Self-Dispersion: Spontaneous Formation of Colloidal Dyes in Water

Spontaneous formation of colloidal dyes in water is investigated by scanning electron microscopy. The authors report that crown ether–substituted perylene dyes spontaneously form solid particles (see Figure) upon contact with water. The colloidal dispersion exhibits a ruby-like color and is very stable. Thus, the dye can be applied as a tracer for the investigation of the movement of water to answer geochemical questions.