Fluorescent colored material made of clay mineral and phycoerythrin pigment derived from seaweed

•Phycoerythrin pigment extracted from seaweed adsorbs synthetic hectorite.•The adsorption on natural montmorillonite was not sufficient.•Bright red fluorescence powder was obtained by the incorporation with hectorite.•Low heat and light fastness which are major drawbacks of phycoerythrin were increased.

In order to obtain a fluorescent colored powder, composites of phycoerythrin pigment extracted from seaweed and clays (hectorite and montmorillonite) were examined. The pigment adsorbed easily on synthetic hectorite in an aqueous solution and a composite with bright fluorescence was obtained. On the other hand, the adsorption of the pigment on natural montmorillonite was not sufficient, and a salt had to be added to the pigment solution to obtain the composite. Low heat and light fastness, which are serious drawbacks of phycoerythrin for practical usage, were increased by the adsorption to the hectorite clay.