Anisotropic layer-by-layer carbon nanotubes/boron nitride/rubber composite and its application in electromagnetic shielding

TL;DR

This paper presents the fabrication of anisotropic layer-by-layer carbon nanotubes and boron nitride/rubber composites with tailored properties for electromagnetic shielding and thermal applications, demonstrating significant EMI shielding effectiveness and thermal performance.

Contribution

It introduces a novel layer-by-layer assembly method combining CNTs and hBN on rubber to create anisotropic composites with customizable electrical, thermal, and electromagnetic properties.

Findings

Achieved EMI shielding effectiveness of 22.41 dB at 10.3 GHz.

Layered composites exhibit anisotropic thermal and electrical conductivities.

Surface temperature of ~103°C reached in 2 minutes under 2.5 V.

Abstract

Multifunctional polymer composites with anisotropic properties are attracting interests as they fulfil the growing demand of multitasking materials. In this work, anisotropic polymer composites are fabricated by combining the layer-by-layer (LBL) filtration method with the alternative assembling of carbon nanotubes (CNTs) and hexagonal boron nitride flakes (hBN) on natural rubber latex particles (NR). The layered composites exhibit anisotropic thermal and electrical conductivities, which are tailored through the layer formulations. The best composite consists of four layers of NR modified with 8 phr (parts per Hundred Rubber) CNTs (~7.4 wt%) and four alternated layers with 12 phr hBN (~10.7 wt%). The composites exhibit an electromagnetic interference (EMI) shielding effectiveness of 22.41+-0.14 dB mm-1 at 10.3 GHz and a thermal conductivity equal to 0.25 W/(mK). Furthermore, when the layered composite is used as an electrical thermal heater the surface reaches a stable temperature of ~103 C in approx. 2 min, with an input bias of 2.5 V.