Asymptotic solution of the cylindrical nonlinear Poisson-Boltzmann equation at low salt concentration: analytic expressions for surface potential and preferential interaction coefficient.

ABSTRACT: The analytic solution to the nonlinear Poisson-Boltzmann equation describing the ion distributions surrounding a nucleic acid or other cylindrical polyions as a function of polyion structural quantities and salt concentration ([salt]) has been sought for more than 80 years to predict the effect of these quantities on the thermodynamics of polyion processes. Here we report an accurate asymptotic solution of the cylindrical nonlinear Poisson-Boltzmann equation at low to moderate concentration of a symmetrical electrolyte (< or = 0.1 M 1:1 salt). The approximate solution for the potential is derived as an asymptotic series in the small parameter var epsilon(-1), where var epsilon identical with kappa(-1)/a, the ratio of the Debye length (kappa(-1)) to the polyion radius (a). From the potentia

SUBMITTER: Shkel IA 

PROVIDER: S-EPMC122393 | biostudies-literature | 2002 Mar

REPOSITORIES: biostudies-literature