Molecular-Dynamic Simulations on Aqueous Solutions Confined Between Uniformly Charged Hydrophobic Plates

In this paper, we present the numerical study on the properties of aqueous solution confined between uniformly charged hydrophobic plates using the molecular-dynamic simulations. Two kinds of aqueous solutions used in our study are aqueous sodium and aqueous chloride. The SPC/E model and combination of quaternion coordinates with Euler angles are used to model the water molecules and constraint the structure of water molecules, respectively. The hydrophobic plates are separated by 2.6 nm and the space contains 680 water molecules and 20 ions. The charge density on each surface of the plate is the same with each other and satisfies the charge-neutralization criterion over the whole domain. We employed the modified Ewald summation for the uniformly charged surface PPPM method (particle-particle-particle-mesh) to compute the long-range interactions. The static and dynamic properties of solvent and ions are computed. We also compare our results with those provided by solving the Poisson-Boltzmann equation.