In order to improve the dispersibility, thermal stability and pH adaptability of organic pigments in water, submicrometer copper phthalocyanine (CuPc)/SiO2 composite particles (CPs) were prepared through a simple one-pot wet ball-milling process under acidic conditions without using any organic surfactant. In the as-obtained CPs, the surface of the CuPc particles was homogeneously decorated with SiO2 nanoparticles (NPs) through hydrogen bonding interactions. Due to the surface-attached SiO2 NPs, the CuPc/SiO2 CPs present a high aqueous dispersibility and a pH-dependent colloidal stability. Furthermore, both the thermal stability and color intensity of CuPc were increased by encapsulation of CuPc particles within SiO2 NPs.
