Increase in the surface energy of metal and polymeric surfaces using the one atmosphere uniform glow discharge plasma (OAUGDP).

Plasma processed materials are used in our daily lives. Increasing the surface energy of metal and polymeric materials can make possible better coating, printing, bonding, and dyeing of their surfaces. With the patented technology of a One Atmosphere Uniform Glow Discharge Plasma (OAUGDP) reactor developed at the UTK Plasma Sciences Laboratory, one can obtain up to 70 dynes/cm, or erg/cm², in a few seconds of exposure for most materials. The surface energy is measured with a series of mixtures of reagent-grade formamide (HCONH) and reagent-grade ethyl cellosolve (CH CH O-CH OH), which span the range from 30 dynes/cm to 70 dynes/cm. Several polymeric films, including samples made from linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and polyethylene terephathalate (PET) films, as well as metalized paper have been exposed at an RF frequency of 5 kHz and at 6 kV(RMS) for various exposure durations, including 1, 2, 5, 10, 15, 30 and 60 seconds. These samples were exposed in open air to check the aging effect at various times after exposure. The behavior of surface energy with time after exposure shows a wide range of behavior, depending on the specific material under test. Photomicrographs of the surfaces were taken after selected exposure durations, and the morphological characteristics of the surface compared to the surface energy measurements.