Crystal structures in binary hard-sphere colloid-droplet mixtures with patchy cross interactions
| Autor: | Andrea Fortini, Hai Pham Van, Matthias Schmidt |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
endocrine system
Materials science digestive oral and skin physiology technology industry and agriculture Close-packing of equal spheres Crystal structure Cubic crystal system Tetrahedral symmetry complex mixtures 01 natural sciences Molecular physics 010305 fluids & plasmas Condensed Matter::Soft Condensed Matter Condensed Matter::Materials Science Colloid Molecular geometry 0103 physical sciences Physics::Atomic and Molecular Clusters 010306 general physics Anisotropy Phase diagram |
| Zdroj: | Physical Review E. 101 |
| ISSN: | 2470-0053 2470-0045 |
| Popis: | A binary mixture of droplets and patchy colloids, where patches are arranged in tetrahedral symmetry, is studied with Metropolis Monte Carlo simulations. The colloidal patches attract droplets, while both the colloid-colloid and the droplet-droplet interactions are hard sphere like. We find stable crystal structures with atomic analogs $\mathrm{ZnS}, {\mathrm{CaF}}_{2}$, and fcc or hcp (face centered cubic or hexagonal close packed) of the droplets coexisting with a dispersed fluid of the colloids. The simulated crystal structures agree well with those predicted by close-packing calculations for an intermediate range of droplet-colloid size ratios. A discrepancy between the simulations and theoretical predictions occurs at low and high size ratios. The results of the simulations for mixtures with anisotropic colloid-droplet interactions reveal a richer phase diagram, with ZnS-gas and ZnS-fluid coexistence, as compared to the isotropic case. For the example of a square planar patch arrangement, we find a particular crystal structure, consisting of two interpenetrating fcc or hcp lattices with right bond angles. Such a structure has no known atomic analog. Our study of generic models of anisotropic colloid-droplet mixtures could provide a promising way towards the fabrication of novel and complex colloidal structures. |
| Databáze: | OpenAIRE |
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