Analysis of the Compositions on PET Surface Layer Modified by Fluorocarbon Plasmas with Angle-dependent XPS Technique

Abstract

The surface of PET was modified by fluorocarbon plasmas. Angle-dependent XPS technique was employed to study the surface structure and compositions of the modified layer on PET surface. It was found that the homogeneous, cross-linking modified layer on PET surface can be formed by CH4/CF4 plasmas, and their composition change a bit with the increase of the sampling depth of XPS. However, for pure CF4 plasma, the modified layer is heterogeneous, and the amount of the fluorine-containing groups on the outmost modified layers is more than that in the inner layer. The structures of the modified layer on the modified PET surface depend on the molar amount of CH4. The relationship between the compositions of the modified layers and the sampling depth will be discussed in details in this paper.