SiO2气凝胶骨架增强研究进展

A Review on Enhancement of Mechanical Properties of Silica Aerogels

SiO2气凝胶是一种具有高气孔率、高比表面积、低导热系数等诸多优异特性的纳米多孔材料,在航天、军事、化工、建筑等众多领域有着广泛的应用前景。然而,SiO2气凝胶力学强度低、质脆、易碎的结构特点极大限制了其应用。目前,主要有结构性增强、聚合物增强和复合增强3类技术路线可用于改善SiO2气凝胶纳米多孔骨架的强度和韧性,不同的增强方法对应不同的制备工艺和制备成本。采用纤维类预制体制备纤维/气凝胶复合材料时,因其工艺简单、成本低、适用范围广,被认为是SiO2气凝胶规模化生产和应用的最有效途径。

Silica aerogel is a nanoporous material with high porosity, large specific surface area and low thermal conductivity. It has potential applications in many fields, such as aerospace, military, chemical industry, energy-saving buildings, etc. However, the low strength and high brittleness are inhibiting the broader application of silica aerogel. At present, there are three main routes to improve the poor mechanical properties of silica aerogel, i.e., structural reinforcement, polymer reinforcement and composite reinforcement. For different reinforcement technologies, the synthetic procedure and cost of silica aerogel are variable. Fiber preform reinforcement is considered to be the most effective way for large-scale production and application of silica aerogels, owing to low cost and a simplified production process.