FRUSTRATION-INDUCED RIPPLE PHASE IN BILAYER-MEMBRANES

A model describing the phase transition from the L(alpha) or L(beta) p hase to the modulated P(beta) (''rippled'') phase in a bilayer membran e is considered within mean-field approximation. The coupling between the curvature and the asymmetry in the area per molecule can destabili ze the flat phase by releasing its frustration energy. We obtain the p ressure-temperature phase diagram which qualitatively accounts for par t of the pressure experiment of DPPC in excess water. The existence of the modulated structure within our model is also confirmed by a cell dynamical simulation.