Spectroscopic Studies of Interactions between Styrene/Acrylic Acid Copolymer and Sodium Dodecyl Sulfate

Abstract

The results obtained from Fourier transform infrared study of sodium dodecyl sulfate (SDS) in water and in the presence of styrene/acrylic acid (S/AA) copolymer are presented. The C-H stretching band of the SDS hydrocarbon tail at 2929 cm−1 and the O-H stretching of H2O are sensitive to changes in the SDS concentrations. With the increasing concentration both bands are shifted to lower frequency. A mutual presence of S/AA copolymer and surfactant in the aqueous solution leads to a splitting of the bands due to COO− groups. It is proposed that the splitting is due to interactions between COO− segments of the copolymer and the “surfaces” of micelles through the Na+ or Li+ ions.