Facile Fabrication of Superhydrophobic Robust Coatings with Solar Reflective Capability by One Step Spraying Method

Building exterior wall coating will inevitably experience (temperature change, ultraviolet radiation, dust pollution, mechanical contact and so on) when it is used outdoors, which will reduce the solar reflectivity. Therefore, improving the durability of the solar reflective coating is the premise to ensure the long-term stable use of the solar reflective coating. In this study, we developed low-cost and eco-friendly ground calcium carbonate (GCC)/TiO2 coatings on the cement substrate using a simple one-step spraying method. The as-sprayed GCC/TiO2 coating surface is superhydrophobic with a sliding angle of 5 +/- 0.6 degrees and a contact angle of 158 +/- 1.1 degrees. The coating remained excellent superhydrophobic even after a 2 m length of abrasion and 50 peelings. Surprisingly, the solar reflectance of the coating surface is up to 0.895, which can lower the cement surface by nearly 10 degrees C. Furthermore, the coating has corrosion resistance, anti-ultraviolet, and self-cleaning properties, suggesting that the coatings have great potential in building cooling applications.