Structure-function dually enhanced graphene/polyimide aerogels towards superior electromagnetic wave absorption with excellent comprehensive properties for complex environments

To improve the multi-scenario adaptability of electromagnetic wave (EMW) absorbing materials, developing high performance and multifunction integrated absorbers is challenging. Herein, three-dimensional (3D) ultralight aerogels are prepared through a one-pot induced assembly (OIA) approach from graphene/polyimide (PI) precursors and Fe 3 O 4 nanospheres (M-GPIs) and M-GPIs cooperated with Kevlar nano-fibers (ANFs) (M-GPIAs), respectively. The highly effective 3D dielectric/magnetic coupling network structure is formed and leads to a superior electromagnetic wave (EMW) absorption performance. An enormous mechanical improvement is also realized due to the high-performance polymer (PI and ANFs) cooperation, achieving structure-function dually enhancement. The absorption intensity of -77.96 dB and the ultrawide absorption bandwidth of 7.64 GHz are achieved for M-GPIs at a low functional-gradient filling ratio of 8 wt%. Comparable electromagnetic wave absorption properties and even more prominent comprehensive properties are accomplished for M-GPIAs. Mechanism analyses verify that highly dispersed 3D interconnected network structure, multiple heterogeneous interfaces and dielectric/magnetic coupling exert the synergistic effect on EMW absorption performance. The present aerogels also exhibit excellent thermal resistance, thermal insulation, nonflammability and organic-liquid selective absorption properties, which qualify them as stable and durable EMW absorption materials working at unpredictable environments such as those with extremely hot and cold transitions and the risk of fire attack and organic pollutant treat.