Lightweight Epoxy/Cotton Fiber-Based Nanocomposites with Carbon and Fe₃O₄ for Electromagnetic Interference Shielding

Abstract

Cotton fiber (CF)-based electroconductive papers were prepared by facile aqueous dispersion and drying processes combined with carbon nanotubes (CNTs) or graphene nanosheets (GNPs). To enhance the electromagnetic interference (EMI) shielding performance of the manufactured nanocomposites, the electroconductive papers were soaked with epoxy resin, which cooperated with the inner sprayed Fe 3 O 4 nanoparticles. The EMI shielding effectiveness of Epoxy/CF-30-Fe 3 O 4 -30GNPs reached 33.1 dB, of which over 85.0% is attributed to absorption, which is mainly believed to be caused by the combination of GNPs and Fe 3 O 4 nanoparticles due to their special structures and synergetic effects. Moreover, the infiltration of epoxy between the randomly distributed loose CFs and the multiple reflections inside the interconnected networks could also help to improve the EMI shielding performance of GNP-added samples. The prepared lightweight and stiff Epoxy/CF-30-Fe 3 O 4 -30GNP composites have promising applications in civil or military fields.

Review on recent progress in epoxy‐based composite materials for Electromagnetic Interference(EMI) shielding applications

“…87 The composite of epoxy/ CF-30-Fe 3 O 4 -30GNPs was fabricated by soaking the 30 wt% of cotton fiber (CF)-graphene nanoplatelets (GNPs) conductive paper with epoxy and sprayed with 5% of Fe 3 O 4 nanoparticles to study EMI SE performance of the fabricated composites. 88 The SEM micrograph of the fractured epoxy/CF-30-Fe 3 O 4 -30GNP is illustrated in Figure 3A-C. The micro-cracks and pores on the surface of CF seem to be filled by the epoxy matrix, and the penetration of the incident EM waves could be considerably restricted through these defects resulting in improved EMI shielding performance.…”

“…Electrical conductivity measurement is performed using a four-probe tester. 64,69,74 Xu et al 88 measured electrical conductivity with a digital multimeter, and Li et al 108 used a teraohmeter to find the thermal conductivity of their sample. Jia et al 40 employed a vibrating sample magnetometer for analyzing the magnetic properties of the shielding NC.…”

Methods for Enhancing the Electrical Properties of Epoxy Matrix Composites

“…The most popular filler currently used to modify the reinforcement of epoxy resin matrix composites is carbon nanotubes. A number of researchers have investigated the possibility of using them to modify various fibers, through the most commonly used are fiberglass [47] and carbon fiber [48] in aviation to cotton fiber [49] and basalt fiber [50]. All researchers obtained epoxy composites with similar conductivities ranging from 10 −3 to 10 −1 S/cm but with significantly different filler contents used to modify the fibers.…”

“…The best electrical conductivity using the least amount of carbon nanotubes (2.65 wt.%) was obtained by Kim et al [50] modifying basalt fibers by soaking the reinforcement in an aqueous solution of CNTs with surfactant in the form of sodium dodecyl sulfate, which raises the possibility of further research in terms of using this reinforcement to produce composites with increased conductivity. In comparison, Xu et al [49] had to use more than ten times (30 wt.%) the amount of CNTs to modify cotton fibers to obtain a conductivity similar to an epoxy composite reinforced with them. A similar content of reinforcement modifier was used by researchers [47,48] to modify glass fiber and carbon fiber, respectively, to obtain a conductivity value similar to composites.…”

Rapid Fabrication of Flexible Cu@Ag Flake/SAE Composites with Exceptional EMIS and Joule Heating Performance

“…The composite of conductive fillers and polymers is a commonly used flexible shielding structure due to its lightweight, thin thickness, good processability, outstanding corrosion resistance, and electromagnetic interference shielding effectiveness. To achieve high EMIS properties and heat management goals, it is a crucial and challenging issue to address filler design and filler/matrix interface bonding control. − …”