Saturated sodium chloride solution under an external static electric field: A molecular dynamics study

Abstract

The behavior of saturated aqueous sodium chloride solutions under a constant external electric field (E) was studied by molecular dynamics (MD) simulation. Our dynamic MD simulations have indicated that the irreversible nucleation process towards crystallization is accelerated by a moderate E, but retarded or even prohibited under a stronger E, which can be understood by the competition between self-diffusion and drift motion. The former increases with E resulting in the acceleration of the nucleation process, and the latter tears oppositely charged ions more apart under a stronger E leading to the deceleration of nucleation. Moreover, our steady-state MD simulations have indicated that a first-order phase transition happens in saturated solutions only when the applied E is below a certain threshold E c , and the ratio of crystallized ions does not change with the electric field. The magnitude of E c increases with concentration, because larger clusters are easy to form in a more concentrated solution and require a stronger E to dissociate them.2

Accurate treatments of electrostatics for computer simulations of biological systems: A brief survey of developments and existing problems

“…[21] An insightful review of the optical response of peptide systems has been given by Zhuang and coworkers [22] who have shown that a simplified implicit treatment of electrostatics can often provide adequate physical explanations for a specific purpose. Moreover, molecular dynamics studies of ionic liquids and ionic solutions in response to an external electric field have been constantly focused by Wang's group [23][24][25][26] which may provide guidelines for experimental designs of unexplored systems of interest. The importance of a detailed investigation of electrostatics under the usual periodic boundary condition may be related to other subtle problems as well.…”

Suppression of ice nucleation in supercooled water under temperature gradients

“…[13] It has been proved that the behaviors of nucleation can also be affected by a variety of external perturbations such as pressure, mechanical stimulus, flows, electric and magnetic fields and so on. [14][15][16][17][18][19][20][21] Temperature as a decisive factor for nucleation, [22,23] if there are fluctuations or gradients, is deemed to be a thermal disturbance to influence the stability of supercooled water. [24] Meanwhile, the temperature differences are actually present in some practical applications.…”

Fractional variant of Stokes–Einstein relation in aqueous ionic solutions under external static electric fields*

“…However, recent studies suggested that ions tend to form clusters even in diluted solution. [7][8][9][10] The microscopic structures of ions are essential for many processes, including nucleation, [11,12] battery performance, [13][14][15] and biological systems. [16][17][18] Moreover, ion transport properties usually dominantly determine the performance of ionic solutions working in a non-equilibrium processes, e.g., driven by an external electric field E.…”