Harnessing acrylic-PVDF binders in paint formulation for enhanced passive cooling performance

Global energy consumption and climate change have caused an increase in urban heat islands effect and global warming, cooling lifestyles have been desired and cooling solutions have become challenging. Passive radiative cooling is a unique technology which utilizes the “atmospheric window” (8–13 μm) to emit thermal infrared radiation to the atmosphere. It does not require additional energy (i.e. electricity) input and has great potential for various applications. In general, the solar radiation would be reflected by the paint coating and existing thermal infrared radiation would be emitted from the surface to the atmospheres which would lead to lower surface temperature. In this work, titanium dioxide (TiO2) cooling paint has been successfully fabricated under Malaysia's tropical climate. The effects of adding polyvinylidene fluoride (PVDF) along with acrylic as the binder for the paint were studied and various concentrations were tested to determine the optimum composition of the paint. The cooling paint is able to outperform the chosen commercial white paint in terms of cooling performance on various types of surfaces. Results obtained from field tests indicate that the cooling paint was able to achieve efficient cooling performance under direct solar irradiation. The average net cooling power of the titanium dioxide paint was 90.87 W/m2. The relationship between weather conditions on the net cooling power of the cooling paint was also investigated.