Onsager-Manning-Oosawa condensation phenomenon and the effect of salt

Emmanuel Trizac 1, 2, Gabriel Tellez 3

Physical Review Letters 96 (2006) 038302

Making use of results pertaining to Painleve III type equations, we revisit the celebrated Onsager-Manning-Oosawa condensation phenomenon for charged stiff linear polymers, in the mean-field approximation with salt. We obtain analytically the associated critical line charge density, and show that it is severely affected by finite salt effects, whereas previous results focused on the no salt limit. In addition, we obtain explicit expressions for the condensate thickness and the electric potential. The case of asymmetric electrolytes is also briefly addressed.

  • 1. Laboratoire de Physique Théorique et Modèles Statistiques (LPTMS),
    CNRS : UMR8626 – Université Paris XI - Paris Sud
  • 2. Theoretical Biological Physics,
    University of California, San Diego
  • 3. Departamento de Fisica,
    Universidad de Los Andes