Modeling and measurement of effective thermal conductivity of core-shell-structured SiO2 MHSPs-silica aerogel composite

To explore and optimize silica aerogel's thermal insulation performance, we model and test the effective thermal conductivity (lambda) of SiO2 micro hollow sphere particle (MHSP)-silica aerogel. The models are for the infrared radiative lambda of SiO2 MHSP-silica aerogel, with different core/shell ratios (l(d)), and the hot surface's temperature response is measured by the steady-state method. The results show that the radiative lambda of aerogel doping SiO2 MHSP with l(d)=0.75 is equivalent to that of doping with solid spheres, whose weight is reduced by 42.19%, and the solid lambda is reduced by 88.24%. Furthermore, the lambda of aerogel with 60 mu m SiO2 MHSPs of 0, 6.89, and 16.28 vol % is 0.02504 similar to 0.02613, 0.02847 similar to 0.03100, and 0.03635 similar to 0.03955 W.m(-1).K-1, respectively, at small temperature difference (Delta T <20 K). As Delta T increases (> 550 K), the 'lambda' of aerogel with 16.28% SiO2 MHSP becomes smaller than aerogel with 6.89% SiO2 MHSP, indicating the optimal insulation performance.

Automated summary

This study investigates the thermal conductivity and temperature response of silica aerogel doped with SiO2 micro hollow sphere particles (MHSP) using modeling and experimental testing. The results demonstrate a significant improvement in the thermal insulation performance of the aerogel when doped with SiO2 MHSP, particularly at larger temperature differences.