Abstract
The generalized Lin–Taylor model defined on the hexagonal lattice is used to investigate the phase separation in an asymmetric binary liquid mixture consisting of large A (hexagons) and small B (triangles) particles. By considering interaction energies between A–A and A–B pairs of particles that occupy nearest-neighbour cells of the hexagonal lattice, we have derived an exact solution for the considered model system having established a mapping correspondence with the two-dimensional Ising model on its dual triangular lattice. Altogether, six different types of coexistence curves including those with re-entrant miscibility regions (i.e. closed-loop coexistence curves) were found with dependence on the relative strength between both coupling constants.
Acknowledgements
J. Strecka would like to thank José Manuel Romero-Enrique and George Jackson for stimulating correspondence and for sending several relevant articles on the re-entrant phenomena cited in this work.
The authors greatly acknowledge financial support of this work provided under the grant VEEA 1/2009/05.