Environmentally safe, substrate-independent and repairable nanoporous coatings: large-scale preparation, high transparency and antifouling properties

Superhydrophobic self-cleaning coatings have attracted significant attention from the scientific community and the industrial world. However, their real-world applications are still restricted by their low transparency that will destroy the intrinsic properties of substrates, poor durability, expensive toxic reagents and complex preparation processes. In this context, we developed a versatile and efficient method to fabricate environmentally safe and self-cleaning coatings based on the self-assembly of modified porous chain-like SiO2 nanoparticles. The properties of the coating layer were tunable by changing the coating conditions including the concentration of ingredients and thickness of the film. The optimal coatings display a fractal-like nanoporous structure and high transmittance. The low surface roughness and porous structure contribute to their high transparency via reducing the light scattering and suppressing the reflection of surfaces. Importantly, the versatile transparent coatings can be applied on any solid substrate with great waterproof ability, self-cleaning effect and antifouling performance, over a large area without destroying their intrinsic properties. Moreover, the coated substrates also exhibit excellent thermal stability (400 degrees C) and humidity resistance. Importantly, the superhydrophobic coatings can be easily and rapidly repaired regardless of the number of cycles after damage, which provides a promising strategy to tackle low durability.