Plasma treatments of Polyethylene in modulated NH3 r.f. discharges.

Plasma treatments in power-modulated NH3 RF glow discharges have been performed as a new tool for the preferential grafting of -NH2 groups onto polyrthylene (PE) surface respect to all other N-containing functionalities. Time Resolved Optical Emission Spectroscopy (TR-OES) has been used for monitoring the emission of active species during the modulation period of the discharge. The surface composition of PE samples before and after the derivatization technique of plasma-grafted -NH2 groups has been evaluated by means of Electron Spectroscopy for Chemical Analysis (ESCA). Our work shows that modulated NH3 plasma can effectively improve the grafting selectivity of -NH2 respect to all other N-containing groups.