Colorful superhydrophobic concrete coating

Abstract

Concrete is widely used in architecture because of its advantages such as high strength, low cost, good durability and plasticity. However, due to its hydrophilicity and porous structures, the concrete suffers from damages caused by oxidative corrosion, freezing environment, acid rain, etc. Superhydrophobic coating with excellent water-repellent property has great potential to solve this problem. However, a colorful and robust superhydrophobic coating which meets both performance and aesthetic requirements is still not reported. Here, we develop a colorful and robust superhydrophobic concrete (CSC) coating with a water contact angle of 158 ± 0.5° and a sliding angle of 5 ± 0.8° and composing of cement, sand, water-based stone protector, and dyes for concrete coloring. Four kinds of colors including red, yellow, blue, and green can be obtained by adding red, yellow, blue, and green iron oxide dyes, respectively. The high robustness is originated from the high adhesive force between the coating and the substrate, the inherent high hardness of concrete itself, and self-similarity of inside micro-structures. The CSC coating also exhibit excellent chemical durability and weather resistance. Thus, this kind of CSC coating has promising application prospects in the outside wall of concrete architecture to improve decorative and waterproof effects and keep clean.