In nature, there are vast singular structures or morphologies on biological surfaces that exhibit super-water-repellent properties. [1,2] The two-length-scaled hierarchical structure of the surface of the sacred lotus leaf is a good example. [3] In the meantime, the wetting ability of liquids on solid surfaces has become very important in daily life as well as in many industrial processes. Super-hydrophobic surfaces and super-amphiphobic surfacesÐi.e., surfaces that exhibit both water-repellent and oil-repellent propertiesÐhave attracted much interest because of potential practical applications.[4] Previous works on obtaining super-hydrophobic or super-amphiphobic surfaces have often used a combination of depressed surface energy and enhanced surface roughness.[4±16] However, the strict preparation conditions, multi-step processes, limited applicability, and high cost of the previous methods made forming large-area super-hydrophobic surfaces in ambient atmosphere for applications very difficult. Hence real applications of such super-hydrophobic or super-amphiphobic surfaces have been very limited. We describe in this communication a simple one-step casting process for creating a super-amphiphobic polymeric coating from two easily synthesized or commonly available polymer materialsÐpoly(methyl methacrylate) (PMMA) and fluorine-end-capped polyurethane (FPU)Ðin air without further modification. It is very exciting that such a polymer coating exhibits super-hydrophobic and lypophobic properties. The study also shows that the polymer surface possesses natural lotus-like micro-and nano-hierarchical structure. Our method reveals the possibility of one-step preparation of a super-hydrophobic polymer surface utilizing the difference in solubility of two common polymers in a solvent. We believe that this is the first report of creating a super-hydrophobic surface with such a simple casting process under ambient atmosphere.The scanning electron microscopy (SEM) images of the synthesized polymer surfaces are shown in Figure 1. No obvious structures were observed by SEM for the pure FPUcoated surface (Fig. 1a). The contact angle (CA) on the surface is about 95 (Fig. 2a), which indicates that FPU film has better hydrophobicity than pure polyurethane without the fluorine group, whose CA is about 65. The pure PMMA surface (Figs. 1b,c) is rough and the water CA on it is relatively high (145, Fig. 2b). However, the water drop is pinned on the PMMA surface. It is interesting that the hydrophobicity of the polymer surface changes dramatically if the film is directly prepared by a one-step coating of a FPU/PMMA mixture solution between 10 and 40 C. The CA increases to 166 (Fig. 2c).We also use sliding angle (SA) as a criterion for the evaluation of hydrophobicity of a solid surface. SA is a measure of the sliding properties of water droplets on the surface and is also considered an important property in deciding the superhydrophobicity. [17,18] Figure 3a shows that SA can be dramatically decreased with a small amount of FPU, reaching...

Inverted perovskite solar cells (IPSCs) have attracted great attention in recent years due to reliable operational stability, negligible hysteresis and low-temperature fabrication process. To accelerate its commercialization, the focus of...

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