Confinement-Induced Transition of Topological Defects in Smectic Liquid Crystals: From a Point to a Line and Pearls

Jeong, Joonwoo; Kim, Mahn Won

doi:10.1103/physrevlett.108.207802

Cited by 28 publications

(18 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Droplets can also be formed with phase separation as in polymer-dispersed LC [69], or with microfluidics which gives substantial control over their sizes [70,71]. Droplets of various LC phases have been studied so far: smectic [26,72], columnar [73] and blue phases [74][75][76], but by far the most frequently studied are nematic and cholesteric droplets.…”

Section: Liquid Crystal Dropletsmentioning

confidence: 99%

Topological Formations in Chiral Nematic Droplets

Posnjak¹

2018

Springer Theses

View full text Add to dashboard Cite

Section: Liquid Crystal Dropletsmentioning

confidence: 99%

Topological Formations in Chiral Nematic Droplets

Posnjak¹

2018

Springer Theses

View full text Add to dashboard Cite

“…emulsions | complex colloids T he director configurations of confined liquid crystals exhibit a rich phenomenology, the physics of which is determined by a delicate interplay of topology, elastic free energy, and anchoring conditions at the boundaries (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12). Droplets present arguably the simplest and most symmetric confining container for liquid crystals.…”

mentioning

confidence: 99%

Chiral symmetry breaking and surface faceting in chromonic liquid crystal droplets with giant elastic anisotropy

Jeong

Davidson

Collings

et al. 2014

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

127

135

View full text Add to dashboard Cite

Confined liquid crystals (LC) provide a unique platform for technological applications and for the study of LC properties, such as bulk elasticity, surface anchoring, and topological defects. In this work, lyotropic chromonic liquid crystals (LCLCs) are confined in spherical droplets, and their director configurations are investigated as a function of mesogen concentration using bright-field and polarized optical microscopy. Because of the unusually small twist elastic modulus of the nematic phase of LCLCs, droplets of this phase exhibit a twisted bipolar configuration with remarkably large chiral symmetry breaking. Further, the hexagonal ordering of columns and the resultant strong suppression of twist and splay but not bend deformation in the columnar phase, cause droplets of this phase to adopt a concentric director configuration around a central bend disclination line and, at sufficiently high mesogen concentration, to exhibit surface faceting. Observations of director configurations are consistent with Jones matrix calculations and are understood theoretically to be a result of the giant elastic anisotropy of LCLCs.emulsions | complex colloids T he director configurations of confined liquid crystals exhibit a rich phenomenology, the physics of which is determined by a delicate interplay of topology, elastic free energy, and anchoring conditions at the boundaries (1-12). Droplets present arguably the simplest and most symmetric confining container for liquid crystals. Droplets of thermotropic liquid crystals (TLCs) and the manipulation of their director configurations, for example, are actively studied, in part because of their demonstrated use as core materials in display technologies (3, 13) and their potential applications ranging from biosensors (14, 15) to microlasers (16). Indeed, significant fundamental and technological progress has been made with TLC droplets, because their bulk elasticity and surface anchoring phenomena are now well understood and easily controlled.Lyotropic chromonic liquid crystals (LCLCs) are composed of organic, charged, and plank-like mesogens that self-assemble in water into columnar aggregates via noncovalent electrostatic, excluded volume, hydrophobic, and pi-pi stacking interactions (17)(18)(19)(20). The aggregates, in turn, assemble into nematic or columnar phases, depending on temperature and concentration. A variety of organic molecules such as dyes, drugs, and biomolecules form LCLCs (17-28). However, far less is known about the fundamental science and applications potential of LCLCs than the more-studied TLCs. Indeed, basic properties of LCLCs, including aggregate size distribution and formation dynamics, bulk elasticity, and surface anchoring are neither fully characterized nor understood and are the subject of exciting ongoing research. Only recently, for example, have measurements been made of fundamental properties, such as the FrankOseen elastic constants (28, 29), of any LCLC, and they have revealed unusual concentration and temperature dependences of the splay ...

show abstract

“…Below the N -SmA transition the elastic modulus varies as B ∼ t 0.38 [43]. If the discontinuity angle exceeds a critical value, it may further create edge dislocations in the confined region [46]. In the present system the length of the defect line increases and the colloidal particles are pushed apart, thereby increasing the center-to-center separation.…”

Section: Resultsmentioning

confidence: 78%

N−SmA−SmCphase transitions probed by a pair of elastically bound colloids

Zuhail

Roy

et al. 2018

Phys. Rev. E

View full text Add to dashboard Cite

The competing effect of surface anchoring of dispersed microparticles and elasticity of nematic and cholesteric liquid crystals has been shown to stabilize a variety of topological defects. Here we study a pair of colloidal microparticles with homeotropic and planar surface anchoring across N-SmA-SmC phase transitions. We show that below the SmA-SmC phase transition the temperature dependence of interparticle separation (D) of colloids with homeotropic anchoring shows a power-law behavior; D∼(1-T/T_{AC})^{α}, with an exponent α≈0.5. For colloids with planar surface anchoring the angle between the joining line of the centers of the two colloids and the far field director shows characteristic variation elucidating the phase transitions.

show abstract

Confinement-Induced Transition of Topological Defects in Smectic Liquid Crystals: From a Point to a Line and Pearls

Cited by 28 publications

References 39 publications

Topological Formations in Chiral Nematic Droplets

Topological Formations in Chiral Nematic Droplets

Chiral symmetry breaking and surface faceting in chromonic liquid crystal droplets with giant elastic anisotropy

N−SmA−SmCphase transitions probed by a pair of elastically bound colloids

Contact Info

Product

Resources

About