LAUSR

Abstract Polyelectrolyte complex formation of a long chain poly(sodium styrene sulfonate) (NaPSS) with short chain poly(vinylbenzyltrimethylammonium chloride) homopolymer (pVBTA) and block copolymers (PEG- b -pVBTA) was investigated. The effect of the PEG chain and the pVBTA block length was studied on the complex formation. Then the exchange of the complex bound pVBTA for cetyltrimethylammonium bromide (CTAB) was studied using complexes that contained excess of pVBTA segments. First we characterized the effect of ionic strength on the complex stability. Then we studied how the addition of CTAB affects the stability of the complexes with increasing ionic strength. We found that three ionic strength ranges could be distinguished. In the lowest ionic strength range, the formation of stable mixed complexes could be observed. In the intermediate ionic strength range the pVBTA polymer was mostly substituted by CTAB, leading to the aggregation and precipitation of the complexes under the investigated conditions. Finally, at the highest ionic strength the formation of equilibrium NaPSS/CTAB complexes could be hypothesized.