50 x 50 µm² AFM images of a polydiacetylene (PDA) monolayer, formed using a Langmuir trough and transferred to a mica substrate. The blue scale bar represents 5 µm. (a) Topography. (b) Friction. The topography is flat to within 2-3 Å, with the exception of some material piled up at a fraction of the domain boundaries. The friction image reveals a rich array of domains. Friction within each domain depends on the orientation of the PDA backbone with respect to the scanning direction (which is horizontal for these images). The white arrows indicate the domain orientation, determined from higher resolution images where the backbone direction is revealed by the appearance of parallel striations. Friction varies as much as a factor of 3, where high friction occurs when the tip scans perpendicular to the PDA backbone.

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Maintained by A.R.Burns. Last updated 06/28/01.