Mesophase behaviour of polyhedral particles
Agarwal, U.; Escobedo, F.A.
Translational and orientational excluded-volume fields encoded in particles with anisotropic shapes can lead to purely entropy-driven assembly of morphologies with specific order and symmetry. To elucidate this complex correlation, we carried out detailed Monte Carlo simulations of six convex space-filling polyhedrons, namely, truncated octahedrons, rhombic dodecahedrons, hexagonal prisms, cubes, gyrobifastigiums and triangular prisms. Simulations predict the formation of various new liquid-crystalline and plastic-crystalline phases at intermediate volume fractions. By correlating these findings with particle anisotropy and rotational symmetry, simple guidelines for predicting phase behaviour of polyhedral particles are proposed: high rotational symmetry is in general conducive to mesophase formation, with low anisotropy favouring plastic-solid behaviour and intermediate anisotropy (or high uniaxial anisotropy) favouring liquid-crystalline behaviour. It is also found that dynamical disorder is crucial in defining mesophase behaviour, and that the apparent kinetic barrier for the liquid-mesophase transition is much lower for liquid crystals (orientational order) than for plastic solids (translational order).
This work was supported by a Department of Energy Basic Energy Science Grant ER46517. This publication is based on work supported in part by award no. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST).
NATURE PUBLISHING GROUP
PHASE-BEHAVIOR; NANOPARTICLES; GOLD; NANOCRYSTALS; PACKINGS; CRYSTALS; CUBOIDS; FLUID
Previously Published As
Nature Materials 10,230–235(2011)doi:10.1038/nmat2959