Analysis of heat transfer in ordered and disordered mesoporous TiO2 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.

The thermal conductivity of the ordered mesoporous film was lower than that of the disordered mesoporous film due to the increased scattering of heat flux in the pore structure with short paths, as confirmed by the simulation analysis of the heat flux vector.Figure optionsDownload as PowerPoint slideHighlights
► Mesoporous TiO2 films with low thermal conductivity.
► Despite same porosity, thermal conductivity was varied according to pore ordering.
► Heat transfer simulation in nanoporous structure using finite element analysis.
► Heat flux vector was scattered differently by different pore structure.
► Ordered pore structure with short heat path is effective for thermal insulation.