AUTHOR=Zhang Anjie , Mu Bin , Wang Xiaowen , Wen Lixin , Wang Aiqin 

TITLE=Formation and Coloring Mechanism of Typical Aluminosilicate Clay Minerals for CoAl2O4 Hybrid Pigment Preparation

JOURNAL=Frontiers in Chemistry

VOLUME=6

YEAR=2018

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2018.00125

DOI=10.3389/fchem.2018.00125

ISSN=2296-2646

ABSTRACT=<p>Different kinds of aluminosilicate minerals were employed to fabricate CoAl<sub>2</sub>O<sub>4</sub> hybrid pigment for studying its formation and coloring mechanism. It revealed that the color of the obtained hybrid pigments was determined by the content of Al<sub>2</sub>O<sub>3</sub> and lightness of clay minerals. The higher the Al<sub>2</sub>O<sub>3</sub> content and the lightness of clay minerals, the better the color parameters of hybrid pigments. During the preparation of hybrid pigments, CoAl<sub>2</sub>O<sub>4</sub> nanoparticles were confined to be loaded on the surface of the aluminosilicate minerals, which effectively prevented from the aggregation and the size increase of CoAl<sub>2</sub>O<sub>4</sub> nanoparticles. What's more, aluminosilicate mineral might be an ideal natural aluminum source to compensate the aluminum loss due to the dissolution of Al(OH)<sub>3</sub> at alkaline medium during precursor preparation, keeping an optimum molar ratio of Co<sup>2+</sup>/Al<sup>3+</sup> for formation of spinel CoAl<sub>2</sub>O<sub>4</sub> pigments in the process of high-temperature crystallization.</p>