Triphenyl- and tributyl-phosphonium head groups contributions in mixed cationic surfactants and anionic polyelectrolytes aggregates

Cationic micelle-anionic polyelectrolyte interactions of hexadecyltrimethyl ammonium bromide (HTAB), hexadecyltriphenylphosphonium bromide (HTPB), hexadecyltributylphosphonium bromide (HTBB), and their mixtures with carboxymethylcellulose (CMC) sodium salt, dextran (DX) sulfate sodium salt, polystyrene sulfonate (PSS) sodium salt, and polyacrylic acid (PAA) sodium salt were studied with the help of conductivity (κ), viscosity (η), turbidity (τ), and NMR studies. The results showed that among the phosphonium surfactants, HTPB interacts more strongly with polyelectrolytes than HTBB since the butyl chains of the latter screen the electropositive centre which has to interact with the active sites of anionic polyelectrolytes. This was explained on the basis of folding of butyl chains in the head group region of the micelle. 1H NMR results further concluded that HTAB+HTPB produced compact mixed micelles, which interacted more strongly with polyelectrolytes in comparison to HTAB+HTBB mixed micelles.