Lei Wang*, Li Lang, Weining Ren, Zelong Yang, Tiantian Gao, Zhongguo Zhao*, Mohamed Kallel, Yuezhou Liu*. Electrically insulating composite films with outstanding electromagnetic interference shielding performance enabled by multilayer structure. Engineered Science, 2025, 34: 1477.

DOI：10.30919/es1477

Abstract

Insulating polymer-based electromagnetic interference (EMI) shielding composites play a pivotal role in electronic packaging and flexible electronics. In this work, insulating poly(3,4-ethylene dioxythiophene):polystyrene sulfonic acid (PEDOT:PSS)/bacterial cellulose (BC) EMI shielding composite films with excellent mechanical properties and superior flexibility are prepared by layer-by-layer assembly. The PEDOT:PSS/BC composite films present excellent electrical insulation properties, mechanical properties and chemical stability. When the mass fractions of PEDOT:PSS are 50 wt%, the PEDOT:PSS/BC composite films exhibit volume resistivity as high as 2.0x10⁶ Ω·cm and EMI shielding effectiveness (SE) of 72 dB in the X-band (8.2-12.4 GHz), and they can maintain efficient EMI shielding performance under various harsh conditions (high temperature, low temperature and ultrasonication). Furthermore, the PEDOT:PSS/BC composite films possess excellent flexibility, mechanical properties, and long-term durability (harsh chemical environments and severe mechanical wearing). This work proposes a facile strategy to design insulating polymer-based EMI shielding composite films with excellent mechanical properties and superior flexibility, which shows great potential for applications in electronic packaging, flexible electronic devices, aeronautics and astronautics.