Effect of pressure on the ionic conductivity of Li+ and Cl- ions in water

Varanasi, Srinivasa R and Kumar, Parveen and Subramanian, Yashonath (2012) Effect of pressure on the ionic conductivity of Li+ and Cl- ions in water. In: JOURNAL OF CHEMICAL PHYSICS, 137 (14).

PDF Jol_Chem_Phys_137-14_144506_2012.pdf - Published Version Restricted to Registered users only Download (1MB) | Request a copy

Abstract

A molecular dynamics simulation study of aqueous solution of LiCl is reported as a function of pressure. Experimental measurements of conductivity of Li+ ion as a function of pressure shows an increase in conductivity with pressure. Our simulations are able to reproduce the observed trend in conductivity. A number of relevant properties have been computed in order to understand the reasons for the increase in conductivity with pressure. These include radial distribution function, void and neck distributions, hydration or coordination numbers, diffusivity, velocity autocorrelation functions, angles between ion-oxygen and dipole of water as well as OH vector, mean residence time for water in the hydration shell, etc. These show that the increase in pressure acts as a structure breaker. The decay of the self part of the intermediate scattering function at small wave number k shows a bi-exponential decay at 1 bar which changes to single exponential decay at higher pressures. The k dependence of the ratio of the self part of the full width at half maximum of the dynamic structure factor to 2Dk(2) exhibits trends which suggest that the void structure of water is playing a role. These support the view that the changes in void and neck distributions in water can account for changes in conductivity or diffusivity of Li+ with pressure. These results can be understood in terms of the levitation effect. (C) 2012 American Institute of Physics. http://dx.doi.org/10.1063/1.4756909]

Item Type:	Journal Article
Publication:	JOURNAL OF CHEMICAL PHYSICS
Publisher:	American Institute of Physics.
Additional Information:	Copyright for this article belongs to American Institute of Physics.USA
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit Division of Physical & Mathematical Sciences > Physics
Date Deposited:	31 Dec 2012 07:02
Last Modified:	31 Dec 2012 07:02
URI:	http://eprints.iisc.ac.in/id/eprint/45486

Actions (login required)

View Item