Recyclable, self-healing, absorption-dominated and highly effective electromagnetic shielding elastomers based on bridged micro capacitance structures

Abstract

It is a challenge for carbon based conductive polymer composites (CPC) to combine easiness of fabrication, high EMI shielding effectiveness (EMI SE), high absorptivity, high mechanical properties and self-healing property in one material. Here, a flexible, self-healing and recyclable EMI shielding material is fabricated based on a bridged micro capacitance structure spontaneously formed in ionomer/carbon fillers nanocomposites. The anionic groups in the ionomer phase-separate into aggregates and moreover drive the carbon fillers to align along the aggregates through the anion-π interaction, thereby forming the bridged micro capacitance structure. This structure leads to outstanding EMI SE of 64 dB and high absorption coefficient of 0.82. Meanwhile, the material is self-healable and recyclable due to the dynamic anion-π interaction and autonomous nature of phase separation. In particular, the healed or recycled material shows nearly 100% recovery of EMI SE. The structural design of bridged micro capacitance can be easily extended to other ionomers, leading to a novel class of CPC with significant promise in electronic fields.