A Biocompatible Slippery Surface Based on a Boehmite Nanostructure with Omniphobicity for Hot Liquids and Boiling Stability

Omniphobic surfaces have attracted much attention and have a lot of applications in various fields. In particular, the application of omniphobicity to containers of prepackaged foods such as curry is extremely important for reducing food waste because they are especially liable to remain in the container owing to their high viscosity. To realize such application, the surface must be biocompatible to prevent health damage to the human body. However, few omniphobic surfaces with biocompatibility have been developed. Here, we present a silicone oil-immobilized biocompatible slippery surface with omniphobicity. A biocompatible base layer to immobilize the silicone oil as a lubricant was fabricated by combining a boehmite nanostructure and silicone oil grafting through thermal treatment. The slippery surface demonstrated omniphobicity not only for room-temperature liquids but also for high-temperature liquids including hot liquid foods. In addition, the surface exhibited long-term stability against boiling in hot water. Moreover, the surface could be fabricated within an hour. We believe that because of its excellent biocompatibility and omniphobicity, this surface will be applied to not only food containers but also various other applications.