The study of non-uniform or inhomogeneous fluids is of great interest because they play an important role in different phenomena in chemical and petroleum engineering, such as surface tension on liquid-liquid and vapor-liquid interfaces, capillarity, adsorption, wettability, confining geometries, etc.
The aim of this project is the study of the thermodynamic properties of non-uniform fluids. Uniform fluids, or bulk fluids, are those in which the local density is constant and equal to the average density of the total system. However, the homogeneity of bulk fluids is broken with the presence of interfaces or surfaces where the local density of the system varies along the interface or surface producing inhomogeneities, e.g. confining walls or coexistence of different fluids phases.
Statistical mechanics has become an important tool for the study of uniform and non-uniform thermodynamic systems because it provides a link between the microscopic probability distribution of particles and the macroscopic state properties of these systems. In this project, the thermodynamic properties of inhomogeneous fluids will be studied within the framework of the classical density functional theory (DFT). Classical DFT offers the versatility of retaining the theoretical concepts of statistical mechanics and only requiring a modest amount of computation power in comparison to molecular simulations.
The key of the classical DFT is that it defines the Helmholtz free energy as a functional of the particle density distribution, which for uniform fluids reduces to the average bulk density, and for non-uniform fluids is variable along the presence of inhomogeneities caused by confining surfaces or an interface between coexisting phases. The Helmholtz free energy is therefore a unique functional of the particle density distribution, and in practice, most resulting functionals are designed specifically for the application of interest.
Main supervisor:
Georgios Kontogeorgis
Co- supervisor:
Xiaodong Liang