【摘要】 采用激光脉冲法成功地测量了Si基底上多孔SiO2 薄膜的纵向热导率 .致密SiO2 薄膜的热导率测试数据与已有多篇文献报导值一致 .对多孔SiO2 薄膜的热导率测试结果表明 :薄膜化有利于降低材料的热导率 ,提高隔热效果 ;随着孔率增大 ,薄膜热导率明显下降 ;溶胶 凝胶法制备的孔率为 4 0 %的SiO2 多孔薄膜的热导率为 0 11W /m·K ,属隔热材料 .更多还原

【Abstract】 A laser flash method for the measurement of longitudinal thermal conductivity of porous films is proposed. The results show that the thermal conductivity of SiO 2 thin films is lower than that of bulk silica. The thermal conductivity of porous SiO 2 films decreases with increasing porosity. It is about 0 11 W/m·K for 40% porosity by the sol-gol process.更多还原