Deposition of silicon oxide onto polyethylene and polyethyleneterephthalate: An x-ray photoelectron spectroscopy interfacial study

Abstract

X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy were used to study the physico–chemical interaction between evaporated silicon oxide and polymers. SiO1.5 was shown to deposit as clusters onto polyethylene, not covering the whole surface of the substrate. Argon, oxygen, and nitrogen plasma treatments were tested to improve the reactivity of polyethylene, but only nitrogen was found to be reactive enough to allow for a uniform layer of silicon oxide, as on polyethyleneterephthalate. The high resolution XPS study of the interface between nitrogen plasma treated polyethylene and in situ deposited silicon oxide showed the formation of silicon–oxygen–carbon or silicon–nitrogen–carbon bonds while silicon–carbon bonds were only observed with polyethyleneterephthalate.