Alignment of Nematic Liquid Crystal on the Surface with Spatial Distribution of Easy Axis and Anchoring Energy

Aryasova, Natalie; Reznikov, Yuriy; Reshetnyak, Victor

doi:10.1080/15421400490440165

Cited by 9 publications

(10 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The HNF walls act on the director field of the guest as strongly anchoring, nanotextured sheets, with n(r) disordered on the nanoscale near the HNF sheets but annealing to order out to larger length scales with increasing distance from the HNFs, a scale comparable to the pore dimension in the middle of a pore. This results in an effective orientational anchoring that is much weaker than that on the HNF surface, in the same way that solid substrates having random orientations patterned on the nanoscale produce nearly-degenerate azimuthal alignment of a contacting bulk nematic [64][65][66][67] .…”

Section: δN<0 δN<0mentioning

confidence: 99%

Diastereomeric liquid crystal domains at the mesoscale

et al. 2015

View full text Add to dashboard Cite

In many technologies used to achieve separation of enantiomers, chiral selectors are designed to display differential affinity for the two enantiomers of a chiral compound. Such complexes are diastereomeric, differing in structure and free energy for the two enantiomers and enabling chiral discrimination. Here we present evidence for strong diastereomeric interaction effects at the mesoscale, manifested in chiral liquid crystal guest materials confined in a chiral, nanoporous network of semi-crystalline helical nanofilaments. The nanoporous host is itself an assembly of achiral, bent-core liquid crystal molecules that phase-separate into a conglomerate of 100 micron-scale, helical nanofilament domains that differ in structure only in the handedness of their homogeneous chirality. With the inclusion of a homochiral guest liquid crystal, these enantiomeric domains become diastereomeric, exhibiting unexpected and markedly different mesoscale structures and orientation transitions producing optical effects in which chirality has a dominant role.

show abstract

Section: δN<0 δN<0mentioning

confidence: 99%

Diastereomeric liquid crystal domains at the mesoscale

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Placing the LC layer between two polarizers, one can obtain the interference oscillations with the light intensity maxima and minima by changing the phase difference between the ordinary and extraordinary beams using an external electric or magnetic field under the conditions of the Frederiks transition [2]. In the misoriented LC layers, the birefringence effects can be observed without polarizers [3][4][5]. In [3], the interference maxima and minima were found using the monochromatic light.…”

Section: Introductionmentioning

confidence: 99%

Interference of nonpolarized light in liquid crystal domains on a polymer surface

et al. 2019

View full text Add to dashboard Cite

The interference of the nonpolarized light transmitted through an ensemble of nematic liquid crystal domains formed on the polycarbonate surface has been investigated. A model based on the superposition of the ordinary and extraordinary beams passed through domains with the radial structure has been developed. Expressions for the phase difference and intensity of the interfering beams, which take into account the distribution of the liquid crystal director field, have been derived. The dependences of the optical transmittance of a domain layer on the applied voltage have been calculated with regard to the material and optical constants of a liquid crystal and structural features and averaged morphological parameters of individual domains in the experimental sample. The results of the calculation are consistent with the experimental data, which confirms the validity of the proposed model.

show abstract

“…30 Surface randomness and resulting orientational quenched disorder also are important in liquid crystalline systems. [35][36][37][38] In their pioneering experiment Nespoulous, et al used a two-dimensional CCD array to image a 10 mm thick hybrid cell, planar alignment imposed by oblique evaporation of SiO x at one surface and vertical alignment at the other, which was arranged between crossed polarizers. Both theory and experiment are well represented, covering not only the nematic phase, but smectic phases as well.…”

Section: Introductionmentioning

confidence: 99%

Liquid crystal quenched orientational disorder at an AFM-scribed alignment surface

et al. 2015

View full text Add to dashboard Cite

A polyimide substrate was scribed using the stylus of an atomic force microscope, then covered with a nematic liquid crystal. The fiber from a near field scanning optical microscope was immersed into the liquid crystal and rastered approximately 80 nm above the surface, thereby obviating smearing effects that occur in thicker samples. By appropriate averaging of multiple data sets, a histogram of the "frozen-in" director deviation Δφ from the average easy axis was obtained, having a full-width-half-maximum of ∼0.02 rad. Additionally, the spatial autocorrelation function of Δφ was extracted, where the primary correlation length was found to be comparable to, but larger than, the liquid crystal's extrapolation length. A secondary characteristic length scale of a few μm was observed, and is thought to be an artifact due to material ejection during the scribing process. Our results demonstrate the utility of nanoscale imaging of the interface behavior inside the liquid crystal.

show abstract

Alignment of Nematic Liquid Crystal on the Surface with Spatial Distribution of Easy Axis and Anchoring Energy

Cited by 9 publications

References 6 publications

Diastereomeric liquid crystal domains at the mesoscale

Diastereomeric liquid crystal domains at the mesoscale

Interference of nonpolarized light in liquid crystal domains on a polymer surface

Liquid crystal quenched orientational disorder at an AFM-scribed alignment surface

Contact Info

Product

Resources

About