Electrostatic interactions in phospholipid membranes I: Influence of monovalent ions

摘要: Electrostatic interactions in monolayers and vesicles of acidic phospholipids are studied by thermodynamical optical techniques conjunction with numerical calculations. A nonmonotonic ionic strength dependence an extremum at 0.1 M (NaCl) is observed for the phase transition temperature as well surface pressure low molecular density. This finding accordance calculations predicting dominance charge screening monovalent counterions only concentrations above M. For lower salt content, however, its increase causes elevation degree dissociation thus also electrostatic repulsion. leads to a higher pressure, smaller size solid domains liquid/solid coexistence range monolayers. supports previously published idea, that finite repulsion arise from different density fluid lipid phases.