scholarly journals Liquid Crystals Templating

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 648 ◽  
Author(s):  
Mamatha Nagaraj

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.

2020 ◽  
Vol 98 (7) ◽  
pp. 379-385
Author(s):  
Carson O. Zellman ◽  
Danielle Vu ◽  
Vance E. Williams

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.


1986 ◽  
Vol 41 (8) ◽  
pp. 1011-1014 ◽  
Author(s):  
W. Calaminus ◽  
F. Vögtle ◽  
R. Eidenschink

AbstractSeveral 3 .11-disubstituted dispiro[5.1.5.1]tetradecane-7,14-dions were prepared and the cis/trans-isomers were separated. The trans -stereoisomers were converted into the gem-dihalide ketones and mono- and dithioketones. The phase transfer temperatures were determined. Liquid crystal phases were observed.


Crystals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 678
Author(s):  
Yuqi Han ◽  
Yan Jiang ◽  
Wei Guo ◽  
Bing Li ◽  
Lu Zhang ◽  
...  

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.


Author(s):  
H. N. W. Lekkerkerker ◽  
G. J. Vroege

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.


MRS Bulletin ◽  
1991 ◽  
Vol 16 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Patrick Oswald ◽  
John Bechhoefer ◽  
Francisco Melo

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.


2008 ◽  
Vol 1134 ◽  
Author(s):  
John William Goodby ◽  
Martin Bates ◽  
Isabel Saez ◽  
Ewa Gorecka ◽  
Heinz Kitzerow ◽  
...  

AbstractLC-NANOP is an ESF EUROCORES SONS Collaborative Research Project that is addressing an innovative approach to self-organized nanostructures by combination of a variety of organic, inorganic and metal scaffolds with the unique self-organization properties of liquid crystals to obtain liquid crystal nano-particles. LC-NANOP is concerned with the synthesis, analysis, characterization, modeling and physico-chemical properties of super- and supra-molecular systems which are formed from a nano-particle as a central scaffold, surrounded by a layer of liquid crystal. The self-organization properties of the liquid crystal coating is the driving force leading to the self-assembly of the nano-particles into secondary or tertiary hierarchical structures, with emphasis on the systematic variation of nano-particle size, chirality, shape and functionality. This bottom-up approach to nano-structuring is very powerful as it combines the extraordinary variety of morphologies that liquid crystals present with the combination of functional entities, relevant for chemical, biological, optoelectronic, and photonic tasks, etc, to create ordered nano-structures that can be controlled by external stimuli.


Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 604 ◽  
Author(s):  
Ingo Dierking ◽  
Antônio Martins Figueiredo Neto

We introduce and shortly summarize a variety of more recent aspects of lyotropic liquid crystals (LLCs), which have drawn the attention of the liquid crystal and soft matter community and have recently led to an increasing number of groups studying this fascinating class of materials, alongside their normal activities in thermotopic LCs. The diversity of topics ranges from amphiphilic to inorganic liquid crystals, clays and biological liquid crystals, such as viruses, cellulose or DNA, to strongly anisotropic materials such as nanotubes, nanowires or graphene oxide dispersed in isotropic solvents. We conclude our admittedly somewhat subjective overview with materials exhibiting some fascinating properties, such as chromonics, ferroelectric lyotropics and active liquid crystals and living lyotropics, before we point out some possible and emerging applications of a class of materials that has long been standing in the shadow of the well-known applications of thermotropic liquid crystals, namely displays and electro-optic devices.


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