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By use of the equilibrium dialysis technique, the extent of binding (Γ₂¹) of cationic surfactants cetyltrimethylammonium bromide (CTAB), myristyltrimethylammonium bromide (MTAB), and dodecyltrimethylammonium bromide (DTAB) with dextrin and carboxymethyl cellulose (CMC) respectively have been measured as a function of surfactant concentration (C₂), pH, ionic strength, and temperature. Γ₂¹ increases with increase of C₂ until it reaches a maximum value, Γ₂^m. On further increase of C₂, Γ₂¹ in all cases sharply decreases linearly with C₂ until its value becomes zero at the azeotropic state when surfactant concentration is considerably higher than the bulk critical micelle concentration (cmc). With further increase of C₂, Γ₂¹ becomes negative and its magnitude increases with further increase of C₂ without reaching a limiting value. Using the concept of the Gibbs surface excess, it has been shown that binding …