Poly(ethylene terephthalate) surface and alumina/poly(ethylene terephthalate) interface studied using sum-frequency generation spectroscopy

The surface molecular conformation of poly(ethylene terephthalate) (PET) and the interface between alumina and PET has been investigated by sum-frequency generation (SFG). An increase of the SFG peak intensity is observed after plasma treatment. Density functional theory confirms that the vibrational intensities from the PET surface are related to the surface molecular conformation. By depositing AlOx, an increase of the SFG intensities and the appearance of a new peak at 1685 cm−1 are observed, indicating the formation of a CO⋯Al bond at the interface.