Surface Treatment of Hydrophobic Polymers by Atmospheric-Pressure Plasma

Surfaces of hydrophobic polymers were treated by atmospheric pressure plasma. The plasma system used was a newly developed damage-free dielectric barrier glow discharge. Ar was mainly used as a carrier gas. The treated polymer surfaces were mainly analyzed with contact angle measurement and X-ray photoelectron spectroscopy (XPS). In the treatment of high-density polyethylene (HDPE), atmospheric Ar plasma was found to alter the surface very hydrophilic, which is comparable to low-pressure O-2 plasma. The addition of O-2 in the plasma gas hardly improved the hydrophilicity. In the treatment of polytetrafluoroethylene (PTFE), atmospheric H-2 (0.1%) plasma showed the greatest hydrophilicity but it was not as good as the treatment by low-pressure H-2 plasma.