Abstract
Nonequilibrium molecular dynamics simulations were conducted for lipid bilayers with ambient water under two directions of shear flow along the bilayer plane to investigate mechanisms of momentum transfer characteristics in the membranes. Under a shear flow parallel to the bilayer plane, intermolecular interaction contributes to momentum flux positively in the lipid tail area, while negative flux due to intramolecular interaction arises. In the lipid head area, positive and negative contributions of each interaction invert. Under a shear flow perpendicular to the bilayer plane, the largest fraction to total momentum flux in the lipid bilayer is in the lipid head groups. This indicates that the contribution of the head group is the most dominant to surface shear viscosity in the lipid bilayer.
