Electron Microscopy of Lyotropic Mesomorphic Phases

Electron, microscopy can provide direct visual confirmation of mesomorphic phase structure in surface-active agent + water systems. Several different specimen preparative techniques have been used to examine the structures of the two most commonly occurring mesomorphic phases in such systems, neat phase and middle phase. Surface replicas of both anhydrous and quench-frozen specimens have clearly illustrated the domain structures which give rise to the characteristic optical textures of these two mesomorphic phases. In several systems osmium tetroxide fixation followed by thin sectioning has permitted the examination of neat and middle phase structures in cross-section. Polymerisation of a suitable compound in the mesomorphic state has provided non-labile structures for examination in the electron microscope as thin sections, using either pre-or post-staining with heavy metal reagents.