THE RELATIONSHIP BETWEEN THE INTERFACIAL FREE-ENERGY AND THE FREE-ENERGY OF MICELLIZATION OF TRITON X-100 AND SODIUM DODECYL SULFONATE

The contact angles for water and Triton X-100 on Teflon; for water, gl ycerol, formamide, and diiodomethane on Teflon covered with a Triton X -100 film and a sodium dodecyl sulfonate film and glass covered with a sodium dodecyl sulfonate film; and for water, glycerol, and diiodomet hane on glass were measured, Also, the surface tension of Triton X-100 and the interfacial tensions of Triton X-100-n-dodecane and Triton X- 100-diiodomethane were measured. From the results of these measurement s, the Lifshitz-van der Waals component and the electron-acceptor and electron-donor parameters of the acid-base component of the apolar and polar moieties of Triton X-100 and sodium dodecyl sulfonate were dete rmined. Next, taking into account the molecular dimensions of these su rfactants, the free energy of interfacial interaction through water wa s calculated for the apolar and polar parts of Triton X-100 and sodium dodecyl sulfonate. Also, the electrostatic free energy of interaction s between DSs(-) ions was evaluated. Good agreement between the free e nergy of micellization obtained from the cmc data and the free energy of interaction between molecules of surfactant through water was found . (C) 1995 Academic Press, Inc.