Enhancing the electromagnetic interference shielding performance of composite paper with corrugated paper-like structure

The structural design of material significantly influences its electromagnetic interference (EMI) shielding performance, providing an intelligent approach to attain desirable EMI shielding performances. Inspired by the ultra-large distance of the middle layer in corrugated paper, we proposed a novel composite paper with corrugated paper-like structure via the assembling of two pieces of surface-modified filter paper and an aerogel film. Specifically, a conventional filter paper was modified with the conductive hydrogel film consisting of TEMPO- oxidized cellulose nanofibers (TOCNF), cationic starch (CS) and Ti3C2Tx. 3 C 2 T x . The TOCNF and CS rapidly formed a composite hydrogel when mixed, due to their electrostatic interactions. The aforementioned aerogel film was produced through the freeze-drying of TOCNF/CS hydrogel, and it enlarged the distance between two conductive hydrogel film modified papers when inserted. The assembled composite papers demonstrated a maximum EMI SE of 71.0 dB, improved by 19.7 % as compared to the control without the aerogel film (59.3 dB). The expansion of the distance between conductive layers likely facilitated the enhancement in the multiple reflections and absorptions of electromagnetic waves. This novel composite paper showed better EMI shielding performance than many previously-reported materials considering the thickness and conductive filler dosage. In addition, the composite paper also showed exceptional infrared stealth capabilities since it effectively shielded the thermal radiation from human body. The composite paper still exhibited good infrared stealth ability at high temperature conditions (up to 120 degree celsius). Therefore, this research could inspire innovative concepts in designing highperformance and multifunctional EMI shielding materials in an economical way.