Lightweight and multifunctional super-hydrophobic aramid nanofiber/multiwalled carbon nanotubes/Fe3O4 aerogel for microwave absorption, thermal insulation and pollutants adsorption

Lightweight and multifunctional aerogel has attracted increasing attention in microwave absorption, thermal insulation and pollutant recovery due to the increase of electromagnetic radiation and pollution, global warming and environmental pollution, which is an ideal material to meet the technical needs of today's society. In this study, aerogel composites (M-AMF), consisted of aramid nanofiber, multiwall carbon nanotubes and Fe3O4 nanoparticles modified by methyl trimethoxy silane, are prepared via a combination of a facile vacuum assisted filtration, freeze drying and vapor deposition, which show superhydrophobic property, low density and high mechanical properties. M-AMF32 aerogel composite as microwave absorber shows that a minimum reflection loss can reach up to ‐45.83 dB at microwave frequency of 5.46 GHz and a maximum effective absorption bandwidth is 4.0 GHz. Moreover, surface temperature of M-AMF aerogel composite as thermal insulation material is only 50 °C after placed on heating plate of 100 °C. The adsorption capacity of M-AMF32 aerogel can still maintain at about 30 g/g after 100 cycles for oil. Moreover, M-AMF aerogel exhibits excellent thermal insulation performance and certain selective absorbability to non-polar liquids, which can be applied in the harsh environment applications and the treatment of pollutants.