Solution Microstructure of Confined Fluids with Directional Interactions under the Influence of an External Field: Mean Field Considerations

Abstract

Lattice density functional theory (DFT) and Monte Carlo simulations are used to probe the phase behavior and equilibrium structure of molecules with directional interactions with and without the influence of body forces. It is found that the application of a position-specific external field can be used to control the microstructure of confined fluids. In the absence of an external field, a condensation transition can take place within the pore at sufficiently high densities. This phase transition results in a solution microstructure made up of chains of monomers oriented parallel to the pore walls. With the application of a weak field, it is possible to disrupt this solution microstructure. This type of effect could allow controlled mixing at a local level. Upon application of a stronger field, chains reform in a direction perpendicular to the walls.

Keywords:

• Adsorption
• Monte Carlo
• Density functional theory
• Phase transition
• External field

Acknowledgements

This work was supported by the Division of Chemical Sciences of the Office of Basic Energy Sciences, US Department of Energy under contract DE-FG0287ER13777.