Ultrafine V-ZrSiO4 pigment prepared by a bottom-up approach: Particle size evolution and chromatic properties

Abstract To solve the contradiction between particle size and color performance, an ultrafine V-ZrSiO4 pigment was successfully synthesized by sol–gel-microemulsion-hydrothermal (S-G-M-H) method in this paper. Meanwhile, the effects of hydrothermal time on the chromatic parameter, particle size distribution, phase composition, valence bond species and microstructure of the precursor and pigment were systematically investigated. Moreover, the color deterioration mechanism of V-ZrSiO4 nano-grain pigment was also revealed. The results demonstrate that the median diameter (D50) of the obtained V-ZrSiO4 pigment is only 0.972 μm. Besides, the synthesized pigment has vivid blue hue and superior tinting strength. As the increase of hydrothermal time, the particle size of V-ZrSiO4 pigment decreases, while the color performance of the pigment deteriorates. The color deterioration mechanism is attributed to the dual effects of the reduction of vanadium content in the outer layers of pigment particles and the enhancement of visible light reflection intensity.