THE EFFECT OF INORGANIC SALTS AND UREA ON THE VISCOSITY BEHAVIOR OF SODIUM LINEAR ALKYL BENZESULFONAT SOLUTION WITH HIGH-CONCENTRATION

The relative viscosity-concentration curves of sodium linear aIkyl benzesulfonat (SLABS), 1/2. Li2SO4, 1/2. Na2SO4, NaI and N2H4 CO solutions vs. water and of mixed solutions of SLABS and additive vs the SLABS solution have been determined at 303.2+/-0.1K. The determinations show, the thickening efficiency of inorganic salts is remarkable for concentrated SLABS solutions. The maximum viscosity values which various salts can reach are markedly different. When the salt concentration reaches a certain value, SLABS forms a precipitate with the salt and the thickening ability of the salt reaches its limit. These results are interpreted in terms of the structure of the micelle solution, electrostatic interactions between ions and micelles, ionic hydratability, changes in the water structure and an activity product effect. Urea diminishes markedly the viscosity values of concentrated SLABS solutions. When using 1/2. Na2SO4 as a thickening agent, the higher the concentrations of urea are, the lower the maximum viscosity values are and the higher the concentrations of salt corresponding to the values. These results are interpreted in terms of forming the individual of urea adduct between urea and the hydrated individual (of surfactant), and dimishing SLABS actual concentration of the equilibria between the hydrated individual and micelle.