Refined dynamic structure factor of a lipid bilayer on scales comparable to its thickness

Resumo

The structural inhomogeneity of a lipid bilayer is an obstacle to applying the classical Canham–Helfrich model to describe its dynamics on nanometer length scales. In this paper, a refined expression for the free energy of a single-component lipid bilayer is used to describe the dynamics of lipid density fluctuations. In particular, the expression with a term involving the gradient of the area per lipid [8] is used for the free energy per lipid. A refined expression has been derived for the dynamic structure factor of a free lipid bilayer in the hydrodynamic region. It leads to differences in the interpretation and values of the bilayer parameters in comparison with the standard model.