Charge Separation and Isolation in Water and Ice Particles on Strong Impacts

Abstract

Charge separation is a general phenomenon in nature. There has been vivid speculation and discussion about the mechanism of charge separation in condensed matter on strong impacts at small energies. Here we show that charge separation naturally occurs if water aggregates or particles with embedded charge carriers, e.g. ions, encounter a high energy impact even though no plasma occurs and the involved kinetic energies are much below any molecular ionization energy. We find that the charge distribution in the fragments resulting from a strong impact can simply be described by a three step model. The first level of the model is a simple statistical description of the resulting charge distribution at low salt concentrations by making usage of the Poisson distribution. The second step of describing the charge distribution of the dispersed fragments involves the mutual interaction between the charge particles in the condensed matter, which allows us to describe the charge process at higher salt concentrations. We achieved this by using implicit water Monte Carlo Simulation methods of the charged particles. Finally we included the full dynamics of the separation process into our model by using non-equilibrium Molecular Dynamics Simulations to describe the charge separation at high salt concentrations and high separation process velocities. We present a microscopic model of the charging mechanism of fragments, that contributes to the understanding of a larger range of phenomena related to charges and charge separation in Nature. With this model we shed light on the charge mechanism of laser desorption experiments and discuss the impact of the current results for particle detection in space and possible implications for lightning formation in the atmosphere.