Superhydrophobic tough hierarchical porous thermal insulation composites prepared by in situ formation of silica aerogel in collagen fiber matrix

The serious problem of energy consumption and the requirement for sustainable development has attracted people's extensive attention. The application of high-efficiency thermal insulation materials can reduce consumption and waste in the process of energy transfer, and is the most effective way to save energy and protect the environment. Among many thermal insulation materials, silica aerogel, especially biomass fiber-reinforced silica aerogel with good mechanical strength, shows great practical application potential. In this article, the collagen fiber-silica aerogel composite (MCFF@SiO2) was successfully prepared by in situ sol-gel method and freeze-drying method, innovatively using skin collagen fiber matrix with natural porous skeleton as reinforcing template. MCFF@SiO2 has good thermal stability, and has a hierarchical porous structure formed by filling nanoscale mesopores of silica aerogel in the macropores of collagen fiber matrix, thus delaying the spread of heat. Particularly, MCFF@SiO2 exhibits good thermal insulation performance, and its thermal conductivity is 0.068 W/(m K), which is lower than that of MCFF. In addition, MCFF@SiO2 shows superhydrophobicity, good mechanical properties, excellent flame retardancy, and self-extinguishing performance. The prepared composite aerogels have potential application value in the field of thermal management, and this work is expected to provide inspiration for the preparation of biomass-based porous functional materials.