Patternable cellulose/MWCNT laminated nanocomposites with anisotropic thermal and electrical conductivity

Abstract

To construct eco-friendly materials with anisotropic thermal/electrical conductivity and designable structure and shape not only is the goal of electrical materials, but also meets the requirement of sustainable society. In this work, patternable and laminated cellulose/MWCNT nanocomposites with excellent anisotropic thermal and electrical conductivity are prepared by a scalable and eco-friendly process, including a paper-making step, assembly step and in-situ welding step. In the obtained nanocomposites, the cellulose layer acts as the insulator, and the cellulose/MWCNT layer as the electrical and thermal conductor with a special segregated MWCNT network. As a result, the in-plane and through-plane electrical conductivity of the cellulose/MWCNT nanocomposite with 22.7 wt% MWCNT are 1458 and 1.48 × 10-10 S/m, respectively, and the in-plane and through-plane thermal conductivity are 1.98 and 0.34 W·m-1·K-1, respectively. Moreover, the cellulose/MWCNT nanocomposites have high electromagnetic shielding effectiveness of 31.1 dB when the thickness is 0.9 mm, good tensile strength of 156 MPa, and high shape stability at 240 °C. More interestingly, the laminated cellulose/MWCNT materials with patterned shape and sophisticated conductive circuit can be easily fabricated to work as a special and custom-tailor electronic element, thermal management device and electric-heating anti-counterfeiting pattern. Such novel cellulose/MWCNT nanocomposites prepared by a simple, effective and scalable process exhibit a huge potential in environmentally-friendly electrical and thermal management device, electromagnetic shielding element and advanced electronic anti-counterfeiting tag.