Spontaneous Assembly in Organic Thin Films Spread on Aqueous Subphase: A Scanning Force Microscope (SFM) Study

Structure, morphology, and mechanical properties of mono‐ and several‐layer structures of amphiphiles or pure n‐alkane crystallites generated by spontaneous self‐assembly on aqueous subphase have been analyzed by scanning force microscopy (SFM). Pure‐component and heterogeneous mixtures of molecules were allowed to spread and self‐assemble without compression on an aqueous subphase. The self‐assembled films were transferred to an atomically smooth mica substrate by drainage for measurement using SFM. Results were compared with a variety of techniques including cryo‐transmission electron microscopy, grazing incidence X‐ray diffraction, X‐ray reflectivity, and reflectance/absorption infrared spectroscopy. Whereas the collaborative techniques provide spatially‐averaged information, we find that the SFM accesses both individual crystallites and amorphous material, thus providing unique information on the morphology, number of layers, and complementary structural features.