Khodaparast Sepideh, Boulogne François, Poulard Christophe, Stone Howard A
Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Laboratoire de Physique des Solides, CNRS, Univ. Paris-Sud, Université Paris-Saclay, Orsay 91400, France.
Phys Rev Lett. 2017 Oct 13;119(15):154502. doi: 10.1103/PhysRevLett.119.154502.
Inks of permanent markers and waterproof cosmetics create elastic thin films upon application on a surface. Such adhesive materials are deliberately designed to exhibit water-repellent behavior. Therefore, patterns made up of these inks become resistant to moisture and cannot be cleaned by water after drying. However, we show that sufficiently slow dipping of such elastic films, which are adhered to a substrate, into a bath of pure water allows for complete removal of the hydrophobic coatings. Upon dipping, the air-water interface in the bath forms a contact line on the substrate, which exerts a capillary-induced peeling force at the edge of the hydrophobic thin film. We highlight that this capillary peeling process is more effective at lower velocities of the air-liquid interface and lower viscosities. Capillary peeling not only removes such thin films from the substrate but also transfers them flawlessly onto the air-water interface.
永久性记号笔墨水和防水化妆品在涂覆于表面时会形成弹性薄膜。这类粘性材料特意设计成具有防水性能。因此，由这些墨水构成的图案具有防潮性，干燥后无法用水清洗掉。然而，我们发现，将附着在基底上的此类弹性薄膜以足够慢的速度浸入纯水中，能够完全去除疏水涂层。浸入时，水槽中的气 - 水界面在基底上形成一条接触线，该接触线在疏水薄膜边缘施加毛细作用引起的剥离力。我们强调，这种毛细剥离过程在气 - 液界面速度较低和粘度较低时更有效。毛细剥离不仅能将此类薄膜从基底上移除，还能将它们完美地转移到气 - 水界面上。
