Visualization of Ultraviolet Irradiation using WO3-Cellulose Derivatives Composite Film
S. Yamazaki, K. Isoyama, D. Shimizu
Optical Mater., 2020, 106, 109929
DOI: 10.1016/j.optmat.2020.109929

Abstract: Tungsten oxide (WO3) based photochromic films consisting of methyl cellulose (MC), hydroxyethyl cellulose, carboxymethyl cellulose (CMC) or cellulose nanofiber (CNF) are fabricated for monitoring ultraviolet (UV) light. The opaque WO3/MC film becomes transparent by adding ethylene glycol (EG) whereas the WO3/CMC and WO3/CNF are transparent without EG. The WO3/EG/MC film possesses much higher sensitivity to the UV light than the WO3/CNF film. Visually, the blue color of the WO3/CNF film after UV irradiation for 8 h is almost equivalent to that of the WO3/EG/MC film after irradiation for 1 min. The color change of the WO3/CNF and the WO3/EG/MC film can be used to monitor UV from the sun light. We also demonstrated that the WO3/EG/MC film can be used to measure the UV intensity quantitatively up to 6 mW cm-2.