Facile aqueous synthesis and thermal insulating properties of low-density glass/TiO2 core/shell composite hollow spheres--颗粒学报PARTICUOLOGY

Yuan, J., An, Z., Li, B., & Zhang, J. (2012). Facile aqueous synthesis and thermal insulating properties of low-density glass/TiO2 core/shell composite hollow spheres. Particuology, 10(4), 475–479. https://doi.org/10.1016/j.partic.2011.08.005

Facile aqueous synthesis and thermal insulating properties of low-density glass/TiO₂ core/shell composite hollow spheres

Jing Yuan ^{a b}, Zhenguo An ^a, Bing Li ^a, Jingjie Zhang ^a *

a Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China
b Graduate School of the Chinese Academy of Sciences, Beijing 100049, China

10.1016/j.partic.2011.08.005

Volume 10, Issue 4, August 2012, Pages 475-479

Received 3 May 2011, Revised 22 August 2011, Accepted 30 August 2011, Available online 12 April 2012.

E-mail: jjzhang@mail.ipc.ac.cn

Highlights

► TiO₂ particles can grow on hollow glass microspheres by chemical precipitation.

► The resulting low-density (0.40 g/cm³) core/shell composite possessed low conductivity coefficient and emissivity in the infrared region.

Abstract

Anatase TiO₂shells assembled on hollow glass microspheres (HGM) with tunable morphologies were successfully prepared through a controllable chemical precipitation method with urea as the precipitator. Thus, glass/TiO₂ core/shell composite hollow spheres with low particle density (0.40 g/cm³) were fabricated. The phase structures, morphologies, particle sizes, shell thicknesses, and chemical compositions of the composite microspheres were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS). The morphology of the TiO₂ shell can be tailored by properly monitoring the reaction system component and parameters. The probable growth mechanism and fabrication process of the core/shell products involving the nucleation and oriented growth of TiO₂ nanocrystals on hollow glass microspheres was proposed. A low infrared radiation study revealed that the radiation properties of the products are greatly influenced by the unique product shell structures. A thermal conductivity study showed that the TiO₂/HGM possess low thermal conductivity that is similar to that of the pristine HGMs. This work provides an additional strategy to prepare low-density thermal insulating particles with tailored morphologies and properties.

Graphical abstract

Keywords

Hollow glass microspheres; TiO₂; Core/shell; Emissivity; Thermal conductivity

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