Aerogels with regularly porous structure and uniformly distributed conductive networks have received extensive attention in wearable electronic sensors, electromagnetic shielding, and so on. However, the poor mechanical properties of the emerging nanofibers-based aerogels are limited in practical applications. In this work, we developed a synchronous deprotonation–protonation method in the KOH/dimethyl sulfoxide (DMSO) system at room temperature for achieving chitin cross-linked aramid nanofibers (CANFs) rather than chitin nanofibers (ChNFs) and aramid nanofibers (ANFs) separately by using chitin and aramid pulp as raw materials. After freeze-drying process, the cross-linked chitin/aramid nanofibers (CA) aerogel exhibited the synergetic properties of ChNF and ANF by the dual-nanofiber compensation strategy. The mechanical stress of CA aerogel was 170 kPa at 80% compressive strain, increased by 750% compared with pure ChNF aerogel. ​Similarly, the compressibility of CA aerogel was somewhat improved compared to ANF aerogel. The enhancement verified that the crosslinking reaction between ANF and ChNF during the synchronous deprotonation process was formed. Afterwards, the conductive aerogels with uniform porous structure (CA-M) were successfully obtained by vacuum impregnating CA aerogels in Ti₃C₂T_x MXene solution, displaying low thermal conductivity (0.01 W/(m·K)), high electromagnetic interference (EMI) shielding effectiveness (SE) (75 dB), flame retardant, and heat insulation. Meanwhile, the as-obtained CA-M aerogels were also applied as a pressure sensor with excellent compression cycle stability and superior human motion monitoring capabilities. As a result, the dual-nanofiber based conductive aerogels have great potentials in flexible/wearable electronics, EMI shielding, flame retardant, and heat insulation.

Flexible electromagnetic interference (EMI) shielding films with high stability have shown promising prospect in harsh working conditions such as military, communication, and special protection fields. Herein, flexible aramid nanofibers@polypyrrole (ANF@PPy) films with high stability were easily achieved by the in-situ growth of PPy on the surface of ANF and the subsequent pressured-filtration film-forming process. When the amount of pyrrole (Py) monomer is 40 µL, the ANF@PPy (AP40) film exhibited excellent EMI shielding performance with shielding effectiveness (SE) of 41.69 dB, tensile strength of 96.01 MPa, and fracture strain of 21.95% at the thickness of 75.76 μm. Particularly, the anticipated EMI shielding performance can be maintained even after being heated at 200 °C in air, soaked in 3.5% NaCl solution, repeated folding for one million times, or burned directly, indicating superior environmental durability in harsh conditions. Therefore, it is believed that the ANF@PPy films with high stability offer a facile solution for practical protection for high-performance EMI shielding applications.