A thermoplastic PMMA@W18O46 nanocomposite for UVC optical detection

• A polymeric hybrid UVC sensor integrating tungsten oxide nanorods was developed. • The sensor changes from colorless to grey-blue when exposed to UVC rays. • The sensor shows reversible photochromic properties. • A linear response was observed from 5000 to 300000 µmol/m −2 (−|-) photon quantum flux. The monitoring of ionizing radiation-induced damage is increasingly significant, especially within the framework of extraterrestrial missions, and serves as a critical measure to prevent damage to living beings and to materials. In this work, a passive detector for UVC radiations (280–––100 nm) has been obtained by embedding W 18 O 49 nanorods into a polymethyl methacrylate matrix through a bulk in-situ radical polymerization, ensuring a tungsten-based nanostructures homogeneous dispersion. The photochromic nanocomposite was characterized via thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Gel Permeation Chromatography (GPC), field emission scanning electron microscopy (FEI-SEM), X-rays Photoemission Spectroscopy (XPS), FT-IR, and UV–visible spectroscopies. The efficacy of the UVC sensing was investigated by exposing the nanocomposite to a 254 nm light source and monitoring the sensor response through UV–Vis spectroscopy. Finally, an explanation for the observed photochromic variation is proposed. The nanocomposite thin film exhibits excellent photochromic properties, with a fast and reversible spectroscopic change from colorless to grey-blue color, which could be easily detected visually or by simple optical devices. The obtained system shows a linear detection of UVC rays, from 5000 to 300000µmol/m −2 , highlighting its potential for practical applications in environments where robust, flexible and power-independent devices are required.