Frequency modulated torsional resonance mode atomic force microscopy on polymers
Applied Physics Letters 92(14): 143103
In-plane mechanics of polymers can be probed by integrating frequency modulation and torsional resonance mode atomic force microscopy. We investigated a thin film of polystyrene-block-polybutadiene diblock copolymer. To gain more insight into image contrast formation, we examined displacement curves on polystyrene homopolymer surfaces of different molecular weights focusing on energy dissipation and frequency shift. Data suggest that the transition from a highly motile surface layer to the bulk material depends on the molecular weight of the polymer. This, in turn, indicates that the tip is slightly oscillating within the sample surface during imaging. (C) 2008 American Institute of Physics.