Peach skin effect: a quasi-superhydrophobic state with high adhesive force

The surface of a peach is known to exhibit special wettability and adhesion behaviors. We disclose that the peach surface is covered with long and short indumentums. The long indumentums are covered mainly with hydrophobic wax molecules, while the short indumentums are coated mostly with hydrophilic polysaccharides. Thus, the peach surface exhibits a quasi-superhydrophobic property and high adhesive force. A water droplet on the surface of a peach is a quasi-sphere, which is unable to roll off even when the peach is turned upside down. This is defined as the peach skin effect. We present that the quasi-superhydrophobic state with high adhesive force is attributed to the special coexisting Wenzel’s and Cassie’s state for water droplets, thus creating the strong interaction between the water droplet and surface.摘要桃皮表面具有特殊的浸润和黏附性质。本文揭示了桃皮表面主要由长、短2种绒毛组成。其中长绒毛含有较多疏水的蜡质,短绒毛含有较多亲水的多糖基团。正是由于2种绒毛的化学组成和微观结构使得桃皮表面具有准-超疏水、高黏附的性质。桃皮表面的水滴能够维持良好的球形,即使将桃皮倒立放置,水滴也不会滚动,我们将此定义为桃皮效应。通过化学法和物理法改变其表面化学组成和微观形貌,推断出水滴在桃皮表面以Wenzel和 Cassie共存态存在,使得水滴与桃皮表面产生较强的相互作用,从而使桃皮表面具有超疏水和高黏附性质。