| Abstract: | The present study was conducted in order to confirm C―H insertion of a perfluorophenyl nitrene, produced by UV‐irradiation of a perfluorophenyl azide, to polyethylene surfaces. It was shown previously that water‐repelling, oil‐repelling, and dirt‐repelling polyethylene surfaces can be created by “grafting to” of perfluoroalkanes using a photoreactive surface modifier based on azide/nitrene chemistry. The abrasion resistance of the new surfaces was enhanced compared with a coating using a simple, long‐chain perfluoroalkane. However, covalent binding of the surface modifier was not unequivocally demonstrated. Here, spectroscopic information is presented suggesting that, indeed, a monomolecular, covalently bound grafted layer is formed from the photodecomposition of a perfluorophenyl azide on polyethylene surfaces. Infrared spectroscopy showed that the peak from the azide moiety disappeared upon UV‐irradiation, and the light dose for completion of the photo decomposition was determined to be approximately 322 mJ/cm2. A model compound mimicking the grafted nitrene species was synthesized, having a λmax of 281 nm in hexane. The photografted and washed layer had a λmax of 286 nm, indicating a good conformity with the model compound. X‐ray photoelectron spectroscopy of the nitrogen species from the photografted layer showed a peak at 400.0 eV. The model compound had a N 1s binding energy of 399.7 eV, thus being comparable. |
