3D Printing-Assisted Honeycomb-Structured Bricklike\nAerogels Applied for Infrared Stealth with Good Thermal Management

Delicate\nstructure design with lightweightness and good thermal\nmanagement for infrared (IR) stealth are two important factors since\nrelying solely on low emissivity surfaces to suppress thermal radiation\nwill lead to heat buildup and erratic performance. Inspired by honeycomb\nbricks, an IR stealth aerogel of MXene@poly(vinyl alcohol) (PVA)/phase\nchange material (PCM) is prepared by a 3D-printed mold, freeze-drying,\nand vacuum impregnation. The as-prepared aerogels have excellent properties\nincluding high latent heat (105.3 J/g), high compressive modulus (7.844\nMPa, 80%), and low emissivity (0.273, 8–14 μm). Benefiting\nfrom the design of a honeycomb brick-like structure, which integrated\nheat insulation, heat absorption, and emissivity reduction strategies,\nthe IR stealth performance is outstanding since they are consistent\nwith the surrounding environment even when exposed to a heat source\nat 100 and 120 °C for 5 min, and the radiation temperatures when\nreaching the equilibrium are maintained only 30.9 and 33.8 °C,\nrespectively. The remarkable thermal management and IR stealth properties\nfor long-term use are also confirmed by a Comsol heat transfer simulation.\nFurthermore, they also possess excellent EMI shielding effect (SE),\nwith SE<sub>T</sub> = 43.3 dB in the X-band. Therefore, this multimodal\nstealth composite is expected to be a potential candidate in the field\nof IR stealth.