Vanadium oxide-based photochromic composite film

Abstract

V₂O₅-based composite films were fabricated using peroxo-iso-poly vanadic acid as the filler and transparent urethane resin as the matrix. The size of the V₂O₅ particles in the films was around 60–80 nm and the fabricated composite films exhibited photochromic properties when irradiated with ultraviolet (UV) light. The composite films displayed multichromism (yellow ↔ green ↔ pale blue) under UV irradiation. The absorption edge of the films shifted to lower wavelengths (Bürstein Moss effect) with the increase of the coloring degree of the films. Almost all the colors of the composite film bleached when placed in a dark room.