High electromagnetic interference shielding with high electrical conductivity through selective dispersion of multiwall carbon nanotube in poly (ε‐caprolactone)/MWCNT composites

Abstract

This study presents the preparation of electrically conducting poly(e-caprolactone) (PCL)/multiwall carbon nanotube (MWCNT) composites with very low percolation threshold (p c ). The method involves solution blending of PCL and MWCNT in the presence of commercial PCL beads. The PCL beads were added into high viscous PCL/MWCNT mixture during evaporation of solvent. Here, the used commercial PCL polymer beads act as an 'excluded volume' in the solution blended PCL/MWCNT region. Thus, the effective concentration of the MWCNT dramatically increases in the solution blended region and a strong interconnected continuous conductive network path of CNT2CNT is assumed throughout the matrix phase with the addition of PCL bead which plays a crucial role to improve the electromagnetic interference shielding effectiveness (EMI SE) and electrical conductivity at very low MWCNT loading. Thus, high EMI SE value (23.8 dB) was achieved at low MWCNT loading (1.8 wt %) in the presence of 70 wt % PCL bead and the high electrical conductivity of 2.49310 22 S cm 21 was achieved at very low MWCNT loading (0.15 wt %) with 70 wt % PCL bead content in the composites. The electrical conductivity gradually increased with increasing the PCL bead concentration, as well as, MWCNT loading in the composites.

Recent advances in carbon-based polymer nanocomposites for electromagnetic interference shielding

“…Bera et al [351] considered the preparation of electrically-conductive PCL-MWNT nanocomposites through solution blending of PCL and MWNTs in the presence of PCL beads, selectively dispersing the nanotubes in the solution blended region and guaranteeing the formation of an MWNT interconnected conductive network (see scheme of nanocomposite preparation shown in Figure 33). As a result, electrical conductivity (approximately 2.5 × 10 -2 S/cm for 0.15 wt% MWNT) and EMI SE in the X-band frequency range (around 24 dB at 1.8 wt% MWNT), in both cases in the presence of 70 wt% PCL beads, were significantly increased at very low MWNT concentration.…”

NaCl leached sustainable porous flexible Fe3O4 decorated RGO-polyaniline/PVDF composite for durable application against electromagnetic pollution

“…These insulating gaps are created by the thin insulated polymer layer among conductive fillers. The tunneling and hopping of electron occur from one filler to another through this insulating gap, as reported between CNT-CNT in polymer/CNT composites [40]. The properties of the matrix phase and the method of composites formation control the energy barrier of tunneling.…”

Extreme environment-bearable polyimide film with a three-dimensional Ag microfiber conductive network for ultrahigh electromagnetic interference shielding

“…Improving conductivity is generally considered to effectively improve EMI shielding performance [25][26][27][28][29][30]. Presently, constructing uniformly distributed Ag fiber architectures [28,31,32] and three-dimensional (3D) conductive skeletons [7,20,[33][34][35][36] are the two main strategies for improving the electrical conductivity of polymer/Ag fiber composites for efficient EMI shielding materials. Uniformly distributed Ag fiber architectures are usually fabricated by solution blending or melt blending [37].…”