Orientational ordering in a fluid of hard kites: A density-functional-theory study.

摘要: Using density-functional theory we theoretically study the orientational properties of uniform phases hard kites---two isosceles triangles joined by their common base. Two approximations are used: scaled particle and a new approach that better approximates third virial coefficients two-dimensional particles. By varying some geometrical parameters, kites can be transformed into squares, rhombuses, triangles, also very elongated particles, even reaching hard-needle limit. Thus, fluid kites, depending on shape, stabilize isotropic, nematic, tetratic, triatic phases. Different phase diagrams calculated, including those with two equal interior angles fixed to ${90}^{\ensuremath{\circ}}, {60}^{\ensuremath{\circ}}$, ${75}^{\ensuremath{\circ}}$. Kites one unequal ${72}^{\ensuremath{\circ}}$, which have been recently studied via Monte Carlo simulations, considered. We find rhombuses right not too large anisometry tetratic but latter it much higher degree. contrast, ${60}^{\ensuremath{\circ}}$ extent, although is sensitive changes in geometry. ${75}^{\ensuremath{\circ}}$ diagram both phases, show nonexistence shape for stable at different densities. Finally, success description order shown comparing simulations case where ${72}^{\ensuremath{\circ}}$. These particles present