Preparation and characterization of PVC/CsxWO3 composite film with excellent near-infrared light shielding and high visible light transmission

Near-infrared (NIR) shielding is essential not only in the building and automobile glass films but also in achieving energy conservation. However, effectively shielding NIR and maintaining high transmittance in the visible light region have been great challenges in the past decade. Recently, hexagonal cesium tungsten bronze (CsxWO3) nanoparticles have been widely studied due to the excellent transparency in the visible light region and strong heat-shielding ability in the NIR region. Herein, a design concept of transparent polyvinyl chloride (PVC)/CsxWO3 composite film, as a heat insulation material for glasses, was proposed. To achieve this purpose, the PVC/CsxWO3 composite film was prepared by incorporating CsxWO3 slurry with better dispersion than traditional CsxWO3 nanoparticles powder into a transparent PVC matrix. By the UV-Vis-NIR spectrophotometer characterization, the PVC/CsxWO3 composite film containing 2.1 phr CsxWO3 slurry displays high blocking of NIR (78%) and high transmittance of visible light (76%). In order to further understand the actual heat insulation effect from the PVC/CsxWO3 composite films, the indoor sunlight simulation test and outdoor cooling experiment with solar illumination variations were carried out, which both showed heat insulation that is superior to the antimony tin oxide and indium tin oxide thin films prepared in our previous work. In addition, the mechanical property of PVC/CsxWO3 composite films shows almost no change with the increase of CsxWO3 slurry. The PVC/CsxWO3 composite films simultaneously achieve excellent shielding of NIR and high transmittance of visible light, which makes it an ideal material to alleviate the current building energy consumption issues.