Malani, Ateeque and Murad, Sohail and Ayappa, KG (2010) Hydration of ions under confinement. In: 24th European Photovoltaic Solar Energy Conference, SEP 21-25, 2009, Hamburg, pp. 579-589.Full text not available from this repository.
Molecular dynamics simulations are used to examine the changes in water density and hydration characteristics of NaCl solutions confined in slit-shaped graphitic pores. Using a structural signature, we define the hydration limit as the salt concentration at which a sharp drop in the hydration number is observed. At small pores (H = 8.0-10 angstrom), confined water does not possess bulk-like features and remains in a layered arrangement between two surfaces. Despite this high degree of confinement, ions are able to form a quasi-2D hydration shell between two surfaces. Our results indicate the strong propensity of ions to form the first hydration shell, even under extremely confined aqueous environments. The hydration of ions is seen to weakly perturb the oxygen density distributions between two surfaces. The hydration number of Na+ reduces to about 4.15 at a pore width of H = 0.8 nm, when compared with the bulk hydration number of 6.25. At larger pore widths, above H = 16 angstrom, where bulk-like water densities are observed in the central regions of the pore, the hydration number is above 6.
|Item Type:||Conference Paper|
|Additional Information:||Copyright of this article belongs to Taylor and Francis Group.|
|Keywords:||confinement ion-hydration;graphite;molecular dynamics|
|Department/Centre:||Division of Mechanical Sciences > Chemical Engineering|
|Date Deposited:||23 Aug 2010 10:53|
|Last Modified:||23 Aug 2010 10:53|
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