Controlled TiO2 coating on hollow glass microspheres and their reflective thermal insulation properties--颗粒学报PARTICUOLOGY

Long, J., Jiang, C., Zhu, J., Song, Q., & Hu, J. (2020). Controlled TiO2 coating on hollow glass microspheres and their reflective thermal insulation properties. Particuology, 49, 33-39. https://doi.org/10.1016/j.partic.2019.03.002

Controlled TiO₂ coating on hollow glass microspheres and their reflective thermal insulation properties

Jie Long ^a, Chongwen Jiang ^{a b *}, Jundong Zhu ^a, Quzhi Song ^a, Jiang Hu ^a

a College of Chemistry and Chemical Engineering, Central South University, Hunan 410083, China
b Hunan Provincial Key Laboratory of Efficient and Clean Utilization of Manganese Resources, Central South University, Hunan 410083, China

10.1016/j.partic.2019.03.002

Volume 49, April 2020, Pages 33-39

Received 26 December 2018, Revised 13 March 2019, Accepted 22 March 2019, Available online 26 June 2019, Version of Record 26 February 2020.

E-mail: jcwcsu@csu.edu.cn

Highlights

• TiO₂ loading on hollow glass microsphere (HGM) was controlled by ethanol addition and coating number.

• Hydrogen bonding and electrostatic forces gave close contact between HGMs and TiO₂.

• 15.9% loading of TiO₂ yielded optimum reflective thermal insulation properties.

Abstract

Hollow glass microspheres (HGMs) have great potential in building energy-saving and industrial insulation. Anatase TiO₂-modified HGMs were prepared by a sol‒gel method in acetic acid-ethanol solution. Scanning electron microscopy, X-ray diffraction, zeta-potential measurements, nitrogen-sorption measurements, and Fourier-transform infrared and ultraviolet-visible-near-infrared diffuse reflectance spectroscopies showed that the alkali modification of the HGMs greatly influenced the loading and microstructure of the TiO₂ film. The TiO₂ loading could be accurately controlled by ethanol addition and the TiO₂ coating time. A mechanism for the TiO₂ coating of the HGM surface is proposed. The synergistic action of hydrogen bonding and electrostatic forces resulted in close contact between the HGMs and TiO₂ sol at pH 3.5. The effects of different TiO₂ loading rates on the reflective and thermal insulation properties were studied. The near-infrared reflectance of 15.9% TiO₂ coated on HGMs was 96.27%, and the inner surface temperature of the composite pigment coated on aluminum board was reduced by 22.4 °C. The TiO₂/HGM composite pigments exhibited excellent solar reflective and thermal insulation properties, so have potential in the construction of exterior walls and roofs.

Graphical abstract

Keywords

Hollow glass microspheres; TiO₂ loading; Sol‒gel; Reflective insulation; Surface treatment

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