Electro‐optical Memory of a Nanoengineered Amorphous Blue‐Phase‐III Polymer Scaffold

Gandhi, Sahil Sandesh; Kim, Min Su; Hwang, Jeoung‐Yeon; Chien, Liang–Chy

doi:10.1002/adma.201603226

Cited by 39 publications

(67 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Under crossed polarizers, the dark blue image is observed as other BPIII system shows [33]. Deviation of the angle results in the observation of different color due to the optical activity of BP [21,22]. The color becomes greenish blue and brownish for positive and negative φ, which is similar to the observation of BPIII by Kim and Chien [22].…”

Section: 0supporting

confidence: 70%

“…However, absence of the platelet texture and dark blue texture do not always indicate the formation of BPIII, as Kim and Chien presented [22]. Chien et al provided an accurate method to distinguish BPIII from other BPs by observing optical activity [21,24,25]. Figure 2 shows polarized microscope image at T = 35.1 • C. Image in the center was taken under crossed polarizers, while images on left and right sides were taken at deviation angle between the analyzer and polarizer of φ = ±4 • by following the method established by Chien's group [21,24].…”

Section: 0mentioning

confidence: 99%

“…Chien et al provided an accurate method to distinguish BPIII from other BPs by observing optical activity [21,24,25]. Figure 2 shows polarized microscope image at T = 35.1 • C. Image in the center was taken under crossed polarizers, while images on left and right sides were taken at deviation angle between the analyzer and polarizer of φ = ±4 • by following the method established by Chien's group [21,24]. Under crossed polarizers, the dark blue image is observed as other BPIII system shows [33].…”

Section: 0mentioning

confidence: 99%

See 2 more Smart Citations

Nonlinear Rheology and Fracture of Disclination Network in Cholesteric Blue Phase III

Fujii

Sasaki

Orihara

2018

Fluids

View full text Add to dashboard Cite

Nonlinear rheological properties of chiral crystal cholesteryl oleyl carbonate (COC) in blue phase III (BPIII) were investigated under different shear deformations: large amplitude oscillatory shear, step shear deformation, and continuous shear flow. Rheology of the liquid crystal is significantly affected by structural rearrangement of defects under shear flow. One of the examples on the defect-mediated rheology is the blue phase rheology. Blue phase is characterized by three dimensional network structure of the disclination lines. It has been numerically studied that the rheological behavior of the blue phase is dominated by destruction and creation of the disclination networks. In this study, we find that the nonlinear viscoelasticity of BPIII is characterized by the fracture of the disclination networks. Depending on the degree of the fracture, the nonlinear viscoelasticity is divided into two regimes; the weak nonlinear regime where the disclination network locally fractures but still shows elastic response, and the strong nonlinear regime where the shear deformation breaks up the networks, which results in a loss of the elasticity. Continuous shear deformation reveals that a series of the fracture process delays with shear rate. The shear rate dependence suggests that force balance between the elastic force acting on the disclination lines and the viscous force determines the fracture behavior.

show abstract

Section: 0supporting

confidence: 70%

Section: 0mentioning

confidence: 99%

Section: 0mentioning

confidence: 99%

See 1 more Smart Citation

Nonlinear Rheology and Fracture of Disclination Network in Cholesteric Blue Phase III

Fujii

Sasaki

Orihara

2018

Fluids

View full text Add to dashboard Cite

show abstract

“…Up to now, most LC‐based devices for light modulation have employed defect‐free systems, but regular arrays of topological defects have opened new routes for polymer templating and colloidal self‐assembly, and for the design of innovative applications, such as optical vortex generation, metasurfaces, bistable devices, and optical diffraction gratings . Optically functional materials are much sought‐after for creating novel displays and optoelectronic devices.…”

Section: Introductionmentioning

confidence: 99%

Tunable Dynamic Topological Defect Pattern Formation in Nematic Liquid Crystals

Kim

Serra

2019

Advanced Optical Materials

View full text Add to dashboard Cite

Soft materials are ideal candidates for the creation of tunable, self‐assembled structures. Herein, reconfigurable and switchable dynamic patterns are created using topological defects in nematic liquid crystals. The elastic properties of liquid crystals combined with their responsiveness to electric field are used to control the periodicity and the symmetry of an array of topological defects, assisted by polymeric micropillars. The switching between stable configurations is perfectly reversible and repeatable, and there is no limitation on the length scale of the regular array of defects. The array is used to create 2D diffraction patterns that can be tuned both in the azimuthal and in the polar directions. In addition, the refractive index of the liquid crystal mixture is controlled to optimize the diffraction efficiency. This system, with its flexibility and controllability, offers a promising route for the design of patters with arbitrary symmetry that can be employed in optics and reversible self‐assembly.

show abstract

“…Such structures are accompanied by the formation of ordered networks of topological defects that reflect light in the visible range. A third BP, the so-called BPIII, exhibits a disordered structure34. The highly ordered morphology of BPI and BPII gives rise to unusual physical properties, including a high viscosity, Bragg reflection of visible light, a finite shear modulus and a fast optical response (much faster than that of traditional nematic liquid crystals).…”

mentioning

confidence: 99%

Directed self-assembly of liquid crystalline blue-phases into ideal single-crystals

et al. 2017

View full text Add to dashboard Cite

Chiral nematic liquid crystals are known to form blue phases—liquid states of matter that exhibit ordered cubic arrangements of topological defects. Blue-phase specimens, however, are generally polycrystalline, consisting of randomly oriented domains that limit their performance in applications. A strategy that relies on nano-patterned substrates is presented here for preparation of stable, macroscopic single-crystal blue-phase materials. Different template designs are conceived to exert control over different planes of the blue-phase lattice orientation with respect to the underlying substrate. Experiments are then used to demonstrate that it is indeed possible to create stable single-crystal blue-phase domains with the desired orientation over large regions. These results provide a potential avenue to fully exploit the electro-optical properties of blue phases, which have been hindered by the existence of grain boundaries.

show abstract

Electro‐optical Memory of a Nanoengineered Amorphous Blue‐Phase‐III Polymer Scaffold

Cited by 39 publications

References 40 publications

Nonlinear Rheology and Fracture of Disclination Network in Cholesteric Blue Phase III

Nonlinear Rheology and Fracture of Disclination Network in Cholesteric Blue Phase III

Tunable Dynamic Topological Defect Pattern Formation in Nematic Liquid Crystals

Directed self-assembly of liquid crystalline blue-phases into ideal single-crystals

Contact Info

Product

Resources

About