Interfacial properties and stability of oil-in-water emulsions stabilized with binary mixtures of surfactants

Adsorption of Cetyldimethylbenzylammonium Chloride on Octane Emulsions Droplets: The Effect of the Presence of Tween 80

“…The presence of both surfactants in the mixed surfactant layer leads to positive -potential values even at very low concentrations of the cationic surfactant. The charged groups will be orientated toward the diffusion layer, resulting in an increase of charge at the shear plane and thus an increase in the surface charge (11,12). The electrostatic interactions are of great importance in the adsorption of ionic surfactants onto oppositely charged surfaces, and consequently the concentration of the surfactant ions is an important parameter governing the initial adsorption of the surfactant.…”

“…Various concentrations of the nonionic surfactant are added before [9] or after the emulsification [10]. The same with [9] and [10] is done in [11] and [12], with the concentration of CDBACl being in these cases higher and above its CMC, while the same concentrations of the nonionic surfactant are added before [11] or after the emulsification [12]. The emulsion droplets prepared without emulsifier and/or using the nonionic surfactant Tween 80 have a very small negative charge.…”

“…Figure 6 gives the ⌫ values versus the concentration of Tween 80. Two different concentrations of CDBACl are used, one below [9], [10] and one above its CMC [11], [12], while the nonionic surfactant is added before [9], [11] or after [10], [12] the emulsification. A general remark is that in all cases there is a small decrease in ⌫ above the CMC of Tween 80.…”

“…When surfactants are mixed in aqueous solutions, a kind of interaction is observed which depends on the properties of the surfactants, their concentration, and the medium in which they are dissolved. However, a few papers deal with the adsorption of a surfactant in the presence of a second one, when the adsorbent system is not solid but an emulsion droplet, i.e., (11,12). Some deal with the competitive adsorption of a surfactant and a protein (13).…”

The ζ-Potential of Silicone Oil Droplets Dispersed in Aqueous Solutions

“…Using the electrophoresis technique, the -potential of the O/W emulsion droplets is determined by measuring the electrophoretic mobilities of the oil droplets in a static electric field externally applied to the colloidal system (2-6). However, this technique requires measuring the electrophorectic mobilities only at the so-called stationary level (5,6). Furthermore, the electrophoresis technique is restricted in its applicability by the special requirements of the dilution of the colloids, the optical properties, and the size range of the colloidal particles.…”