Sedimentation of a Two-Dimensional Colloidal Mixture Exhibiting Liquid-Liquid and Gas-Liquid Phase Separation: A Dynamical Density Functional Theory Study

0425957 - ÚCHP 2014 RIV US eng J - Journal Article
Malijevský, Alexandr - Archer, A.J.
Sedimentation of a Two-Dimensional Colloidal Mixture Exhibiting Liquid-Liquid and Gas-Liquid Phase Separation: A Dynamical Density Functional Theory Study.
Journal of Chemical Physics. Roč. 139, č. 14 (2013), s. 144901. ISSN 0021-9606. E-ISSN 1089-7690
R&D Projects: GA ČR GA13-09914S
Institutional support: RVO:67985858
Keywords : directed spinodal decomposition * fluids * systems
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 3.122, year: 2013

We present dynamical density functional theory results for the time evolution of the density distribution of a sedimenting model two-dimensional binary mixture of colloids. The interplay between the bulk phase behaviour of the mixture, its interfacial properties at the confining walls, and the gravitational field gives rise to a rich variety of equilibrium and non-equilibrium morphologies. In the fluid state, the system exhibits both liquid-liquid and gas-liquid phase separation. As the system sediments, the phase separation significantly affects the dynamics and we explore situations where the final state is a coexistence of up to three different phases. Solving the dynamical equations in two-dimensions, we find that in certain situations the final density profiles of the two species have a symmetry that is different from that of the external potentials, which is perhaps surprising, given the statistical mechanics origin of the theory. The paper concludes with a discussion on this.
Permanent Link: http://hdl.handle.net/11104/0231781