Shape fluctuations and elastic properties of two-component bilayer membranesA. Imparato, J. C. Shillcock and R. Lipowsky
Max-Planck-Institut für Kolloid- und Grenzflächenforschung 14424 Potsdam, Germany
received 28 July 2004; accepted in final form 7 December 2004
published online 19 January 2005
The elastic properties of two-component bilayer membranes are studied using a coarse-grain model for amphiphilic molecules. The two species of amphiphiles considered here differ only in their length. Molecular-dynamics simulations are performed in order to analyze the shape fluctuations of the two-component bilayer membranes and to determine their bending rigidity. Both the bending rigidity and its inverse are found to be nonmonotonic functions of the mole fraction of the shorter B-amphiphiles and, thus, do not satisfy a simple lever rule. The intrinsic area of the bilayer also exhibits a nonmonotonic dependence on and a maximum close to .
87.16.Dg - Membranes, bilayers, and vesicles.
82.70.-y - Disperse systems; complex fluids.
61.20.Ja - Computer simulation of liquid structure.
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