Tunable Electromagnetic Interference Shielding Properties of Binary Thermoplastic Composites Prepared by Reactive Microencapsulation

Abstract

Thermoplastic composites integrating carbon nanotubes (CNT) and micron-sized metal particles dispersed in polymer matrices can address emerging multifunctional needs, e.g., good electrical conductivity and electromagnetic interference (EMI) shielding combined with easy processing and affordable costs. Herein, an approach based on reactive microencapsulation is reported to prepare polyamide 6 (PA6)-based composites comprising binary loads of CNT and Al, Cu, or Fe particles. The microencapsulation is performed by activated anionic polymerization of ε-caprolactam in solution, in the presence of the metal/CNT loads. The resulting hybrid microparticles are compression-molded into plates containing effective metal/CNT loads in the range of 12–17 wt %. Among the materials synthesized, the one containing Al/CNT binary load (3:7 wt %) displays the highest EMI shielding effectiveness (SE) of 43.5 dB at 12 GHz, with a 2 mm thickness and an electrical conductivity σdc of 6.61 × 10–3 S/cm. A synergetic effect is observed in all of the metal/CNT PA6 samples in terms of both σdc and SE increase. Evidently, the presence of metal particles well dispersed in the conductive CNT network contributes to the mobility of the carriers and thus to the effective attenuation of the electromagnetic waves. Therefore, the binary composites of this study can be efficient thermoplastic EMI shielding materials.

Evaluating the Electromagnetic Shielding of Continuous Carbon Fiber Parts Produced by Additive Manufacturing

“…The EM shielding of a given material can also be described according to the following equation [ 43 , 44 , 55 , 56 , 57 ]: where SE R is the shielding by reflection, SE A is the shielding by absorption, and SE M is the shielding by multiple reflections. SE R and SE A were calculated using the following equations: wherein the reflected coefficient ( R ) and transmission coefficient ( T ) were directly obtained as: …”

“…The EM shielding of a given material can also be described according to the following equation [43,44,[55][56][57]:…”

Preparing a Compound of New Nanoparticles of Lactam, PE to Improve Their Specifications

“…This acknowledgment provides valuable data for the advancement of nanoparticles in the polymer matrix 15 . The first recompense of besprinkle conductivity must be achieved in two ways: (i) by using natural conductive polymers or (ii) by adding electrically conductive fillers to an insulating polymer matrix 16 .A variety of polymers had been examined as matrices for Xerox allotrope/thermoplastic irate composites, including polyamides, polyesters, pungent polyethers, and polyolefins.…”

Electromagnetic Interference Shielding by Reduced Graphene Oxide Foils

“…Nevertheless, the existing technologies are a source of electromagnetic (EM) radiation almost impossible to avoid and susceptible to electromagnetic interference (EMI). As such, issues of protecting devices and facilities from any damage and health and environmental concerns have been considered more than before, as revealed by the increased interest in both fields of civil and military. − …”