Hard competition: stabilizing the elusive biaxial nematic phase in suspensions of colloidal particles with extreme lengths
| Autor: | Dussi, Simone, Tasios, Nikos, Drwenski, Tara, van Roij, René, Dijkstra, Marjolein |
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| Rok vydání: | 2018 |
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| Zdroj: | Phys. Rev. Lett. 120, 177801 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.120.177801 |
| Popis: | We use computer simulations to study the existence and stability of a biaxial nematic $N_b$ phase in systems of hard polyhedral cuboids, triangular prisms, and rhombic platelets, characterized by a long ($L$), medium ($M$), and short ($S$) particle axis. For all three shape families, we find stable $N_b$ states provided the shape is not only close to the so-called dual shape with $M = \sqrt{LS}$ but also sufficiently anisotropic with $L/S>9,11,14, 23$ for rhombi, prisms, and cuboids, respectively, corresponding to anisotropies not considered before. Surprisingly, a direct isotropic-$N_b$ transition does not occur in these systems due to a destabilization of $N_b$ by a smectic (for cuboids and prisms) or a columnar (for platelets) phase at small $L/S$, or by an intervening uniaxial nematic phase at large $L/S$. Our results are confirmed by a density functional theory provided the third virial coefficient is included and a continuous rather than a discrete (Zwanzig) set of particle orientations is taken into account. Comment: minor changes to the introduction, numbering of bibliography corrected |
| Databáze: | arXiv |
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