Characterization of carbon nanolayers flash evaporated on PET and PTFE

Carbon nanolayers were prepared by flash evaporation of carbon filaments onto polyethyleneterephthalate and polytetrafluoroethylene substrates. The chemical composition of the deposited layers was determined using Raman, XPS, RBS and ERDA. Also the concentration of free radicals in the deposited layer was determined by EPR method. The thickness of the deposited carbon layer as a function of the deposition distance was determined by a scratch technique and AFM. Surface morphology of the samples was examined by AFM and nanointendation was used to determine microhardness and elasticity modulus and to perform scratch tests. The thickness of the deposited carbon layer decreases with increasing distance between the substrate and the filament. In addition to the dominant amorphous carbon fraction (a-C), various oxidized structures and hydrogen admixture in the deposited material were observed. The deposition of carbon leads to a significant decline of surface electrical resistance in comparison with pristine polymer, the change being a function of the deposition distance. The deposited carbon layer has semicrystalline character and it exhibits higher microhardness and elastic modulus than pristine polymer. (C) 2009 Elsevier Ltd. All rights reserved.