Aramid nanofiber assisted preparation of self-standing liquid metal-based films for ultrahigh electromagnetic interference shielding

Liquid metals (LM) have a high potential for Electromagnetic interference (EMI) shielding application, due to their soft feature and excellent electrical conductivity. However, it still remains a huge challenge to fabricate a self-standing LM film for EMI shielding, due to the liquid feature of LM. Herein, we designed a self-standing LM -based film by incorporating minute quantities of aramid nanofiber (ANF) to construct a supporting framework via vacuum filtration. Due to the formation of highly conductive LM networks, the resulting LM/ANF film achieved a remarkable electrical conductivity of 7752 S/cm. The promising electrical conductivity endowed the LM/ANF film with an extremely high EMI shielding effectiveness (EMI SE) of 78.2 dB at a mere 20 mu m thickness. The LM/ANF film also possessed excellent reliability and superior thermostability, without an obvious decline in the EMI SEs after 5000 folding cycles and thermal treatment (250 degrees C) for 20 h, respectively. This study offers a novel design strategy to develop ultrathin EMI shielding films combined with high reliability and thermostability for application in modern high-power electronic devices.

Automated summary

This research successfully designed a self-standing LM/ANF film with remarkable electrical conductivity, achieving a high EMI shielding effectiveness at a mere thickness. Additionally, the LM/ANF film demonstrated excellent reliability and superior thermostability even after folding cycles and thermal treatment.