Photochromic dyes are a new class of functional dyes. The solution formed by dissolving such dyes in organic solvents is colorless indoors when the concentration is certain. Outdoors, the solution will slowly develop a specific color when exposed to sunlight. Put it back indoors (or in a dark place) and the color will slowly fade. The solution is coated on various substrates (such as; paper, plastic or wall), when the solvent evaporates, it can leave an invisible imprint on the substrate, exposed to strong light or sunlight, the imprint color will be displayed.

Post time: Aug-05-2022