Thermal conductivity of porous silica films using modified polydimethylsiloxane and polyethyleneglycol as templates by sol–gel process

This paper reports the heat-resistant property of porous silica films synthesized using the sol–gel method. In the sol–gel system, a mixture solvent was adopted and side-chain polyether modified polydimethylsiloxane and polyethyleneglycol were introduced as the template and viscosity adjusting agent, respectively. Differential thermal analysis/thermogravimetric analysis, Fourier transform infrared spectroscopy, field emitted scanning electron microscope, and high-resolution transmission electron microscopy were employed to characterize the samples. Thermal conductivity measured by the 3ω method as functions of porosity, thickness, and annealing temperature was discussed in detail.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideResearch highlights► Side-chain polyether modified PDMS and PEG are used to prepare porous silica films. ► Large area porous silica film with crack-free is easy to be prepared. ► Thermal conductivity as a function of porosity is in agreement with the PWSM model. ► Thermal conductivity is dependent of film thickness. ► Thermal conductivity is also dependent of annealing temperature.