Highly stable fluorine-free slippery liquid infused surfaces

Abstract

A promising Slippery Liquid Infused Surface (SLIS) has been developed, that is both easy-to-produce and environmentally friendly. Using a double replication method, a 200 µm-thick texturized cross-linked PDMS film was obtained, leading to a grid of micrometric hills and deep wells. A comparison between perfluoropolyether (PFPE) lubricant and silicone oil of different viscosities highlights the advantage of silicone oil, which penetrates the cross-linked PDMS matrix even at high viscosity. Chemical modification with OTS (octadecyltrichlorosilane) and introduction of secondary structures through plasma etching, increased the surface's shear resistance. As a result, stable sliding properties were maintained after hundreds of cycles of immersion in water and, more originally still after tests under wind blowing exposure up to 78 m/s. Furthermore, addition of water sprayed during wind blowing exposure allows partial fouling release of the surface.