SWELLING OF PLASMA-POLYMERIZED TETRAFLUOROETHYLENE FILMS

Swelling of micrometer thick films of plasma-polymerized tetrafluoroethylene has been measured for a range of solvents using an optical-interferometric technique. For low gas-phase concentrations of the solvent, the swelling is found to correlate with the ionization potential of the solvent. Photothermal deflection spectroscopy of the films shows optical absorption in the infrared, which changes with exposure to different solvents. Both of these results suggest weak electron transfer from the solvent to the polymer as the dominant interaction mechanism.