MIXED-SOLUTIONS OF SURFACTANT AND HYDROPHOBICALLY-MODIFIED POLYMER - CONTROLLING VISCOSITY WITH MICELLAR SIZE

The viscosity of mixtures of a hydrophobically modified cellulose poly mer (HMHEC) and surfactants in aqueous solution was determined as a fu nction of the concentration of mixed micelles. It was shown that, in s olutions of low viscosity where the ratio between polymer hydrophobic tails and mixed micelles is low, a high viscosity can be recovered by increasing the surfactant aggregation number in the mixed micelles. Th e surfactant aggregation number of the mixed micelles was increased by adding either a screening electrolyte or an oppositely charged surfac tant to solutions containing the hydrophobically modified polymer and an ionic surfactant. Time-resolved fluorescence quenching (TRFQ) was u sed to investigate the size of the mixed micelles.