PDMS-brush modified dual-phase lubricant-infused slippery oleogel for sustainable shear resistance

Abstract

The strong potential of oleogel surfaces in marine environments is to reduce frictional drag. Conventional slippery surfaces, while resistant to water pollutants, face challenges in retaining infused lubricants under intense marine shear flows, rendering them vulnerable to fouling by marine foulants. Further, there is a critical need to develop a simple, rapid, and environmentally benign process for fabricating durable oleogel surfaces. In this study, we proposed a covalently cross-linked dual-phase (solid/liquid) lubricant-infused slippery oleogel for the first time to achieve excellent shear stable lubrication performance by rapid one-step grafting of poly(dimethylsiloxane) (PDMS) brushes (solid lubricant) on erucamide-crosslinked PDMS composite surface followed by infusion of liquid-lubricant. Covalent attachment of liquid-like slippery PDMS brushes on the dual-phase slippery oleogel (denoted as EPC-PB oleogel) further enhanced lubricant retention ability, resulting in longevity of lubrication property even after exposure to various physical abrasions, chemically-contaminated solutions, and high/low temperatures. The chemically modified oleogel exhibited droplet-sliding behavior, coupled with sustained high lubrication in marine environments, without any fouling adhesion for over 2 months during the summer season. Given its exceptional slippery performance and ease of manufacture, the proposed coating has immense potential to address the issue of lubricant depletion in high-speed marine flow scenarios.