Characterization of a low-wettable surface based on perfluoroalkyl acrylate copolymers

The low-wettable surfaces based on perfluoroalkyl acrylate (FA)/n-alkyl acrylate copolymers with various amounts of FA units were presented to analyze their surface properties. The FA copolymers were prepared by soap-free emulsion polymerization in the presence of sodium 2-acrylamide-2-methyl propanesulfonate (AMPSNa) used as a reactive surfactant. Low-wettability properties resulted from the self-assembly of fluorine-containing side chains, surface density and extent of orientation of perfluoroalkyl (RF) groups. The wetting behavior of the low-wettable surfaces was discussed from a standpoint of dynamic contact angles measurement, which implied an enrichment of perfluoroalkyl groups on the topmost surface. Increased RF surface densities and orientation, measured by attenuated total reflectance spectra of infrared (ATR-IR), X-ray photoelectron spectroscopy (XPS) and scanning force microscopy (SFM), respectively, were consistent with higher angles.