scholarly journals Adjacent functional group effects on the assembly of columnar liquid crystals

2020 ◽  
Vol 98 (7) ◽  
pp. 379-385
Author(s):  
Carson O. Zellman ◽  
Danielle Vu ◽  
Vance E. Williams
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Room Temperature ◽  
Functional Group ◽  
The Self ◽  
Clearing Temperature ◽  
Crystal Phases ◽  
Potential Strategy ◽  
The Impact

Although the impact of individual functional groups on the self-assembly of columnar liquid crystal phases has been widely studied, the effect of varying multiple substituents has received much less attention. Herein, we report a series of dibenzo[a,c]phenazines containing an alcohol or ether adjacent to an electron-withdrawing ester or acid. With one exception, these difunctional mesogens form columnar phases. The phase behavior appeared to be dominated by the electron-withdrawing substituent; transition temperatures were similar to derivatives with these groups in isolation. In most instances, the addition of an electron-donating group ortho to an ester or acid suppressed the melting temperature and elevated the clearing temperature, leading to broader liquid crystal thermal ranges. This effect was more pronounced for derivatives functionalized with longer chain hexyloxy groups. These results suggest a potential strategy for controlling the phase ranges of columnar liquid crystals and achieving room temperature mesophases.

scholarly journals Liquid Crystals Templating

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 648 ◽  
Author(s):  
Mamatha Nagaraj
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Inorganic Materials ◽  
The Self ◽  
Thermotropic Liquid Crystals ◽  
Versatile Technique ◽  
Crystal Phases ◽  
Nanoscale Features ◽  
Mesoporous Membranes ◽  
Liquid Crystal Templating

Liquid crystal templating is a versatile technique to create novel organic and inorganic materials with nanoscale features. It exploits the self-assembled architectures of liquid crystal phases as scaffolds. This article focuses on some of the key developments in lyotropic and thermotropic liquid crystals templating. The procedures that were employed to create templated structures and the applications of these novel materials in various fields including mesoporous membranes, organic electronics, the synthesis of nanostructured materials and photonics, are described.

scholarly journals Optical Response Associated with the Orientation and Structure of Liquid Crystals with Respect to Phosphatidylcholine Concentration

Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 678
Author(s):  
Yuqi Han ◽  
Yan Jiang ◽  
Wei Guo ◽  
Bing Li ◽  
Lu Zhang ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Reflectance Spectrum ◽  
Optical Response ◽  
The Self ◽  
Cholesteric Liquid Crystals ◽  
Anchoring Effect ◽  
Self Assembling ◽  
Sensitization Effect ◽  
Structure Of Liquid

Based on the anchoring effect due to the self-assembling behavior of the phospholipid molecules at the interface between the liquid crystal and water phases on the orientation of liquid crystals, the optical response associated with the orientation and structure of liquid crystals with respect to the concentration of 1,2-didodecanoyl-sn-glycero-3-phosphocholine solution has been investigated. The optical response owing to changes in the orientation and structure of the mixed cholesteric liquid crystals with respect to the change in the concentration of phosphatidylcholine has been obtained. Moreover, the feasibility of using as-prepared mixed cholesteric liquid crystals to measure the phosphatidylcholine concentration has been verified. A methodology to measure the reflectance spectrum by using mixed cholesteric liquid crystals to sensitize the phosphatidylcholine concentration has been further realized. The sensitization effect of the mixed cholesteric liquid crystals on the measurement of phosphatidylcholine concentration was also verified.

scholarly journals Liquid crystal phase transitions in suspensions of mineral colloids: new life from old roots

2013 ◽  
Vol 371 (1988) ◽  
pp. 20120263 ◽  
Author(s):  
H. N. W. Lekkerkerker ◽  
G. J. Vroege
Keyword(s):  
Phase Transitions ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Colloidal Suspensions ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Future Developments ◽  
Mineral Particles ◽  
Crystal Phases ◽  
Liquid Crystal Phases

A review is given of the field of mineral colloidal liquid crystals : liquid crystal phases formed by individual mineral particles within colloidal suspensions. Starting from their discovery in the 1920s, we discuss developments on the levels of both fundamentals and applications. We conclude by highlighting some promising results from recent years, which may point the way towards future developments.

Discotic Liquid Crystals of Transition metal Complexes 23: Synthesis and Mesomorphism of Tetrakis(3,4-di-n-alkylphenyl)porphyrin Derivatives and Their Metal Complexes

1999 ◽  
Vol 03 (04) ◽  
pp. 249-258 ◽  
Author(s):  
KAZUCHIKA OHTA ◽  
MASAHIRO ANDO ◽  
IWAO YAMAMOTO
Keyword(s):  
Liquid Crystal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Room Temperature ◽  
Discotic Liquid Crystals ◽  
X Ray ◽  
Alkyl Chains ◽  
Porphyrin Derivatives ◽  
Crystal Phases ◽  
Long Chain

Five novel long-chain-substituted porphyrin derivatives, tetrakis(3,4-dialkylphenyl)porphyrins (abbreviated as (Cn)8 TPPH 2 (n = 8, 12, 18), ( C 18)8 TPPCu and ( C 18)8 TPPNi ), were synthesized and their mesomorphism was investigated. It was found that the (Cn)8 TPPH 2 (n = 8, 12), derivatives are isotropic liquids at room temperature and that each of the ( C 18)8 TPPM ( M ≡ H 2, Cu , Ni ) derivatives has two liquid crystal phases M1 and M2 and two unidentified phases X1 and X2. It was revealed by X-ray studies that the M2 phase is a discotic lamellar (DL) phase. Interestingly, these porphyrin derivatives exhibit not a columnar but a lamellar mesophase, even though they have a disk-like central core with eight alkyl chains in the surroundings.

Hydrothermal Syntheses, Crystal Structures, and Luminescent Properties of Two MnII Coordination Polymers: From Two-Fold Interpenetrated pcu Topological Net to Polycatenated 2D+2D→3D Framework

2015 ◽  
Vol 68 (2) ◽  
pp. 322 ◽  
Author(s):  
Wenlong Liu ◽  
Mengqiang Wu ◽  
Xueying Wang ◽  
Wei Wang ◽  
Dayu Liu ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Coordination Polymers ◽  
Self Assembly ◽  
Room Temperature ◽  
Luminescent Properties ◽  
The Self ◽  
X Ray Diffraction ◽  
X Ray ◽  
3D Framework ◽  
Dimethyl Benzene

Using a hydrothermal synthesis, the self-assembly of MnII ions and 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene with two dicarboxylate ligands, 2-nitrobenzene-1,4-dicarboxylic acid (2-H2ata) and 5-methylbenzene-1,3-dicarboxylic acid (5-CH3-H2ip) constructed two interesting coordination polymers: [Mn(2-ata)(bimb)]n (1) and {[Mn(5-CH3-ip)(bimb)1.5]·2H2O}n (2), where bimb refers to 1,4-bis(1-imidazol-yl)-2,5-dimethyl benzene. Their structures were determined by single-crystal X-ray diffraction, elemental analysis, and infrared spectroscopy. Complex 1 exhibits a 2-fold interpenetrated pcu net. Complex 2 shows an unusual polycatenated 2D+2D→3D framework. In addition, the solid-state photoluminescent properties of 1 and 2 were investigated at room temperature.

Pattern Formation During the Growth of Liquid Crystal Phases

MRS Bulletin ◽  
1991 ◽  
Vol 16 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Patrick Oswald ◽  
John Bechhoefer ◽  
Francisco Melo
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Unit Vector ◽  
The Other ◽  
Two Dimensional ◽  
Smectic A ◽  
Anisotropic Plastic ◽  
Fundamental Research ◽  
Crystal Phases ◽  
Columnar Mesophases

Liquid crystals, discovered just a century ago, have wide application to electrooptic displays and thermography. Their physical properties have also made them fascinating materials for more fundamental research.The name “liquid crystals” is actually a misnomer for what are more properly termed “mesophases,” that is, phases having symmetries intermediate between ordinary solids and liquids. There are three major classes of liquid crystals: nematics, smectics, and columnar mesophases. In nematics, although there is no correlation between positions of the rodlike molecules, the molecules tend to lie parallel along a common axis, labeled by a unit vector (or director) n. Smectics are more ordered. The molecules are also rodlike and are in layers. Different subtypes of smectics (labeled, for historical reasons, smectic A, smectic B,…) have layers that are more or less organized. In the smectic A phase, the layers are fluid and can glide easily over each other. In the smectic B phase, the layers have hexagonal ordering and strong interlayer corrélations. Indeed, the smectic B phase is more a highly anisotropic plastic crystal than it is a liquid crystal. Finally, columnar mesophases are obtained with disklike molecules. These molecules can stack up in columns which are themselves organized in a two-dimensional array. There is no positional correlation between molecules in one column and molecules in the other columns.

scholarly journals Supramolecular self-assembly and physical-gel formation in disc-like liquid crystals: a scalable predictive model for gelation and an application in photovoltaics

RSC Advances ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 6335-6345
Author(s):  
Sehrish Iqbal ◽  
Ammar A. Khan
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Predictive Model ◽  
Self Assembly ◽  
Gel Formation ◽  
Discotic Liquid Crystal ◽  
Physical Gel

The application of triphenylene-based discotic liquid crystal derivatives as physical gelators is investigated.

Temperature-responsive proton-conductive liquid crystals formed by the self-assembly of zwitterionic ionic liquids

RSC Advances ◽  
2015 ◽  
Vol 5 (78) ◽  
pp. 63732-63737 ◽  
Author(s):  
Xinpei Gao ◽  
Fei Lu ◽  
Bin Dong ◽  
Tao Zhou ◽  
Yizhi Liu ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Liquid Crystals ◽  
Self Assembly ◽  
Proton Conduction ◽  
Proton Conductors ◽  
The Self ◽  
Conductive Liquid ◽  
Temperature Responsive ◽  
Conduction Behavior

Nanostructured proton conductors having hexagonal and cubic structures were constructed by the self-assembly of zwitterionic ionic liquids. These nanostructured proton conductors all exhibited an assembled-structure dependent proton conduction behavior.

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