scholarly journals Lyotropic Liquid Crystals from Colloidal Suspensions of Graphene Oxide

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 455 ◽  
Author(s):  
Adam P. Draude ◽  
Ingo Dierking
Keyword(s):  
Carbon Nanotubes ◽  
Graphene Oxide ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Colloidal Particles ◽  
Colloidal Suspensions ◽  
Lyotropic Liquid Crystals ◽  
Nanoscience And Nanotechnology ◽  
And Behavior

Lyotropic liquid crystals from colloidal particles have been known for more than a century, but have attracted a revived interest over the last few years. This is due to the developments in nanoscience and nanotechnology, where the liquid crystal order can be exploited to orient and reorient the anisotropic colloids, thus enabling, increasing and switching the preferential properties of the nanoparticles. In particular, carbon-based colloids like carbon nanotubes and graphene/graphene–oxide have increasingly been studied with respect to their lyotropic liquid crystalline properties over the recent years. We critically review aspects of lyotropic graphene oxide liquid crystal with respect to properties and behavior which seem to be generally established, but also discuss those effects that are largely unfamiliar so far, or as of yet of controversial experimental or theoretical outcome.

Electric-Field Effects in Dilute Suspensions of Carbon Nanotubes Dispersed in Nematic Liquid Crystals

2010 ◽  
Vol 428-429 ◽  
pp. 173-181 ◽  
Author(s):  
Muklesur Rahman ◽  
Wei Lee
Keyword(s):  
Carbon Nanotubes ◽  
Liquid Crystal ◽  
Carbon Nanotube ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Colloidal Particles ◽  
Liquid Crystal Display ◽  
New Physics ◽  
Colloidal System ◽  
Colloidal Systems

Colloids composed of liquid-crystal hydrosols exhibit a rich set of interesting phenomena. The coupling between liquid-crystalline media and colloidal particles plays an essential role leading to an abundant source of new physics. In the last few years, peculiar behaviors of carbon-nanotube-doped calamitic liquid crystals have attracted considerable attention. This paper provides a brief introduction to this alluring subject for its on-going research development in this laboratory. First presented are our current understandings of the nematic colloidal system comprising carbon nanotubes and of their possible orientation and dynamics under the application of an external field. Various electro-optical and electrical properties of a liquid-crystal display rectified by the nanoscale carbonaceous guest are then addressed to a larger extent. Dielectric relaxation obtained from a nematic impregnated with carbon nanotubes is also discussed. With historical significance for the dawn of the liquid-crystal–carbon-nanotube research, several important findings of enhanced nonlinear optical properties in typical nematic mesomaterials consisting of suspended nanotubes are delineated. With the new colloidal systems of elongated nanoscale solids dispersed in anisotropic fluids in the mesophase, many new intriguing phenomena are awaiting theoretical and experimental explorations. Collaborations are called to draw attention of interested theoretical physicists, in particular.

scholarly journals Novel Trends in Lyotropic Liquid Crystals

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 604 ◽  
Author(s):  
Ingo Dierking ◽  
Antônio Martins Figueiredo Neto
Keyword(s):  
Graphene Oxide ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Soft Matter ◽  
Anisotropic Materials ◽  
Lyotropic Liquid Crystals ◽  
Electro Optic ◽  
Thermotropic Liquid Crystals ◽  
Active Liquid ◽  
Biological Liquid

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.

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.

scholarly journals Aligning lyotropic liquid crystals with unconventional organic layers

2017 ◽  
Vol 9 (1) ◽  
pp. 8 ◽  
Author(s):  
Eva Otón ◽  
Morten Andreas Geday ◽  
Caterina Maria Tone ◽  
José Manuel Otón ◽  
Xabier Quintana
Keyword(s):  
Liquid Crystal ◽  
Liquid Crystals ◽  
Chem Phys ◽  
Water Soluble ◽  
Lyotropic Liquid Crystals ◽  
Sunset Yellow ◽  
Lab On Chip ◽  
Wide Range ◽  
Homeotropic Alignment ◽  
Alignment Layers

Lyotropic chromonic liquid crystals (LCLC) are a kind of LCs far less known and more difficult to control than conventional thermotropic nematics. Nevertheless, LCLCs are a preferred option -often the only one- for applications where hydrophilic materials must be employed. Being water-soluble, LCLC can be used in numerous biology related devices, for example in target detection in lab-on-chip devices. However, their properties and procedures to align them are still less explored, with only a very limited number of options available, especially for homeotropic alignment. In this work, novel organic alignment layers and alignment properties have been explored for selected LCLCs. Non-conventional organic alignment layers were tested and new suitable procedures and materials for both homogeneous and homeotropic alignments have been found. Full Text: PDF ReferencesS.L. Hefinstine, O.D. Lavrentovich, C.J. Woolverton, "Lyotropic liquid crystal as a real-time detector of microbial immune complexes", Lett. Appl. Microbiol. 43, 27 (2006). CrossRef M.A. Geday, M. Ca-o-García, J.M. Escolano, E. Otón, J.M. Otón, X. Quintana, Conference on Liquid Crystals CLC'16, Poland (2016).M.A. Geday, E. Otón, J.M. Escolano, J.M. Otón, X. Quintana, Patent WO 2015193525 (2015). DirectLink Yu.A. Nastishin et al., "Optical characterization of the nematic lyotropic chromonic liquid crystals: Light absorption, birefringence, and scalar order parameter", Phys. Rev. E, 72 (4) 41711 (2005). CrossRef A. Mcguire, et al., "Orthogonal Orientation of Chromonic Liquid Crystals by Rubbed Polyamide Films", Chem. Phys. Chem. 15 (7) (2014). CrossRef J. Jeong, et al., "Homeotropic Alignment of Lyotropic Chromonic Liquid Crystals Using Noncovalent Interactions", Langmuir 30(10) 2914 (2014). CrossRef J.Y. Kim, H.-Tae Jung, "Macroscopic alignment of chromonic liquid crystals using patterned substrates", Phys. Chem. Chem. Phys. 18, 10362 (2016). CrossRef E. Otón, J.M. Escolano, X. Quintana, J.M. Otón, M.A. Geday, "Aligning lyotropic liquid crystals with silicon oxides", Liq. Cryst. 42 (8) 1069 (2015). CrossRef H.S. Park, et al., "Condensation of Self-Assembled Lyotropic Chromonic Liquid Crystal Sunset Yellow in Aqueous Solutions Crowded with Polyethylene Glycol and Doped with Salt", Langmuir 27, 4164 (2011). CrossRef H.S. Park, et al., "Self-Assembly of Lyotropic Chromonic Liquid Crystal Sunset Yellow and Effects of Ionic Additives", J. Phys. Chem. B 112, 16307 (2008). CrossRef R Caputo et al., "POLICRYPS: a liquid crystal composed nano/microstructure with a wide range of optical and electro-optical applications", J. Opt. A: Pure Appl. Opt. 11, 024017 (2009). CrossRef

Fabrication and Characterizes of TiO2 Nanomaterials Templated by Lyotropic Liquid Crystal

2011 ◽  
Vol 399-401 ◽  
pp. 532-537
Author(s):  
Li Hua Liu ◽  
Ying Bai ◽  
Fu Min Wang ◽  
Ning Liu
Keyword(s):  
Aqueous Solution ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Nonionic Surfactant ◽  
Formation Mechanism ◽  
Lyotropic Liquid Crystals ◽  
Lyotropic Liquid Crystal ◽  
Micro Structure ◽  
Ft Ir ◽  
Rod Structures

TiO2 nanomaterials were synthesized in lyotropic liquid crystal formed by nonionic surfactant TritonX-100 and TiOSO4 aqueous solution with NH3•H2O as precipitator. The lyotropic liquid crystals were characterized by means of POM and Low-angle XRD. FT-IR, TGA, XRD, TEM were used to characterize the TiO2 samples. It was found that all the lytropic liquid crystal were in lamellar liquid crysal phase and after casting the micro-structure of the LLC phase, the TiO2 samples were self-assemble to form lamellar, sphere and rod structures. According to the characterization results, possible formation mechanism was proposed.

scholarly journals Directional freezing of binary colloidal suspensions: a model for size fractionation of graphene oxide

Soft Matter ◽  
2019 ◽  
Vol 15 (2) ◽  
pp. 243-251 ◽  
Author(s):  
Xin Xu ◽  
Luofu Liu ◽  
Hongya Geng ◽  
Jianjun Wang ◽  
Jiajia Zhou ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Theoretical Model ◽  
Colloidal Particles ◽  
Colloidal Suspensions ◽  
Size Fractionation ◽  
Preferential Adsorption ◽  
Directional Freezing ◽  
Ice Phase

A theoretical model of a binary colloid suspension was developed by incorporating both the moving freezing boundary and the preferential adsorption of colloidal particles to the ice phase.

A pirfenidone loaded spray dressing based on lyotropic liquid crystals for deep partial thickness burn treatment: healing promotion and scar prophylaxis

2020 ◽  
Vol 8 (13) ◽  
pp. 2573-2588 ◽  
Author(s):  
Jintian Chen ◽  
Hui Wang ◽  
Liling Mei ◽  
Bei Wang ◽  
Ying Huang ◽  
...  
Keyword(s):  
Wound Healing ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Lyotropic Liquid Crystals ◽  
Lyotropic Liquid Crystal ◽  
Burn Treatment ◽  
Partial Thickness ◽  
Partial Thickness Burn

This study develops a HA combined lyotropic liquid crystal based spray dressing loaded with pirfenidone for wound healing and scar prophylaxis.

Liquid Crystal Behavior of V2O5·nH2O Gels

1998 ◽  
Vol 547 ◽  
Author(s):  
J. Livage ◽  
P. Davidson ◽  
X. Commeinhes ◽  
O. Pelletier
Keyword(s):  
Liquid Crystal ◽  
Vanadium Pentoxide ◽  
Colloidal Particles ◽  
Organic Molecules ◽  
Polarized Light ◽  
Colloidal Suspensions ◽  
Acid Dissociation ◽  
Polymeric Particles ◽  
Nematic Phases ◽  
Electrostatic Repulsions

AbstractMost liquid crystals are made of organic molecules, very few of them are based on mineral compounds. Vanadium pentoxide gels and sols have been shown to give mesophases. They are made of ribbon-like polymeric particles of vanadium pentoxide dispersed in water. Ansitropic xerogel layers are formed when these gels are deposited and dried onto flat substrates. Dehydration is reversible and fluid phases are again obtained via a swelling process when water is added to the xerogel.When observed by polarized light microscopy, colloidal suspensions of V2O5 ribbons display defects typical of lyotropic nematic phases. Dilute nematic suspensions can even be oriented by applying a magnetic field of about 0.5 Tesla. Such a liquid crystal behavior is mainly due to the highly anisotropic shape of vanadium oxide colloidal particles. Acid dissociation at the oxide/water interface gives rise to surface electrical charges and electrostatic repulsions should also be responsible for the stabilization of the nematic phase.

Liquid crystal/glass interface effects on the orientation of lyotropic liquid crystals in magnetic fields

1978 ◽  
Vol 56 (16) ◽  
pp. 2178-2183 ◽  
Author(s):  
Fred Y. Fujiwara ◽  
Leonard W. Reeves
Keyword(s):  
Magnetic Field ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Cylindrical Tube ◽  
Lyotropic Liquid Crystals ◽  
Crystal Glass ◽  
Type I ◽  
Type Ii ◽  
Glass Interface ◽  
Interface Effects

Lyotropic mesophases of both positive (type I) and negative (type II) diamagnetic anisotropy have been prepared. The deuterium magnetic resonance signal from D2O in the sample bas been studied during the process of orientation in a magnetic field. A type II mesophase oriented by a magnetic field in a cylindrical tube perpendicular to the lines of force does not achieve a uniform distribution of directors in a plane perpendicular to the field. The re orientation of a type I mesophase after an initial displacement of the director at an angle to the field has been studied. Previous equations derived for thermotropic liquid crystals are applicable but the velocity of re-orientation was found to be an inverse function of the radius, for nmr tubes of less than 4 mm in diameter, indicating that liquid crystal/glass interface effects are important.

Antiferroelectric Liquid Crystals from Achiral Molecules And A Liquid Conglomerate

1999 ◽  
Vol 559 ◽  
Author(s):  
David M. Walba ◽  
Eva Körblova ◽  
Renfan Shao ◽  
Joseph E. Maclennan ◽  
Darren R. Link ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Crystal Phase ◽  
Liquid Crystal Phase ◽  
Crystalline Structures ◽  
Chiral Liquid Crystal ◽  
Antiferroelectric Liquid Crystals ◽  
Liquid Crystal Structure

ABSTRACTUntil recently, it was an empirical fact that creation of a chiral liquid crystal phase required enantiomerically enriched molecules. In addition, to date known ferroelectric and antiferroelectric smectics have also been composed of enantiomerically enriched molecules. Herein are described the first examples of the formation of chiral and antiferroelectric supermolecular liquid crystalline structures from achiral molecules. In one case (apparently metastable) the liquid crystal structure is macroscopically chiral, with samples composed of heterochiral macroscopic domains: a liquid conglomerate.

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