1
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Rust C, Schill E, Garrity O, Spari M, Li H, Bacher A, Guttmann M, Reich S, Flavel BS. Radial Alignment of Carbon Nanotubes via Dead-End Filtration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2207684. [PMID: 36775908 DOI: 10.1002/smll.202207684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 01/25/2023] [Indexed: 05/11/2023]
Abstract
Dead-end filtration is a facile method to globally align single wall carbon nanotubes (SWCNTs) in large area films with a 2D order parameter, S2D , approaching unity. Uniaxial alignment has been achieved using pristine and hot-embossed membranes but more sophisticated geometries have yet to be investigated. In this work, three different patterns with radial symmetry and an area of 3.8 cm2 are created. Two of these patterns are replicated by the filtered SWCNTs and S2D values of ≈0.85 are obtained. Each of the radially aligned SWCNT films is characterized by scanning cross-polarized microscopy in reflectance and laser imaging in transmittance with linear, radial, and azimuthal polarized light fields. The former is used to define a novel indicator akin to the 2D order parameter using Malu's law, yielding 0.82 for the respective film. The films are then transferred to a flexible printed circuit board and terminal two-probe electrical measurements are conducted to explore the potential of those new alignment geometries.
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Affiliation(s)
- Christian Rust
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287, Darmstadt, Germany
| | - Elias Schill
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Oisín Garrity
- Institute of Experimental Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Manuel Spari
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Han Li
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Andreas Bacher
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Markus Guttmann
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Stephanie Reich
- Institute of Experimental Physics, Freie Universität Berlin, Arnimallee 14, 14195, Berlin, Germany
| | - Benjamin S Flavel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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2
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Singh PK, Dhar R, Dabrowski R. Enhancement of dielectric and electro-optical characteristics of liquid crystalline material 4'-octyl-4-cyano-biphenyl with dispersed functionalized and nonfunctionalized multiwalled carbon nanotubes. Phys Rev E 2023; 107:044704. [PMID: 37198864 DOI: 10.1103/physreve.107.044704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 03/01/2023] [Indexed: 05/19/2023]
Abstract
For recent applications, liquid crystal-carbon nanotube based nanocomposite systems have been proven to be highly attractive. In this paper, we give a thorough analysis of a nanocomposite system made of both functionalized and nonfunctionalized multiwalled carbon nanotubes that are disseminated in a 4'-octyl-4-cyano-biphenyl liquid crystal medium. Thermodynamic study reveals a decrease in the nanocomposites' transition temperatures. In contrast to nonfunctionalized multiwalled carbon nanotube dispersed systems, the enthalpy of functionalized multiwalled carbon nanotube dispersed systems has increased. In comparison to the pure sample, the dispersed nanocomposites have a smaller optical band gap. A rise in the longitudinal component of permittivity and, consequently, the dielectric anisotropy of the dispersed nanocomposites has been observed by dielectric studies. When compared to the pure sample, the conductivity of both dispersed nanocomposite materials has increased by two orders of magnitude. For the system with dispersed functionalized multiwalled carbon nanotubes, the threshold voltage, splay elastic constant, and rotational viscosity all decreased. For the dispersed nanocomposite of nonfunctionalized multiwalled carbon nanotubes, the value of the threshold voltage is somewhat decreased but the rotational viscosity and splay elastic constant both are enhanced. These findings show the applicability of the liquid crystal nanocomposites for display and electro-optical systems with appropriate tuning of the parameters.
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Affiliation(s)
- Praveen Kumar Singh
- Centre of Material Sciences, University of Allahabad, Prayagraj-211002, India
| | - Ravindra Dhar
- Centre of Material Sciences, University of Allahabad, Prayagraj-211002, India
| | - Roman Dabrowski
- Institute of Applied Sciences and Chemistry, Military University of Technology, Warsaw 00-908, Poland
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3
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Rust C, Shapturenka P, Spari M, Jin Q, Li H, Bacher A, Guttmann M, Zheng M, Adel T, Walker ARH, Fagan JA, Flavel BS. The Impact of Carbon Nanotube Length and Diameter on their Global Alignment by Dead-End Filtration. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 19:e2206774. [PMID: 36549899 DOI: 10.1002/smll.202206774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/06/2022] [Indexed: 06/17/2023]
Abstract
Dead-end filtration has proven to effectively prepare macroscopically (3.8 cm2 ) aligned thin films from solutionbased single-wall carbon nanotubes (SWCNTs). However, to make this technique broadly applicable, the role of SWCNT length and diameter must be understood. To date, most groups report the alignment of unsorted, large diameter (≈1.4 nm) SWCNTs, but systematic studies on their small diameter are rare (≈0.78 nm). In this work, films with an area of A = 3.81 cm2 and a thickness of ≈40 nm are prepared from length-sorted fractions comprising of small and large diameter SWCNTs, respectively. The alignment is characterized by cross-polarized microscopy, scanning electron microscopy, absorption and Raman spectroscopy. For the longest fractions (Lavg = 952 nm ± 431 nm, Δ = 1.58 and Lavg = 667 nm ± 246 nm, Δ = 1.55), the 2D order parameter, S2D, values of ≈0.6 and ≈0.76 are reported for the small and large diameter SWCNTs over an area of A = 625 µm2 , respectively. A comparison of Derjaguin, Landau, Verwey, and Overbeek (DLVO) theory calculations with the aligned domain size is then used to propose a law identifying the required length of a carbon nanotube with a given diameter and zeta potential.
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Affiliation(s)
- Christian Rust
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
- Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287, Darmstadt, Germany
| | - Pavel Shapturenka
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Manuel Spari
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Qihao Jin
- Light Technology Institute, Karlsruhe Institute of Technology, Engesserstraße 13, 76131, Karlsruhe, Germany
| | - Han Li
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Andreas Bacher
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Markus Guttmann
- Institute of Microstructure Technology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
| | - Ming Zheng
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Tehseen Adel
- Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Angela R Hight Walker
- Quantum Measurement Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Jeffrey A Fagan
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, 20899, USA
| | - Benjamin S Flavel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz Platz 1, 76344, Eggenstein-Leopoldshafen, Germany
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4
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Guan Z, Wang L, Bae J. Advances in 4D printing of liquid crystalline elastomers: materials, techniques, and applications. MATERIALS HORIZONS 2022; 9:1825-1849. [PMID: 35504034 DOI: 10.1039/d2mh00232a] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Liquid crystalline elastomers (LCEs) are polymer networks exhibiting anisotropic liquid crystallinity while maintaining elastomeric properties. Owing to diverse polymeric forms and self-alignment molecular behaviors, LCEs have fascinated state-of-the-art efforts in various disciplines other than the traditional low-molar-mass display market. By patterning order to structures, LCEs demonstrate reversible high-speed and large-scale actuations in response to external stimuli, allowing for close integration with 4D printing and architectures of digital devices, which is scarcely observed in homogeneous soft polymer networks. In this review, we collect recent advances in 4D printing of LCEs, with emphases on synthesis and processing methods that enable microscopic changes in the molecular orientation and hence macroscopic changes in the properties of end-use objects. Promising potentials of printed complexes include fields of soft robotics, optics, and biomedical devices. Within this scope, we elucidate the relationships among external stimuli, tailorable morphologies in mesophases of liquid crystals, and programmable topological configurations of printed parts. Lastly, perspectives and potential challenges facing 4D printing of LCEs are discussed.
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Affiliation(s)
- Zhecun Guan
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
| | - Ling Wang
- School of Materials Science and Engineering, Tianjin University, Tianjin 300350, P. R. China.
| | - Jinhye Bae
- Department of Nanoengineering, University of California San Diego, La Jolla, CA 92093, USA.
- Chemical Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
- Materials Science and Engineering Program, University of California San Diego, La Jolla, CA 92093, USA
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5
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Subedi S, Rella AK, Trung LG, Kumar V, Kang SW. Electrically Switchable Anisometric Carbon Quantum Dots Exhibiting Linearly Polarized Photoluminescence: Syntheses, Anisotropic Properties, and Facile Control of Uniaxial Orientation. ACS NANO 2022; 16:6480-6492. [PMID: 35343230 DOI: 10.1021/acsnano.2c00758] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Carbon quantum dots (CQDs) have been extensively explored in diverse fields because of their exceptional features. The nanometric particles with photoluminescence (PL) benefit various optical and photonic applications. However, the majority of previous reports have mainly focused on either unpolarized or circular-polarized (CP) PL. Linearly polarized (LP) emission of CQDs is limited mainly because of their isometric shape and difficulties in macroscopic orientation control. Herein, we report syntheses of anisometric CQDs and facile control of the uniaxial orientation on a macroscopic scale, which results in linearly polarized photoluminescence (LP-PL). The anisometric CQDs are synthesized from rigid-rod-shaped precursors and evenly dispersed in the rod-like liquid crystal (LC) host. As-synthesized CQDs exhibit a PL quantum yield as high as 35% in chloroform. In addition to uniform alignment, facile directional switching of the elongated CQD is established by employing the electrical responsiveness of the CQD and host LC. Therefore, the dichroic photophysical properties of anisometric CQDs have been beneficially adopted for fabrications of polarization-sensitive and electrically switchable PL devices. Also, anisometric CQDs are embedded in polymer films with molecular orientational patterns and clearly recognized by LP-PL.
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Affiliation(s)
- Subhangi Subedi
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
- Department of Chemistry, Tri-Chandra Multiple Campus, Tribhuvan University, Kathmandu, 44613, Nepal
| | - Avinash K Rella
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Le Gia Trung
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Vineet Kumar
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
| | - Shin-Woong Kang
- Department of Nano Convergence Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea
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6
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S J S, Mishra S, Dutta K, Gupta RK, V M. Frequency dependence of dielectric permittivity and conductivity of functionalized carbon nanotube-nematic liquid crystal nanocomposite. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.118168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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7
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Senyuk B, Mundoor H, Smalyukh II, Wensink HH. Nematoelasticity of hybrid molecular-colloidal liquid crystals. Phys Rev E 2021; 104:014703. [PMID: 34412251 DOI: 10.1103/physreve.104.014703] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Accepted: 06/25/2021] [Indexed: 11/07/2022]
Abstract
Colloidal rods immersed in a thermotropic liquid-crystalline solvent are at the basis of so-called hybrid liquid crystals, which are characterized by tunable nematic fluidity with symmetries ranging from conventional uniaxial nematic or antinematic to orthorhombic [Mundoor et al., Science 360, 768 (2018)SCIEAS0036-807510.1126/science.aap9359]. We provide a theoretical analysis of the elastic moduli of such systems by considering interactions between the individual rods with the embedding solvent through surface-anchoring forces, as well as steric and electrostatic interactions between the rods themselves. For uniaxial systems, the presence of colloidal rods generates a marked increase of the splay elasticity, which we found to be in quantitative agreement with experimental measurements. For orthorhombic hybrid liquid crystals, we provide estimates of all 12 elastic moduli and show that only a small subset of those elastic constants play a relevant role in describing the nematoelastic properties. The complexity and possibilities related to identifying the elastic moduli in experiments are briefly discussed.
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Affiliation(s)
- B Senyuk
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - H Mundoor
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA
| | - I I Smalyukh
- Department of Physics, University of Colorado, Boulder, Colorado 80309, USA.,Department of Electrical, Computer, and Energy Engineering, Materials Science and Engineering Program and Soft Materials Research Center, University of Colorado, Boulder, Colorado 80309, USA.,Chemical Physics Program, Departments of Chemistry and Physics, University of Colorado, Boulder, Colorado 80309, USA.,Renewable and Sustainable Energy Institute, National Renewable Energy Laboratory and University of Colorado, Boulder, Colorado 80309, USA
| | - H H Wensink
- Laboratoire de Physique des Solides, Université Paris-Saclay & CNRS, UMR 8502, 91405 Orsay, France
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8
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Jalili AR, Satalov A, Nazari S, Rahmat Suryanto BH, Sun J, Ghasemian MB, Mayyas M, Kandjani AE, Sabri YM, Mayes E, Bhargava SK, Araki J, Zakri C, Poulin P, Esrafilzadeh D, Amal R. Liquid Crystal-Mediated 3D Printing Process to Fabricate Nano-Ordered Layered Structures. ACS APPLIED MATERIALS & INTERFACES 2021; 13:28627-28638. [PMID: 34110785 DOI: 10.1021/acsami.1c05025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The emergence of three-dimensional (3D) printing promises a disruption in the design and on-demand fabrication of smart structures in applications ranging from functional devices to human organs. However, the scale at which 3D printing excels is within macro- and microlevels and principally lacks the spatial ordering of building blocks at nanolevels, which is vital for most multifunctional devices. Herein, we employ liquid crystal (LC) inks to bridge the gap between the nano- and microscales in a single-step 3D printing. The LC ink is prepared from mixtures of LCs of nanocellulose whiskers and large sheets of graphene oxide, which offers a highly ordered laminar organization not inherently present in the source materials. LC-mediated 3D printing imparts the fine-tuning required for the design freedom of architecturally layered systems at the nanoscale with intricate patterns within the 3D-printed constructs. This approach empowered the development of a high-performance humidity sensor composed of self-assembled lamellar organization of NC whiskers. We observed that the NC whiskers that are flat and parallel to each other in the laminar organization allow facile mass transport through the structure, demonstrating a significant improvement in the sensor performance. This work exemplifies how LC ink, implemented in a 3D printing process, can unlock the potential of individual constituents to allow macroscopic printing architectures with nanoscopic arrangements.
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Affiliation(s)
- Ali Rouhollah Jalili
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney 2052, New South Wales, Australia
| | - Alexandra Satalov
- Institut für Anorganische Chemie, Leibniz Universität Hannover, Callinstr. 9, Hannover 30167, Germany
| | - Sahar Nazari
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney 2052, New South Wales, Australia
| | - Bryan Harry Rahmat Suryanto
- Australian Centre for Electromaterials Science, School of Chemistry, Monash University, Clayton 3800, Victoria, Australia
| | - Jing Sun
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney 2052, New South Wales, Australia
| | - Mohammad Bagher Ghasemian
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney 2052, New South Wales, Australia
| | - Mohannad Mayyas
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney 2052, New South Wales, Australia
| | - Ahmad E Kandjani
- School of Science, RMIT University, Melbourne 3001, Victoria, Australia
| | - Ylias M Sabri
- School of Science, RMIT University, Melbourne 3001, Victoria, Australia
| | - Edwin Mayes
- School of Science, RMIT University, Melbourne 3001, Victoria, Australia
| | - Suresh K Bhargava
- School of Science, RMIT University, Melbourne 3001, Victoria, Australia
| | - Jun Araki
- Faculty of Textile Science and Technology, Shinshu University, Tokida 3-15-1, Ueda 386-8567, Nagano prefecture, Japan
- Institute for Fiber Engineering (IFES), Interdisciplinary Cluster for Cutting Edge Research (ICCER), Shinshu University, Tokida 3-15-1, Ueda 386-8567, Nagano prefecture, Japan
| | - Cécile Zakri
- Centre de Recherche Paul Pascal-CNRS, University of Bordeaux, Pessac 33600, France
| | - Philippe Poulin
- Centre de Recherche Paul Pascal-CNRS, University of Bordeaux, Pessac 33600, France
| | - Dorna Esrafilzadeh
- Graduate School of Biomedical Engineering, University of New South Wales, Sydney 2031, New South Wales, Australia
| | - Rose Amal
- School of Chemical Engineering, University of New South Wales (UNSW), Sydney 2052, New South Wales, Australia
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9
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Garbovskiy Y. Conventional and unconventional ionic phenomena in tunable soft materials made of liquid crystals and nanoparticles. NANO EXPRESS 2021. [DOI: 10.1088/2632-959x/abe652] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Abstract
A great variety of tunable multifunctional materials can be produced by combining nanoparticles and liquid crystals. Typically, the tunability of such soft nanocomposites is achieved via external electric fields resulting in the field-induced reorientation of liquid crystals. This reorientation can be altered by ions normally present in liquid crystals in small quantities. In addition, nanomaterials dispersed in liquid crystals can also affect the behavior of ions. Therefore, an understanding of ionic phenomena in liquid crystals doped with nanoparticles is essential for future advances in liquid crystal-aided nanoscience and nanotechnology. This paper provides an overview of the ionic effects observed in liquid crystals doped with nanomaterials. An introduction to liquid crystals is followed by a brief overview of nanomaterials in liquid crystals. After giving a basic description of ions in liquid crystals and experimental methods to measure them, a wide range of ionic phenomena in liquid crystals doped with different types of nanomaterials is discussed. After that, both existing and emerging applications of tunable soft materials made of liquid crystals and nanodopants are presented with an emphasis on the role of ionic effects in such systems. Finally, the discussion of unsolved problems and future research directions completes the review.
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10
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Draude AP, Dierking I. Thermotropic liquid crystals with low-dimensional carbon allotropes. NANO EXPRESS 2021. [DOI: 10.1088/2632-959x/abdf2d] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Abstract
As display devices based on liquid crystals have matured over the last decades, liquid crystal research has shifted its priorities in slightly different directions, such as sensors, photonics, nanotechnology and even more biologically related fields like drug delivery. This implied a change of emphasis in the development of novel materials, of which a completely new class of liquid crystal based composites emerged, that of nanoparticle-dispersed liquid crystals. The underlying ideas were to add functionality, while maintaining switchability, and the exploitation of liquid crystal self-organisation to build hierarchical nanostructures. Of particular interest for applications are dispersions of carbon nanomaterials, such as fullerenes, nanotubes and the graphene variants, due to their interactions with conventional liquid crystals. While such systems have been investigated for the past two decades, we concentrate in this review on the effects of dimensionality of the dispersed carbon nanoparticles, which goes hand in hand with the more recent developments in this field. Examples are the doping of 0D fullerenes in liquid crystals and implications for Blue Phase stability, or 1D nanotubes in nematic and ferroelectric liquid crystals, questions of dispersibility and applications as alignment media in ITO-free devices. Graphene (2D) and especially graphene oxide are mainly investigated for their formation of lyotropic liquid crystals. We here discuss the more recent aspects of dispersion in thermotropics.
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11
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Pal K, Aljabali AA, Kralj S, Thomas S, Gomes de Souza F. Graphene-assembly liquid crystalline and nanopolymer hybridization: A review on switchable device implementations. CHEMOSPHERE 2021; 263:128104. [PMID: 33297099 DOI: 10.1016/j.chemosphere.2020.128104] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 08/18/2020] [Accepted: 08/21/2020] [Indexed: 06/12/2023]
Abstract
Two-dimensional graphene and its hybrid derivatives combined with liquid crystals, polymers, and nanomaterials enable the formation of hybrid nanocomposites possessing extraordinary and unique properties. Among others, these assemblies could exhibit stimulus-induced optical and electrical changes, which are essential for many new switchable device technologies. The current review deals straight forward and versatile techniques of the fabrication of exclusive graphene self-assembly of liquid crystalline polymer nanocomposite which exhibiting novel emerging equities as well as unique functionalities. Unique design makes hybrid composite matrix multidomain structures serve as both alignment and conductive layers, thus sustaining novel switchable device fabrication mechanism. Exhibited ultra thin-film nanocomposite based smart switchable devices are promising candidates for diverse applications in the field of stretchable electronics, energy storage, photodetectors, high contrast displays, and optoelectronics. Furthermore, the brand new device implementation through novel materials have the potentials of cost-effective production, large-area compatibility and scalability, and seamless heterogeneous integration.
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Affiliation(s)
- Kaushik Pal
- Federal University of Rio de Janeiro, Cidade Universitária, Rio de Janeiro, RJ, 21941-901, Brazil; Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroska 160, 2000, Maribor, Slovenia.
| | - Alaa Aa Aljabali
- Department of Pharmaceutical Sciences, Yarmouk University-Faculty of Pharmacy, Irbid, 566, Jordan
| | - Samo Kralj
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroska 160, 2000, Maribor, Slovenia; Solid State Department, "Jozef Stefan" Institute, Jamova 39, 1000 Ljubljana, University of Maribör, Koroska 160, 2000, Maribör, Slovenia.
| | - Sabu Thomas
- International and Inter-University Centre for Nanoscience and Nanotechnology, School of Energy Materials, Mahatma Gandhi University, Kottayam, Kerala, 686560, India
| | - Fernando Gomes de Souza
- Laboratório de Biopolímeros e Sensores/LaBioS Centro de Tecnologia - Cidade Universitária, Federal University of Rio de Jenerio, Brazil
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12
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Derbali M, Guesmi A, Hamadi NB, Soltani T. Dielectric, electrooptic and viscoelastic properties in cybotactic nematic phase doped with ferroelectric nanoparticles. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113768] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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13
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Debnath A, Mandal PK, Sarma A, Gutowski O. Effect of silver nanoparticle doping on the physicochemical properties of a room temperature ferroelectric liquid crystal mixture. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.114185] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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14
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Ganea CP, Cîrcu V, Manaila-Maximean D. Effect of titanium oxide nanoparticles on the dielectric properties and ionic conductivity of a new smectic bis-imidazolium salt with dodecyl sulfate anion and cyanobiphenyl mesogenic groups. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113939] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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15
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Gangopadhyay R. How does PEDOT grow like nanoropes? A theoretical investigation in pace with experimental insights. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Garbovskiy Y, Emelyanenko AV, Glushchenko A. Inverse "guest-host" effect: ferroelectric nanoparticles mediated switching of nematic liquid crystals. NANOSCALE 2020; 12:16438-16442. [PMID: 32756694 DOI: 10.1039/d0nr05301e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Liquid crystals are widely used as a host matrix to embed different materials: dyes, fullerenes, carbon nanotubes, various nanoparticles (metallic, semiconductor, ferromagnetic, ferroelectric). The usual approach is related to the so called "guest-host" effect: external electric (or magnetic) fields drive liquid crystals (host), and liquid crystals reorient embedded particles (guest). In this paper we report an experimental observation of the effect that is completely opposite to the classical "guest-host" phenomenon: ferroelectric nanoparticles being switched by an external field mediate the switching of liquid crystals. Our experiments show that ferroelectric nanoparticles reorient and hold liquid crystal molecules in a direction of the ferroelectric nanoparticles orientation even when an external electric field attempts to orient a liquid crystal in an orthogonal direction.
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Affiliation(s)
- Y Garbovskiy
- Department of Physics and Engineering Physics, Central Connecticut State University, New Britain, CT 06050, USA.
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17
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Abstract
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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Finner SP, Pihlajamaa I, van der Schoot P. Geometric percolation of hard nanorods: The interplay of spontaneous and externally induced uniaxial particle alignment. J Chem Phys 2020; 152:064902. [PMID: 32061208 DOI: 10.1063/1.5141481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
We present a numerical study on geometric percolation in liquid dispersions of hard slender colloidal particles subject to an external orienting field. In the formulation and liquid-state processing of nanocomposite materials, particle alignment by external fields such as electric, magnetic, or flow fields is practically inevitable and often works against the emergence of large nanoparticle networks. Using continuum percolation theory in conjunction with Onsager theory, we investigate how the interplay between externally induced alignment and the spontaneous symmetry breaking of the uniaxial nematic phase affects cluster formation in nanoparticle dispersions. It is known that particle alignment by means of a density increase or by an external field may result in a breakdown of an already percolating network. As a result, percolation can be limited to a small region of the phase diagram only. Here, we demonstrate that the existence and shape of such a "percolation island" in the phase diagram crucially depends on the connectivity length-a critical distance defining direct connections between neighboring particles. For some values of the connectivity range, we observe unusual re-entrance effects, in which a system-spanning network forms and breaks down multiple times with increasing particle density.
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Affiliation(s)
- Shari P Finner
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 3500 MB Eindhoven, The Netherlands
| | - Ilian Pihlajamaa
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 3500 MB Eindhoven, The Netherlands
| | - Paul van der Schoot
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 3500 MB Eindhoven, The Netherlands
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19
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Finner SP, Atashpendar A, Schilling T, van der Schoot P. Unusual geometric percolation of hard nanorods in the uniaxial nematic liquid crystalline phase. Phys Rev E 2020; 100:062129. [PMID: 31962472 DOI: 10.1103/physreve.100.062129] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Indexed: 11/07/2022]
Abstract
We investigate by means of continuum percolation theory and Monte Carlo simulations how spontaneous uniaxial symmetry breaking affects geometric percolation in dispersions of hard rodlike particles. If the particle aspect ratio exceeds about 20, percolation in the nematic phase can be lost upon adding particles to the dispersion. This contrasts with percolation in the isotropic phase, where a minimum particle loading is always required to obtain system-spanning clusters. For sufficiently short rods, percolation in the uniaxial nematic mimics that of the isotropic phase, where the addition of particles always aids percolation. For aspect ratios between 20 and infinity, but not including infinity, we find reentrance behavior: percolation in the low-density nematic may be lost upon increasing the amount of nanofillers but can be regained by the addition of even more particles to the suspension. Our simulation results for aspect ratios of 5, 10, 20, 50, and 100 strongly support our theoretical predictions, with almost quantitative agreement. We show that a different closure of the connectedness Ornstein-Zernike equation, inspired by scaled particle theory, is as least as accurate in predicting the percolation threshold as the Parsons-Lee closure, which effectively describes the impact of many-body direct contacts.
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Affiliation(s)
- Shari P Finner
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 3500 MB Eindhoven, The Netherlands
| | - Arshia Atashpendar
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Tanja Schilling
- Physikalisches Institut, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Paul van der Schoot
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 3500 MB Eindhoven, The Netherlands.,Institute for Theoretical Physics, Utrecht University, Princetonplein 5, 3584 CC Utrecht, The Netherlands
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20
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Evolution of morphology and electrochemical properties of colloidal nematic liquid crystal doped with carbon nanotubes and magnetite. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.110927] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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21
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Carbon Nanotube and Cellulose Nanocrystal Hybrid Films. Molecules 2019; 24:molecules24142662. [PMID: 31340473 PMCID: PMC6681000 DOI: 10.3390/molecules24142662] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 06/14/2019] [Accepted: 06/20/2019] [Indexed: 11/29/2022] Open
Abstract
The use of cellulose nanocrystals (CNC) in high performance coatings is attractive for micro-scale structures or device fabrication due to the anisotropic geometry, however CNC are insulating materials. Carbon nanotubes (CNT) are also rod-shaped nanomaterials that display high mechanical strength and electrical conductivity. The hydrophobic regions of surface-modified CNC can interact with hydrophobic CNT and aid in association between the two anisotropic nanomaterials. The long-range electrostatic repulsion of CNC plays a role in forming a stable CNT and CNC mixture dispersion in water, which is integral to forming a uniform hybrid film. At concentrations favorable for film formation, the multiwalled nanotubes + CNC mixture dispersion shows cellular network formation, indicating local phase separation, while the single-walled nanotube + CNC mixture dispersion shows schlieren texture, indicating liquid crystal mixture formation. Conductive CNT + CNC hybrid films (5–20 μm thick) were cast on glass microscope slides with and without shear by blade coating. The CNT + CNC hybrid films electrical conductivity increased with increasing CNT loadings and some anisotropy was observed with the sheared hybrid films, although to a lesser extent than what was anticipated. Percolation models were applied to model the hybrid film conductivity and correlate with the hybrid film microstructure.
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22
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Petrov DA, Skokov PK, Zakhlevnykh AN, Makarov DV. Magnetic segregation effect in liquid crystals doped with carbon nanotubes. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2019; 10:1464-1474. [PMID: 31431859 PMCID: PMC6664398 DOI: 10.3762/bjnano.10.145] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2019] [Accepted: 07/09/2019] [Indexed: 06/10/2023]
Abstract
We study the orientational transitions in a suspension of carbon nanotubes in a nematic liquid crystal induced by an external magnetic field. The case of a finite orientational anchoring of liquid crystal molecules at the surface of doped carbon nanotubes is considered. It is shown that in a magnetic field the initial homogeneous planar texture of the liquid crystal-carbon nanotubes mixture is disturbed in a threshold manner (Fréedericksz transition). The orientational and concentration distributions of the suspension are studied for different values of the magnetic field strength and segregation intensity of the impurity subsystem. The optical phase lag between ordinary and extraordinary rays of light transmitted through a layer of a liquid crystal composite is calculated. The possibility of changing the nature of the Fréedericksz transition from second order to first order is shown. This tricritical behavior is related to the redistribution of the carbon nanotubes (segregation effect) inside the layer.
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Affiliation(s)
- Danil A Petrov
- Physics of Phase Transitions Department, Perm State University, 614990 Perm, Russia
| | - Pavel K Skokov
- Physics of Phase Transitions Department, Perm State University, 614990 Perm, Russia
- Institute of Continuous Media Mechanics, Russian Academy of Sciences, Ural Branch, Perm, 614013, Russia
| | | | - Dmitriy V Makarov
- Physics of Phase Transitions Department, Perm State University, 614990 Perm, Russia
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Suppression of the reentrant nematic and stabilization of the smectic phases by carbon nanotubes. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2019.04.135] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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24
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Gao W, Kono J. Science and applications of wafer-scale crystalline carbon nanotube films prepared through controlled vacuum filtration. ROYAL SOCIETY OPEN SCIENCE 2019; 6:181605. [PMID: 31032018 PMCID: PMC6458426 DOI: 10.1098/rsos.181605] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 02/06/2019] [Indexed: 05/26/2023]
Abstract
Carbon nanotubes (CNTs) make an ideal one-dimensional (1D) material platform for the exploration of novel physical phenomena under extremely strong quantum confinement. The 1D character of electrons, phonons and excitons in individual CNTs features extraordinary electronic, thermal and optical properties. Since their discovery in 1991, they have been continuing to attract interest in various disciplines, including chemistry, materials science, physics and engineering. However, the macroscopic manifestation of 1D properties is still limited, despite significant efforts for decades. Recently, a controlled vacuum filtration method has been developed for the preparation of wafer-scale films of crystalline chirality-enriched CNTs, and such films have enabled exciting new fundamental studies and applications. In this review, we will first discuss the controlled vacuum filtration technique, and then summarize recent discoveries in optical spectroscopy studies and optoelectronic device applications using films prepared by this technique.
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Affiliation(s)
- Weilu Gao
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA
| | - Junichiro Kono
- Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA
- Department of Physics and Astronomy, Rice University, Houston, TX 77005, USA
- Department of Materials Science and NanoEngineering, Rice University, Houston, TX 77005, USA
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25
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Influence of ZnO nanoparticles on the polarization, dielectric and electro-optic behaviour in the smectic C* and hexatic I* phases. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.11.100] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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Mrukiewicz M, Kowiorski K, Perkowski P, Mazur R, Djas M. Threshold voltage decrease in a thermotropic nematic liquid crystal doped with graphene oxide flakes. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2019; 10:71-78. [PMID: 30680280 PMCID: PMC6334787 DOI: 10.3762/bjnano.10.7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 11/30/2018] [Indexed: 05/04/2023]
Abstract
We report a threshold voltage decrease in a nematic liquid crystal compound, 4-cyano-4'-pentylbiphenyl (5CB), doped with graphene oxide (GO) flakes at a concentration of 0.05-0.3 wt %. The threshold voltage decrease was observed at the same concentration in electro-optic and dielectric spectroscopy measurements. The effect is related to the disrupted planar alignment due to the strong π-π stacking between the 5CB's benzene rings and the graphene oxide's structure. Additionally, we present the GO concentration dependence on the isotropic-nematic phase transition temperature, electric anisotropy, splay elastic constant, switch-on time, and switch-off time. The shape and dimensions of the GO flakes were studied using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The influence of the GO concentration on the physical properties and switching process in the presence of the electric field was discussed.
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Affiliation(s)
- Mateusz Mrukiewicz
- Institute of Applied Physics, Military University of Technology, 00-908 Warsaw, Poland
| | - Krystian Kowiorski
- Department of Chemical Synthesis and Flake Graphene, Institute of Electronic Materials Technology, 01-919 Warsaw, Poland
| | - Paweł Perkowski
- Institute of Applied Physics, Military University of Technology, 00-908 Warsaw, Poland
| | - Rafał Mazur
- Institute of Applied Physics, Military University of Technology, 00-908 Warsaw, Poland
| | - Małgorzata Djas
- Department of Chemical Synthesis and Flake Graphene, Institute of Electronic Materials Technology, 01-919 Warsaw, Poland
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27
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Varshini GV, Shankar Rao DS, Mukherjee PK, Krishna Prasad S. Nanophase Segregation of Nanostructures: Induction of Smectic A and Re-Entrance in a Carbon Nanotube/Nematic Liquid Crystal Composite. J Phys Chem B 2018; 122:10774-10781. [PMID: 30384607 DOI: 10.1021/acs.jpcb.8b08887] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Although representing drastically different chemical natures and types of interactions, the similarity of shape anisotropy of the constituents has created much interest in composites of calamitic liquid crystals (LCs) and carbon nanotubes (CNTs). Despite significant volume of studies on the physical properties of such composites, influence of CNTs on the celebrated re-entrant phenomenon in LCs has not been studied. We report here that a small concentration of CNTs doped to a "nematic mesophase-only" material not only induces the layered smectic A mesophase but also leads to the nematic-smectic-nematic re-entrant sequence as well, demonstrating the delicate interplay between the two entities. To explain this unusual observation, we propose nanophase segregation of the CNT as a possible mechanism. A combination of Flory-Huggins theory and Landau-de Gennes theory has also been provided supporting the observed feature.
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Affiliation(s)
- G V Varshini
- Centre for Nano and Soft Matter Sciences , Jalahalli, Bengaluru 560013 , India
| | - D S Shankar Rao
- Centre for Nano and Soft Matter Sciences , Jalahalli, Bengaluru 560013 , India
| | - Prabir K Mukherjee
- Government College of Engineering and Textile Technology , Serampore 712201 , India
| | - S Krishna Prasad
- Centre for Nano and Soft Matter Sciences , Jalahalli, Bengaluru 560013 , India
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28
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Oh J, Dierking I. Rotation of topological defects by trapped micro-rods in the nematic phase of a liquid crystal. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2017.12.063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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29
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Kasprzak CR, Scherzinger ET, Sarkar A, Miao M, Porcincula DH, Madriz AM, Pennewell ZM, Chau SS, Fernando R, Stefik M, Zhang S. Ordered Nanostructures of Carbon Nanotube–Polymer Composites from Lyotropic Liquid Crystal Templating. MACROMOL CHEM PHYS 2018. [DOI: 10.1002/macp.201800197] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Christopher R. Kasprzak
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Evan T. Scherzinger
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Amrita Sarkar
- Department of Chemistry and Biochemistry University of South Carolina Columbia SC 29208 USA
| | - Miranda Miao
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Dominique H. Porcincula
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Alejandro M. Madriz
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Zachary M. Pennewell
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Sophia S. Chau
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Raymond Fernando
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
| | - Morgan Stefik
- Department of Chemistry and Biochemistry University of South Carolina Columbia SC 29208 USA
| | - Shanju Zhang
- Department of Chemistry and Biochemistry California Polytechnic State University San Luis Obispo CA 93407 USA
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30
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Finner SP, Kotsev MI, Miller MA, van der Schoot P. Continuum percolation of polydisperse rods in quadrupole fields: Theory and simulations. J Chem Phys 2018; 148:034903. [PMID: 29352778 DOI: 10.1063/1.5010979] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
We investigate percolation in mixtures of nanorods in the presence of external fields that align or disalign the particles with the field axis. Such conditions are found in the formulation and processing of nanocomposites, where the field may be electric, magnetic, or due to elongational flow. Our focus is on the effect of length polydispersity, which-in the absence of a field-is known to produce a percolation threshold that scales with the inverse weight average of the particle length. Using a model of non-interacting spherocylinders in conjunction with connectedness percolation theory, we show that a quadrupolar field always increases the percolation threshold and that the universal scaling with the inverse weight average no longer holds if the field couples to the particle length. Instead, the percolation threshold becomes a function of higher moments of the length distribution, where the order of the relevant moments crucially depends on the strength and type of field applied. The theoretical predictions compare well with the results of our Monte Carlo simulations, which eliminate finite size effects by exploiting the fact that the universal scaling of the wrapping probability function holds even in anisotropic systems. Theory and simulation demonstrate that the percolation threshold of a polydisperse mixture can be lower than that of the individual components, confirming recent work based on a mapping onto a Bethe lattice as well as earlier computer simulations involving dipole fields. Our work shows how the formulation of nanocomposites may be used to compensate for the adverse effects of aligning fields that are inevitable under practical manufacturing conditions.
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Affiliation(s)
- Shari P Finner
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 3500 MB Eindhoven, The Netherlands
| | - Mihail I Kotsev
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Mark A Miller
- Department of Chemistry, Durham University, South Road, Durham DH1 3LE, United Kingdom
| | - Paul van der Schoot
- Department of Applied Physics, Eindhoven University of Technology, P.O. Box 513, 3500 MB Eindhoven, The Netherlands
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31
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Zhang S, Pelligra CI, Feng X, Osuji CO. Directed Assembly of Hybrid Nanomaterials and Nanocomposites. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2018; 30:e1705794. [PMID: 29520839 DOI: 10.1002/adma.201705794] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2017] [Revised: 11/22/2017] [Indexed: 05/19/2023]
Abstract
Hybrid nanomaterials are molecular or colloidal-level combinations of organic and inorganic materials, or otherwise strongly dissimilar materials. They are often, though not exclusively, anisotropic in shape. A canonical example is an inorganic nanorod or nanosheet sheathed in, or decorated by, a polymeric or other organic material, where both the inorganic and organic components are important for the properties of the system. Hybrid nanomaterials and nanocomposites have generated strong interest for a broad range of applications due to their functional properties. Generating macroscopic assemblies of hybrid nanomaterials and nanomaterials in nanocomposites with controlled orientation and placement by directed assembly is important for realizing such applications. Here, a survey of critical issues and themes in directed assembly of hybrid nanomaterials and nanocomposites is provided, highlighting recent efforts in this field with particular emphasis on scalable methods.
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Affiliation(s)
- Shanju Zhang
- Department of Chemistry and Biochemistry, California Polytechnic State University, San Luis Obispo, CA, 93407, USA
| | - Candice I Pelligra
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, 06511, USA
| | - Xunda Feng
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, 06511, USA
| | - Chinedum O Osuji
- Department of Chemical and Environmental Engineering, Yale University, New Haven, CT, 06511, USA
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32
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Chang C, Zhao Y, Liu Y, An L. Liquid crystallinity of carbon nanotubes. RSC Adv 2018; 8:15780-15795. [PMID: 35539493 PMCID: PMC9080064 DOI: 10.1039/c8ra00879e] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 04/12/2018] [Indexed: 01/30/2023] Open
Abstract
In this review, we first briefly recapitulate the orientation characteristics of liquid crystalline carbon nanotubes (CNTs), emphasizing their inherent properties. Both the high Young's modulus and the strong attractive interaction between them make the liquid crystallinity apt to show splay deformations (splay defects). It is these defects that often produce apparent low-order structures for long and deformed nanotubes. However, the application of doping, shearing, magnetic or electric fields will be efficient routes toward highly ordered CNT assemblies from such defects. Then, we describe the electrical behavior of CNTs in the electric field, which combines desirable features of the CNTS with those of classical liquid crystals (LCs). An electric field will generate an induced dipole moment on CNTs and align them in the field direction, minimizing the dipolar energy. Finally, we review the potential application of CNTs in the area of liquid crystal displays (LCD). In the LC cell unit, CNTs as dopants in LC layers can have compatible stability with LCs, with the orientation consistent and with surprising complementary advantages. And also CNT films as nanostructured electrodes can substitute ITO electrodes in the LC cell unit, exhibiting a strong electrical anisotropy due to their excellent axial conductivity. Furthermore, CNT films as an alignment layer have the potential to replace the traditional PI film, aligning LC molecules effectively along the direction of the nanotubes. Besides, CNTs acting as polarizers can absorb or transmit incident light when the electric vector propagates parallel or perpendicular to the nanotube axis. All of these applications demonstrate that CNTs in LC ordering will effectively improve the performance of materials and their related devices. Thus, we should improve the ordering of CNT assemblies as far as possible, which is critical to make full use of their exceptional axial properties and further to develop novel materials and applications successfully.
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Affiliation(s)
- Chunrui Chang
- North China University of Science and Technology, College of Science Tangshan 063009 China +86 18032513036
| | - Ying Zhao
- Hebei Milestone Electronic Material Limited Company, Research and Development Department of Liquid Crystal Mixture Shijiazhuang 050600 China
| | - Ying Liu
- North China University of Science and Technology, College of Science Tangshan 063009 China +86 18032513036
| | - Libao An
- North China University of Science and Technology, College of Mechanical Engineering Tangshan 063009 China
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33
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Maximean DM, Cîrcu V, Ganea CP. Dielectric properties of a bisimidazolium salt with dodecyl sulfate anion doped with carbon nanotubes. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2018; 9:164-174. [PMID: 29441262 PMCID: PMC5789394 DOI: 10.3762/bjnano.9.19] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 12/20/2017] [Indexed: 05/14/2023]
Abstract
A new bisimidazolium salt with dodecyl sulfate as counterion has been designed and prepared. This salt shows a SmA phase that is stable at room temperature. The new ionic liquid crystal (ILC) was characterized by 1H NMR, 13C NMR and IR spectroscopy. Its liquid crystalline properties were analyzed by polarizing optical microscopy (POM), differential scanning calorimetry (DSC) and powder X-ray diffraction (XRD) studies. The dielectric spectra of the ILC doped with different concentrations of carbon nanotubes (CNT) were recorded over a wide frequency and temperature range of 10-1 to 107 Hz and 293-338 K, respectively. The values of the activation energy were found in the range of 0.46-0.61 eV; the characteristic time was obtained by fitting the spectra of the dielectric loss with the Havriliak-Negami functions. As a result of doping the ILC with CNT, the electric conductivity increases significantly. Ionic conductivity is dominant and it was indirectly observed through the electrode polarization (EP) effect. The very high dielectric permittivity values and the decrease of the electric conductivity at low frequencies confirm the presence of EP.
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Affiliation(s)
- Doina Manaila Maximean
- University Politehnica of Bucharest, Department of Physics, 313 Spl. Independentei, 060042, Bucharest, Romania
| | - Viorel Cîrcu
- Department of Inorganic Chemistry, University of Bucharest, 23 Dumbrava Rosie st, sector 2, Bucharest 020464, Romania
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34
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Wang Q, Liu L, Xu L. Coupling free energy and surface anchoring mechanism in gold nanorod–nematic liquid crystal dispersions. RSC Adv 2018. [DOI: 10.1039/c7ra09378k] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dependence of both the induced optical birefringence signals and simulated free energy ftotal with the pump H.
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Affiliation(s)
- Qi Wang
- Key Lab for Micro and Nanophotonic Structures (Ministry of Education)
- Department of Optical Science and Engineering
- School of Information Science and Engineering
- Fudan University
- Shanghai 200433
| | - Liying Liu
- Key Lab for Micro and Nanophotonic Structures (Ministry of Education)
- Department of Optical Science and Engineering
- School of Information Science and Engineering
- Fudan University
- Shanghai 200433
| | - Lei Xu
- Key Lab for Micro and Nanophotonic Structures (Ministry of Education)
- Department of Optical Science and Engineering
- School of Information Science and Engineering
- Fudan University
- Shanghai 200433
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35
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Petrov DA, Skokov PK, Zakhlevnykh AN. Magnetic field induced orientational transitions in liquid crystals doped with carbon nanotubes. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2017; 8:2807-2817. [PMID: 29354352 PMCID: PMC5753054 DOI: 10.3762/bjnano.8.280] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/01/2017] [Indexed: 06/07/2023]
Abstract
We propose a continuum theory of orientational phase transitions induced by an external magnetic field in a suspension of carbon nanotubes in a nematic liquid crystal. It is shown that in a magnetic field a non-uniform and two different uniform phases are possible in the suspension. The uniform phases of the suspension differ by the type of orientational coupling of nanotubes with the liquid crystal matrix (the planar type when the nanotubes are oriented along the matrix director, and the homeotropic type when the nanotubes are perpendicular to the director). The possibility of a redistribution of the nanotube concentration (segregation effect) is shown. The fields of orientational transitions between uniform and non-uniform phases of the suspension are found analytically. It is shown that, when the nanotubes are weakly coupled to the matrix, the magnetic field induces reentrant transitions (uniform planar phase-non-uniform phase-uniform homeotropic phase-non-uniform phase). These transitions can be of first or of second order depending on the carbon nanotubes segregation intensity.
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Affiliation(s)
- Danil A Petrov
- Physics of Phase Transitions Department, Perm State University, Bukireva St. 15, 614990 Perm, Russia
| | - Pavel K Skokov
- Physics of Phase Transitions Department, Perm State University, Bukireva St. 15, 614990 Perm, Russia
| | - Alexander N Zakhlevnykh
- Physics of Phase Transitions Department, Perm State University, Bukireva St. 15, 614990 Perm, Russia
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37
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Dierking I, Al-Zangana S. Lyotropic Liquid Crystal Phases from Anisotropic Nanomaterials. NANOMATERIALS (BASEL, SWITZERLAND) 2017; 7:E305. [PMID: 28974025 PMCID: PMC5666470 DOI: 10.3390/nano7100305] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 09/14/2017] [Accepted: 09/14/2017] [Indexed: 01/23/2023]
Abstract
Liquid crystals are an integral part of a mature display technology, also establishing themselves in other applications, such as spatial light modulators, telecommunication technology, photonics, or sensors, just to name a few of the non-display applications. In recent years, there has been an increasing trend to add various nanomaterials to liquid crystals, which is motivated by several aspects of materials development. (i) addition of nanomaterials can change and thus tune the properties of the liquid crystal; (ii) novel functionalities can be added to the liquid crystal; and (iii) the self-organization of the liquid crystalline state can be exploited to template ordered structures or to transfer order onto dispersed nanomaterials. Much of the research effort has been concentrated on thermotropic systems, which change order as a function of temperature. Here we review the other side of the medal, the formation and properties of ordered, anisotropic fluid phases, liquid crystals, by addition of shape-anisotropic nanomaterials to isotropic liquids. Several classes of materials will be discussed, inorganic and mineral liquid crystals, viruses, nanotubes and nanorods, as well as graphene oxide.
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Affiliation(s)
- Ingo Dierking
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, UK.
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38
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Tortora MMC, Doye JPK. Perturbative density functional methods for cholesteric liquid crystals. J Chem Phys 2017. [DOI: 10.1063/1.4982934] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Affiliation(s)
- Maxime M. C. Tortora
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Jonathan P. K. Doye
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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39
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Manepalli RKNR, Madhav BTP, Giridhar G, Srinivasulu M, Tejaswi M, Sivaram K, Jayaprada P, Pisipati VGKM. Characterisation and mesomorphic behaviour of liquid crystals with dispersed PdCl 2 nanoparticles. LIQUID CRYSTALS TODAY 2017. [DOI: 10.1080/1358314x.2017.1313538] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
| | | | - G. Giridhar
- Department of Nanotechnology, Acharya Nagarjuna University , Guntur, India
| | - M. Srinivasulu
- Department of Chemistry, Manipal Institute of Technology, Manipal University , Manipal, India
| | - M. Tejaswi
- Department of Physics, The Hindu College, Krishna University , Machilipatnam, India
| | - K. Sivaram
- Department of Physics, The Hindu College, Krishna University , Machilipatnam, India
| | - P. Jayaprada
- Department of Physics, The Hindu College, Krishna University , Machilipatnam, India
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40
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Oh J, Gleeson HF, Dierking I. Electric-field-induced transport of microspheres in the isotropic and chiral nematic phase of liquid crystals. Phys Rev E 2017; 95:022703. [PMID: 28297920 DOI: 10.1103/physreve.95.022703] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Indexed: 06/06/2023]
Abstract
The application of an electric field to microspheres suspended in a liquid crystal causes particle translation in a plane perpendicular to the applied field direction. Depending on applied electric field amplitude and frequency, a wealth of different motion modes may be observed above a threshold, which can lead to linear, circular, or random particle trajectories. We present the stability diagram for these different translational modes of particles suspended in the isotropic and the chiral nematic phase of a liquid crystal and investigate the angular velocity, circular diameter, and linear velocity as a function of electric field amplitude and frequency. In the isotropic phase a narrow field amplitude-frequency regime is observed to exhibit circular particle motion whose angular velocity increases with applied electric field amplitude but is independent of applied frequency. The diameter of the circular trajectory decreases with field amplitude as well as frequency. In the cholesteric phase linear as well as circular particle motion is observed. The former exhibits an increasing velocity with field amplitude, while decreasing with frequency. For the latter, the angular velocity exhibits an increase with field amplitude and frequency. The rotational sense of the particles on a circular trajectory in the chiral nematic phase is independent of the helicity of the liquid crystalline structure, as is demonstrated by employing a cholesteric twist inversion compound.
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Affiliation(s)
- Jiyoung Oh
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Helen F Gleeson
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| | - Ingo Dierking
- School of Physics and Astronomy, University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
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41
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Verma R, Mishra M, Dhar R, Dabrowski R. Single walled carbon nanotubes persuaded optimization of the display parameters of a room temperature liquid crystal 4-pentyl-4′cyanobiphenyl. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.05.045] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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42
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He X, Gao W, Xie L, Li B, Zhang Q, Lei S, Robinson JM, Hároz EH, Doorn SK, Wang W, Vajtai R, Ajayan PM, Adams WW, Hauge RH, Kono J. Wafer-scale monodomain films of spontaneously aligned single-walled carbon nanotubes. NATURE NANOTECHNOLOGY 2016; 11:633-8. [PMID: 27043199 DOI: 10.1038/nnano.2016.44] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Accepted: 02/19/2016] [Indexed: 05/02/2023]
Abstract
The one-dimensional character of electrons, phonons and excitons in individual single-walled carbon nanotubes leads to extremely anisotropic electronic, thermal and optical properties. However, despite significant efforts to develop ways to produce large-scale architectures of aligned nanotubes, macroscopic manifestations of such properties remain limited. Here, we show that large (>cm(2)) monodomain films of aligned single-walled carbon nanotubes can be prepared using slow vacuum filtration. The produced films are globally aligned within ±1.5° (a nematic order parameter of ∼1) and are highly packed, containing 1 × 10(6) nanotubes in a cross-sectional area of 1 μm(2). The method works for nanotubes synthesized by various methods, and film thickness is controllable from a few nanometres to ∼100 nm. We use the approach to create ideal polarizers in the terahertz frequency range and, by combining the method with recently developed sorting techniques, highly aligned and chirality-enriched nanotube thin-film devices. Semiconductor-enriched devices exhibit polarized light emission and polarization-dependent photocurrent, as well as anisotropic conductivities and transistor action with high on/off ratios.
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Affiliation(s)
- Xiaowei He
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
| | - Weilu Gao
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
| | - Lijuan Xie
- College of Biosystems Engineering and Food Science, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Bo Li
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - Qi Zhang
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
| | - Sidong Lei
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - John M Robinson
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
| | - Erik H Hároz
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Stephen K Doorn
- Center for Integrated Nanotechnologies, Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - Weipeng Wang
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - Robert Vajtai
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - Pulickel M Ajayan
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - W Wade Adams
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
| | - Robert H Hauge
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
- Department of Chemistry, Rice University, Houston, Texas 77005, USA
| | - Junichiro Kono
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005, USA
- Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005, USA
- Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA
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43
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Bale S, Liyana-Arachchi TP, Hung FR. Molecular dynamics simulation of single-walled carbon nanotubes inside liquid crystals. MOLECULAR SIMULATION 2016. [DOI: 10.1080/08927022.2016.1174859] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Shivkumar Bale
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA, USA
| | - Thilanga P. Liyana-Arachchi
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA, USA
- Department of Chemistry, University of Florida, Gainesville, FL, USA
| | - Francisco R. Hung
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, LA, USA
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44
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Thermodynamical, optical, electrical and electro-optical studies of a room temperature nematic liquid crystal 4-pentyl-4′-cyanobiphenyl dispersed with barium titanate nanoparticles. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2015.11.007] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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45
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Nano-Objects and Ions in Liquid Crystals: Ion Trapping Effect and Related Phenomena. CRYSTALS 2015. [DOI: 10.3390/cryst5040501] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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46
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Urbanski M. On the impact of nanoparticle doping on the electro-optic response of nematic hosts. LIQUID CRYSTALS TODAY 2015. [DOI: 10.1080/1358314x.2015.1059586] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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47
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Popa-Nita V. The phase behavior of rigid rods in an anisotropic mean field with applications to carbon nanotubes in nematic liquid crystals. J Chem Phys 2015; 143:094901. [PMID: 26342384 DOI: 10.1063/1.4928655] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The phenomenological model [van der Schoot et al., J. Phys. Chem. B 112, 4512 (2008)] for predicting the alignment of carbon nanotube (CNT) dispersions in thermotropic liquid crystals is extended to include the attractive interactions between CNTs. The influence of the attractive forces (described by a spatially uniform mean field) on the phase behavior and orientational properties of the mixture are analyzed.
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Affiliation(s)
- V Popa-Nita
- Faculty of Physics, University of Bucharest, P.O. Box MG-11, Bucharest 077125, Romania
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48
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Shendruk TN, Yeomans JM. Multi-particle collision dynamics algorithm for nematic fluids. SOFT MATTER 2015; 11:5101-5110. [PMID: 26035731 DOI: 10.1039/c5sm00839e] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Research on transport, self-assembly and defect dynamics within confined, flowing liquid crystals requires versatile and computationally efficient mesoscopic algorithms to account for fluctuating nematohydrodynamic interactions. We present a multi-particle collision dynamics (MPCD) based algorithm to simulate liquid-crystal hydrodynamic and director fields in two and three dimensions. The nematic-MPCD method is shown to successfully reproduce the features of a nematic liquid crystal, including a nematic-isotropic phase transition with hysteresis in 3D, defect dynamics, isotropic Frank elastic coefficients, tumbling and shear alignment regimes and boundary condition-dependent order parameter fields.
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Affiliation(s)
- Tyler N Shendruk
- The Rudolf Peierls Centre for Theoretical Physics, Department of Physics, Theoretical Physics, University of Oxford, 1 Keble Road, Oxford, OX1 3NP, UK.
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49
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Lin P, Cong Y, Zhang B. Dispersing carbon nanotubes by chiral network surfactants. ACS APPLIED MATERIALS & INTERFACES 2015; 7:6724-6732. [PMID: 25789867 DOI: 10.1021/acsami.5b00168] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Chiral network surfactants (CNSs) possessing miscibility with carbon nanotubes (CNTs) and chiral materials are applied to disperse CNTs. Ultraviolet-visible absorption spectroscopy is used to quantitatively determine the CNT concentration in homogeneous CNT-CNS dispersions, results indicate that CNSs with more mole fraction of polycyclic conjugated structure have better ability to load and disperse CNTs and the maximal concentration reaches 0.79 mg mL(-1). Fourier transform infrared imaging system is utilized to analyze the dispersibility of CNTs in CNT-CNS composites, and CNS with 6 mol % nonmesogens (S6) induces the best dispersibility. The CNT doped CNSs exhibit lower glass transition temperature, strengthened thermal stability, decreased the thermochromic temperature and enriched reflected colors of CNSs. Furthermore, S6 are used as a promoter to disperse CNTs in chiral host, here, a left-handed chiral liquid crystal (CLC) is selected, the miscibility between CNTs and CLCs is studied by polarized optical microscope, and CNTs can be effectively dispersed in CLCs by S6. The CNT dispersed CLCs can exhibit a faster electro-optical response process than neat CLCs.
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Affiliation(s)
- Pengcheng Lin
- Center for Molecular Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Yuehua Cong
- Center for Molecular Science and Engineering, Northeastern University, Shenyang 110819, China
| | - Baoyan Zhang
- Center for Molecular Science and Engineering, Northeastern University, Shenyang 110819, China
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50
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Yevdokimov YM, Salyanov VI, Skuridin SG, Shtykova EV, Khlebtsov NG, Kats EI. Physicochemical and nanotechnological approaches to the design of 'rigid' spatial structures of DNA. RUSSIAN CHEMICAL REVIEWS 2015. [DOI: 10.1070/rcr4454] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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