Design and Characterization of Thermal and Optical Properties of Nano-Composite Self-Cleaning Refractive Transparent-Opaque Smart Window

Today, polymer-based smart windows have been considered for their thermal capabilities to reduce energy consumption in the buildings. The important issue about these smart products is their optimal design and construction which is the main focus of this study. The proposed window operates the way that the percentage of the light passing through the window depends on the degree of conformity of the refractive index of the nanofluid inside the window and the polymeric plates. Nanocomposite film has also been used to provide self-cleaning and photocatalytic behavior on the external surfaces. The materials used include polymethyl methacrylate (plates), methyl salicylate (fluid), and zinc oxide nanoparticles, which have been used to fabricate the nanocomposite, and nanofluid. After accomplishing the design and fabrication steps, characterization tests have been performed to determine mechanical (tensile strength, toughness, flexural strength), physical (contact angle), structural (size and shape of nanoparticles), optical (light transmission rate), and thermal (temperature ranges, heat transfer coefficient) properties. In addition, the performance of the window has been analyzed and compared with the other smart windows in terms of energy consumption and light transmission, in a quantitative analysis by two dimensionless parameters of light transmission ratio and temperature difference. According to the results, the range of variation in the transparency has been more than the maximum for other smart windows by 2 times while its energy consumption and temperature adjustment performance index has been higher than the other smart windows by 2.1 times.