SGs-CNTs/PAM/CCS Triple Network Hydrogel: Neural Architecture Inspired for Broadband EMI Shielding and Environmental Resilience

Abstract

Improving traditional multi-network hydrogels by introducing a low-density rigid filler network to optimize a single ionic conductivity and overcome the limited electromagnetic properties to produce electromagnetic interference (EMI) shielding hydrogels is a pioneering challenge. Drawing inspiration from the neural network, this research introduces a novel triple-network (TN) hydrogel. The single-layer graphenes (SGs) and carbon nanotubes (CNTs) mimic the conductive channels similar to neurons and axons/dendrites, respectively, and assist the dispersion-lap-fixation process of the filler by carboxymethyl chitosan (CCS) and polyacrylamide (PAM). This collaborative assembly of SGs-CNTs, coupled with the presence of water molecules, imparts SGs-CNTs/CCS/PAM (SCCP) hydrogel with exceptional EMI shielding effectiveness (SE) across the 8.2–26.5 GHz range (X, Ku, and K bands), reaching SE of 42.31, 50.20, and 60.78 dB, respectively. Moreover, the photothermal properties of SGs-CNTs enable CCS/PAM to heal sections efficiently and recover electromagnetic properties when exposed to near-infrared (NIR) light. SCCP also boasts a significant depression of the freezing point to −43 °C, achieved through the hydration of LiCl. Boasting diversified manufacturing, self-healing properties, and exceptional environmental durability, SCCP stands out as an ideal candidate for EMI shielding and shows excellent potential for multifunctional applications in flexible electronics.