title: Helically Twisted Chiral Arrays of Gold Nanoparticles Coated with a Cholesterol Mesogen.
abstract: Gold nanoparticles have been prepared and surface-functionalized with a 1:1 molar mixture of a hexylthiol ligand and a chiral mesogenic ligand consisting of a cholesterylbenzoate attached via an undecylthiol spacer. Grazing incidence X-ray diffraction showed that upon annealing a columnar liquid crystal (LC) structure develops with the nanoparticles forming strings on a regular oblique 2d lattice. Synchrotron radiation circular dichroism is substantially enhanced upon the isotropic-LC transition. In the proposed structural model, layers of Au columns rotate by a small angle relative to their neighbors, with the columns winding around a helical axis. The work demonstrates that it is possible to obtain chiral LC superstructures from nanoparticles coated with chiral mesogen without the addition of a separate LC or chiral dopants. The results provide direction in the development of plasmonic metamaterials interacting selectively with circularly polarized light.
authors.affiliation: Department of Chemistry, University of Hull , Hull HU6 7RX, United Kingdom.
authors.forename: Liliana
authors.initials: L
authors.lastname: Cseh
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield , Sheffield S1 3JD, United Kingdom.
authors.forename: Xiaobin
authors.initials: X
authors.lastname: Mang
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield , Sheffield S1 3JD, United Kingdom.
authors.forename: Xiangbing
authors.initials: X
authors.lastname: Zeng
authors.affiliation: Department of Materials Science and Engineering, University of Sheffield , Sheffield S1 3JD, United Kingdom.|State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an, 710049, PR China.
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Chemistry, University of Hull , Hull HU6 7RX, United Kingdom.
authors.forename: Georg H
authors.initials: GH
authors.lastname: Mehl
authors.affiliation: Department of Physics, Zhejiang Sci-Tech University , Hangzhou 310018, PR China.|Department of Materials Science and Engineering, University of Sheffield , Sheffield S1 3JD, United Kingdom.
authors.forename: Goran
authors.initials: G
authors.lastname: Ungar
authors.affiliation: Diamond Light Source , Harwell, Didcot OX11 0DE, United Kingdom.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Siligardi