Encapsulation of the chromophores into the sodalite structure during the synthesis of the blue ultramarine pigment

Abstract

Encapsulation of the chromophores into the sodalite structure during the synthesis of the blue ultramarine pigment from metakaolin, sulfur, sodium carbonate and a reducing agent was investigated. The insertion of the chromophores occurs during the formation of the sodalite structure, and also after its formation, by diffusion into the sodalite cages. The possibility of diffusion of the chromophores into the sodalite structure was proved independently by syntheses of blue ultramarine pigments from sodalite, previously synthesised, mixed with a source of polysulfides.