Phase-Transition Microcapacitor Network in Organohydrogel for Absorption-Dominated Electromagnetic Interference Shielding and Multi-Mode Intelligent Responsiveness

Hydrogels/organohydrogels show promise for flexible, intelligent electromagnetic interference (EMI) shielding, yet simultaneously achieving absorption-dominated shielding performance, excellent mechanical properties and multi-mode intelligent responsiveness remains challenging. This study presents a microcapacitor network strategy as an alternative to the traditional conductive percolation network for EMI shielding materials. Paraffin-nanoclay/MXene core-shell microspheres are uniformly integrated into the hydrogel matrix via in situ polymerization, forming a microcapacitor network where the microsphere shells and hydrogel serve as capacitor plates and dielectric layers, respectively. Microcurrents and interfacial polarization at capacitor plates, along with dipole polarization within dielectric layer, significantly promote EM wave attenuation for absorption-dominated EMI shielding (absorption coefficient >0.7). Meanwhile, the abundant hydrogen bonds and paraffin phase synergistically enhance mechanical strength (≈0.64 MPa) and stretchability (elongation at break > 1000%). Due to the solid-liquid phase transition of the paraffin phase in microspheres, organohydrogel exhibits a unique ability to retain high-temperature shielding performance at room temperature. This feature enhances room-temperature shielding effectiveness and enables multi-mode intelligent responsiveness. Under the same room-temperature deformation mode, it exhibits programmable shielding performance regulation in response to different external stimuli, following room-temperature changes or simulating high-temperature changes.