Comparison of the van der Waals and undulation interactions between uncharged lipid bilayers

A numerical analysis of the long-range interaction energies between neutral multilamellar lecithin systems has been conducted. The analysis was made in order to verify if the long-range swelling behavior that occurs between the two undulating lipid bilayer are really due to undulation repulsion. The results, which include a long-range van der Waals interaction that continues to be more than 1 order of magnitude greater than the measured undulation repulsion, suggest a different cause for the swelling.