Carboxymethyl Cellulose Composite Aerogel Loaded With Silica Aerogel for Flexible Thermal Insulation Materials

ABSTRACT This study presents a novel composite aerogel material based on carboxymethyl cellulose (CMC), bamboo fibers, and polyvinyl alcohol, loaded with silica aerogel, to address the limitations of traditional inorganic fiber‐reinforced aerogel materials in terms of flexibility, mechanical strength, and environmental friendliness. Four different formulations of composite aerogels (SiO 2 @CMCA‐1 to SiO 2 @CMCA‐4) were successfully synthesized via sol–gel method and supercritical drying technology. The results show that the introduction of bamboo fibers and polyvinyl alcohol (PVA) significantly improves the mechanical properties and thermal stability of the composite aerogels. Specifically, the SiO 2 @CMCA‐4 sample exhibits the most excellent tensile strain (10.33%), compressive stress (0.27 MPa), and thermal conductivity (0.058 W/(m·K)). In addition, SiO 2 @CMCA‐4 exhibits good hydrophobicity and flame retardancy, with a water contact angle reaching 137°, indicating its broad application prospects in the field of flexible thermal insulation materials. This research provides new ideas for the development of flexible thermal insulation materials, especially in application scenarios requiring low intensity, high toughness, and environmental friendliness.