Clay-assisted dispersion of organic pigments in water

Abstract

We reported a new method for dispersing insoluble organic pigments (OPs) in water by simply pulverizing with the selected clay. The smectite clay of synthetic fluorinated mica (Mica) enabled to homogenize the pigments due to its inherent colloidal properties of surface ionic charges and unique plate-like geometric shape in an average dimension of 300 × 300 × 1 nm 3. Five pigments of different colors were homogeneously dispersed in water and maintained their nanoscale particle sizes in ca. 70 nm–2 μm. The zeta potential data revealed a strong surface-charge interaction between the OPs and Mica with a noticeable charge measurement varying from −40 mV to −24 mV. For practical applications, the homogeneous dispersion of pigments was mixed with PVA and spin-coated into polymer films exhibiting the possibility of fabricating color filters. The process has the advantage of avoiding the conventional uses of organic surfactants and solvents.