Synthesis and application of C@ZrSiO4 inclusion ceramic pigment from cotton cellulose as a colorant

A zircon-based black pigment, which consists of in-situ carbon transformed from cotton cellulose as core and zircon as shell (C@ZrSiO4), was prepared via non-hydrolytic sol-gel (NHSG) method. The ZrSiO4 sol reached homogeneous mixing at atomic level and then directly turned into gel through polycondensation on NHSG process. The cotton cellulose was well dispersed in the ZrSiO4 sol due to its hollow fibrous filament structure, and then was carbonized and occluded in zircon matrix which preserved against carbon oxidation and pyrolysis at high temperature. The chromatic value L* decreased gradually and then increased slightly with increasing the chromophoric carbon amount. The coupling agent (3-aminopropyl) triethoxysilane (APTES) enhanced the connection between cotton cellulose and zircon, resulting in the deeper hue at 950 °C, as L* value was 39.09 and 53.37, respectively. The as-prepared inclusion pigments possessed strong tinting strength in glaze at 1200 °C, making them promising candidates for ceramic-ware decoration.