Intertwined spontaneous helix formation in achiral bent-core liquid crystals

ORAL

Abstract

Inspired by several reports of spontaneous helix formation in bent-core smectics, we have investigated the smectic phases of a series of bent-core mesogens with 4-cyanoresorcinol bisbenzoate cores. In PAL30, the homolog with n=14 alkyl tails, we observed an incommensurate, bent-core phase with a single helix incommensurate with the smectic layering [1], a structure broadly analogous to the phase of rod-shaped molecules. In the PAL29, the n=16 homolog, we have confirmed, using both resonant and non-resonant x-ray diffraction, as well as electro-optical methods, the existence of a phase with intertwined helices, similar to the structure recently reported by Salamonczyk and co-workers [2]. Establishing the existence of the intertwined double-helical phase and the single-helical phase in such closely related homologs is an important step in understanding the competing interactions that lead to such exotic phase structures.
[1] A. Green et al., PRL 122, 107801 (2019).
[2] M. Salamonczyk et al., Nature Communications 10, 1922 (2019).

**This work was supported by the Soft Materials Research Center under NSF MRSEC Grant No. DMR-1420736. and by NASA Grant Nos. NNX-13AQ81G and NAG No. NNX17AC74G.

Presenters

  • Vikina Martinez

    • Physics and Soft Materials Research Center, University of Colorado Boulder

Authors

  • Vikina Martinez

    • Physics and Soft Materials Research Center, University of Colorado Boulder
  • Adam Green

    • Physics and Soft Materials Research Center, University of Colorado Boulder
  • Cheol Park

    • Physics and Soft Materials Research Center, University of Colorado Boulder
    • Physics and Soft Materials Research Center, University of Colorado
  • Matthew Glaser

    • Physics and Soft Materials Research Center, University of Colorado Boulder
    • University of Colorado, Boulder
    • Department of Physics, University of Colorado, Boulder
    • Institute of Solid State Physics, Otto von Guericke University
  • Joseph E MacLennan

    • Physics and Soft Materials Research Center, University of Colorado Boulder
    • University of Colorado, Boulder
    • Department of Physics, University of Colorado, Boulder
    • Physics and Soft Materials Research Center, University of Colorado
  • Noel Anthony Clark

    • Physics and Soft Materials Research Center, University of Colorado Boulder
    • University of Colorado, Boulder
    • Department of Physics, University of Colorado, Boulder
    • Physics and Soft Materials Research Center, University of Colorado