Topological and chemical investigation on super-hydrophobicity of PTFE surface caused by ion irradiation

Super-hydrophobic PTFE surfaces were obtained by irradiation of 200 keV Xe+ ion with the fluence of 6.2×1013 ions/cm2. The contact angle of water on such surface is as large as 161±3°. SEM and XPS were used to investigate how the topological and chemical changes affect the wettability of the irradiated surface. Needle like structures at nanometer scale caused by irradiation are considered to be the reason of the super-hydrophobicity. The formation of oxygen containing group and defluorination effect on the treated surface are inferred to have negative contribution to the hydrophobic optimization of PTFE surface.