Poly (tetrafluoroethylene) (PTFE), ethylene vinyl alcohol (EVOH) and these composite thin films were deposited by a conventional vacuum evaporation apparatus and characterized by a scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). The deposition rates of these thin films increased dramatically with increase of the evaporation temperature. They decreased slightly with increase of pressures during the evaporation. Stripped patterns and micrometer size particles could be seen on the surfaces of these thin films deposited at room temperature. In stead, fibril structures could be seen on the surfaces of those thin films deposited at 250°C. Although elemental compositions of these thin films deposited at 250°C were almost the same as those deposited at room temperature, the amount of -CF
3 moiety in the PTFE thin film deposited at 250°C decreased compared to that deposited at room temperature. Pull strength between these thin films and stainless steel (SUS) substrate was evaluated. The pull strength of EVOH thin film was highest and that of PTFE thin film was lowest of the three. The pull strength decreased with decrease of the surface free energies of these thin films and it was in proportion to the PTFE and EVOH mixing ratio.
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