT.…”

“…Other studies also proposed the surface modification of glass fiber fabrics with nanoparticles, such as CNT [14][15][16][17][18][19] , Fe 3 O 4 [18,19] , and graphene [22] , aiming to enhance the electromagnetic shielding effectiveness of epoxy-matrix composites. Some techniques to disperse CNT in epoxy resin/GF composites include sonication with solvent and then deposition by hand lay-up, immersion, conventional painting with paintbrush, or growth of CNT on GF surface [5,[13][14][15][16][17][18][19][20][21] , but there are some problems such as waste of raw materials, thickness control and industrial scalability. Da Silva et al [15] showed that resin transfer molded (RTM) epoxy composites reinforced with plain weave GF fabric coated with 2 wt% CNT by roll painting reached 18.3 dB (98.54% of attenuation) in the X-band.…”

Nano-additives and their effects on the microwave absorptions and mechanical properties of the composite materials

“…Carbon fibers of three various lengths (80, 150, and 350 mm), two different fiber densities (1000 and 2000 fibers/mm 2 ), along with two different quantities of Fe 3 O 4 nanoparticles were used to study the effect (0.5 and 1 wt%) on EM properties. Composite with micro carbon fibers of 350 mm length and a density of 2000 fibers/mm 2 with 1 wt.% of Fe 3 O 4 nanoparticles had the highest total SE value [75].…”

Electromagnetic Shielding Effectiveness and Impact Test Performance of Carbon Fiber Reinforced Polymer Composites with Hematite and Goethite

“…Here, the fibers assume the primary load-bearing role, while the matrix serves as both a load transfer medium and a protective barrier against harsh environmental conditions. [11][12][13][14][15][16][17] Epoxy, among thermosetting polymers, holds particular significance due to its outstanding mechanical properties, cost-effectiveness, ease of fabrication, thermal stability, and resistance to chemical degradation. Consequently, it finds application in diverse industries, including automotive, construction, aerospace, energy storage, petrochemicals, and composites.…”