AFM SURFACE INVESTIGATION OF POLYETHYLENE MODIFIED BY ION-BOMBARDMENT

Polyethylene (PE) was irradiated with 63 keV Ar+ and 155 keV Xe+ ions to fluences of 1 x 10(13) to 3 x 10(15) cm(-2) with ion energies being chosen in order to achieve approximately the same penetration depth f or both species. The PE surface morphology was examined by means of at omic force microscopy (AFM), whereas the concentration of free radical s and conjugated double bonds, both created by the ion irradiation, we re determined using electron paramagnetic resonance (EPR) and UV-VIS s pectroscopy, respectively. As expected, the degradation of PE was high er after irradiation with heavier Xe+ ions but the changes in the PE s urface morphology were more pronounced for Ar+ ions. This newly observ ed effect can be explained by stronger compaction of the PE surface la yer in the case of the Xe+ irradiation, connected with a reduction of free volume available. (C) 1998 Elsevier Science B.V. All rights reser ved.