SURFACE CHARACTERIZATION OF POLYMER-MODIFIED BY HE-ION BOMBARDMENT

Surface modification of polymers by ion bombardment and its characteri zation have been carried out to investigate the mechanism of cell adhe sion interaction to polymers. Two kinds of substrates, polypropylene ( PP) and polyethylene (PE), were He-ion bombarded because they were exp ected to suffer different surface modifications. He-ion bombardment wa s performed at an energy of 150 keV with fluences between 1 x 10(12) t o 1 x 10(15) ions/cm(2). The surface chemical states were evaluated by X-ray photoelectron spectroscopy (XPS). The FWHM of C is XPS spectra of He bombarded specimens increased according to the increase of the f luence in the following two stages. The first stage was that ion bomba rdment destroys the original structure of substrates to form an amorph ous carbon-like structure. Secondly, with higher fluence ion bombardme nt, the original structure of substrates were destroyed completely to create both amorphous carbon and introduce new functional groups. Cons equently, He-ion bombardment modified PP and PE surfaces had similar s tructure, having amorphous carbon and new functional groups. (C) 1998 Elsevier Science B.V.