Developing Lightweight Silanized Cellulose Ultramaterials as the Strongest Engineered Aerogel

Abstract Silica aerogel materials exhibit exceptional properties, including unique light, heat, fluid, and ion characteristics with vast potential. Despite similarities in composition to glass, silica aerogel lacks ductility and is prone to breakage upon impact. Therefore, the development of advanced engineering aerogel ultra materials that combine the mechanical strength of engineered materials with the ultralight superinsulation of aerogels remains a significant challenge. Herein, a multidimensional and multiscale gradient‐pore strategy is proposed for the scalable production of nanostructured silanized cellulose (SiCell) nanofibrous frameworks through colloidal self‐assembly using an active earth‐abundant biopolymer from the wood as a functional component. The configuration of the SiCell/polymer‐crosslinked silica‐aerogel‐powder (SiAP)‐locked structure creates a regional framework that forms SiCell/polymer‐crosslinked SiAP‐locked aerogels (SiCSiPA) with a 3D nanoporous architecture. With an ultralow thermal conductivity of 15.9 mW m −1 K −1 , the lightweight super insulating SiCSiPA emerges as a prime candidate for thermal insulation, offering exceptional strength for practical applications. Moreover, SiCSiPA exhibits superior strength, stiffness, and toughness, making it the best insulating material. Owing to its outstanding strength‐to‐weight ratio and robust thermomechanical stability, SiCSiPA introduces a new technology for lightweight construction applications requiring superior thermal insulation.