Regenerated Cellulose/Lignin Composite Aerogel with Unique Toast‐Like Structure and Their Potential Applications in Thermal Camouflage

Abstract Camouflage clothing and cloaks are widely used in the military field. However, the widespread use of unmanned aerial vehicles (UAV) equipped with infrared thermal imaging devices has rendered traditional camouflage ineffective in the face of its unparalleled detection capabilities in modern warfare. Inspired by the enhancement principles of cellulose and lignin in natural wood, the interfacial engineering of biomineralization, and the scale structure of pangolins, herein, a regenerated cellulose/lignin composite aerogel with a toast‐like structure by integrating all three biomimetic techniques into a single biomimetic design is developed. The unique toast‐like structure allows effective protection of the internal porous structure during surface modification. The prepared composite aerogel not only exhibits excellent mechanical properties but also demonstrates a desert sand‐like color, superior thermal insulation, and effective infrared blocking capabilities, highlighting its potential in thermal camouflage applications. This work proposes a green method for preparing regenerated cellulose composite aerogel sheets, which is expected to provide a design concept for the preparation, functionalization, and application of regenerated cellulose aerogel materials. In addition, factors such as the generalizability of the study, environmental impacts, and economic benefits are discussed.