Adsorption and ion-pairing interactions of phospholipids in the system of two immiscible electrolyte solutions - Part III: The behaviour of a lecithin layer at the water/1,2-dichloroethane interface at interfacial potential differences lower than the zero-charge potential difference

作者：Janchenova Hana; Stulik Karel; Marecek Vladimir^*

来源：Journal of Electroanalytical Chemistry, 2008, 612(2): 186-190.

DOI：10.1016/j.jelechem.2007.09.024

• liquid vertical bar liquid interfaces
• surface tension
• adsorption of phospholipids
• L-alpha-lecithin (DPPC)

The behaviour Of L-alpha-lecithin (DPPC) was studied at the water/1,2-dichloroethane interface within a range of interfacial potential differences below the zero-charge potential difference, using surface tension and voltammetric measurements. The general five-step model, established in Parts I and II of this series, has been confirmed. The surface pressure of DPPC adsorbed at the interface exhibits a maximum in acidic media close to the zero-charge potential difference, E-pzc, of the base electrolytes. It is demonstrated that, in contrast to the potentials higher than E-pzc, where the change in the surface pressure is due to desorption of the protonated form of DPPC, the observed change in the surface pressure at interfacial potential differences below E-pzc can be explained by alterations in the concentrations of the adsorbed zwitter-ionic and protonated forms of DPPC governed by the general acid/base equilibrium.

• 出版日期2008-1-15