In order to enhance the degree of binding reaction of TiO
2 in titanium-containing ceramic glazes and prevent the reaction of its transformation into rutile to eliminate the yellowing phenomenon of the glaze surface, an apatite–TiO
2 composite opacifier (ATO) was prepared through
[...] Read more.
In order to enhance the degree of binding reaction of TiO
2 in titanium-containing ceramic glazes and prevent the reaction of its transformation into rutile to eliminate the yellowing phenomenon of the glaze surface, an apatite–TiO
2 composite opacifier (ATO) was prepared through the mechanical grinding of hydroxyapatite and anatase TiO
2. The properties, opacification mechanism, and yellowing inhibition of the prepared ceramic glazes were studied. The results show that the ATO is characterized by a uniform coating of TiO
2 on the surface of the apatite and the formation of close chemical bonding between the apatite and TiO
2. The ceramic glaze surface when using an ATO has a white appearance and excellent opacification performance. When an ATO was used, the L*, a*, and b* values of the glaze were 89.99, −0.85, and 3.37, respectively, which were comparable to those of a ZrSiO
4 glaze (L*, a*, and b
* were 88.24, −0.02, and 2.29, respectively). The opacification of the glaze was slightly lower than that of the TiO
2 glaze (L* value was 92.13), but the appearance changed from yellow to the white of the TiO
2 glaze (b* value was 9.18). The ceramic glaze layer when using an ATO mainly consists of titanite, glass phase, and a small amount of quartz, and the opacification mechanism is the crystallization of the generated titanite. ATOs can play an active role in solving the critical problem that arises when TiO
2 replaces ZrSiO
4 as an opacifier.
Full article
