Characterization of PEEK, PET and PI implanted with Mn ions and sub-sequently annealed

Abstract

Polyimide (PI), polyetheretherketone (PEEK) and polyethylene terephthalate (PET) foils were implanted with 80keV Mn+ ions at room temperature at fluencies of 1.0×1015–1.0×1016cm−2. Mn depth profiles determined by RBS were compared to SRIM 2012 and TRIDYN simulations. The processes taking place in implanted polymers under the annealing procedure were followed. The measured projected ranges RP differ slightly from the SRIM and TRIDYN simulation and the depth profiles are significantly broader (up to 2.4 times) than those simulated by SRIM, while TRIDYN simulations were in a reasonable agreement up to the fluence 0.5×1016 in PEEK. Oxygen and hydrogen escape from the implanted layer was examined using RBS and ERDA techniques. PET, PEEK and PI polymers exhibit oxygen depletion up to about 40% of its content in virgin polymers. The compositional changes induced by implantation to particular ion fluence are similar for all polymers examined. After annealing no significant changes of Mn depth distribution was observed even the further oxygen and hydrogen desorption from modified layers appeared. The surface morphology of implanted polymers was characterized using AFM. The most significant change in the surface roughness was observed on PEEK. Implanted Mn atoms tend to dissipate in the polymer matrix, but the Mn nanoparticles are too small to be observed on TEM micrographs. The electrical, optical and structural properties of the implanted and sub-sequently annealed polymers were investigated by sheet resistance measurement and UV–Vis spectroscopy. With increasing ion fluence, the sheet resistance decreases and UV–Vis absorbance increases simultaneously with the decline of optical band gap Eg. The most pronounced change in the resistance was found on PEEK. XPS spectroscopy shows that Mn appears as a mixture of Mn oxides. Mn metal component is not present. All results were discussed in comparison with implantation experiment using the various ion species (Ni, Co) and energies used in our former experiments. Interesting differences were found in Mn concentration distribution, Mn nano-particle creation and structural changes comparing to Ni, Co ions implantation into the same polymers.