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

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.

超疏水表面由于其微/纳米多孔结构通常容易受损。作为一种解决方案，可以用润滑剂填充这种多孔表面，形成一种替代的防水表面，即注入润滑剂的光滑表面（LISS），由于其致密的质地，它应该具有更强的机械性能。然而，在没有深入了解的情况下，机械增强能达到何种程度仍然是一个问题。在这项研究中，一种极脆弱的纳米结构超疏水二氧化硅涂层被证明能够通过一个简单的润滑过程转化为一种坚固、耐用且抗反射的光滑表面。将不同粘度的硅油注入二氧化硅涂层中，发现20和50厘沲的油能产生优异的液滴脱落性能。这些光滑涂层对水射流冲击和热水飞溅具有很强的排斥性，能承受棉布和砂纸的磨损，在连续刮擦、长期浸泡、高速旋转、水剪切摩擦以及不同pH值的液体环境下仍能保持其光滑性能。这些性能反映了注入的油在增强涂层内聚力以及涂层与基底之间的相互作用方面所起的强大作用，并说明了机械增强能够达到的程度。这项研究深入了解了多孔涂层和注入的润滑剂之间的相互作用，也提供了一种制造坚固的注入润滑剂的光滑表面的简便方法。