Modulated nematic structures induced by chirality and steric polarization

Abstract

What kind of one-dimensional modulated nematic structures (ODMNS) can form nonchiral and chiral bent-core and dimeric materials? Here, using Landau-deGennes theory of nematics, extended to account for molecular steric polarization, we study a possibility of formation of ODMNS, both in nonchiral and intrinsically chiral liquid crystalline materials. Besides nematic and cholesteric phases, we find four bulk ODMNS for nonchiral materials, two of which have not been reported so far. These new structures are longitudinal ($N_{LP}$) and transverse ($N_{TP}$) periodic waves where the polarization field being periodic in one dimension stays parallel and perpendicular, respectively, to the wave vector. The other two phases have all characteristic features of the twist-bend nematic phase ($N_{TB}$) and the splay-bend nematic phase ($N_{SB}$), but their fine structure appears more complex than that considered so far. The presence of molecular chirality converts nonchiral $N_{TP}$ and $N_{SB}$ into new $N_{TB}$ phases. Interestingly, the nonchiral $N_{LP}$ phase can stay stable even in the presence of intrinsic molecular chirality. Exemplary phase diagrams provide further insights into the relative stability of these new modulated nematic structures.

arXiv comment5 pages, 5 figures

References in corpus (8)

• Nematic twist-bend phase with nanoscale modulation of molecular orientation
• A Twist-Bend Chiral Helix of 8nm Pitch in a Nematic Liquid Crystal of Achiral Molecular Dimers
• Twist-bend heliconical chiral nematic liquid crystal phase of an achiral rigid bent-core mesogen
• Statistical mechanics of bend flexoelectricity and the twist-bend phase in bent-core liquid crystals
• Theory of Banana Liquid Crystal Phases and Phase Transitions
• Theory of Polar Blue Phases
• Chiral Symmetry Breaking in Bent-Core Liquid Crystals
• Flexoelectric blue phases

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• In silico study of liquid crystalline phases formed by bent-shaped molecules with excluded-volume type interactions
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• Confinement Reveals Hidden Splay-Bend Order in Twist-Bend Nematics