THERMODYNAMICS OF THE SOLUBILIZATION OF 2-UNDECANONE IN AQUEOUS-SOLUTIONS OF POLY(SODIUM STYRENESULFONATE-CO-2-VINYLNAPHTHALENE)

Poly(sodium styrenesulfonate-co-2-vinylnaphthalene) (PSSS-VN) displays a pseudomicellar conformation in aqueous solution. Such a conformation enables the solubilization of large hydrophobic organic compounds. A two-phase model is proposed to describe the solubilization of 2-undecanone in aqueous solutions of PSSS-VN. Thermodynamic parameters for the solubilization of 2-undecanone in aqueous solutions of PSSS-VN have been determined. Two approaches, based on mole fraction and weight fraction as reference functions, for the determination of the distribution coefficients of 2-undecanone between water and polymer pseudophase are presented. The values of the distribution coefficients of 2-undecanone between polymer pseudophase and water are high. Solubilization is a spontaneous process (∆G° = -33.9 kJ mol-1). The influence of ionic strength and pH on the solubilization efficiency has also been studied. An increase in the ionic strength causes a decrease in solubilization. The solubilizing ability of PSSS-VN has been found to be highest at neutral pH and decreased with increased acidity and basicity of the solution.Ionic strength and pH effects have been explained in terms of induced changes in the effective hydrodynamic volume of the polymer. © 1990, American Chemical Society. All rights reserved.