Durable and hydrophobic surface modification by plasma polymers deposited from acetylene/hexafluoroacetone ethylene/hexafluoroacetone, and ethane/hexafluoroacetone mixtures

Plasma polymerization of mixtures of ethane/hexafluoroacetone (HFA), ethylene/HFA, and acetylene/HFA deposit hydrophobic and thin films. The IR and XPS measurements of the deposited films show that fluorination with HFA occur to yield hydrophobic plasma films which possess CF 3 , CF 2 , and CF moieties. The advancing contact angle of water on the surface of the deposited films increases with increasing the HFA concentration, especially plasma polymer films prepared from the acetylene/HFA mixture (87.5 mol % HFA) show an advancing contact angle of 126 degrees. Such high hydrophobicity of the plasma polymer surface is attributed to high concentration of fluorinated carbons, especially CF 3 side groups. The CF 3 concentration in the plasma polymers reach about 30 mol % of the total carbon units. These surfaces show no change in advancing contact angle even when stored in a moist atmosphere of 60% RH at 20°C for at least 2 weeks.