Sedimentation in the ultracentrifuge and diffusion of macromolecules carrying electrical charges

The calculation of Alexandrowicz and Daniel of the charge effect in the sedimentation of macromolecules carrying electrical charges was reformulated by introducing buoyant molecular weights and concentrations of electroneutral components only (rather than those of the ionized species) in the final equations. Some interesting limiting cases are discussed. A similar calculation was performed for the case of isothermal diffusion. It is also shown how the present discussion relates to more elaborate treatments of the sedimentation and diffusion of polyelectrolytes by the methods of irreversible thermodynamics.