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 generate d by spontaneous self-assembly on aqueous subphase have been analyzed by scanning force microscopy (SFM). Pure-component and heterogeneous m ixtures of molecules were allowed to spread and self-assemble without compression on an aqueous subphase. The self-assembled films were tran sferred to an atomically smooth mica substrate by drainage for measure ment using SFM. Results were compared with a variety of techniques inc luding cryo-transmission electron microscopy, grazing incidence X-ray diffraction, X-ray reflectivity, and reflectance/absorption infrared s pectroscopy. Whereas the collaborative techniques provide spatially-av eraged information, we find that the SFM accesses both individual crys tallites and amorphous material, thus providing unique information on the morphology, number of layers, and complementary structural feature s.