The Energy Barrier to Recombination in Hydrated Plasma

2016

Russ J Electrochem

Self Cite

The effect of hydrophilic walls on the structure of the hydration shell of a ion is studied in terms of the model flat nanopore in contact with water vapors at room temperature by the Monte Carlo computerassisted simulations. In the field of hydrophilic walls, the hydration shell falls into two parts: the ion-enveloping part and the molecular-film spots spread over the wall surface above and under the ion. Both parts have the pronounced radial-layered structure. The three-dimensional scheme of distribution of the averaged local shell density represents a system of conical coaxial layers expanding in the direction from wall to ion. The effect of forcing out the ion from its own hydration shell is also observed for hydrophilic walls. The specific electric polarizability of the shell is strongly anisotropic. Its longitudinal component is several times larger than the transversal component and behaves nonmonotonically as the hydration shell grows, passing through the maximum. The molecular order near the walls is characterized by the preferential orientation of the molecule plane in parallel to the wall plane and the turn of symmetry axes of molecules in the direction parallel to the normal to the pore plane in the vicinity of the ion.

Section: Simulation Conditionsmentioning

confidence: 99%

“…The mass of hydrated ions and their scattering cross-section determine the conductivity of the steam-gas mixture. Even at relatively low humidity, all ions are hydrated under the natural atmospheric conditions, carrying from several to several tens of water molecules [1][2][3][4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

Structure and electric properties of the hydration shell of a singly charged chloride ion in a nanopore with hydrophilic walls

2016

Russ J Electrochem

Self Cite

“…The probability of realization of the states that corre spond to different interionic distances in an ion pair exponentially depends on the mean force potential expressed in heat energy units [41]. A special sto chastic method has been developed [42,43] and applied [44][45][46] for the calculations of systems with high barriers in the mean force potential. In [40], the use of this method resulted in finding that, in an unsat urated water vapor with a fixed pressure, the mean force potential has a single minimum, which corre sponds to the contact distance between the counteri ons, with the depth of the minimum being nearly 100…”

Section: Mechanism Of Dissociation In Clustersmentioning

confidence: 99%

Thermodynamic stability of finely dispersed Na+Cl−(H2O) n aerosol particles in water vapor

2015

Colloid J

Self Cite

Four qualitatively different thermodynamic states have been identified for hydrated sodium chlo ride ion pairs in water vapor. Two of the states are stable, and the other two are unstable. The stable states of a contact ion pair (CIP) and a solvent separated ion pair (SSIP) represent sites of heterogeneous nucleation in supersaturated vapors. The unstable states form free energy barriers that separate the stable states. As the temperature is elevated, the SSIP states become more stable than the CIP states already in unsaturated water vapors. Hydrated ion pairs that contain hydroxonium ions instead of alkali metal cations are absolutely stable in the SSIP state already in the range of unsaturated vapors and low temperatures. Computer assisted calcu lations of the free energy and work of hydration have been carried out by the Monte Carlo bicanonical statis tical ensemble method in terms of a detailed model of interactions comprising polarization, many particle covalent interactions, and charge transfer phenomena.

“…The presence of these clusters in high concentrations causes abnormal spec tral phenomena in the infrared spectral range in the upper atmosphere [9,10]. The accumulation of non recombined charges in molecular water clusters underlies the mechanism of an increase in the effect of radioactive irradiation on the dielectric properties of the atmosphere and results in the abnormally high coefficient of reflection of centimetric radio waves from the radioactive cloud in the atmosphere [11][12][13][14]. Ionization of molecular water clusters is a key factor in the mechanism of chlorine accumulation and the depletion of the ozone protective layer in the strato sphere [15][16][17].…”

Section: Introductionmentioning

confidence: 99%

Water vapor clustering in the field of a chlorine anion occurring in a planar nanopore with structureless walls

2014

Colloid J

Self Cite

The Monte Carlo bicanonical statistical ensemble method has been employed to calculate the free energy, entropy, and work of Clion hydration in model planar pores 0.5 and 0.7 nm wide at 298 and 400 K. A detailed model of many body interactions with the ion has been used, the model being matched to exper imental data with respect to the free energy and enthalpy of attachment reaction in water vapor. Under the conditions of a restricted volume, the equilibrium size of a hydration shell substantially decreases, with the effect becoming stronger in the range of moderate and large sizes. In moderately supersaturated vapors, under the conditions of a nanopore, the ion loses its hydration shell as the temperature is decreased. In supersatu rated vapors, the hydration shell formed on the ion is thermodynamically stable, while the stability crisis shifts to the region of larger sizes. The enhancement of the thermodynamic stability in the pore results from a rise in the chemical potential of molecules due to the deficiency of closet neighbors and a reduction in the entropy under the conditions of the restricted volume. As the temperature is elevated, the effect of ion displacement out of its hydration shell is leveled. The regularities derived in terms of the estimation model based on the cap illary approximation are in qualitative agreement with the results of computer simulation.