Preparation and analysis of multi-scale colored superhydrophobic coatings with excellent mechanical strength and self-cleaning properties

Since most commercial building coatings are porous in structures, the building facades are easily to be damaged by acid rain, harmful particles in the air, and drastic temperature changes. Superhydrophobic coatings have great potential to solve these problems on account of their excellent water-repellent and self-cleaning properties. Previous studies have focused on improving the durability of superhydrophobic coatings. However, a colorful superhydrophobic coating that meets both durability and aesthetic requirements is rarely reported. Therefore, we developed a self-cleaning and colorful superhydrophobic (SCS) coating consisting of silica nanoparticles (nano-SiO2 particles), quartz sands, silicone sealant, and latex paint. The thickness of the SCS coating could be adjusted from 0.05 to 0.3 mm, the average contact angle (CA) was 155.09 ± 1.9° and the average sliding angle (SA) was 3.6 ± 0.2°. The SCS coating could be still retained superhydrophobicity after 350 cycles of mechanical abrasion under the weight of 200 g and 100 cycles of tape peeling. It was shown that there were no evident changes after immersing in chemical solutions and irradiating under ultraviolet (UV) light in the aging test. The mechanism of the excellent performance was studied by scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The facile fabricated SCS coating with excellent mechanical stability, anti-corrosion, and UV-resistance performance is expected to apply in the building engineering field for keeping clean and waterproof.