Sum-frequency generation spectroscopy experiments and the equilibrium adsorption measurements show that the presence of NaCl in CTAB solution leads to the formation of ion pairs at the surface, thereby neutralizing the charge of the head group of CTAB. For the ionic surfactant, the dynamics agree with the usual diffusion-limited interfacial adsorption kinetics however, the kinetics become orders of magnitude slower when NaCl is present. Dynamic surface tension measurements allow comparing the surface tension as a function of time for pure surfactant solutions and in the presence of NaCl. Equilibrium surface tension measurements show that NaCl significantly reduces the critical micellar concentration (CMC) of CTAB but has no effect on the CMC of Tween 80. We study the influence of high NaCl concentrations on the equilibrium and dynamic surface tensions of ionic (CTAB) and nonionic (Tween 80) surfactant solutions.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |