One-step fabrication of robust and optically transparent slippery coatings

Abstract

The fabrication of lubricants-infused textured surfaces has opened up a new route towards omniphobicity. However, achieving a homogeneous thin film of lubricating material on a flat/smooth surface still remains a challenge. This work shows the successful fabrication of a thin, transparent, and homogeneous coating of perfluoropolyether (PFPE, a lubricating material) on a smooth glass surface by the electrospraying technique. The sol–gel solution for electrospraying was prepared by adding a small amount of (tridecafluoro-1,1,2,2-tetrahydrooctyl)-1-trichlorosilane (FTS) with PFPE which was subsequently electrosprayed on a glass substrate. After curing the coated samples at 80 °C, a transparent, homogeneous, and slippery coating with a low surface energy (12.5 mN m⁻¹) was obtained. It was observed that the presence of FTS with PFPE, assisted significantly in the stacking of PFPE on the substrate resulting in the formation of smooth, uniform blended (PFPE + FTS) films. The surface nature of the blended films was characterized by spectroscopy and microscopy. The blended surface exhibited omniphobic properties. The surface contact angles and slipping angles made by water and acetone droplets were measured to be (116°, 40.8°) and (6°, 10°), respectively. Furthermore, the coating showed good optical (transmittance – 91%) and mechanical properties with strong adherence to glass surfaces, thus revealing the potential for applications in windows and solar modules.