Polyimide aerogels with a dual electrically conductive network for electromagnetic interference shielding, piezoresistive sensing, and thermal management

Abstract

The constant iteration of wearable devices necessitates lightweight electromagnetic shielding materials with multiple functions. In this study, an elastic reduced graphene oxide/polyimide (rGO/PI) aerogel skeleton was prepared through freeze-drying and thermal annealing. Then the highly conductive two-dimensional (2D) transition metal carbide (MXene) was coated onto the rGO/PI skeleton using vacuum impregnation to fabricate MXene@rGO/PI composite aerogels. Due to the dual electrically conductive network formed by rGO and MXene, the MXene@rGO/PI composite aerogels exhibit exceptional electromagnetic interference shielding effectiveness (EMI SE) of 58.7 dB in the X-band at a density of 0.063 g cm−3. Additionally, these composite aerogels demonstrate sensitive piezoresistive sensing capabilities (the electrical resistance variation caused by compressive stress) for detecting human body motion and also possess excellent thermal management properties including efficient Joule heating (up to 108 °C at 10 V) and superior thermal insulation performance. This work presents a feasible strategy for developing polymer-based composites for multi-functional applications such as wearable electronics.