Outnumbered! How ions and water affect the structure of polyelectrolyte complexes

Although polyelectrolyte complexation has been studied for over a century, many aspects of this complexation process are still not understood. A better understanding of this process is essential for the sustainable production of porous membranes, anion and cation exchange membranes and aqueous two-phase systems that can be used for separations. We recently developed an NMR based methodology with which we can determine the composition of the polyelectrolyte and the dilute phase in terms of polyelectrolyte content and their counterions. Currently we are extending this method to study the effect of different salts. Interestingly, the type of salt seems to affect the water content and structure of the complex. To better understand how these small compounds, that outnumber the polyelectrolytes, affect the macroscopic phase separation we would like to combine SANS and SESANS measurement to obtain information about the porosity of the complex as well as their water content.