nano hematite, inclusion pigment, zircon, silica, ceramic glaze
Hematite pigment has a long history, but it cannot be used for ceramic application, because it must be thermally and chemically stable at high firing temperature when using a pigment in a glaze or ceramic body. Recently, through encapsulated systems, a new pigment with suitable thermal and chemical stability can be obtained by encapsulating hematite crystals into selected silica or zircon matrices. It means that nano-sized red hematite has been encapsulated into the protected phases. Transmission electron micrographs of hematite encapsulated into silica and zircon matrices by sol–gel method show spherical single crystals with diameter of about 5–10 nm. In order to optimize ceramic glaze formulations for application of the synthesized red inorganic nanocomposite inclusion pigment by sol–gel method, four different types of glazes (i.e., alkalis, borate, earth alkalis, and leaded glazes) have been tested. The results show that the substitution of a fraction of zircon by cristobalite in hematite-zircon pigment produces acceptable stability with red hue.
Tsinghua University Press
Maryam HOSSEINI-ZORI. Substitution of a fraction of zircon by cristobalite in nano hematite encapsulated pigment and examination of glaze application. Journal of Advanced Ceramics 2013, 2(2): 149-156.