Analysis of heat transfer in ordered and disordered mesoporous TiO ₂ films by finite element analysis

Ordered mesoporous oxide films have lower thermal conductivities than their corresponding dense films. In order to apply ordered mesoporous oxide films, which possess excellent properties, in various fields, it is necessary to determine their thermal insulation mechanism. In this study, we synthesized ordered and disordered mesoporous TiO₂ films as a function of the drying time. While they had similar porosities, they had different pore structures and thermal conductivities. In order to reveal the relationship between the pore structure and thermal conductivity, a simulation of the heat transfer was performed. The thermal properties, temperature distribution, and heat flux vector of the mesoporous films were simulated by finite element analysis. From the comparison of the experimental and simulated results, the mechanism of thermal insulation in the pore structure could be demonstrated.