New System for Green EMI shielding: Organohydrogel with Multi-band Green Electromagnetic Shielding, Sensing, and Infrared-Stealth Capacity

Current research on green EMI shielding materials is often based on the misconception that absorption-dominated shielding is achieved when reflection loss (SE_R) exceeds absorption loss (SE_A). Although this misconception has been corrected by a large body of literature, few studies have actually achieved absorbed power (A) greater than reflected power (R). In this study, PVA, glycerol and MXene were combined to form an organohydrogel (PMG) with oriented pores. The gel displays remarkable flexibility and strength, attributed to its robust network of hydrogen bond cross-links (the hysteresis return line remains stable under 1000 compression cycles). The PMG20-3 organohydrogel (0.78 wt% MXene) demonstrates a shielding performance of 42.34 dB (A/R=1.38) in the X-band and absorbs 99.9% of power in the terahertz band. This performance exceeds that of most previously reported systems and represents a new system for green electromagnetic shielding materials. Additionally, the PMG organohydrogel has flexible sensing and infrared stealth capabilities. These findings hold great promise for the development of green electromagnetic shielding multifunctional devices.