Highly transparent, hot water and scratch resistant, lubricant-infused slippery surfaces developed from a mechanically-weak superhydrophobic coating

Abstract

Superhydrophobic surfaces are usually easy to damage due to their micro/nanoporous structures. As a solution, such a porous surface can be filled with lubricant forming an alternative water-repellent surface, namely, lubricant-infused slippery surface (LISS), which is supposed to be mechanically stronger owing to its dense texture. However, to what degree the mechanical reinforcement could achieve remains an issue without deep understanding. In this study, an extremely weak nanostructured superhydrophobic SiO2 coating is demonstrated capable of being converted into a robust, durable, and antireflective slippery surface with a simple lubrication process. Silicone oils of different viscosities are infused into the SiO2 coatings and the 20 and 50 cSt oils are found to generate superior droplet-shedding properties. These slippery coatings exhibit robust repellency against water jet impacts and hot-water splashes, withstand cotton and sandpaper abrasions, retain their slippery property when subjected to consecutive scratches, long-term immersion, high-speed spinning, water shear friction, and different pH liquids. These performances reflect the powerful role played by the infused oil in enhancing the cohesion of coating and the interactions between coating and substrate, and illustrate the available degree to which the mechanical reinforcement could achieve. This study provides a deep insight into the interactions between a porous coating and infused lubricant, and also a facile method for producing robust LISSs.