Inflence of diffusion and dipping time on the inner structure of polyelectrolyte multilayers

Neutron Reflctometry was used to investigate the inflence of two fundamental preparation parameters time and salt concentration on the internal structure and swelling behavior of strong Polyelectrolyte Multilayers PEM exposed to water. A two block structure of a deuterated and a protonated stack of PEM was built to reveal variations in the inner structure of PEM with respect to its vertical position relative to the solid substrate. Contrary to the common perception, no signifiant change in internal roughness was observed for different preparation time. The extent of swelling of PEM in water D2O appears strongly inflenced by the distance of the polyelectrolyte from the substrat