Optimizing the emissivity regulation performance of a multilayer adaptive infrared camouflage structure based on transport ability control of an ionic liquid

The dynamic regulation of infrared signals has received widespread attention. For the typical multilayer adaptive infrared camouflage structure, many efforts have been made to explore a variety of materials; metals, carbon nanomaterials and polymers can all be used in this field. However, little attention has been given to the mechanism of mass transfer within the structure, which could play a decisive role in the infrared camouflage performance. In this paper, the influence of cation and anion enrichment on the band structure and density of states of multiwalled carbon nanotubes (MWCNTs) is discussed through density functional theory (DFT), and the results show that ion migration plays an important role in the regulation of the emissivity. On the basis of theoretical research, a novel waterborne polyurethane (WPU)/ionic liquid (IL) gel is further prepared to realize control of the ionic transport capability, and a MWCNT film-based sandwich structure is fabricated to achieve adaptive infrared camouflage. The maximum emissivity regulation coefficient reaches 0.85, which is the highest to the best of our knowledge. The optimization scheme proposed in this work can provide a good reference for other similar problems.