Dynamic tuning of the director field in liquid crystal shells using block copolymers

  title={Dynamic tuning of the director field in liquid crystal shells using block copolymers},
  author={JungHyun Noh and Yiwei Wang and Hsin-Ling Liang and Venkata Subba Rao Jampani and Apala Majumdar and Jan P. F. Lagerwall},
  journal={arXiv: Soft Condensed Matter},
When a nematic liquid crystal (LC) is confined on a self-closing spherical shell, topological constraints arise with intriguing consequences that depend critically on how the LC is aligned in the shell. We demonstrate reversible dynamic tuning of the alignment, and thereby the topology, of nematic LC shells stabilized by the nonionic amphiphilic block copolymer Pluronic F127. Deep in the nematic phase, the director is tangential to the interface, but upon approaching the temperature TNI of the… 
Liquid crystal elastomer shells with topological defect-defined actuation: Complex shape morphing, opening/closing, and unidirectional rotation
We produce hollow sphere liquid crystal elastomer (LCE) actuators from a nematic precursor mixture, brought into the shape of a self-closing shell with tangential anchoring of the director field n (
Topological Defect-Guided Regular Stacking of Focal Conic Domains in Hybrid-Aligned Smectic Liquid Crystal Shells
We study liquid crystal (LC) shells in hybrid configuration (director tangential to the inside but normal to the outside) as they slowly undergo a transition from a nematic (N) to a smectic-A (SmA)
Measuring the Anisotropy in Interfacial Tension of Nematic Liquid Crystals
Liquid crystal (LC) phases typically show anisotropic alignment-dependent properties, such as viscosity and dielectric permittivity, so it stands to reason that LCs also have anisotropic interfacial
Temperature-driven anchoring transitions at liquid crystal / water interfaces.
The ability to change the anchoring of 4-cyano-4'-pentylbiphenyl (5CB), one of the most widely used liquid crystals, at the interface with dilute water solutions of polyvinyl alcohol (PVA), a polymer commonly used for stabilizing liquid crystal shells, simply by controlling the temperature in the close vicinity of the liquid crystal clearing point is reported.
Design of nematic liquid crystals to control microscale dynamics
ABSTRACT Dynamics of small particles, both living and inanimate, has fascinated scientists for centuries. Learning how to control it could open technological opportunities in the transformation of
Quantitative Volatile Organic Compound (VOC) Sensing with Liquid Crystal Core Fibers
We present a quantitative assessment of the ability of liquid crystal (LC)-filled polymer fibers to sense volatile organic compounds (VOCs). By correlating the birefringence ∆n of two LCs with
Electronic and electro-optical properties of 5CB and 5CT liquid crystal molecules: A comparative DFT study
In the present work, electro-optical and electronic properties of 4-n-pentyl- $$4^{\prime }$$ -cyanobiphenyl (5CB) and $$4^{\prime }$$ -cyano-4-n-pentyl-p-terphenyl (5CT) liquid crystal molecules
Modelling and computation of liquid crystals
  • Wei Wang, Lei Zhang, Pingwen Zhang
  • Computer Science, Mathematics
    Acta Numerica
  • 2021
This paper reviews the mathematical models and their connections to liquid crystals, and survey the developments of numerical methods for finding rich configurations of liquid crystals.
Quantitative volatile organic compound sensing with liquid crystal core fibers
Summary Polymer fibers with liquid crystals (LCs) in the core have potential as autonomous sensors of airborne volatile organic compounds (VOCs), with a high surface-to-volume ratio enabling fast and


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It is demonstrated that inclusions in a shell can seed defects that cannot form in a pristine shell, adding a further means of tuning the defect configuration, and that shells in which the internal aqueous phase is not density matched with the LC will gently rearrange the internal structure upon a rotation that changes the influence of gravity.
Realignment of Liquid Crystal Shells Driven by Temperature-Dependent Surfactant Solubility
It is suggested that LC shells can detect solutes in the continuous phase, provided there is sufficient probability that the solute migrates through the LC into the inner aqueous phase.
Towards tunable defect arrangements in smectic liquid crystal shells utilizing the nematic–smectic transition in hybrid-aligned geometries
We produce and investigate liquid crystal shells with hybrid alignment—planar at one boundary, homeotropic at the other—undergoing a transition between the nematic (N) and smectic-A (SmA) phases. The
Nematic-smectic transition under confinement in liquid crystalline colloidal shells.
We carry out the first study of smectic liquid crystalline colloidal shells and investigate how their complex internal structure depends on the director configuration in the nematic phase, preceding
Dielectrophoretic manipulation of the mixture of isotropic and nematic liquid
It is shown that a nematic–isotropic mixture, a unique bi-liquid system, has potential for the fabrication of microstructures having an ordered phase within a disordered phase, or vice versa.
Influence of interface stabilisers and surrounding aqueous phases on nematic liquid crystal shells.
In hybrid-aligned shells, with planar outer and homeotropic inner boundary (or vice versa), the N-I transition splits into two steps, with a consequent three-step textural transformation, as a result of the order-enhancing effect of a monolayer of radially aligned SDS molecules adsorbed at the homeotropic interface.
Sub-second dynamic phototuning of alignment in azodendrimer-doped nematic liquid crystal shells
Abstract The alignment of nematic liquid crystal 5CB in micron-thick shells, suspended in and containing aqueous liquid phases, can be rapidly switched between radial (homeotropic) and tangential
Topological transformations in bipolar shells of nematic liquid crystals.
In the case of nematic shells the two defects on the inner surface play a relevant role in the overall evolution process, and both involve the generation of a disclination ring that shrinks with time, eventually disappearing.
Extrinsic curvature effects on nematic shells.
The nematic elastic energy promotes the alignment of the flux lines of the nematic director towards geodesics and/or lines of curvature of the surface, which enables the manipulation of nematic alignment for the design of new materials and technological devices.
Spherical nematic shells with a prolate ellipsoidal core.
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