Free energy increment of multilayer membrane system due to membrane-membrane interaction potentials

The free energy increment due to the electrostatic repulsive potential in multilayer membrane system is investigated. The analysis based on the membrane-membrane distance distribution function shows the free energy increment per unit volume is proportional to rho(4), where rho(4) is the membrane density. Comparing with the mean field estimation for the electrostatic repulsive potential effect, this free energy increment is quite large. To verify the rho(4) behavior of the free energy increment, a Monte Carlo calculation based on the solid-on-solid membrane model was performed. The Monte Carlo result supports the rho(4) behavior. This shows the validity of the analysis based on he membrane-membrane distance distribution function.