Solving the Poisson-Boltzmann Equation to Obtain Interaction Energies Between Confined, Like-charged Cylinders

We numerically solve the non-linear Poisson-Boltzmann equation for two cylinders confined by two parallel charged plates. The repulsive electrical double layer component of the cylinder pair potential is substantially reduced by confinement between like-charged plates. While the effective cylinder surface charge is increased by the confinement, the effective interaction screening length is reduced, this effect being dominant so that the repulsive confined cylinder-cylinder interaction potential is reduced.