The Influence of pH and Temperature on the Equilibrium and Dynamic Surface Tension of Aqueous Solutions of Sodium Oleate

Miniemulsions via in situ Surfactant Generation

“…[21,22] As the pH of the system increases, carboxylic acids begin to form a range of molecular complexes such as protonated anions, dimers and soaps (if neutralised). Each complex contributes a certain surface activity and depending on the ratio of the species available, their presence strongly influences the interfacial properties.…”

Impact of polyethylene glycol on aqueous micellar solutions of sodium oleate studied by small-angle neutron scattering

“…Other micelles parameters (degree of micelle ionization, charge per micelle and surface potential) keep constant or just slightly decrease with increasing SO concentration (Fig.2 b, c, d). It should be mentioned that the well-known tendency of SO to form soaps at near-neutral pH is of little significance in the studied natural solutions of SO (pH~10) [17].…”

“…The solutions were prepared on the basis of heavy water, D 2 O, usually used to enhance the scattering contrast between hydrogen-containing organic molecules and solvent and to reduce the incoherent scattering background by hydrogen/deuterium substitution in the solvent. As regards SO aqueous solutions, the given work to some extent compensates for the lack of information on the structure and interaction of SO micelles in addition to the numerous experimental studies concerning surface tension, conductivity, Raman scattering, molar volume, osmotic pressure, surface partitioning, and transport numbers [e.g., [16][17][18][19][20][21]. The previous SANS applications to the neat aqueous solutions of PEG in a wide range of molecular masses showed [22;23] that the polymer matches well the structure of Gaussian coils in solutions.…”

Kinetic study of adsorption of some biocompounds at the oil/water interface

“…Another example is related to the adsorption of some salts of fatty acids, like sodium laurate [10,11,13], sodium myristate [10,11], and sodium oleate [14], from aqueous solutions to the air/water interface, which was analyzed by means of diffusion controlled kinetics. However, the very slow adsorption of fatty acids from oil phases to the oil/water interface has previously received only marginal attention [5].…”

“…Generally, the adsorption of surfactant molecules from a solution to a liquid/gas [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] or to a liquid/liquid interface [1,5,[16][17][18][19][20][21][22][23][24] occurs in two steps. Surfactant molecules are first transported from the bulk to the subsurface by diffusion (the subsurface is a liquid layer just below the interface, belonging still to the bulk).…”