Helical nanofilament phases.
In the formation of chiral crystals, the tendency for twist in the orientation of neighboring molecules is incompatible with ordering into a lattice: Twist is expelled from planar layers at the expense of local strain. We report the ordered state of a neat material in which a local chiral structure is expressed as twisted layers, a state made possible by spatial limitation of layering to a periodic array of nanoscale filaments. Although made of achiral molecules, the layers in these filaments are twisted and rigorously homochiral--a broken symmetry. The precise structural definition achieved in filament self-assembly enables collective organization into arrays in which an additional broken symmetry--the appearance of macroscopic coherence of the filament twist--produces a liquid crystal phase of helically precessing layers.
Hough
L E
LE
Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, CO 80309, USA. hough@colorado.edu
Jung
H T
HT
Krüerke
D
D
Heberling
M S
MS
Nakata
M
M
Jones
C D
CD
Chen
D
D
Link
D R
DR
Zasadzinski
J
J
Heppke
G
G
Rabe
J P
JP
Stocker
W
W
Körblova
E
E
Walba
D M
DM
Glaser
M A
MA
Clark
N A
NA
D003460:Crystallization; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D008859:Microscopy, Polarization; D015394:Molecular Structure; D049329:Nanostructures; D014961:X-Ray Diffraction