Li. Jong et Nl. Abbott, RATE-DEPENDENT LOWERING OF SURFACE-TENSION DURING TRANSFORMATIONS OF WATER-SOLUBLE SURFACTANTS FROM BOLAFORM TO MONOMERIC STRUCTURES, Langmuir, 14(9), 1998, pp. 2235-2237
We report the synthesis of water-soluble, bolaform surfactants contain
ing disulfide bonds (Br-N+(CH3)(3)(CH2)(8)SS(CH2)(8)N+(CH3)(3)Br-, 1)
and measurements of the surface tensions of aqueous solutions of these
surfactants during their reduction to monomeric, thiol-containing fra
gments (Br-N+(CH3)(3)(CH2)(8)SH, 2). Surface tensions measured during
the redox induced transformation of 1 to 2 were found to he tower, by
up to 10 mN/m, as compared to surface tensions of solutions of 1 or 2.
The extent of lowering of the surface tension was dependent on the ra
te of transformation of 1 to 2. These results and others suggest that,
during the transformation of 1 to 2 at the surface of the solution, s
low desorption of 2 leads to a transient accumulation of 2 at the surf
ace of the solution and thus to low surface tensions. We believe that
redox-induced transformations of surfactants may form the basis of a g
eneral principle to create low (transient) surface tensions.