Structure of polymers after ion beam treatment

The treatment of polymers by ion beam changes their color. The color changes are observed for all kinds of polymers, but mainly strong changes are observed for polymers with high carbonization ability such as polyethylene and polystyrene. The changes in the modified layer are observed in transmission UV visual spectra. The UV spectra of untreated polymer film shows peaks of light absorbance corresponding to energetic levels of valence electrons in polymer macromolecules. It is essential that the ion beam implantation process must not deform or melt the polyethylene, which means that a non-thermal ion beam implantation regime must be used. The absorbance of UV-visible light of modified polymer depends on the type of polymer, and specifically its degree of carbonization in response to ion beam implantation. The appearance of unsaturated carbon bonds in ion beam implanted polymer in the form of diene structures and condensed aromatic structures occurs in the local field by track of ion penetration. The carbonization of the surface layer is well observed by Raman spectra. A highly degradable polymer under ion beam is polytetrafluorethylene (PTFE). Careful treatment of PTFE before and after implantation results in an absence of any hydrocarbons on the top layer of the PTFE after ion beam treatment. In comparison with plasma treatment without bias, ion beam treatment has a longer period of oxidation kinetics under normal atmospheric conditions. The wettability of the polymer surface after ion beam implantation is a result of free radicals, oxygen containing groups, and carbonization of the polymer surface layer.