Improvement of Hydrophilicity of Polymer Surface by Surface-Wave Excited Ar Plasma with Acetic Acid

Plasma surface treatment has many advantages over other wet techniques. In this work, we focused on surface modification by introducing -COOH groups onto the polymer surface by means of surface-wave plasma. To introduce -COOH groups onto the surface, we added a small amount of acetic acid (CH3COOH) vapor to the argon plasma. The water contact angle on the polycarbonate surface decreased from 70 degrees to 0 degrees after plasma treatment. Atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS) measurements revealed that the surface roughness increased and oxygen molecules were introduced. These results suggest that functional groups on the polymer surface were replaced by highly hydrophilic groups as a result of Ar + CH3COOH plasma treatment. (C) 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(4): 1-6, 2011; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21137