Molecular Dynamics Simulation of Micellar Shape Transition in Amphiphilic Solutions

The micellar shape transition in amphiphilic solutions is studied by coarse-grained molecular dynamics simulations of rigid amphiphilic molecules with explicit solvent molecules. Our simulations show that the dominant micellar shape changes from disc to cylinder, and then to sphere as the hydrophilic interaction increases. We find that, as the hydrophilic interaction increases, the potential energy decreases monotonically even during the micellar shape transition, whereas the slope of the potential energy decreases in a stepwise manner in relation to the micellar shape transition. We also ascertained that there exists a wide coexistence region in the intensity of the hydrophilic interaction between a cylinder and a sphere, whereas the coexistence region between a cylinder and a disc is very narrow.