Hydrophobicity and micro-/nanotribological properties of polymeric nanolines

Abstract

This paper presents an investigation of the effects of a topographical modification, namely, nanolines, on the hydrophobicity and micro-/nanotribological properties of poly(methyl methacrylate) surfaces. The polymeric line patterns were fabricated on the poly(methyl methacrylate) films by using the capillary force lithography technique. Examinations of the water contact angle revealed that the line patterns exhibited increased hydrophobicity compared to the flat film, along with an anisotropic wetting. It was observed that the presence of the nanolines greatly reduced the adhesion and micro-/nanofriction. Furthermore, the friction behaviour varied depending upon the sliding direction as the counter bodies slid over the line structure. It was also observed that the shape of the top of the nanolines noticeably influenced nanoscale adhesion and friction. Both the flat film and the nanolines were damaged in the microscale tests; however, the nanolines exhibited less damage than the film, presumably due to their enhanced adhesion and friction properties.