Preparation and properties of water‐based photochromic polyurethane coatings containing Er(III)‐doped WO3

Abstract

Photochromic coatings have been widely used in many fields such as architecture, transportation, and military because of the combination of reversible color‐changing properties with the insulation and protection of substrates. Conventionally, organic photochromic components are used for the preparation of photochromic coatings with fast photo‐response and excellent fatigue resistance, but the preparation of these coatings is costly and time‐consuming. Here, we have developed a relatively simple and cost‐effective strategy for the preparation of water‐based photochromic polyurethane coatings. Er(III)‐doped WO3 was synthesized and used as the photochromic component for the preparation of polyurethane/Er(III)‐doped WO3 composites, which were further used for the preparation of photochromic coatings. The properties of the coatings were tested and characterized. Due to their excellent thermal stability, water resistance, fatigue resistance, and photochromism, these coatings might have practical applications in various areas.