Preparation and Properties of Sepiolite Fiber Enhanced Silica Aerogel

The efficiency and performs nee of silica (SiO2) aerogel prepared by sol-gel method un der atmospheric pressure are insufficient, which limits its in dustrial scale application. In this work, sepiolite nan ofibers were used as enhan cement, tetraethyl orthosilicate was used as silic on source precursor, and trimethylchlorosilane was used as modifier. Sepiolite fiber/silica aerogel bulk materials were prepared by sol-gel method and atmospheric drying. The mechanical properties, thermal properties and fire safety properties were tested, and the pore structure, infrared spectrum and micro-morphology were analyzed and characterized. The fiber skelet on of sepiolite can inhibit the shrinkage and cracking of aerogel block. Fibers have heterogeneous nucleation in the sol formation stage, which refines the particles, increases the specific surface area of aerogels and changes the pore structure. The introduction of fiber improves the mechanical properties, high temperature and ablation stability and fire safety properties, and reduces the thermal conductivity. The thermal conductivity of mass sepiolite fiber/silica aerogel can reach 0.0128W/(m·K), the compressive strength is 1.20 MPa, the flame retardancy is V-0, the shape remains stable after ablation at 1 300°C, and the comprehensive performance is excellent. © 2024 Cailiao Daobaoshe/ Materials Review. All rights reserved.