| Abstract
| - The surface of isotactic polypropylene (iPP) filmsmodified by oxyfluorination was studiedby a combination of complementary techniques to elucidate the effect ofthe modification on the chemicalcomposition, surface energy, and morphology. The elementalcomposition was measured by X-rayphotoelectron spectroscopy (XPS), and the surface free energy wascharacterized by contact anglemeasurements with different liquids. Following the approach byGood and co-workers, the acid−basecharacteristics of the modified polymer surfaces were estimated.Subsequently, the modified iPP filmswere investigated by scanning force microscopy (SFM). In tappingmode SFM, the sample topographywas imaged and the surface roughness was quantitatively determined.Gold-covered SFM probes modifiedwith carboxylic acid and methyl terminated self-assembled monolayers ofthiols were used to determinethe pull-off force distributions in ethanol. The interaction ofthe treated polymer film surfaces withchemically functionalized SFM tips was shown to correlate with thesurface tensions obtained by contactangle measurements. In particular, pull-off forces measured withcarboxylic acid functionalized tips inethanol depended approximately linearly on the basic part of thesurface free energy of the polymer filmsurface.
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