Photothermal spectroscopies, photopyroelectric spectroscopy and photoacoustic spectroscopy (PAS), were used to study the thermal and optical properties of untreated and N+ ion implanted polyetheretherketone (PEEK) films. The photopyroelectric (PPE) intensity signal and its phase were independently measured as a function of wavelength and chopping frequency in the saturation part of the PPE spectrum. Equations for both the intensity and the phase of the PPE signal were used to fit the experimental results. From these fits we obtained the thermal diffusivity coefficient, the thermal conductivity, and the specific heat of the samples, as well as a value for the condensed phase optical gap. Additionally, using PAS we carried out a quantitative depth profile analysis of the optical properties of the ion implanted PEEK films. Since the thermal diffusion length varies inversely with the square root of chopping modulation frequency, at high chopping frequencies surface information is obtained. At low chopping frequencies information concerning the properties of the bulk is obtained. The overall objectives of this study are to understand and quantify how ion implantation affects the thermal and optical properties of the polymer, particularly within the implant region. We find that significant changes do occur, and our results have implications for the use of ion implantation to create plastic electronic and sensor devices.
展开▼
