PANG Yifan, WU Chunyu, JI Huiming
(Key Laboratory of Advanced Ceramics and Machining Technology, Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China)
Abstract: Materials in the form of hollow spheres are ideal candidates for thermal insulation, because they exhibit various characteristics, such as low apparent density, low air convection heat transfer, large heat reflection and low thermal conductivity.Therefore, hollow spheres have a great application prospect in the fields of architecture, coating, decoration and so on.Nano-sized SiO2 hollow spheres were prepared by using polystyrene microspheres as template, from which SiO2/TiO2 composite hollow spheres were obtained by using a precipitation coating method. The SiO2 hollow spheres had an average diameter of about 150 nm and a shell thickness of less than 10 nm, while the diameter of the SiO2/TiO2 composite hollow spheres was about 150 nm and the shell thickness was about 20 nm, in which TiO2 was mainly present on surface of the shell.
Key words: SiO2 hollow spheres; SiO2 / TiO2 composite hollow spheres; thermal conductivity