4 research outputs found
Molecular simulation of chevrons in confined smectic liquid crystals
Chevron structures adopted by confined smectic liquid crystals
are investigated via molecular dynamics simulations of the Gay-Berne
model. The chevrons are formed by quenching nematic films confined
between aligning planar substrates whose easy axes have opposing
azimuthal components. When the substrates are perfectly smooth, the
chevron formed migrates rapidly towards one of the confining walls to
yield a tilted layer structure. However, when substrate roughness is
included, by introducing a small-amplitude modulation to the particle-
substrate interaction well-depth, a symmetric chevron is formed which
remains stable over sufficiently long runtimes for detailed structural
information, such as the relevant order parameters and director orien-
tation, to be determined. For both smooth and rough boundaries, the
smectic order parameter remains non-zero across the entire chevron,
implying that layer identity is maintained across the chevron tip. Also, when the surface-stabilised chevron does eventually revert to a tilted layer structure, it does so via surface slippage, such that layer integrity is maintained throughout the chevron to tilted layer relaxation process.
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