The local structure of electrically stressed liquid water and implications for modelling of dielectric relaxation

TL;DR

This study investigates how moderate electric fields affect the local structure of liquid water, revealing subtle environmental changes and highlighting the need for improved simulation methods for dielectric relaxation.

Contribution

It provides experimental and simulation insights into electric field effects on water's local structure, emphasizing limitations of current modeling approaches.

Findings

No significant change in static structure detected by scattering experiments.

Simulation shows altered local potential energy surface under electric stress.

Current models are insufficient for non-equilibrium water systems.

Abstract

In a floating water bridge the total radiation scattering of water stressed by a moderately strong electric field (1mV/nm) was compared to water without an applied electric field using X-ray and small angle neutron scattering. Structure refinement was carried out using the EPSR method and the TIP4P/2005 water model. These results did not reveal a significant difference in the local static structure of water however analysis of the simulation indicated that the modeled local potential energy surface reveals a departure between electrically stressed and unstressed water. The observed differences show that the local environment is changed by the applied electric field although weak relative to the intermolecular coulombic field. When discussing the results we show that the current methods used to simulate the pair potentials are still insufficient to treat such non-equilibrium systems and further simulation techniques have to be developed to properly reconstruct the microscopic dielectric relaxation process.