ARTICLES HAVING SUPERHYDROPHOBIC AND OLEOPHOBIC SURFACES

摘要

A thermoplastic article has a surface with a multiplicity of re-entrant structures extending from the article's surface where a con formal coating comprising a perfluoroalkane covers at least the distal portion of the re-entrant structures to render the article superhydrophobic and oleophobic. A method to prepare the article having a superhydrophobic and oleophobic surface comprises contacting a heated thermoplastic and a mold with voids having at least one dimension of 100 nm to 10 µ?? with a sufficient pressure to cause the thermoplastic to extend into the voids to form features that upon removal of the mold from the thermoplastic article results in re-entrant structures having at least one dimension of 100 nm to 5 µ??. The surface having the re-entrant structures is conformally coated with a compound comprising a perfluoroalkane. Another method to prepare the article having a superhydrophobic and oleophobic surface comprises deposition of microparticlcs or nanoparticles and a resin on a surface of a substrate and curing the resin such that the microparticles or nanoparticles are adhered or mechanically fixed to the substrate with a portion of the microparticles or nanoparticles extending from the surface to form re-entrant structures. The microparticlcs or nanoparticles can comprise a perfluoroalkane or can be conformally coated with a compound comprising a perfluoroalkane, to render the surface superhydrophobic and oleophobic.