This thesis is concerned with the methods of mean field calculations of the properties of soft matter systems. The first part deals with the application of mean field density functional theory to fluid systems containing small numbers of particles. This is relevant to nucleation studies that can be performed using mean field density functional theory (MFDFT), where the critical clusters that constitute the transition states for phase transitions can be very small. It is also relevant for studies of the behaviour of confined fluids such as fluids in nanopores. The problems in applying MFDFT to small systems are investigated, and modifications to improve the accuracy are identified. These principles are tested on a highly simplified model system of attractive hard rods in one dimension. The second part of the thesis investigates the mean field description of interactions in charged colloidal suspensions within the primitive (PM) model. The phase behaviour of these systems is discussed. In particular, the question of whether experimental observations of coexistence between dense and rarefied phases can be accounted for by mean field theory is discussed. A new approximate method for solving the nonlinear mean field Poisson-Boltzmann equation in the limit of dilute suspensions is proposed. This method is applied to the simple case of charged plates, as well as arrays of spherical colloidal particles. For the latter case, comparisons are made between spherical and cubic Wigner-Seitz cell geometries.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:639538 |
| Date | January 2007 |
| Creators | Khakshouri, S. |
| Publisher | University College London (University of London) |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://discovery.ucl.ac.uk/1444771/ |
Page generated in 0.0016 seconds