Effects of Multilayer Thin Film Coatings on Different Thermochromic Materials for Thermal Storage Applications

A significantly large amount of thermal energy is lost from or gained in buildings as a result of solar radiation. A comfortable temperature can be maintained by correctly designing and arranging a building's windows and smart roof coatings. Single layer or multilayer thin film coatings, with spectrally desirable characteristics, are deposited on glass or roof surfaces and can greatly improve a building's energy efficiency. Thermochromic materials present some advantages due to their reversible color and phase change behavior near ambient temperature. For example, a thennochromic coating on a roof's surface can change color (black to white) reversibly when heated at around 30 degrees C, reflecting solar radiation and reducing a building's cooling needs. In the present study, various thermochromic coatings on glass slides are investigated. In this work, the effect of non-toxic titanium dioxide (TiO2), used as a UV radiation protective coating on thermochromic particles (such as a three-component blue dye synthesized in the lab or a commercially available black dye), is discussed. The composite coatings of the chosen components can reduce a building's cooling and heating energy needs and provide an environmentally sustainable solution for a green economy. Several physico-chemical characterization techniques were used to understand the surface, interfacial, spectroscopic, and thermal behavior of TiO2 or SiO2 coatings and phase change thermochromic materials for applications in thermal storage and enhanced energy efficiency.