Anti-impact electromagnetic shielding hydrogel with solvent-driven tunability

Smart electromagnetic shielding materials have attracted great attention in increasingly complex electromagnetic environments. In addition, impact protection is also highly important for precision instruments to avoid mechanical injury. However, it is rare and challenging to enable anti-impact behavior and adjustable electromagnetic shielding into one soft hydrogel. Herein, a graphene-assisted smart electromagnetic shielding hydrogel with post-tunable mechanical behaviors and impact resistance is successfully prepared through the precipitation polymerization of the methacrylamide in binary solvents of water and dimethyl sulfoxide. The precipitation polymerization imparts the hydrogels with a unique spherical molecular network conformation, which enables high and tough mechanical performance, impact resistance, anti-swelling, and structural stability. Moreover, the hydrogels demonstrate excellent electromagnetic shielding performance, mechanical anti-interference, and low-temperature resistance. More importantly, the hydrogels possess solvent-response reversible on–off electromagnetic shielding and a post-tunable mechanical performance (Elastic modulus from 0.14 MPa to 37.13 MPa, tensile strength from 70 kPa to 1400 kPa). It is envisioned that the strategy of the impact-resistant and switchable electromagnetic shielding hydrogel would provide an insightful outlook for constructing promising electromagnetic shielding and impact-resistance materials.