Interactions of polyelectrolytes with the lyotropic liquid crystalline system hexadecyltrimethylammonium bromide/decanol/water

The influence of oppositely charged polyelectrolytes on the interlayer spacing of the lamellar liquid crystalline system hexadecyltrimethylammonium bromide/decanol/water was investigated by means of small angle X-ray diffraction and polarized microscopy. It could be demonstrated that a liquid crystalline phase was still formed by introducing a cationic polymer of low molecular weight into the lamellar structure. A disordering of the preformed structure and a decrease of the interlayer spacing occurred via penetration of the macromolecule between the hydrocarbon chains of the surfactant molecules. By using a ''penetration'' model for the disordering phenomena, ''folded'' and ''telescoped'' structures are discussed. The polyanion in a polyanion/polycation mixture gave the same structural change as when added alone.