Twist-bend nematic phases of bent-shaped biaxial molecules

Abstract

How change in molecular structure can affect relative stability and structural properties of the twist-bend nematic phase (N${}_{\text{TB}}$)? Here we extend the mean-field model [C. Greco et al., Soft Matter, 2014, 10, 9318] for bent-shaped achiral molecules, to study the influence of arm molecular biaxiality and the value of molecule's bend angle on relative stability of N${}_{\text{TB}}$. In particular we show that by controlling biaxiality of molecule's arms up to four ordered phases can become stable. They involve locally uniaxial and biaxial variants of N${}_{\text{TB}}$, together with the uniaxial and the biaxial nematic phases. However, the V-shaped molecule show stronger ability to form stable N${}_{\text{TB}}$ than a biaxial nematic phase, where the latter phase appears in the phase diagram only for bend angles greater than $140^{\circ }$ and for large biaxiality of the two arms.

arXiv comment8 pages, 8 figures

References in corpus (13)

• 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
• Resonant carbon K-edge soft x-ray scattering from lattice-free heliconical molecular ordering: soft dilative elasticity of the twist-bend liquid crystal phase
• Statistical mechanics of bend flexoelectricity and the twist-bend phase in bent-core liquid crystals
• Theory of Banana Liquid Crystal Phases and Phase Transitions
• A Molecular Theory of the Nematic-Nematic Phase Transitions in Mesogenic Dimers
• Elastic continuum theory: Fully understanding of the twist-bend nematic phases
• Modulated nematic structures induced by chirality and steric polarization
• Landau theory for helical nematic phases
• Chiral Symmetry Breaking in Bent-Core Liquid Crystals
• Stability of Biaxial Nematic Phase in Model Bent-Core Systems
• Unwinding of the twist-bend nematic structure under an external field

Cited by in corpus (6)

• Nematic twist--bend phase in an external field
• Uniform distortions and generalized elasticity of liquid crystals
• Twist-bend nematic phase from Landau-de Gennes perspective
• Liquid Crystal Distortions Revealed by an Octupolar Tensor
• In silico study of liquid crystalline phases formed by bent-shaped molecules with excluded-volume type interactions
• Classifying local anisotropy formed by rigid molecules: symmetries and tensors