Size control of C@ZrSiO4 pigments via soft mechano-chemistry assisted non-aqueous sol-gel method and their application in ceramic glaze

The zircon-based encapsulation carbon black (C@ZrSiO 4 ) inorganic pigments with controllable size were successfully prepared by non-aqueous sol-gel method with the assistance of soft mechano-chemistry (SMC) activation precursors. The XRD and FT-IR results showed that the SMC activation enhanced the reactivity of precursors and facilitated the formation of ZrSiO 4 phase with the calcination temperature at 900–1050 °C, indicating the successfully synthesis of pure ZrSiO 4 phase. The average size of C@ZrSiO 4 inorganic pigments significantly declined from 45.20 to 4.50 μm with the increase of SMC activation time of precursors, however, the L* values of pigments increased from 24.11 to 46.35. It was mainly because of the decreased amounts of protected carbon in ZrSiO 4 matrix and the enhanced light reflectance, which lead to the slight color change from deep black to gray black tone. The colored glaze samples presented a black hue after applied in the ceramic glaze at 1200 °C. Moreover, the black hue intensity of glazed samples was higher than that of the corresponding C@ZrSiO 4 inorganic pigments, indicating the prepared pigments have excellent tinctorial strength and hiding power. These results ensure that the obtained C@ZrSiO 4 inorganic pigments possess the outstanding chromatic performance, excellent high-temperature stability, high chemical stability and suitable particle size, and exhibit great potential in the application of the industrial ceramic decoration.