Robust multi-scale bionic ANF/PMSQ aerogel featuring impact protection, thermal insulation and anti-icing functions

To address the complex threats in extreme surroundings, it is urgent to develop novel safeguarding devices with multiple defensive properties. Traditional bionic structures typically exhibit only single defense function, making comprehensive protection against diversified threats strenuous. In this study, a novel aerogel material is developed by growing polymethylsesquisiloxane (PMSQ) in situ on the honeycomb skeleton of aramid nanofibers (ANF) to form multi-scale pomelo-peel/honeycomb bionic porous structures. ANF-PMSQ (ANFP) aerogel exhibits superb mechanical strength, which can support 10370 times its own weight. More importantly, ANFP effectively dissipates the impact force from 6.30 kN to 0.19 kN. Besides, mesoporous PMSQ inhibits heat convection within the directional skeleton pores, markedly reducing the thermal conductivity to 64.6 mW/(m·K), and providing outstanding thermal insulation over a wide range from −188 °C to 400 °C. In addition, the rough surface structure and large number of hydrophobic groups endow ANFP with hydrophobic and anti-icing properties. At −10 °C, the freezing time of water droplet on the ANFP surface is extended to an impressive 4547 s, significantly delaying the freezing process. Finally, ANFP provides mechanical-thermal coupling defense and anti-icing properties for outdoor pipelines and batteries in complex conditions. Thus, this work develops a multifunctional protective ANFP material for further engineering applications.