疏水二氧化硅气凝胶粉体燃烧行为及其隔热性能研究

Hydrophobic SiO2 aerogel (HSA) is an excellent thermal insulation material, exploration on the influence mechanism of combustion to the thermal insulation property of HSA is a key factor to apply it in insulation filed. In this study, For HSAs’ special nanoporous structure, chemical composition and application environment, TG-IR-MS analysis is used to study the HSAs’ gas products in thermal decomposition. Under this background, Planar Laser Induced Fluorescence (PLIF) technology combining with cone calarimeter are introduced to study the combustion mechanism and characterization of HSA. During combustion, the HSAs’ microstructure will be changed. Technologies including BET, SEM, XPS, et al will be used to explore the HSA’ structure. And the strucrure parameters will be obtained. At the same time, a heat transfer model combination of solid, gas, solid-gas coupling and radiation heat trassfer will be proposed to predict the HSAs’ effective thermal conductivity with help of structure parameters. To imporve and validate the model, the HSAs’ thermal conductivity before and after combustion will be measured using transient hot-wire method. The HSAs’ thermal response under high temperature can be largely improved through the combustion analysis. What is more, this study can provide useful theoretical reference and data support to prevent and repress the HSA-induced thermal accident. And the heat transfer model can evaluate the recycle property of HSA based materials after thermal accident.

疏水二氧化硅（SiO2）气凝胶是一种高性能隔热材料，探究燃烧行为对其隔热性能的影响机理是将其应用于隔热领域的关键之一。鉴于疏水SiO2气凝胶特殊的微观结构、化学组成与应用环境，项目以自制的疏水SiO2气凝胶为研究对象，借助热重-红外-质谱联用、平面激光诱导荧光等技术结合锥形量热仪研究该材料的燃烧机理，分析其燃烧特性，探索燃烧对其微观结构的影响规律。通过表征与测试手段得到燃烧前后该材料的结构参数。以由材料燃烧引起的结构变化为桥梁，建立疏水SiO2气凝胶粉体的传热模型，分析燃烧对隔热性能的影响机理。对疏水SiO2气凝胶燃烧机理与特性的研究可以丰富与完善该材料的高温热响应机理与特性；理论传热模型的建立可以更好地揭示该材料的传热机理，明晰其结构变化对隔热性能的影响机理。本项目的研究可为疏水SiO2气凝胶材料的热灾害防治提供重要的理论依据和数据支撑，为灾后该材料的重复利用性能的评估提供模型支撑。

疏水SiO2气凝胶的应用是高性能隔热材料领域的前沿与热点问题之一。鉴于疏水SiO2气凝胶特殊的微观结构、化学组成与应用环境，项目将借助热重-红外-质谱联用、平面激光诱导荧光等技术结合锥形量热仪研究该材料的燃烧机理，分析其燃烧特性，探索燃烧对其微观结构的影响规律，同时通过多种表征与测试手段得到燃烧前后该材料的结构参数。以由材料燃烧引起的结构变化为桥梁，建立堆积状态下疏水SiO2气凝胶粉体的理论传热模型，并通过实验测量结果对气凝胶的传热模型进行完善。对疏水SiO2气凝胶燃烧机理与燃烧特性的研究可以丰富与完善该材料在高温高热下的热响应机理与特性；而理论传热模型的建立可以更好地揭示该材料的传热机理，明晰气凝胶的结构变化对其隔热性能的影响。本项目的研究可以为疏水SiO2气凝胶及其复合材料的热灾害防治提供重要的理论依据和数据支撑，为灾后疏水SiO2气凝胶及其复合材料的重复利用性能的评估提供模型支撑。