Preparation of hollow double-shell SiO2@ATO microspheres and applications in thermal insulation coatings

The hollow double-shell Silicon dioxide/antimony doped tin oxide (SiO2@ATO) spherical microspheres with size of 320 nm were prepared by hydrothermal method using PS spheres as templates. The morphology, crystal structure and microstructure of hollow SiO2@ATO microspheres were characterized by XRD, SEM, EDS and HRTEM. In addition, the composite coatings were prepared by adding different contents of hollow SiO2@ATO to the acrylic matrix, and their optical and thermal insulation properties were studied. The light transmittance of the acrylic matrix coating with 1.5 wt% hollow double-shell SiO2@ATO can reach ∼80%. Moreover, it was found that the hollow double-shell SiO2@ATO/acrylic matrix coating lowered the indoor temperature of a homemade incubator by 9.5 °C. Overall, the prepared hollow SiO2@ATO microspheres show a great potential in the application of energy saving windows.