Preparation And Characterization Of Silica Aerogels By Supercritical Drying Technique

Silica aerogels are low density nano-porous non-crystalline solids. Aerogels have the extraordinary properties on optical, acoustical, thermal and mechanical. Due to such exceptional properties, the aerogels have received significant attention in many fields such as catalysis, adsorption, and high-efficient thermal insulator, etc.However, pure silica aerogels have the disadvantages of low-intensity and poor-toughness. In this dissertation, silica aerogels had been prepared by sol-gel method and supercritical drying technique, using nano fiber brucite as reinforcing material. The magnitude of natural fiber brucite was micron level, and fiber brucite were scattered to achieve the nano-order of magnitude by dispersing. The results showed that the mechanical properties of silicon aerogels were enhanced evidently by adding dispersant-treated fibers.A series of physical and chemical properties such as strength, toughness and heat resistance had been improved through doped with titanium dioxide and fiber brucite, so that the silica aerogels can play a greater role in industry and life.