title: Derivation of analytical expressions for the electrical potential distribution in lipid structures.
abstract: The electrical potential inside a lipid structure, which is described by a modified Poisson-Boltzmann equation in the literature (Borukhov et al. Electrochim. Acta 2000, 46, 221), is solved, taking into account the effects of ionic sizes. Here, a micelle comprises an ionic surfactant layer and an aqueous core; the dissociation of the former yields a charged surface. The governing equation, which was solved numerically in a previous study for spherical geometry (Hsu et al. J. Phys. Chem. B 2003, 107, 14429), is solved analytically in this study for planar, cylindrical, and spherical geometries. The analytical results obtained are readily applicable for the evaluation of the spatial distributions of counterions inside a lipid structure. We show that if the linear size of a reverse micelle is fixed, the degree of dissociation of the surfactant layer follows the order planar > cylindrical > spherical.
authors.affiliation: Department of Mathematics, Tamkang University, Tamsui, Taipei 25137, Taiwan.
authors.forename: Shiojenn
authors.initials: S
authors.lastname: Tseng
authors.forename: Ji-Ming
authors.initials: JM
authors.lastname: Jiang
authors.forename: Jyh-Ping
authors.initials: JP
authors.lastname: Hsu
mesh_terms: D003198:Computer Simulation; D008055:Lipids / Q000737:chemistry*; D008564:Membrane Potentials / Q000502:physiology*; D008956:Models, Chemical; D055672:Static Electricity
chemical_list: D008055:Lipids