Surface modification of polytetrafluoroethylene with tetraethoxysilane by using remote argon/dinitrogen oxide microwave plasma

The use of remote microwave plasma for the polymerization and deposition of tetraethoxysilane on the surface of polytetrafluoroethylene was investigat ed using a mixture of Argon and dinitrogen oxide as carrier gas. Layers wit h thicknesses of 0.5-3 mu m were obtained, differing in chemical compositio n, surface energy, and flexibility/ brittleness, depending on the plasma po wer and both the treatment and aging times. In general, milder treatments a nd shorter aging times resulted in higher contents of organic structural el ements in the layers and greater flexibility and surface energy. Anchoring between the layers and the bulk polytetrafluoroethylene was at least partia lly caused by fibrils interconnecting the two components. These results wer e obtained by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy in the attenuated total reflection mode, contact angle measure ments, and scanning electron microscopy combined with energy dispersive X-r ay analysis. (C) 2000 John Wiley & Sons, Inc.