title: Colloidal cholesteric liquid crystal in spherical confinement.
abstract: The organization of nanoparticles in constrained geometries is an area of fundamental and practical importance. Spherical confinement of nanocolloids leads to new modes of packing, self-assembly, phase separation and relaxation of colloidal liquids; however, it remains an unexplored area of research for colloidal liquid crystals. Here we report the organization of cholesteric liquid crystal formed by nanorods in spherical droplets. For cholesteric suspensions of cellulose nanocrystals, with progressive confinement, we observe phase separation into a micrometer-size isotropic droplet core and a cholesteric shell formed by concentric nanocrystal layers. Further confinement results in a transition to a bipolar planar cholesteric morphology. The distribution of polymer, metal, carbon or metal oxide nanoparticles in the droplets is governed by the nanoparticle size and yields cholesteric droplets exhibiting fluorescence, plasmonic properties and magnetic actuation. This work advances our understanding of how the interplay of order, confinement and topological defects affects the morphology of soft matter.
authors: Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
authors: Yunfeng
authors: Y
authors: Li
authors: Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
authors: Jeffrey
authors: J
authors: Jun-Yan Suen
authors: Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
authors: Elisabeth
authors: E
authors: Prince
authors: Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
authors: Egor M
authors: EM
authors: Larin
authors: Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
authors: Anna
authors: A
authors: Klinkova
authors: Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.
authors: Héloïse
authors: H
authors: Thérien-Aubin
authors: State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
authors: Shoujun
authors: S
authors: Zhu
authors: State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China.
authors: Bai
authors: B
authors: Yang
authors: The Edward S. Rogers Sr. Department of Electrical and Computer Engineering and the Institute of Optical Sciences, University of Toronto, Toronto, Ontario, Canada M5S 3G4.
authors: Amr S
authors: AS
authors: Helmy
authors: Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, Ohio 44242, USA.
authors: Oleg D
authors: OD
authors: Lavrentovich
authors: Department of Chemistry, University of Toronto, Toronto, Ontario, Canada M5S 3H6.|Institute of Biomaterials &Biomedical Engineering, University of Toronto, 164 College Street, Toronto, Ontario, Canada M5S 3G9.|Department of Chemical Engineering and Applied Chemistry, University of Toronto, 200 College Street, Toronto, Ontario, Canada M5S 3E5.
authors: Eugenia
authors: E
authors: Kumacheva