Re-entrant geometries can effectively trap air pockets, increase air/liquid interface fraction, prevent the penetration of low surface tension organic liquids, and achieve super-oleophobic performance. However, the creation of re-entrant geometries usually involving expensive lithographic tools, or complicated chemical procedures, and cannot be applied on a large scale, such super-oleophobic surfaces are unsuitable for practical application. Constructing hierarchical micro/nanostructure on substrates is a feasible solution to achieve super-oleophobicity through facile spraying method. Herein, we report a super-oleophobic TiO₂/SiO₂ composite coatings by taking advantage of an exceedingly simple spraying method. The dendritic structures produced by spraying the TiO₂/SiO₂ mixture play the critical role in obtaining the re-entrant geometry required for oleophobic surface, and the introduction of micron-scale TiO₂ particles and nano-scale SiO₂ particles provide an enough dual-scale rough structure for the coating. The TiO₂/SiO₂ composite coatings exhibit superior repellence to high and low surface tension liquids as well long-term durability. This design strategy may provide useful guidelines for the fabrication of particle-based spray-coated super-oleophobic surfaces.

重入几何形状可以有效地捕获气穴，增加气/液界面分数，防止低表面张力有机液体的渗透，并实现超疏油性能。然而，重入几何的创建通常涉及昂贵的光刻工具或复杂的化学程序，并且不能大规模应用，这种超疏油表面不适合实际应用。在基材上构建分级微/纳米结构是通过简便的喷涂方法实现超疏油性的可行解决方案。在此，我们利用极其简单的喷涂方法报道了一种超疏油性 TiO ₂ /SiO ₂复合涂层。喷涂TiO ₂产生的树枝状结构/SiO ₂混合物在获得疏油表面所需的重入几何形状方面起着关键作用，微米级TiO ₂颗粒和纳米级SiO ₂颗粒的引入为涂层提供了足够的双尺度粗糙结构。TiO ₂ /SiO ₂复合涂层表现出对高和低表面张力液体的优异排斥性以及长期耐久性。这种设计策略可以为基于粒子的喷涂超疏油表面的制造提供有用的指导。