Modelling plasma-induced reactions on polymer surfaces using aliphatic self-assembling and LB layers

Abstract

Oxygen functional groups can be formed at the surface of aliphatic monolayers, 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 than ~25% of all carbon atoms are functionalized. Longer exposure to oxygen plasma results in further increases in functionalization accompanied by cross-linking, degradation and disorientation of molecular chains. Polymer-specific degradation was exemplified by the cracking and splitting up of aromatic rings as seen in the NEXAFS spectra and by random cracking or depolymerization of macromolecular chains evidenced by an occurrence of new fragment peaks and by shifts in the molecular weight distribution as detected by MALDI mass spectrometry.