Microspace regulation inspired by water permeation phenomenon for the preparation of high-conductivity composite films with efficient electromagnetic shielding performance

Abstract

Conductive polymers, integral to advancements in wearable devices, energy storage, healthcare and more, are crafted by integrating polymers with conductive elements like carbon substances, metals, and their particles. Drawing inspiration from natural water movement, this study introduces a method for crafting high-performance conductive composite films. This technique involves regulating the microstructure space of GaIn-based polymers under the mechanical pressure, where the fluid metal improves the internal microstructure gaps of the material. The presence of hydroxyl/carboxyl groups within the polymer enables the bonding with Ga3+ ions from the liquid metal (LM), securing them in place. This innovative process significantly boosts the material's electrical and thermal conductivity, as well as its mechanical integrity. This methodology has been successfully applied to enhance the attributes of GaIn-based composite films, utilizing nanocellulose fibers, chitosan nanofibers, and Kevlar-29 fibers as foundational materials. To demonstrate the method's effectiveness, a durable, highly thermally and electrically conductive GaIn-based MXene/nanocellulose composite film was developed and investigated in detail. This film showcased remarkable electromagnetic shielding with a high SSE/t value of 7718.91 dB cm2 g−1, and its performance mechanism was detailed through finite element analysis. Notably, the inclusion of GaIn endowed the film with excellent opto-electro-thermal conversion and heat-responsive deformation capabilities, highlighting its suitability for smart applications. Therefore, this research establishes a versatile approach for designing conductive films by merging liquid metal with polymers, potentially setting the stage for the creation of highly conductive composites in future.