Charge Renormalization of Charged Spheres based on Thermodynamic Properties
Resource
The Journal of Chemical Physics 121: 5494
Journal
The Journal of Chemical Physics
Journal Issue
5494
Pages
-
Date Issued
2004
Date
2004
Author(s)
Abstract
At strong electrostatic coupling, counterions are accumulated in the vicinity of the surface of the charged particle with intrinsic charge Z. In order to explain the behavior of highly charged particles, effective charge Z* is therefore invoked in the models based on Debye-Hückel approximation, such as the Derjaguin-Landau-Verwey-Overbeek potential. For a salt-free colloidal suspension, we perform Monte Carlo simulations to obtain various thermodynamic properties ω in a spherical Wigner-Seitz cell. The effect of dielectric discontinuity is examined. We show that at the same particle volume fraction, counterions around a highly charged sphere with Z may display the same value of ω as those around a weakly charged sphere with Z*, i.e., ω(Z)=ω(Z*). There exists a maximally attainable value of ω at which Z=Z*. Defining Z* as the effective charge, we find that the effective charge passes through a maximum and declines again due to ion-ion correlation as the number of counterions is increased. The effective charge is even smaller if one adopts the Debye-Hückel expression ωDH. Our results suggest that charge renormalization can be performed by chemical potential, which may be observed in osmotic pressure measurements.
Type
journal article
File(s)![Thumbnail Image]()
Loading...
Name
18.pdf
Size
619.54 KB
Format
Adobe PDF
Checksum
(MD5):5575d818b9f576d4f35bd9bb2f64bd28