Preparation and characterization of plasticized polyvinyl chloride composite film based on photochromic intelligent cooling

Indoor temperature adjustment to maintain a relatively comfortable living environment has resulted in different cooling strategies. Often, these strategies are energy consuming as well as energy wasting because of the complex and changing environment. Materials development to achieve intelligent adjustment of indoor temperature through efficient and energy-saving methods is essential. Here, we present a strategy to prepare polyvinyl chloride (PVC)/photochromic powders cooling films. By adding different colors of photochromic powders to PVC substrate and utilizing their properties of changing color and light transmittance according to sunlight intensity to achieve the intelligent cooling effect. The indoor sunlight simulation test indicates that the PVC/red photochromic powders composite film possesses the best cooling performance under ultraviolet (UV) irradiation, and the maximum cooling range is about 10 degrees C compared with the control sample, meanwhile the maximum cooling effect is only 2-3 degrees C without UV irradiation. The PVC/red photochromic powders composite film also shows the best cooling effect (6 degrees C) in the outdoor solar irradiation test with strong sunlight, and all films did not exhibit an obvious cooling effect under weak sunlight. Meanwhile, PVC/photochromic powders composite films also solve the shortcoming of the single color of traditional cooling films, which can better meet the demand of people for color diversity. In addition, the stable mechanical properties of PVC/photochromic powders composite films also give it great application value. Therefore, PVC/photochromic powders composite films can provide a promising energy-saving solution for future intelligent adjustment of indoor temperature.