“…On the other hand, it has been reported [28] that the surface tension for an aqueous solution of DTAB can be affected by the presence of iota-carrageenan at concentrations as low as 1 ppb. Furthermore, these data show a dependence of the CAC value on the polyelectrolyte concentration; there is some disagreement [9,27] on whether such correlation should exist. Such a result would confront the thermodynamic adsorption model, which is based simply on an exchange of the surfactant counterions for the polyelectrolyte ions, which should keep the same partition of the surfactant molecules between micelles and air/liquid interface.…”