Wet ability of PTFE coated diamond films

The wet ability of micro and nanocrystalline diamond films (MCD and NCD) coated with PTFE was investigated. The diamond films were grown by microwave plasma CVD with and without nitrogen addition. Both surfaces of the diamond films were evaluated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). Apparent, advancing and receding water contact angles (WCA) were measured before and after the PTFE coating. The roughness of the microcrystalline diamond films together with the nanostructured PTFE coating resulted in super hydrophobic surfaces with water contact angle of 165° ± 2° and very low hysteresis (4°). For nanocrystalline diamond films, the contact angle was also very high (149° ± 2°) but the hysteresis remained above 90°.