Surface characterization of polymer modified by He-ion bombardment

Surface modification of polymers by ion bombardment and its characterization have been carried out to investigate the mechanism of cell adhesion interaction to polymers. Two kinds of substrates, polypropylene (PP) and polyethylene (PE), were He-ion bombarded because they were expected to suffer different surface modifications. He-ion bombardment was performed at an energy of 150 keV with fluences between 1 x 10(12) to 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 fluence in the following two stages. The first stage was that ion bombardment destroys the original structure of substrates to form an amorphous carbon-like structure. Secondly, with higher fluence ion bombardment, the original structure of substrates were destroyed completely to create both amorphous carbon and introduce new functional groups. Consequently, He-ion bombardment modified PP and PE surfaces had similar structure, having amorphous carbon and new functional groups. (C) 1998 Elsevier Science B.V.