Composite coating with engineered microparticles for multiband infrared stealth and efficient radiative heat dissipation

The fundamental conflict between infrared stealth and thermal management, where suppressing thermal emission for camouflage inevitably causes detrimental heat accumulation, poses a long-standing challenge in modern military technology. This work resolves this paradox through a bottom-up design of a particle composite coating, where complex spectral selectivity is engineered at the single-particle level. We computationally designed and validated a multilayer spherical particle, consisting of a CaMg(CO₃)₂ shell, a VO₂ inner shell, and a Ge core, embedded within a polyethylene (PE) binder. The synergistic roles of the materials allow for precise spectral control: CaMg(CO₃)₂ provides a primary emission peak in the 6-7 µm range, VO₂ broadens this non-atmospheric window for enhanced heat dissipation, and the Ge layer simultaneously shields absorption in the infrared stealth bands and boosts absorption in the VIS-NIR spectrum. The optimized coating achieves a high average emissivity of 0.6471 in the VIS-NIR and 0.5091 in the 5-8 µm band for effective thermal radiation, while maintaining exceptionally low emissivity in the atmospheric window bands (SWIR: 0.2326, MWIR: 0.3208, and LWIR: 0.0915). Simulated thermal imaging demonstrates superior stealth performance. This coating offers a scalable and effective strategy for developing next-generation materials compatible with both multiband stealth and heat dissipation requirements.