Silica aerogel in textiles and nanofibers: a comprehensive review of synthesis techniques and embedding strategies

Silica aerogel is a remarkable material known for its exceptional thermal insulation properties and low density. The synthesis of silica aerogel involves a sol-gel process, which consists of gelation, aging, and drying steps. This process allows for the formation of a highly porous, interconnected network structure. Silica aerogel exhibits unique mechanical properties, such as high compressibility and brittleness, which can be improved through various reinforcement techniques. In this study, four different strategies for reinforcing silica aerogel to enhance its mechanical properties are reviewed. These strategies include the incorporation of hybridization of silica aerogels, compounding the silica network with a polymer, embedding fibers into a silica matrix, padding silica aerogel into multilayer nonwovens/nanofibers, and many more. Each method offers a distinct mechanism for reinforcing the aerogel matrix and improving its strength, flexibility, and durability. Moreover, the electrospinning process is explored as a method for fabricating silica aerogel-embedded nanofibers. Electrospinning equipment, including spinnerets and power supplies, is discussed, along with various techniques used to control fiber morphology and alignment. The integration of silica aerogel into nanofiber provides an opportunity to create lightweight, flexible composites with improved mechanical and thermal properties, making them promising materials for applications requiring efficient heat management that opens up avenues for various technological applications.