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4700633 
Journal Article 
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 
Janchenova, H; Stulik, K; Marecek, V 
2008 
1 
Journal of Electroanalytical Chemistry and Interfacial Electrochemistry
ISSN: 0022-0728 
612 
2 
186-190 
WOS:000252600400005 
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. (c) 2007 Elsevier B.V. All rights reserved. 
liquid vertical bar liquid interfaces; surface tension; adsorption of phospholipids; L-alpha-lecithin (DPPC)