A PBFDO‐Based Protective Material with Tunable Infrared Emissivity Integrating Thermal Management and Electromagnetic Interference Shielding

ABSTRACT Materials capable of simultaneously modulating infrared (IR) signal, shielding electromagnetic interference (EMI), and enabling active thermal management are critical for advanced aerospace and electronic applications. Here, we report a multifunctional composite by integrating the intrinsically conductive polymer poly(benzodifurandione) (PBFDO) with a polyimide (PI) film, a humidity‐adaptive nanoporous polyethylene (HANPE) layer, and a silica aerogel (SA) substrate. This rationally designed multilayer architecture HANPE/PBFDO@PI/SA (HPPS) enables a suite of synergistic functionalities. The core PBFDO@PI layer provides a foundation of high electrical conductivity (1732.1 S/cm) and low intrinsic IR emissivity (0.19 ± 0.02). Leveraging this, the HPPS composite achieves dynamic, passive IR camouflage through a wide tunable emissivity range (0.17–0.60), successfully reducing a 50°C target's apparent temperature by 19.6°C. It also delivers excellent EMI shielding of 43.85 dB for robust electronic protection. Moreover, its superior electrothermal performance enables active control of radiation temperature from 28.9°C to 108°C at low voltages (0–4 V), facilitating on‐demand thermal camouflage and rapid de‐icing. This work presents a versatile design strategy for creating intelligent adaptive materials with integrated passive and active functionalities.