2D structure of unsaturated fatty acid amide mono- and multilayer on graphite:: Self-assembly and thermal behavior

We investigate the self-assembly of oleamide (9-octadecenamide) on graphite by atomic force microscopy (AFM). The molecules, spin-coated from a dilute solution, form a lamellar monolayer due to epitaxial adsorption on the surface. In the monolayer, a small tilt angle boundary is observed indicating a degeneracy in the molecular positioning. The molecular domains preserve their epitaxy to the substrate as the film thickness increases from monolayer to multilayer. Thermal annealing causes changes in the film morphology. Heating the multilayer up to 75 degrees C results in the formation of large rods, and above 90 degrees C, large, highly ordered, smooth islands are observed.