Preparation and characterisation of silica supported organic hybrid pigments

Purpose The purpose of the work reported in this paper is to prepare hybrid pigments fabricated by depositing pigment yellow 12 (PY12) on the surface of silica gel to improve the application performance of the resulting pigments. The particle size distribution, optical properties, thermal stability, water dispersibility and flowability of the pigments with and without silica gel modification were studied. Design/methodology/approach The hybrid pigments were synthesised with different amount of silica gel. The modified pigments were characterised by Fourier transforms infrared spectroscopy, X-ray diffraction, thermal analysis, scanning electron microscopy and transmission electron microscopy. Findings The particle size distribution of the modified pigments was found to have been altered significantly. This can be explained by the interaction between pigments and silica gel, which prevented self-aggregation of pigment particles and hence improved the properties of pigments. Research limitations/implications Only silica supports and pigment yellow 12 were evaluated. Other pigments could also be studied. Practical implications Modification of pigment particles with smaller particle size can increase the efficiency of the modified pigment, in terms of colour shade and tinting strength, due to better particle size distribution. Originality/value The paper demonstrates that inorganic core can prevent self-aggregation of pigment particles, and the application properties of such pigment depend on the resulting degree of dispersion of pigment particles.