Chiral dopants and the twist-bend nematic phase-induction of novel mesomorphic behaviour in an apolar bimesogen

TY - JOUR

T1 - Chiral dopants and the twist-bend nematic phase-induction of novel mesomorphic behaviour in an apolar bimesogen

AU - Archbold, Craig T.

AU - Davis, Edward J.

AU - Mandle, Richard J.

AU - Cowling, Stephen J.

AU - Goodby, John W.

PY - 2015/8/12

Y1 - 2015/8/12

N2 - Herein we report studies on a bimesogen that exhibits a chiral twist bend nematic phase when doped with small weight percentages of a chiral material and a partial phase diagram constructed. At low concentrations a wide temperature range blue phase is observed, whereas at higher concentrations an additional 'nematic-like' mesophase was discovered at a lower temperature than the twist-bend nematic phase. In addition to an apparent isotropic-"isotropic" transition, the doped materials also exhibited a weakly birefringent phase upon annealing in the isotropic liquid phase, implying pretransitional behaviour in the same vein as that seen for TGB phases. When confined in a planar aligned cell, the NTB phase exhibited two domains that alternated between light and dark with rotation of the sample stage, as well as the application of an external electric field. Upon the addition of a chiral dopant one of these domains was eliminated, leading to their assignment as twist domains of opposite handedness.

AB - Herein we report studies on a bimesogen that exhibits a chiral twist bend nematic phase when doped with small weight percentages of a chiral material and a partial phase diagram constructed. At low concentrations a wide temperature range blue phase is observed, whereas at higher concentrations an additional 'nematic-like' mesophase was discovered at a lower temperature than the twist-bend nematic phase. In addition to an apparent isotropic-"isotropic" transition, the doped materials also exhibited a weakly birefringent phase upon annealing in the isotropic liquid phase, implying pretransitional behaviour in the same vein as that seen for TGB phases. When confined in a planar aligned cell, the NTB phase exhibited two domains that alternated between light and dark with rotation of the sample stage, as well as the application of an external electric field. Upon the addition of a chiral dopant one of these domains was eliminated, leading to their assignment as twist domains of opposite handedness.

UR - http://www.scopus.com/inward/record.url?scp=84942346145&partnerID=8YFLogxK

U2 - 10.1039/c5sm01935d

DO - 10.1039/c5sm01935d

M3 - Article

AN - SCOPUS:84942346145

SN - 1744-683X

VL - 11

SP - 7547

EP - 7557

JO - Soft Matter

JF - Soft Matter

IS - 38

ER -