Determination of the Bonding State of the Modified Surface of Polyetheretherketone by the Principal Component Analysis of X-Ray Photoelectron C 1s Spectra

Principal component analysis in a dual formulation is proposed to interpret changes in the C 1s X‑ray photoelectron spectra, arising from modification of the surface of polyetheretherketone. The distribution of the spectral intensities considered together with the spectra on dual graphs is used to construct a model of the peak structure of the C 1s spectra for their subsequent decomposition into components. It is shown that after treatment of the surface of polyetheretherketone with accelerated ion and neutral beams of argon-atom clusters, 288.3- and 285.5-eV peaks appear in the C 1s spectra, which characterize the presence of carboxyl functional groups and aliphatic carbon atoms in the modified surface layer.