Impact of SiO2, TiO2 and ZnO nanoparticles incorporation on the thermo-optical properties of dark-coloured façade coatings

Abstract

In pursuing energy-efficient construction and reduced environmental impact, this study explores the integration of TiO2, SiO2, and ZnO nanoparticles into coatings for thermal-enhanced facade systems. Buildings account for a substantial portion of energy consumption, with facades playing a pivotal role. The impact of nanoparticle type, size, and material combination on thermo-optical performance was investigated through systematic analysis. Our findings reveal significant improvements in near-infrared (NIR) reflectance, a crucial factor in minimising heat absorption. Notably, TiO2 nanoparticles demonstrate a 50 % enhancement in NIR reflectance with a colour difference (Delta E) of 3.4, followed by ZnO (28 %, Delta E 3.2) and SiO2 (22 %, Delta E 4.61). Application-specific variations highlight the improved behaviour of TiO2 in coatings for ETICS (Exterior Thermal Insulation Composite Systems), SiO2 in acrylic paints, and ZnO in dye formulations. These results allow architects and builders to incorporate dark colours into facade aesthetics while maintaining thermo-optical efficiency and durability. As the demand for sustainable building practices grows, our work contributes to the evolving landscape of energy-efficient construction materials and design strategies. Investigating the long-term durability of these nanoparticle-enhanced coatings remains an important future research avenue.