Antioxidative MXene/PTA film in marine environments for low infrared emissivity and long-term infrared camouflage

MXene-based infrared camouflage materials have garnered significant interest due to their intrinsic low emissivity. However, their practical application in marine environments is largely hindered by MXene’s susceptibility to oxidation. To overcome this limitation, we propose a protective strategy involving poly(tannic acid) (PTA), which is grafted onto MXene via hydrogen bonding and coordination interactions. This PTA layer acts as a barrier against H 2 O and O 2 ingress while enhancing the interfacial adhesion between adjacent MXene nanosheets, thereby improving the structural integrity of the composite film. Density functional theory (DFT) calculations reveal a strong affinity between PTA and MXene, confirming that both chemical interactions and physical barrier mechanisms contribute to the significantly improved oxidation resistance. Importantly, the functionalized MXene/PTA composite retains the low infrared emissivity inherent to pristine MXene. After 3 days in a simulated marine environment, the MP-5 (5 wt% PTA-modified MXene) film showed only a slight increase in emissivity, from 0.15 to 0.17. Even after 20 days of exposure to high temperature and humidity, the composite maintained a low emissivity of 0.22, demonstrating exceptional durability in thermal camouflage performance. This work offers a feasible and effective approach for designing environmentally stable MXene-based materials suitable for long-term infrared camouflage in marine settings.