Ultralight and superelastic multifunctional PI composite aerogels with a nanofibrous‐laminar synergistic structure for highly efficient electromagnetic wave absorption

Abstract

AbstractHigh‐performance and lightweight electromagnetic wave‐absorbing materials with broad frequency bandwidths and strong absorption capabilities can effectively protect the human body from electromagnetic radiation hazards. However, manufacturing protective materials that are also flexible, comfortable, and permeable to air and moisture is challenging. In this study, a high‐performing aerogel material that absorbs electromagnetic waves was constructed using electrospinning and freeze‐drying processes. Ce3+‐doped Li0.35Zn0.3Fe2.35O4/silica (CLZFO/SiO2) inorganic magnetic nanofibers and polyamide imide/silicon carbide (PAI/SIC) organic nanofibers were used as the reinforcing phase in the aerogel. These nanofibers were uniformly dispersed in a mixed solution containing polyamic acid (PAA), graphene oxide (GO), and SIC nanoparticles. Subsequent freeze‐drying and thermal amidation produced a PAI/SIC and CLZFO/SiO2 nanofiber‐reinforced (PASI/CLS) polyimide (PI) composite aerogel, which had a nanofibrous‐laminar synergistic structure with a uniform filling of GO and SIC nanoparticles. The PASI/CLS aerogel exhibited efficient electromagnetic wave absorption with a minimum reflection loss (RLmin) of −49 dB at 5.4 GHz and an effective absorption bandwidth of 4.3 GHz. The excellent mechanical properties, thermal insulation performance, and superhydrophobicity of the aerogel ensure the long‐term stability of its microwave absorption capacity in complex and extreme environments.