“…Interactions between SDBS and polyvinyl pyrrolidone [21,22] exhibit similar behavior as the PEO/SDS system. Nevertheless, in a previous work we found significant differences in behavior between the PEO/SDBS and PEO/SDS systems for very high molecular weight PEO (8 × 10 6 g/mol) in extensional flows: addition of SDBS to PEO solutions at concentrations below the CAC induced a strong increase of the critical strain rate for extension thickening, which might be a result of coil contraction [23]. This effect was observed both in the absence and presence of salt and with other sulfonated surfactant (an α-olefin sulfonate).…”