Surface morphologies in polymers by irradiation with argon ions and consecutive swelling

Persistent surface morphologies in extruded polymer substrates can be generated in a first step by projecting a mask with argon ions and, secondly, by a consecutive exposure to solvent. In the first step, the polymer is locally cross-linked as a consequence of the interaction of the Ar-ions with –C–H-groups. During the second step, protrusions occur owing to swelling, which persist after removal of the solvent. The morphology of the protrusions can be tuned by choosing the right set of the experimental parameters, i.e. the ion dose, the size and distance of the holes in the mask, and their height by the duration of swelling.