Deposition of hydrophobic nano-coatings with low-pressure radio frequency CH 2F 2/Ar plasma processing

Abstract

In an attempt to perform hydrophobic nano-coating, this investigation examined various operational parameters including in RF plasma power, system gas pressure, and CH 2F 2:Ar ratio of low-pressure plasma processing. The low-pressure plasma, generated with radio frequency power at 13.56 MHz, was fed difluoromethane (CH 2F 2)/Ar gas mixture. The surface characteristics of the plasma polymerized films were studied by static contact angle measurement (CA) and atomic force microscopy (AFM). As a result, increasing deposition of CH 2F 2 plasma polymerized films was achieved in enhanced RF plasma power input. The CH 2F 2 plasma polymerized films also were conducted in a varying system gas pressure with enhanced hydrophobic surface property. The effects of CH 2F 2/Ar plasma on the surface characteristics of the plasma polymerized films were investigated as a function of the Ar content. The super hydrophobic coating under optimized operational parameters prepared in this study obtained water contact angles greater than 150°. It was found that the maximum water contact angles (161°) was obtained at 1.5:1 (CH 2F 2: Ar) ratio. In addition, AFM analysis shows that possible ion bombardment from CH 2F 2/Ar plasma can increase surface roughness, and effectively form a hydrophobic coating on the surface of heat sensitive materials.