Double layer potential and degree of dissociation in charged lipid monolayers

One of the contributions to the surface potential in charged phospholipid m onolayers at air-water interfaces is the double layer potential. In this no te several misconceptions found in the literature concerning the relationsh ip between the double layer potential and the degree of dissociation of the lipid polar headgroups are critically analyzed. The deviations of the doub le layer potential measurements from the Gouy-Chapman theory observed by se veral authors are explained by taking into account the dependence of the de gree of dissociation with concentration, area per lipid molecule and pH. (C ) 2000 Elsevier Science Ireland Ltd. All rights reserved.