Development of Energy Efficient and Depolluting Ceramic Roof Tiles

Last years, the energy needs of roof systems are greater than before and the design of the so-called “cool roof” is systematically developed. A cool roof is defined as a roof covering system of a building that is capable of reflecting as much sunlight as possible and absorbing as little heat as possible. As a result, is a stable and cool temperature inside. Titanium dioxide (TiO2) is a chemical known for its photocatalyst advantage, its zero toxicity, and its ability to degrade organic pollutants. Due to its white color and high refractive index, titanium dioxide is the proper material. This research aims to develop a new bioclimatic product which will have photo-reflective and photocatalytic properties for use in cool roofs. Aqueous suspensions of TiO₂ nanoparticles were developed along with the addition of PEG (polyethylene glycol), as a surface-active material and sprayed in the form of a photocatalytic active suspension onto the surface of the fired clay roofing tiles. Characterization techniques were carried out, determination of the phases compositions of the samples were examined by XRD Analysis. The diffraction patterns exhibited strong diffraction peaks corresponding to anatase and rutile phases. According to the results, the particle size distribution analysis shown a particle size in average of 50 to 70 nm. Textural characteristics (BET Analysis) of the TiO2 suspensions indicated that temperature and PEG addition can change the surface area. The hydrophilicity of the surfaces of all samples was determined by contact angle measurements, monitoring the change in the glycerine contact angle with UV-irradiation time. The photocatalytic activity of all samples was obtained by monitoring the decomposition/decrease in methylene blue concentration. The results indicate that all the samples of TiO2 photocatalytic coating, exhibit good photocatalytic activity with high hydrophilicity and anti-microbiological activity.