Surface morphology and crystallinity of biaxially stretched PET films on the nanoscale

The surface morphology and crystallinity of biaxially drawn (BD) and amorph ous poly(ethylene terephthalate) (PET) films were investigated by means of scanning probe microscopy. The PET surface is best imaged using non-contact mode atomic force microscopy (NC-AFM). Contact mode (C-AFM) under water ca n also offer a good resolution but the PET surface is not stable for long p eriods under such conditions. The ED film texture appears to be made up of "hillocks" of about 20 nm in d iameter, while amorphous PET films appear featureless. It seems plausible t o suggest that the observed hillocks represent small crystallites formed du ring the production process of BD films. (C) 2000 Elsevier Science Ltd. All rights reserved.