Surface Modification of Biodegradable Poly(D,L-lactic acid) by Nitrogen and Nitrogen/Hydrogen Plasma for Improving Surface Hydrophilicity

Enhancement of the surface hydrophilicity of biodegradable poly (D,L-lactic acid) (PLA) films is studied. The PLA films were treated by nitrogen plasma (PLA-N(2)) and nitrogen/hydrogen plasma (PLA-N(2)/H(2)), respectively. The surface properties and microstructure of PLA-N(2) and PLA-N(2)/H(2) were studied by static contact angle measurement, surface free energy calculation, X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). It is confirmed that the surface hydrophilicity of PLA-N(2) and PLA-N(2)/H(2) was higher than that of pristine PLA, and the surface hydrophilicity of PLA-N(2) films was better than that of PLA-N(2)/H(2).