Enhancing surface energy of polycarbonate by atmospheric pressure plasma jet

A plasma jet system with floating electrode configuration was setup to treat polycarbonate (PC) surface. Enhancement in energy surface and the duration of the effect by plasma treatment were characterized by water contact angles (WCA) of water droplets on the PC surface. Morphological changes of the surface were examined by AFM. The results show that after 60 seconds of treatment by plasma, the WCA decreased from 74° to 38° and the PC surface was not physically damaged. The average change of WCA by plasma treatment is 40% and remained at 20% after 14 days with a treatment time greater than 180 seconds.