MODELING PLASMA-INDUCED REACTIONS ON POLYMER SURFACES USING ALIPHATICSELF-ASSEMBLING AND LB LAYERS

Oxygen functional groups can be formed at the surface of aliphatic mon olayers, oligomers and polymers by short-time oxygen low-pressure glow discharge plasma treatment without degradation of chains and building blocks. The molecular orientation is nearly preserved if not more tha n similar to 25% of all carbon atoms are functionalized. Longer exposu re to oxygen plasma results in further increases in functionalization accompanied by cross-linking, degradation and disorientation of molecu lar chains. Polymer-specific degradation was exemplified by the cracki ng and splitting up of aromatic rings as seen in the NEXAFS spectra an d by random cracking or depolymerization of macromolecular chains evid enced by an occurrence of new fragment peaks and by shifts in the mole cular weight distribution as detected by MALDI mass spectrometry. (C) 1998 Elsevier Science S.A.