OPTIMIZATION OF EXPERIMENT IN SCANNING FORCE MICROSCOPY OF POLYMERS

A scanning force microscopy (SFM) study of an oriented polyethylene (P E) tape and a microporous isotactic polypropylene (iPP) film was condu cted in the contact and tapping mode. In sub-water measurements on pol ymer surfaces with minimal tip-sample interactions, the images obtaine d in both modes correctly reproduce surface morphology and nanostructu re. An advantage of the tapping mode in non-destructive imaging was sh own in the observation of a weakly bound skin layer on the PE tape. Th is layer is destroyed during scanning with higher forces; however, its removal allows one to examine the core nanostructure of this material . Ambient-condition SFM measurements in both modes are accompanied by stronger tip-sample interactions. This leads to an overestimation of t he dimensions of surface features and to a larger contribution of surf ace hardness to the image contrast.