Wettability control on microstructured polypropylene surfaces by means of O2 plasma

Abstract

Durable and wear resistant polypropylene surfaces with static contact angle (SCA) above 140° have been fabricated using standard photolithographic process and O2 plasma etching followed by thermal annealing at 100 °C. This microfabrication process leads to a hierarchical topography derived from the patterned microstructures and the sub‐micron roughness caused by plasma. Hydrophobicity (SCA up to 145°) remained over 14 months after fabrication. This wetting behavior is attributed to the combination of the periodic array of micro‐sized pillars with low aspect‐ratio and the submicron roughness caused by O2 plasma.