The preparation of a high performance near-infrared shielding CsxWO3/SiO2 composite resin coating and research on its optical stability under ultraviolet illumination

Cesium-doped tungsten bronze CsxWO3 is an ideal near infrared (NIR) shielding material for solar filters. However, the CsxWO3 nanoparticle dispersed resin film exhibits obvious photochromic behavior under ultraviolet (UV) illumination, which severely hinders the commercial application of CsxWO3. In this paper, CsxWO3/SiO2 composite resin coatings were successfully prepared with excellent NIR shielding ability and outstanding optical stability under strong UV illumination by combining an ultraviolet-absorbing agent (UVA) with SiO2. The roles of UVA and SiO2 in preventing the photochromic behavior of the CsxWO3/SiO2 composite resin coating were vital, reducing the photochromic reaction rate by UVA and limiting the photochromic reaction areas by SiO2. In sum, our research provides a new solution for eliminating the photochromism of a CsxWO3-based resin film and it may have practical application in architecture and automobiles.