Environmentally friendly wollastonite@TiO2 composite particles prepared by a mechano-chemical method--颗粒学报PARTICUOLOGY

Hou, X., Zhang, Y., Ding, H., & Chu, P. K. (2018). Environmentally friendly wollastonite@TiO2 composite particles prepared by a mechano-chemical method. Particuology, 40, 105-112. https://doi.org/10.1016/j.partic.2017.10.010

Environmentally friendly wollastonite@TiO₂ composite particles prepared by a mechano-chemical method

Xifeng Hou ^a^b, Yihe Zhang ^a *, Hao Ding ^a *, Paul K. Chu ^c

a Beijing Key Laboratory of Materials Utilization of Nonmetallic Minerals and Solid Wastes, National Laboratory of Mineral Materials, School of Materials Science and Technology, China University of Geosciences (Beijing), Beijing 100083, China
b Niushan Mining Co., Ltd., Tongling County, Anhui 244131, China
c Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China

10.1016/j.partic.2017.10.010

Volume 40, October 2018, Pages 105-112

Received 8 February 2017, Revised 26 October 2017, Accepted 27 October 2017, Available online 15 February 2018, Version of Record 28 July 2018.

E-mail: zyh@cugb.edu.cn; dinghao@cugb.edu.cn

Highlights

• Core–shell wollastonite@TiO₂ (W@T) composite particles were prepared by mechano-chemical method.

• Anatase TiO₂ coating was anchored on wollastonite surface by Si—O—Ti and Ca—O—Ti bonds.

• As white pigment, the properties of the W@T were similar to those of TiO₂, but much cheaper.

Abstract

Core–shell wollastonite@TiO₂ (W@T) composite particles are prepared by a mechano–chemical method (MCM) to improve the dispersion of TiO₂ and reduce its dosage, and to achieve synergistic effects with the wollastonite mineral. The crystal structure, morphology, functional groups, and pigment properties of the as-prepared composite powders are determined. The W@T composite particles are formed by van der Waals force in addition to electrostatic attraction and chemical bonding. The anatase TiO₂ coating is anchored on the wollastonite surface by Sisingle bondOsingle bondTi and Casingle bondOsingle bondTi bonds. The W@T powders possess excellent characteristics such as whiteness of 96.6%, hiding power of 17.97 g/m², and oil absorption of 22.72 g/100 g. The properties of the W@T composite are similar to those of TiO₂ and the former, which is much cheaper, can potentially substitute the latter as a white paint in many applications.

Graphical abstract

Keywords

Wollastonite; TiO₂; Composite particles; Mechano-chemical method

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