不同前驱体浓度柔性气凝胶性能研究

以甲基三乙氧基硅烷（MTES）为前驱体，乙醇（EtOH）为溶剂，通过（酸碱）溶胶-凝胶法和超临界干燥技术制备柔性超疏水二氧化硅气凝胶，并研究不同前驱体浓度溶胶-凝胶工艺柔性气凝胶的物理性质、化学组成、微观结构、柔性和回弹性。结果表明，随着前驱体浓度降低，柔性增强但强度逐渐降低，回弹次数减少；导热系数逐渐降低，当MTES/EtOH摩尔比为1:13时，其导热系数最低为0.0270W/(m·K)；平均孔径及孔体积逐渐增大；Si-O-Si, Si-C,C-H键增加，带来更多的三官能团有机硅的交联。

Study on the properties of flexible aerogels with different precursor concentrations

In this paper, flexible superhydrophobic silica aerogel is prepared by methyl triethoxysilane (MTES) as precursor and ethanol (EtOH) as solvent, by sol-gel method (acid-base) and supercritical drying technology, and the physical properties, chemical composition, microstructure, flexibility and resilience of flexible aerogel with different precursor concentration are studied. The results show that with the decrease of precursor concentration, the flexibility increases but strength gradually decreases, and the rebound times decrease. With the decrease of precursor concentration, the thermal conductivity gradually decreases, and when MTES/EtOH ratio is 1:13, the lowest thermal conductivity is 0.0270W/(m·K). With the decrease of precursor concentration, the mean pore size and pore volume gradually increase. With the decrease of precursor concentration, Si-O-Si, Si-C, C-H bond increases, leading to more crosslinking of silicone.