Encapsulating propeller-like columnar liquid crystals with an aromatic outer shell: influence of phenoxy-terminated side chains on the phase behaviour of triphenylbenzenes

Soft Matter ◽  
2018 ◽  
Vol 14 (31) ◽  
pp. 6409-6414 ◽  
Author(s):  
Korinna Bader ◽  
Tobias Wöhrle ◽  
Esra Öztürk ◽  
Angelika Baro ◽  
Sabine Laschat
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Outer Shell ◽  
Phase Behaviour ◽  
Side Chains

Liquid crystalline triphenylbenzenes carrying peripheral phenoxy units stack in helical columns with an aromatic outer shell.

Tuning liquid crystalline phase behaviour in columnar crown ethers by sulfur substituents

2017 ◽  
Vol 4 (5) ◽  
pp. 790-803 ◽  
Author(s):  
Jochen Kirres ◽  
Katharina Schmitt ◽  
Iris Wurzbach ◽  
Frank Giesselmann ◽  
Sabine Ludwigs ◽  
...  
Keyword(s):  
Crown Ethers ◽  
Crystalline Phase ◽  
Liquid Crystalline ◽  
Room Temperature ◽  
Phase Behaviour ◽  
Liquid Crystalline Phase ◽  
Side Chains ◽  
Columnar Mesophases ◽  
Sulfur Containing

Sulfur-containing side chains in the periphery ofo-terphenyl or triphenylene units of crown ethers induce room-temperature columnar mesophases.

Self-order in flexible non-mesogenic macromolecules

1994 ◽  
Vol 348 (1686) ◽  
pp. 45-57 ◽  
Keyword(s):  
Molecular Structure ◽  
Liquid Crystals ◽  
Temperature Stability ◽  
Phase Behaviour ◽  
Side Chains ◽  
Alkyl Side Chains ◽  
Linear Poly ◽  
Mesomorphic State ◽  
High Flexibility ◽  
Columnar Mesophases

Some very flexible linear poly(di-n-alkylsiloxane)s and cyclolinear oligo- and polyorganosiloxanes, which do not contain classical rigid rodlike or disclike mesogens, similar to other semi-organic polymers like polyphosphazenes and polysilanes, can form thermodynamically stable two-dimensionally ordered thermotropic mesophases. In many respects the mesophases in polysiloxanes resemble columnar liquid crystals which seems to be the result of the amphiphilic constitution of the polyorganosiloxanes. The origin of the mesomorphic state seems to be closely related to the competition between the interaction of the polar inorganic backbones and those of the organic side chains facilitated by the high flexibility of the inorganic main chain. Similarily to discotic liquid crystals, mesophases in polysiloxanes consist mostly of columns packed hexagonally (or closely so) with lateral long-range positional order, but with only short-range order along the columns. The unique feature of the columnar mesophases is that the axes of macromolecules lie along the column axes. The influence of molecular structure and molecular mass of linear macromolecules is discussed. It has been demonstrated that the temperature interval of mesophase stability is critically dependent on the length of the alkyl side chains. Both the process of formation of the mesophase from the isotropic melt and the crystallization of the mesophase are nucleation controlled processes, although the crystallization of the mesomorphic state is characterized by some specific features. The phase behaviour of cyclolinear polyorganosiloxanes is described with particular emphasis on the temperature stability as a function of molecular structure, tacticity, substituents and flexible spacers.

scholarly journals Ion conformation and orientational order in a dicationic ionic liquid crystal studied by solid-state nuclear magnetic resonance spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Debashis Majhi ◽  
Sergey V. Dvinskikh
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Liquid Crystals ◽  
Bond Order ◽  
Van Der Waals ◽  
Orientational Order ◽  
Smectic Phase ◽  
Side Chains ◽  
Dicationic Ionic Liquid ◽  
Ionic Liquid Crystals

AbstractIonic liquids crystals belong to a special class of ionic liquids that exhibit thermotropic liquid-crystalline behavior. Recently, dicationic ionic liquid crystals have been reported with a cation containing two single-charged ions covalently linked by a spacer. In ionic liquid crystals, electrostatic and hydrogen bonding interactions in ionic sublayer and van der Waals interaction in hydrophobic domains are the main forces contributing to the mesophase stabilization and determining the molecular orientational order and conformation. How these properties in dicationic materials are compared to those in conventional monocationic analogs? We address this question using a combination of advanced NMR methods and DFT analysis. Dicationic salt 3,3′-(1,6-hexanediyl)bis(1-dodecylimidazolium)dibromide was studied. Local bond order parameters of flexible alkyl side chains, linker chain, and alignment of rigid polar groups were analyzed. The dynamic spacer effectively “decouples” the motion of two ionic moieties. Hence, local order and alignment in dicationic mesophase were similar to those in analogous single-chain monocationic salts. Bond order parameters in the side chains in the dicationic smectic phase were found consistently lower compared to double-chain monocationic analogs, suggesting decreasing contribution of van der Waals forces. Overall dication reorientation in the smectic phase was characterized by low values of orientational order parameter S. With increased interaction energy in the polar domain the layered structure is stabilized despite less ordered dications. The results emphasized the trends in the orientational order in ionic liquid crystals and contributed to a better understanding of interparticle interactions driving smectic assembly in this and analogous ionic mesogens.

Polar Liquid Crystalline Polymers Bearing Mesogenic Side Chains with Large Dipole Moment

2021 ◽  
Author(s):  
Shuqi Dai ◽  
Jinxing Li ◽  
Junichi Kougo ◽  
Huanyu Lei ◽  
Satoshi Aya ◽  
...  
Keyword(s):  
Dipole Moment ◽  
Liquid Crystalline ◽  
Liquid Crystalline Polymers ◽  
Polar Liquid ◽  
Side Chains ◽  
Crystalline Polymers

Liquid-crystalline behaviour and electrorheological effect of phthalocyanine-based ionic liquid crystals

2020 ◽  
pp. 1-10
Author(s):  
Aikebaier Reheman ◽  
Shuangying Hu ◽  
Lianjun Cao ◽  
Danhua Xie ◽  
Guiyang Yan ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Electrorheological Effect ◽  
Ionic Liquid Crystals
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