Macroscopic electrostatic potentials and interactions in self-assembled molecular bilayers: the case of Newton black films.
We propose a very simple but "realistic" model of amphiphilic bilayers, simple enough to be able to include a large number of molecules in the sample but nevertheless detailed enough to include molecular charge distributions, flexible amphiphilic molecules, and a reliable model of water. All these parameters are essential in a nanoscopic scale study of intermolecular and long range electrostatic interactions. We also propose a novel, simple, and more accurate macroscopic electrostatic field for model bilayers. This model goes beyond the total dipole moment of the sample, which on a time average is zero for this type of symmetrical samples; i.e., it includes higher order moments of this macroscopic electric field. We show that by representing it with a superposition of Gaussians, it can be analytically integrated, and therefore its calculation is easily implemented in a molecular dynamics simulation (even in simulations of nonsymmetrical bi- or multilayers). In this paper we test our model by molecular dynamics simulations of Newton black films.
Gamba
Z
Z
Department of Physics, CAC, Comision Nacional de Energia Atomica, Av. Libertador 8250, 1429 Buenos Aires, Argentina. gamba@tandar.cnea.gov.ar
D008958:Models, Molecular; D015203:Reproducibility of Results; D055672:Static Electricity; D013997:Time Factors; D014867:Water / Q000737:chemistry*
D014867:Water