Density functional theory of charged colloidal systems
Abstract
The phase behavior of charged colloidal systems has been studied recently by the density functional theory formalism (DFT) [R. van Roij, M. Dijkstra, and J. P. Hansen, Phys. Rev. E 59, 2010 (1999)]. A key feature of this approach is the appearance of a density and temperature-dependent effective Hamiltonian between the charged colloids. Under certain approximations, the effective Hamiltonian is made up only of a sum of position-independent one-body or volume terms and two-body colloid-separation dependent terms. In the limit of low colloidal densities, the DFT results do not reduce to the familiar Debye-Hückel limiting law nor do the results agree with previous work based on an identical approach but were developed using traditional statistical-mechanical methods [B. Beresford-Smith, D. Y. C. Chan, and D. J. Mitchell J. Colloid Interface Sci. 105, 216 (1985)]. This paper provides a reconciliation of these differences and comments on the significance of the one-body volume terms in the effective Hamiltonian of a system of charged colloids in determining thermodynamics and phase behavior.
- Publication:
-
Physical Review E
- Pub Date:
- June 2001
- DOI:
- 10.1103/PhysRevE.63.061806
- Bibcode:
- 2001PhRvE..63f1806C
- Keywords:
-
- 83.50.-v;
- 64.60.Cn;
- Deformation and flow;
- Order-disorder transformations;
- statistical mechanics of model systems