Monolayer Chemical Lithography and Characterization of Fluoropolymer Films

A means for surface chemical modification with micron level lithographic patterning on fluoropolymers is described. The two-step process involves a novel glow discharge plasma modification. This process allows high densities of reactive linking functionalities to be synthesized at the surface of fluoropolymers without degradation of the morphology. This modification is accomplished with lithographic patterns on poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP). Further functionalization is then accomplished via reactions with (aminopropyl)triethoxysilane (APTES) which results in controlled monolayer coverages of poly[(aminopropyl)siloxane] (APS). Imaging time of flight static secondary ion mass spectrometry provides maps of the resulting surfaces. The resulting surface promotes mouse neuroblastoma cell attachment and in some cases neurite outgrowth only at surface chemically modified regions. The bulk optical properties of the fluoropolymer are preserved.