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 ◽  
...  
2020 ◽  
Vol 301 ◽  
pp. 112369 ◽  
Author(s):  
Yanxing Zheng ◽  
Jiwei Wang ◽  
Xinqiao Tang ◽  
Lei Zhang ◽  
Fanbao Meng

2021 ◽  
Vol 11 (21) ◽  
pp. 10347
Author(s):  
Melina S. Weber ◽  
Margit Schulze ◽  
Giuseppe Lazzara ◽  
Antonio Palumbo Piccionello ◽  
Andrea Pace ◽  
...  

The synthesis and characterization of a new class of 1,2,4-oxadiazolylpyridinium as a cationic scaffold for fluorinated ionic liquid crystals is herein described. A series of 12 fluorinated heterocyclic salts based on a 1,2,4-oxadiazole moiety, connected through its C(5) or C(3) to an N-alkylpyridinium unit and a perfluoroheptyl chain, differing in the length of the alkyl chain and counterions, has been synthesized. As counterions iodide, bromide and bis(trifluoromethane)sulfonimide have been considered. The synthesis, structure, and liquid crystalline properties of these compounds are discussed on the basis of the tuned structural variables. The thermotropic properties of this series of salts have been investigated by differential scanning calorimetry and polarized optical microscopy. The results showed the existence of an enantiotropic mesomorphic smectic liquid crystalline phase for six bis(trifluoromethane)sulfonimide salts.


2020 ◽  
Vol 21 (14) ◽  
pp. 5024
Author(s):  
Debashis Majhi ◽  
Andrei V. Komolkin ◽  
Sergey V. Dvinskikh

Ionic liquid crystals (ILCs) present a new class of non-molecular soft materials with a unique combination of high ionic conductivity and anisotropy of physicochemical properties. Symmetrically-substituted long-chain imidazolium-based mesogenic ionic liquids exhibiting a smectic liquid crystalline phase were investigated by solid state NMR spectroscopy and computational methods. The aim of the study was to reveal the correlation between cation size and structure, local dynamics, and orientational order in the layered mesophase. The obtained experimental data are consistent with the model of a rod-shaped cation with the two chains aligned in opposite directions outward from the imidazolium core. The alignment of the core plane to the phase director and the restricted conformations of the chain segments were determined and compared to those in single-chain counterparts. The orientational order parameter S~0.5–0.6 of double-chain ionic liquid crystals is higher than that of corresponding single-chain analogues. This is compatible with the enhanced contribution of van der Waals forces to the stabilization of smectic layers. Increased orientational order for the material with Br− counterions, which exhibit a smaller ionic radius and higher ability to form hydrogen bonds as compared to that of BF4−, also indicated a non-negligible influence of electrostatic and hydrogen bonding interactions. The enhanced rod-shape character and higher orientational order of symmetrically-substituted ILCs can offer additional opportunities in the design of self-assembling non-molecular materials.


2012 ◽  
Vol 557-559 ◽  
pp. 611-614 ◽  
Author(s):  
Jin Hua He ◽  
Cui Hua Li ◽  
Lian An Qian ◽  
Jian Hong Liu ◽  
Qian Ling Zhang

N-methyl-N-hexadecylpyrrolidinium bromide (IL) was synthesized for the design of ionic liquid crystals which is a fascinating class of molecular materials, offering the combination of order and mobility. In binary mixtures with water, lyotropic liquid crystalline phase appears in the range of IL content from 35% to 70% and the temperature range from -1.1 to 24 °C in the heating run. The SAXS curves explored the self-assembly processes and hexagonal phase of the IL apparent sol. The saturated aliphatic ionic liquid in water assemble less tightly compared with aromatic ionic liquid based on imidazolium in water, which is due to the absence of aromatic package effect.


Soft Matter ◽  
2017 ◽  
Vol 13 (45) ◽  
pp. 8379-8391 ◽  
Author(s):  
Korinna Bader ◽  
Manuel M. Neidhardt ◽  
Tobias Wöhrle ◽  
Robert Forschner ◽  
Angelika Baro ◽  
...  

Introduction of charge simply converted non-conventional tyrosine/crown ether liquid crystals into ionic liquid crystals under change of mesophase type.


RSC Advances ◽  
2014 ◽  
Vol 4 (24) ◽  
pp. 12476-12481 ◽  
Author(s):  
Xinjiao Wang ◽  
Michelle Sternberg ◽  
Florian T. U. Kohler ◽  
Berthold U. Melcher ◽  
Peter Wasserscheid ◽  
...  

New ionic liquids and ionic liquid crystalline materials with custom-tailored properties were synthesized based on long-alkyl-chain-derivatized 1,3-dialkylimidazolium salts.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Debashis Majhi ◽  
Sergey V. Dvinskikh

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.


2021 ◽  
Vol 330 ◽  
pp. 115666
Author(s):  
Mohamed A. Kolmangadi ◽  
Arda Yildirim ◽  
Kathrin Sentker ◽  
Martin Butschies ◽  
Andrea Bühlmeyer ◽  
...  

RSC Advances ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 635-639 ◽  
Author(s):  
Tien Dat Do ◽  
Andreea R. Schmitzer

This paper describes the development of a new family of ionic liquid crystals based on imidazolium salts and their applications as media for intramolecular Diels Alder reactions.


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