Liquid crystals photoalignment by films of side-chain azobenzene-containing polymers with different molecular structure

Bobrovsky, Alexey; Ryabchun, Alexander; Shibaev, Valéry

doi:10.1016/j.jphotochem.2010.12.013

Cited by 31 publications

(22 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The thickness of the test samples was controlled with Teflon spacers. In order to obtain a good planar texture, we have used the LC photo‐alignment technique 43. Glass plates were spin‐coated with 2 mg/mL poly[1‐[4‐(3‐carboxy‐4‐hydroxy‐phenylazo) benzenesulfonamido]‐1,2‐ethanediyl, sodium salt (Sigma‐Aldrich, St. Louis, Missouri, USA).…”

Section: Methodsmentioning

confidence: 99%

Optically and Electrically Controlled Circularly Polarized Emission from Cholesteric Liquid Crystal Materials Doped with Semiconductor Quantum Dots

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

Optically and Electrically Controlled Circularly Polarized Emission from Cholesteric Liquid Crystal Materials Doped with Semiconductor Quantum Dots

et al. 2012

Self Cite

View full text Add to dashboard Cite

show abstract

“…In the case of glass cells for the preparation of uniaxially aligned LC layers, a photoalignment method was used. 35,36 For this purpose, glass substrates spin-coated with a solution of the sodium salt of poly[1-[4-(3-carboxy-4-hydroxy-phenylazo)benzenesulfonamido]-1,2-ethanediyl] (PAzo) (Aldrich) in chloroform (2 mg mL À1 ) were used. 36 Before the cell preparation, the substrates were irradiated with polarized polychromatic light from a mercury lamp (DRSh-350, 20 min, $15 mW cm À2 ).…”

Section: Lc Composite Lm Preparationmentioning

confidence: 99%

Photochromic LC–polymer composites containing azobenzene chromophores with thermally stable Z-isomers

et al. 2014

Self Cite

View full text Add to dashboard Cite

show abstract

“…There are several methods to fabricate patterns based on electro‐induced cholesteric DGs. One of the most versatile approach is based on exploiting photoalignment materials . Unlike the standard method of rubbing widely used for the orientation of LC molecules, photoalignment materials do not lead to physical treatment damaging and contaminating the surfaces.…”

Section: Diffraction Structures In Clc Materials Induced By Electric mentioning

confidence: 99%

Cholesteric Liquid Crystal Materials for Tunable Diffractive Optics

Ryabchun

Bobrovsky

2018

Advanced Optical Materials

Self Cite

186

106

View full text Add to dashboard Cite

refractive, diffraction and optical fiber components. In particular, diffraction grating (DG) is one of the key elements for the design and creation of modern optoelectronic devices. One of the most prominent materials for the creation of DGs is liquid crystals. The main feature of these systems is that liquid crystals combine properties such as optical anisotropy inherent for crystals and molecular mobility. High sensitivity to an external field, in particular to an electric field, makes liquid crystals very useful for the creation of DGs with tunable properties. The combination of these properties enables easy control of optical characteristics of such systems and opens wide perspectives for the design of new materials for diffractive optics.Among the different types of liquid crystalline (LC) phases, cholesteric liquid crystal (CLC) phase possesses intrinsic periodicity in the form of the helical supramolecular structure (Figure 1). With the realization of definite alignment conditions, this periodicity has been exploited for generation of DGs. [8,9] Another remarkable feature of the cholesteric mesophase is selective light reflection with the reflection wavelength determined by the simple Equation (1) where n is the average refractive index, and P is the helix pitch. The specific value of helix pitch depends on the chemical structure of the molecules forming the cholesteric phase and concentration of chiral moieties. One of the easiest ways to obtain the cholesteric mesophase is by doping the nematic matrix with chiral components (Figure 1). Variation of structure of chiral molecules by external stimuli leading, for examples, to the photoisomerization, is effectively used for fine tuning of the helix pitch. [10][11][12][13][14][15][16][17] In addition, the application of an electric field also provides a convenient opportunity to change optical properties of the CLC phase. [18][19][20][21] These unique properties enable to design a great variety of optical elements and devices based on CLC layers, films, or cells. Among them it is necessary to mention the media for photo-optical data recording, [22][23][24][25] electrically switchable mirrors, [26,27] optically controllable linearpolarization rotators, [28] coatings with controllable friction and adhesion, [29] materials for display technology, [23,30] secure Modern optics and photonics constantly require break-through materials and designs in order to achieve miniature, lightweight, highly tunable, and effective optical devices. One of the basic optical components is the diffraction grating (DG), widely used for the dispersion of light, beam steering, etc. This review gathers research efforts on diffractive optical elements based on cholesteric liquid crystal (CLC) materials with a supramolecular helical architecture. All main types and fabrication approaches of periodic diffractive structures from CLCs are classified and described. Key optical properties of DGs, their advantages and drawbacks are considered. Special attention is paid on the tunability of DG...

show abstract

Liquid crystals photoalignment by films of side-chain azobenzene-containing polymers with different molecular structure

Cited by 31 publications

References 32 publications

Optically and Electrically Controlled Circularly Polarized Emission from Cholesteric Liquid Crystal Materials Doped with Semiconductor Quantum Dots

Optically and Electrically Controlled Circularly Polarized Emission from Cholesteric Liquid Crystal Materials Doped with Semiconductor Quantum Dots

Photochromic LC–polymer composites containing azobenzene chromophores with thermally stable Z-isomers

Cholesteric Liquid Crystal Materials for Tunable Diffractive Optics

Contact Info

Product

Resources

About