Polyelectrolyte complex formation in lamellar liquid crystalline systems

The influence of polyelectrolytes on structure formation in liquid crystalline Na-dodecylsulfate/decanol/water systems was investigated by means of small angle X-ray diffraction, theology, NMR spectroscopy, and microscopy. By adding Na-polyacrylate (PPA) into the mesophase, the one-phase region is left and phenomena of phase separation into a solvent-rich and a polymer/surfactant-rich phase occurs. By incorporating an anionic and cationic polyelectrolyte step by step the tendency of phase separation is increased drastically. The self-organization process can be regulated directly by varying the water content of the system. However, at a water content of 30% the properties of the resulting liquid crystal were changed drastically. X-ray diffraction shows a multitude of Bragg peaks, NMR shows a peak-splitting, and theology shows a change from non-Newtonian to Newtonian-flow behavior. On the basis of the experimental results an ordered multilayer associate structure can be assumed. (C) 1997 Academic Press