pNIPAm/Mxene Hydrogel Containing Vertically Graded Nickel Nanowires for Electromagnetic Interference Shielding

Flexible electromagnetic shielding composite hydrogels can prevent electromagnetic radiation, but achieving low reflectivity and high shielding effectiveness simultaneously remains challenging. Herein, an absorption-dominated electromagnetic interference (EMI) shielding composite hydrogel featuring a vertically graded distribution of nickel nanowires (Ni NWs) was developed under an external magnetic field. To synergistically enhance the EMI shielding performance, MXene nanosheets were distributed throughout the system, while silver nanowires (Ag NWs) were spin-coated onto the bottom surface (i.e., the side densely populated with Ni NWs). Consequently, the resultant composite hydrogel exhibited a higher EMI shielding effectiveness of 58.2 dB when electromagnetic waves were incident from the bottom than when they were incident from the top (50.9 dB). Moreover, the composite hydrogel possessed excellent pressure sensitivity of 26.6 kPa–1, coupled with an ultrarapid response time of 0.1 s, enabling rapid and accurate detection of human motion, as well as nearly 0% ultraviolet (UV) transmittance at both 365 and 550 nm, thereby realizing effective protection against ultraviolet radiation. This work provides a strategy for developing multifunctional electromagnetic shielding materials, advancing both material design theory and the fabrication of next-generation shielding materials.