Metal-vapor deposition modulation on polymer surfaces prepared by the coffee-ring effect

We report a novel function of a polymer coffee-ring surface called metal-vapor deposition modulation where metal-vapor atoms are deposited on the center of the polymer coffee-ring surface using vacuum evaporation but not on the ring-shaped areas at the edge. The essential factor of the metal-deposition modulation is the difference of polymer chain mobility between the center and the ring. In the ring, the solvent evaporation process produces large spaces among surface polymer chains, resulting in high mobility of polymer chains. The desorption of metal vapor atoms from the surface was caused by the high mobility of the polymer chains. This result not only provides new knowledge about the fundamentals of a polymer surface but also suggests a novel technology for engineering and industrial fields using metallic coating technology on polymer surfaces.