Multi-layer alternating structured alginate hydrogels featuring exceptional flexibility and electromagnetic shielding...

The booming development of flexible electronic devices requires innovate electromagnetic shielding materials integrated with both superior flexibility and absorption capacities. Hydrogels incorporated with conductive fillers emerge as formidable contenders while suffer inadequate electromagnetic shielding performance and significant secondary pollution. In this work, the efficient synergy of CNTs and Co nanoparticles bestowed the hydrogel with both favorable dielectric and magnetic loss for efficient electromagnetic shielding performance. Concurrently, the Co-CNT hydrogel film exhibits a certain mechanical property owing to the hydrogen bonds between CNT/Co-CNT particles and SA hydrogel. Furthermore, the design of multi-layer structure, intricately interspersed with fillers of Co-CNT and CNT in an alternating pattern, features an "absorption-reflection-reabsorption" mechanism to reinforce the dissipation of electromagnetic waves within the hydrogels. Ultimately, the CNT/Co-CNT multi-layer hydrogel achieves an outstanding mechanical flexibility and considerable electromagnetic shielding performance of 41 dB at 0.7 mm, while the SE_A/SE_T value is greater than 85 %, which is conspicuously superior to the majority of electromagnetic shielding conductive hydrogel materials. This work offers a novel idea for the development of intelligent flexible EMI shielding materials and holds latent application prospects in the fields of wearable smart devices and military applications.