Self-cleaning transparent superhydrophobic coatings through simple sol-gel processing of fluoroalkylsilane

Upon contact with a dusty superhydrophobic surface, moving spherical water drops collect the dust particles and eventually flow off the surface. Herein, we report a very simple one-step approach to fabricate transparent and self-cleaning superhydrophobic coatings via the sol-gel processing of long-chain fluoroalkylsilane. The coating surface exhibited a rough, wrinkled, hill-like morphology similar to the microstructure of the lotus leaf (rough micro-scale papillae), which is promising for superhydrophobicity. The air bags trapped in the rough, hill-like structure allow the water drops to take a round shape with a contact angle of 169°. These round water drops abruptly roll off the coating surface at less than 5°of tilting. No major or minor water-drop pinning was observed during the roll off. The dust-repellent (self-cleaning) property, plastron stability, and durability against water-jet impact were examined on the superhydrophobic coatings.