Surface modification for hydrophilic property of stainless steel treated by atmospheric-pressure plasma jet

Surface of a stainless steel has been modified by atmospheric-pressure plasma jet method at room temperature. The impulse voltage is applied to ignite a plasma discharge using high purity (99.999%) reactive gases: N2 and O2. The treated stainless steel is characterized by the activation property of the surface using a contact angle analyzer. Surface energy for the treated stainless steel is increased remarkably when compared to the untreated surface. From the results of X-ray photoelectron spectroscopy and atomic force microscopy, we could confirm that the main functional groups, causing the change in hydrophilic surface were generated under the surface reactions caused by reactive etching and oxidation of ions and activated species in the plasma. In addition, the aging effect during the duration of the hydrophilic property is also studied to investigate the production cost for the industrial applications.