气体分子对纳米材料硅石气凝胶热传导的影响

以动态热线法测量不同气压下纯硅石凝胶和ＴｉＯ２掺杂硅石气凝胶的气态热导率，研究ＴｉＯ２掺杂对硅石气凝胶气态热传导的影响。实验结果表明，硅石气凝胶的微孔洞中气体分子热运动受限，考虑气体分子间，气体分子与固体颗粒间撞对气体分子平均自由程影响的气态传导理论能很好的解释实验现象，理论和实验都表明，ＴｉＯ２掺杂硅石气凝胶的气态热导率较大。

Gas Thermal Conduction of Nano - porous Silica Aerogels

In this Paper, we measured the gas thermal conductivity of pure and TiO2 doped silica aerogels at low pressure (<105Pa) by using the transient hot wire method, and researched the affection of the dopant on the gas thermalconductivity of silica aerogels. Considering the thermal motion of the gas molecules confined in the micro - holes of thesilica aerogels, and the scattering between the gas molecules and the solid particles affect the mean the Path of the gasmolecules, we explain the gas thermal conduction in silica aerogels. Both the theory and the experiments show that thedopant increases the gas thermal conductivity of TiO2 doped silica aerogels.