Self-consistent field modeling of three-dimensional morphologies of branched lipid surfactant at air-water interface

Three-dimensional mesoscopic morphologies and the thermodynamics of structural phase transitions of amphiphilic lipids at air-water interfaces are studied using self-consistent field theory. Changing the relative amount of lipids in the system led to a series of 3D morphologic phases with varying average interfacial area per molecule, mimicking a compression of the model membranes. Membranes of both saturated and unsaturated lipids undergo a transition from cylindrical micelle to lamella when the lipid content in the system increases from 2% to about 19- 20%. With further increase in the lipid content, saturated lipids first develop non-uniform quasi- 2D distributions in the lamella and then gradually transform into a hybrid morphology containing quasi-planar lamellae. In contrast, unsaturated lipids develop reverse-micellar morphologies.