MXene Assisted Shear Thickening Fluids Reinforced Anti‐Impact Composite Aerogel with Superior Electromagnetic Shielding and Flame Retardant Performance

The ubiquitous mechanical and thermal damage in extreme environments puts new demands on protective equipment. At the same time, with the continuous development of electronic equipment, electromagnetic hazards and information leakage risks are increasing, so equipment with force/thermal/magnetic protection performance needs to be developed urgently. Herein, a shear thickened composite aerogel (MS) with host-guest structure is developed by a two-step reinforcement process involving unidirectional freeze casting and ultrasonic assisted penetration of shear thickening fluid (STF). An interweaved skeleton is established by introducing MXene nanosheets, thus improving the structure stability. Moreover, the MS composite with further reinforced structure is obtained through the synergetic enhancement of STF, which achieves high compressive strength (570 kPa) and superior impact resistance (80% impact dissipation). Meanwhile, MS composite shows reliable heat insulation and flame retardant ability, and the total heat release is as low as 4.8 kJ g^-1. Furthermore, MS demonstrates an efficient shielding performance of 45.5 dB at an extremely low MXene load of 0.43 wt%. As a result, this functionally integrated composite is proving to be a competitive candidate for resistance to impact damage, thermal threats and electromagnetic interference hazards in complex environments.