Interstratified layer structure of the organo-montmorillonites as revealed by electron microscopy

Layer structures of octadecylammonium-montmorillonite and trimethyloctadecylammonium:steramide-montmorillonite were studied by electron microscopy. Curled shapes of some lamella flakes of the organo-montmorillonites were found. Lattice images of the layers observed at the curled edges of the flake showed regular and irregular layer expansions caused by the interlayer adsorption of the organic compounds. Some of the results exhibited local variation of the layer expansion even within one particular layer. The local variation probably originated from the intrinsic nature of the montmorillonite layer. The arrangements of the alkyl chains of the adsorbed organic compounds between the layers of montmorillonite were interpreted on the basis of interlayer distances obtained from the lattice images of the layers.