Change of chemical bond and wettability of polylacticacid implanted with high-flux carbon ion

Polylacticacid (PLA) was submitted to high-flux carbon ion implantation with energy of 40 keV. It was investigated to the effect of ion fluence (1 × 1012-1 × 1015 ions/cm2) on the properties of the polymer. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), wettability, and roughness were employed to study change of structure and properties of the as-implanted PLA samples. Six carbon bonds, that is, C, CH, COC, CO, OCO, and 〉CO, were observed on surfaces of the as-implanted PLA samples. The intensities of various chemical bonds changed with increasing ion fluence. AFM images displayed that there was irradiation damage and that it was related closely with ion fluence. At fluence as high as 1 × 1015 ions/cm2 surface-restructuring phenomenum took place on the surface of the PLA. Wettability was also affected by the variation on the fluence. With increasing ion fluence, the water contact angle of the as-implanted PLA samples changed gradually reaching a maximum of 76.5° with 1 × 1013 ions/cm2. The experimental results revealed that carbon ion fluence strongly affected surface chemical bond, morphology, wettability, and roughness of the PLA samples.