Effect of fuel type on synthesis of holmium molybdate pigment with allochroic effect via solution combustion for use of jet-ink

作者：Li, Xiangyu; Wang, Yanmin^*; Pan, Zhidong^*

来源：Ceramics International, 2022, 48(21): 32241-32255.

DOI：10.1016/j.ceramint.2022.07.166

• Holmium molybdate
• Solution combustion synthesis
• Ink
• Allochroic effect

A holmium molybdate (Ho2MoO6) pigment with allochroic effect was synthesized by a solution combustion method using different fuels (i.e., D-alanine, urea, citric acid, glycine and glucose). The effect of fuel type on the synthesis performance of pigment was investigated by X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, diffuse reflectance spectroscopy and CIE L*a*b* color scale. The dispersive stability of the inks with the pigment were analyzed using Turbiscan LAB. The results show that the pigment can be synthesized via solution combustion in the presence of a certain fuel at 1000 degrees C for a few minutes. All the pigments have honeycomb holes due to the massive gaseous substances released during combustion reactions. The pigment synthesized with glucose as a fuel has the smaller average grain/particle sizes and more fluffy state as well as more hydroxyl groups on the particle surface, resulting in the optimum particle dispersive stability in an ink. Moreover, the adiabatic flame temperature (Tad) of the combustion reaction was calculated by ther-modynamic analysis. The maximum Tad (i.e., 3750 K) can be obtained when glucose is used as a fuel, indicating that glucose as a fuel is more conducive to the combustion reaction. In addition, the allochroic effect of Ho2MoO6 pigment and an ink prepared with the pigment coated and high-temperature sintered on a ceramic tile under different illuminants was also discussed.