title: Entropy-driven formation of large icosahedral colloidal clusters by spherical confinement.
abstract: Icosahedral symmetry, which is not compatible with truly long-range order, can be found in many systems, such as liquids, glasses, atomic clusters, quasicrystals and virus-capsids. To obtain arrangements with a high degree of icosahedral order from tens of particles or more, interparticle attractive interactions are considered to be essential. Here, we report that entropy and spherical confinement suffice for the formation of icosahedral clusters consisting of up to 100,000 particles. Specifically, by using real-space measurements on nanometre- and micrometre-sized colloids, as well as computer simulations, we show that tens of thousands of hard spheres compressed under spherical confinement spontaneously crystallize into icosahedral clusters that are entropically favoured over the bulk face-centred cubic crystal structure. Our findings provide insights into the interplay between confinement and crystallization and into how these are connected to the formation of icosahedral structures.
authors.affiliation: 1] Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands [2].
authors.forename: Bart
authors.initials: B
authors.lastname: de Nijs
authors.affiliation: 1] Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands [2].
authors.forename: Simone
authors.initials: S
authors.lastname: Dussi
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Frank
authors.initials: F
authors.lastname: Smallenburg
authors.affiliation: Electron Microscopy Group, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Johannes D
authors.initials: JD
authors.lastname: Meeldijk
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Groenendijk
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Laura
authors.initials: L
authors.lastname: Filion
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Arnout
authors.initials: A
authors.lastname: Imhof
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Alfons
authors.initials: A
authors.lastname: van Blaaderen
authors.affiliation: Soft Condensed Matter, Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands.
authors.forename: Marjolein
authors.initials: M
authors.lastname: Dijkstra