Abstract:

Traditional electromagnetic shielding materials can no longer meet the rapidly growing demands of modern flexible electronic devices and advanced information technologies. Owing to their excellent flexibility, adhesion, stimuli responsiveness, and ease of processing and functional modification, hydrogels offer promising opportunities for developing flexible wearable electronic devices. In this study, PAM/CMC/Fe₃O₄@ZIF-67 multifunctional composite hydrogels were fabricated through a reverse-growth strategy combined with a one-pot polymerization method. First, flower-like Fe₃O₄ microspheres were prepared via an ethylene glycol-assisted solvothermal method and subsequently coupled with ZIF-67 through a reverse-growth strategy to obtain the Fe₃O₄@ZIF-67 composite. Subsequently, the composites were introduced into a PAM/CMC-based three-dimensional network, forming a multifunctional hydrogel that integrates flexibility, high water content, and synergistic conductive–magnetic effects. The experimental results showed that the 3 mm-thick PCZF-2 hydrogels achieved an average EMI SE of 36.08 dB. It also exhibited a conductivity of 0.93 S m⁻¹, a compressive modulus of 398.0 kPa, a compressive strain of 64.1%, a water content of 625.72%, and a swelling ratio of 240.82%. The hydrogel also exhibited excellent adhesion capability and high sensitivity (GF = 1.40 within the strain range of 0–100%, R² = 0.995), enabling human–machine-interaction-friendly strain sensing. This study provides an effective strategy for constructing tough multifunctional materials with integrated electromagnetic interference shielding and strain-sensing functionalities.

Key words: Fe₃O₄, ZIF-67, Reverse-growth method, Hydrogel, Electromagnetic interference shielding