Using Molecular Dynamics Simulations to Model the DC Electrical Behavior of Confined Layers

A Molecular Dynamics (MD) computer simulation is utilized to qualitatively understand the DC electrical conduction behavior of pentadecane (C H ) layers confined between two graphite slabs as related to the dynamics of the layer. At low temperatures the patch remains together and perpendicular to the confining layers. Then, as temperature is increased, tilting of the molecules begins. The molecules tend to remain straight as they tilt with increasing temperature which, in our model, affects the capacitance somewhat but the resistance little. As temperature is increased further, the molecules exhibit gauche defects which accompany patch collapse. During patch collapse, the system shows dramatic changes in its calculated DC resistance and capacitance. Calculated specific capacitance values are in remarkable agreement with recent experimental measurements. Results for two different confining layer separations are discussed as well as future work related to lipid bilayer systems. 15 32