Polymer–surfactant interaction: differences between alkyl sulfate and alkyl sulfonate

The interactions between sodium alkyl sulfates (CnSO4)/sodium alkyl sulfonates (CnSO3) and polyethylene oxide (PEO) were studied by surface tension, fluorescence and dynamic light scattering measurements, assisted with quantum-chemical calculations. It was found that, although many properties of CnSO4 and CnSO3 were similar, there were striking differences in their interactions with PEO. Sodium alkyl sulfonates were seen to interact more weakly than their sulfate analogs. Such differences were especially distinct when compared C10SO4-PEO with C10SO3-PEO, the former exhibits obvious interactions, but no observable interaction in the latter. With the help of ab initio quantum-chemical calculation, the results were explained.