Effects of Roughness and Chemical Composition of an Ar Ion-Implanted Fluorine-Polymer on Water Repellency

Ion implantation was used to improve the hydrophobicity of a fluorine-polymer (PTFE). The Ar-implanted PTFE is covered with uniform needle-like protuberances that have sharp peaks, separated by a few micrometers. A CF3 structure, which has a very low surface energy, was observed on an ion-implanted surface via X-ray photoelectron spectroscopy (XPS) analysis. The effects of a modification parameter, an accelerated voltage, and a beam current on the roughness, morphology, and structure of the treated surface were analyzed. The resulting optimally-modified surface is strongly hydrophobic. The contact angle with water increased from an initial 103 to 170 degrees. Spectral analysis of the roughness of the modified surface shows that the contact angle with water depends on the spacing and uniformity of the protuberances.