1
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Ohno K, Masuda S, Ogawa H. Polymer-brush-decorated colloidal platelets: precision synthesis and self-assembly. Polym Chem 2019. [DOI: 10.1039/c9py00436j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Polymer-brush-decorated platelets produced through surface-initiated polymerization formed unique self-assembled structures in solution and in the bulk.
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Affiliation(s)
- Kohji Ohno
- Institute for Chemical Research
- Kyoto University
- Kyoto 611-0011
- Japan
| | - Shota Masuda
- Institute for Chemical Research
- Kyoto University
- Kyoto 611-0011
- Japan
| | - Hiroki Ogawa
- Institute for Chemical Research
- Kyoto University
- Kyoto 611-0011
- Japan
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2
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Xu P, Lan Y, Dai L, O’Neill T, Stoev I, Cao T, Eiser E. Discotic liquid crystals of cucurbit[7]uril (CB[7])-functionalised Laponite clays. Mol Phys 2018. [DOI: 10.1080/00268976.2018.1508778] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Peicheng Xu
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Yang Lan
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Chemistry Department, University of Cambridge, Cambridge, UK
| | - Linjie Dai
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Thomas O’Neill
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Iliya Stoev
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
| | - Tianyang Cao
- Chemistry Department, Tsinghua University, Beijing, People's Republic of China
| | - Erika Eiser
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
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3
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Abstract
The phase diagram of colloidal suspensions of electrically charged nanosheets, such as clays, despite their many industrial uses, is not yet understood either experimentally or theoretically. When the nanosheet diameter is very large (∼100 nm to 1 µm), it is quite challenging to distinguish the lamellar liquid-crystalline phase from a nematic phase with strong stacking local order, often called "columnar" nematic. We show here that newly upgraded small-angle X-ray scattering beamlines at synchrotron radiation facilities provide high-resolution measurements which allow us to identify both phases unambiguously, provided that single domains can be obtained. We investigated dilute aqueous suspensions of synthetic Sb3P2O143- nanosheets that self-organize into two distinct liquid-crystalline phases, sometimes coexisting in the same sample. Close examination of their X-ray reflection profiles in the directions perpendicular to the director demonstrates that these two mesophases are a columnar nematic and a lamellar phase. In the latter, the domain size reaches up to ∼20 µm, which means that each layer is made of >600 nanosheets. Because the lamellar phase was only rarely predicted in suspensions of charged disks, our results show that these systems should be revisited by theory or simulations. The unexpected stability of the lamellar phase also suggests that the rims and faces of Sb3P2O143- nanosheets may have different properties, giving them a patchy particle character.
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4
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Xu P, Lan Y, Xing Z, Eiser E. Liquid crystalline behaviour of self-assembled LAPONITE®/PLL-PEG nanocomposites. SOFT MATTER 2018; 14:2782-2788. [PMID: 29457811 DOI: 10.1039/c7sm01613a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Synthetic LAPONITE®-clay particles with platelet-like shape display strong aging when dispersed in aqueous solutions, preventing the latter from reaching their natural liquid-crystalline equilibrium state. Here we introduce a facile method that successfully prevents this aging behaviour and enables accessing the systems' liquid-crystal and crystalline phases. We graft the comb-like polymer PLL-PEG (poly(l-lysine)-g-poly(ethylene glycol)) onto the clay surfaces from solution, thereby screening the negative surface charges and thus ensuring steric stabilisation. We show zeta-sizer and rheology measurements, respectively, confirming complete steric coating and that aging of dilute samples is completely suppressed even after a year. Using evaporation as a means to concentrate the particles, we observe various liquid crystalline textures under a polarized optical microscope (POM). Upon sequential spreading and drying, we are also able to obtain transparent films with hierarchical architecture.
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Affiliation(s)
- P Xu
- University of Cambridge, Cavendish Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, UK.
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5
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Sonin AS, Churochkina NA, Kaznacheev AV, Golovanov AV. Mineral liquid crystals. COLLOID JOURNAL 2017. [DOI: 10.1134/s1061933x17040159] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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6
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Liu Y, Xu Z, Gao W, Cheng Z, Gao C. Graphene and Other 2D Colloids: Liquid Crystals and Macroscopic Fibers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2017; 29:1606794. [PMID: 28233348 DOI: 10.1002/adma.201606794] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 01/19/2017] [Indexed: 06/06/2023]
Abstract
Two-dimensional colloidal nanomaterials are running into renaissance after the enlightening researches of graphene. Macroscopic one-dimensional fiber is an optimal ordered structural form to express the in-plane merits of 2D nanomaterials, and the formation of liquid crystals (LCs) allows the creation of continuous fibers. In the correlated system from LCs to fibers, understanding their macroscopic organizing behavior and transforming them into new solid fibers is greatly significant for applications. Herein, we retrospect the history of 2D colloids and discuss about the concept of 2D nanomaterial fibers in the context of LCs, elaborating the motivation, principle and possible strategies of fabrication. Then we highlight the creation, development and typical applications of graphene fibers. Additionally, the latest advances of other 2D nanomaterial fibers are also summarized. Finally, conclusions, challenges and perspectives are provided to show great expectations of better and more fibrous materials of 2D nanomaterials. This review gives a comprehensive retrospect of the past century-long effort about the whole development of 2D colloids, and plots a clear roadmap - "lamellar solid - LCs - macroscopic fibers - flexible devices", which will certainly open a new era of structural-multifunctional application for the conventional 2D colloids.
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Affiliation(s)
- Yingjun Liu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
| | - Zhen Xu
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
| | - Weiwei Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
| | - Zhengdong Cheng
- Arti McFerrin Department of Chemical Engineering and Department of Materials Science and Engineering, Texas A&M University, College Station, TX, 77843, USA
| | - Chao Gao
- MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Key Laboratory of Adsorption and Separation Materials & Technologies of Zhejiang Province, Zhejiang University, 38 Zheda Road, Hangzhou, 310027, P. R. China
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7
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MIYAMOTO N, YAMAMOTO S. Inorganic Nanosheet Liquid Crystals: Self-Assembled Structures in Dispersions of Two-Dimensional Inorganic Polymers. KOBUNSHI RONBUNSHU 2016. [DOI: 10.1295/koron.2015-0075] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Nobuyoshi MIYAMOTO
- Department of Life, Environment, and Materials Science, Fukuoka Institute of Technology
- Faculty of Engineering, Graduate School of Fukuoka Institute of Technology
- Institute for Materials Chemistry and Engineering, Kyushu University
| | - Shinya YAMAMOTO
- Faculty of Engineering, Graduate School of Fukuoka Institute of Technology
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8
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Li P, White KL, Lin CH, Kim D, Muliana A, Krishnamoorti R, Nishimura R, Sue HJ. Mechanical reinforcement of epoxy with self-assembled synthetic clay in smectic order. ACS APPLIED MATERIALS & INTERFACES 2014; 6:10188-10195. [PMID: 24915977 DOI: 10.1021/am5015293] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Epoxy films containing self-assembled 2D colloidal α-zirconium phosphate nanoplatelets (ZrP) in smectic order were prepared using a simple, energy-efficient fabrication process suitable to industrial processing. The ZrP nanoplatelets form a chiral smectic mesophase with simultaneous lamellar order and helical arrangements in epoxy. The epoxy nanocomposite films are transparent and flexible and exhibit exceptionally high tensile modulus and strength. The findings have broad implications for development of multifunctional materials for engineering applications.
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Affiliation(s)
- Peng Li
- Department of Materials Science and Engineering and ‡Department of Mechanical Engineering, Texas A&M University , College Station, Texas 77843, United States
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9
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Wong M, Ishige R, White KL, Li P, Kim D, Krishnamoorti R, Gunther R, Higuchi T, Jinnai H, Takahara A, Nishimura R, Sue HJ. Large-scale self-assembled zirconium phosphate smectic layers via a simple spray-coating process. Nat Commun 2014; 5:3589. [DOI: 10.1038/ncomms4589] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 03/07/2014] [Indexed: 11/10/2022] Open
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10
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Delhorme M, Jönsson B, Labbez C. Gel, glass and nematic states of plate-like particle suspensions: charge anisotropy and size effects. RSC Adv 2014. [DOI: 10.1039/c4ra05555a] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The influence of the charge anisotropy and platelet size on the formation of gel and glass states and nematic phases in suspensions of plate-like particles is investigated using Monte Carlo simulations in the canonical ensemble.
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Affiliation(s)
- Maxime Delhorme
- Laboratoire Interdisciplinaire Carnot de Bourgogne
- UMR 6303 CNRS
- Université de Bourgogne
- F-21078 Dijon, France
- Theoretical Chemistry
| | - Bo Jönsson
- Theoretical Chemistry
- Lund University
- Chemical Center
- S-221 00 Lund, Sweden
| | - Christophe Labbez
- Laboratoire Interdisciplinaire Carnot de Bourgogne
- UMR 6303 CNRS
- Université de Bourgogne
- F-21078 Dijon, France
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11
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Delhorme M, Labbez C, Jönsson B. Liquid Crystal Phases in Suspensions of Charged Plate-Like Particles. J Phys Chem Lett 2012; 3:1315-20. [PMID: 26286776 DOI: 10.1021/jz300380n] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Anisotropic interactions in colloidal suspensions have recently emerged as a route for the design of new soft materials. Nonisotropic particles can form nematic, smectic, hexatic, and columnar liquid crystals. Although the formation of these phases is well rationalized when excluded volume is solely at play, the role of electrostatic interactions still remains unclear and even less so when particles present a charge heterogeneity, for example, clays. Here, we use Monte Carlo simulations of concentrated suspensions of charged disk-like particles to reveal the role of Coulomb interactions and charge anisotropy underlying liquid crystal formation and structures. We observe a vast zoo of exotic structures, going from hexatic to columnar phases, which are shown to be controlled by the charge anisotropy. The particle volume fraction at which these phases start to form is found to decrease with increasing Coulomb interactions and charge anisotropy, which suggests a route to tune the structure of aqueous liquid crystals.
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Affiliation(s)
- Maxime Delhorme
- †Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Université de Bourgogne, 21078 Dijon Cedex, France
| | - Christophe Labbez
- †Laboratoire Interdisciplinaire Carnot de Bourgogne, UMR 6303 CNRS, Université de Bourgogne, 21078 Dijon Cedex, France
| | - Bo Jönsson
- ‡Department of Theoretical Chemistry, Chemical Center, POB 124, S-221 00 Lund, Sweden
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12
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Hilhorst J, van Schooneveld MM, Wang J, de Smit E, Tyliszczak T, Raabe J, Hitchcock AP, Obst M, de Groot FMF, Petukhov AV. Three-dimensional structure and defects in colloidal photonic crystals revealed by tomographic scanning transmission X-ray microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:3614-3620. [PMID: 22260512 DOI: 10.1021/la204580y] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Self-assembled colloidal crystals have attracted major attention because of their potential as low-cost three-dimensional (3D) photonic crystals. Although a high degree of perfection is crucial for the properties of these materials, little is known about their exact structure and internal defects. In this study, we use tomographic scanning transmission X-ray microscopy (STXM) to access the internal structure of self-assembled colloidal photonic crystals with high spatial resolution in three dimensions for the first time. The positions of individual particles of 236 nm in diameter are identified in three dimensions, and the local crystal structure is revealed. Through image analysis, structural defects, such as vacancies and stacking faults, are identified. Tomographic STXM is shown to be an attractive and complementary imaging tool for photonic materials and other strongly absorbing or scattering materials that cannot be characterized by either transmission or scanning electron microscopy or optical nanoscopy.
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Affiliation(s)
- Jan Hilhorst
- Van 't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for Nanomaterials Science, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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13
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Leferink Op Reinink ABGM, Meijer JM, Kleshchanok D, Byelov DV, Vroege GJ, Petukhov AV, Lekkerkerker HNW. 3D structure of nematic and columnar phases of hard colloidal platelets. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:194110. [PMID: 21525552 DOI: 10.1088/0953-8984/23/19/194110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We present small angle x-ray scattering data of single-domain nematic and columnar liquid crystal phases in suspensions of sterically stabilized gibbsite platelets. The measurements are performed with different sample orientations to obtain information about the three-dimensional structure of the liquid crystalline phases. With the x-ray beam incident along the director of the nematic phase a strong correlation peak is observed corresponding to the side-to-side interparticle correlations, which suggests a columnar nematic structure. Upon sample rotation this side-to-side correlation peak of the nematic shifts to higher Q-values, suggesting the presence of strong fluctuations of small stacks of particles with different orientations, while the overall particle orientation is constant. In the hexagonal columnar phase, clear Bragg intercolumnar reflections are observed. Upon rotation, the Q-value of these reflections remains constant while their intensity monotonically decreases upon rotation. This indicates that the column orientation fluctuates together with the particle director in the columnar phase. This difference between the behaviour of the columnar and the nematic reflections upon sample rotation is used to assign the liquid crystal phase of a suspension consisting of larger platelets, where identification can be ambiguous due to resolution limitations.
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14
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Paineau E, Bihannic I, Baravian C, Philippe AM, Davidson P, Levitz P, Funari SS, Rochas C, Michot LJ. Aqueous suspensions of natural swelling clay minerals. 1. Structure and electrostatic interactions. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:5562-5573. [PMID: 21476528 DOI: 10.1021/la2001255] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In this article, we present a general overview of the organization of colloidal charged clay particles in aqueous suspension by studying different natural samples with different structural charges and charge locations. Small-angle X-ray scattering experiments (SAXS) are first used to derive swelling laws that demonstrate the almost perfect exfoliation of clay sheets in suspension. Using a simple approach based on geometrical constraints, we show that these swelling laws can be fully modeled on the basis of morphological parameters only. The validity of this approach was further extended to other clay data from the literature, in particular, synthetic Laponite. For all of the investigated samples, experimental osmotic pressures can be properly described by a Poisson-Boltzmann approach for ionic strength up to 10(-3) M, which reveals that these systems are dominated by repulsive electrostatic interactions. However, a detailed analysis of the Poisson-Boltzmann treatment shows differences in the repulsive potential strength that are not directly linked to the structural charge of the minerals but rather to the charge location in the structure for tetrahedrally charged clays (beidellite and nontronites) undergoing stronger electrostatic repulsions than octahedrally charged samples (montmorillonites, laponite). Only minerals subjected to the strongest electrostatic repulsions present a true isotropic to nematic phase transition in their phase diagrams. The influence of ionic repulsions on the local order of clay platelets was then analyzed through a detailed investigation of the structure factors of the various clay samples. It appears that stronger electrostatic repulsions improve the liquidlike positional local order.
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Affiliation(s)
- Erwan Paineau
- Laboratoire Environnement et Minéralurgie, Nancy Université-CNRS, UMR 7569, BP40 54501 Vandœuvre Cedex, France.
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15
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Verhoeff A, Brand R, Lekkerkerker H. Tuning the birefringence of the nematic phase in suspensions of colloidal gibbsite platelets. Mol Phys 2011. [DOI: 10.1080/00268976.2011.559006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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van Schooneveld MM, Hilhorst J, Petukhov AV, Tyliszczak T, Wang J, Weckhuysen BM, de Groot FMF, de Smit E. Scanning transmission x-ray microscopy as a novel tool to probe colloidal and photonic crystals. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2011; 7:804-811. [PMID: 21337510 DOI: 10.1002/smll.201001745] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2010] [Indexed: 05/30/2023]
Abstract
Photonic crystals consisting of nano- to micrometer-sized building blocks, such as multiple sorts of colloids, have recently received widespread attention. It remains a challenge, however, to adequately probe the internal crystal structure and the corresponding deformations that inhibit the proper functioning of such materials. It is shown that scanning transmission X-ray microscopy (STXM) can directly reveal the local structure, orientations, and even deformations in polystyrene and silica colloidal crystals with 30-nm spatial resolution. Moreover, STXM is capable of imaging a diverse range of crystals, including those that are dry and inverted, and provides novel insights complementary to information obtained by benchmark confocal fluorescence and scanning electron microscopy techniques.
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Affiliation(s)
- Matti M van Schooneveld
- Inorganic Chemistry & Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Sorbonnelaan 16, 3584 CA Utrecht, The Netherlands
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17
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van den Pol E, Petukhov AV, Thies-Weesie DM, Byelov DV, Vroege GJ. Liquid crystal phase behavior of sterically-stabilized goethite. J Colloid Interface Sci 2010; 352:354-8. [PMID: 20880536 DOI: 10.1016/j.jcis.2010.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2010] [Revised: 09/01/2010] [Accepted: 09/02/2010] [Indexed: 11/24/2022]
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18
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Mourad MCD, Petukhov AV, Vroege GJ, Lekkerkerker HNW. Lyotropic hexagonal columnar liquid crystals of large colloidal gibbsite platelets. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:14182-14187. [PMID: 20712370 DOI: 10.1021/la100797x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
We report the formation of hexagonal columnar liquid crystal phases in suspensions of large (570 nm diameter), sterically stabilized, colloidal gibbsite platelets in organic solvent. In thin cells these systems display strong iridescence originating from hexagonally arranged columns that are predominantly aligned perpendicularly to the cell walls. Small angle X-ray scattering and polarization microscopy indicate the presence of orientational fluctuations in the hexagonal columnar liquid crystal phase. The presence of decoupling of the average platelet orientation and the column axis as well as column undulations leading to a decrease of the effective column diameter are discussed. The fact that these phenomena are particularly pronounced in the vertical direction and are enhanced toward the bottom part of the system points to the role of gravitational compaction on the structure.
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Affiliation(s)
- Maurice C D Mourad
- Van 't Hoff Laboratory for Physical and Colloid Chemistry, Debye Institute for Nanomaterials Science, Utrecht University, The Netherlands.
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19
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Phillips J, Schmidt M. Bulk phase behavior of binary hard platelet mixtures from density functional theory. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 81:041401. [PMID: 20481721 DOI: 10.1103/physreve.81.041401] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2009] [Indexed: 05/29/2023]
Abstract
We investigate isotropic-isotropic, isotropic-nematic, and nematic-nematic phase coexistence in binary mixtures of circular platelets with vanishing thickness, continuous rotational degrees of freedom, and radial size ratios lambda up to 5. A fundamental measure density functional theory, previously used for the one-component model, is presented and results are compared against those from Onsager theory as a benchmark. For lambda<or=1.7 the system displays isotropic-nematic phase coexistence with a widening of the biphasic region for increasing values of lambda . For size ratios lambda>or=2, we find that demixing into two nematic states becomes stable and an isotropic-nematic-nematic triple point can occur. Fundamental measure theory gives a smaller isotropic-nematic biphasic region than Onsager theory and locates the transition at lower densities. Furthermore, nematic-nematic demixing occurs over a larger range of compositions at a given value of lambda than found in Onsager theory. Both theories predict the same topologies of the phase diagrams. The partial nematic order parameters vary strongly with composition and indicate that the larger particles are more strongly ordered than the smaller particles.
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Affiliation(s)
- Jonathan Phillips
- H.H. Wills Physics Laboratory, Bristol University, Royal Fort, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
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20
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Nakato T, Miyamoto N. Liquid Crystalline Behavior and Related Properties of Colloidal Systems of Inorganic Oxide Nanosheets. MATERIALS 2009. [PMCID: PMC5525201 DOI: 10.3390/ma2041734] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Inorganic layered crystals exemplified by clay minerals can be exfoliated in solvents to form colloidal dispersions of extremely thin inorganic layers that are called nanosheets. The obtained “nanosheet colloids” form lyotropic liquid crystals because of the highly anisotropic shape of the nanosheets. This system is a rare example of liquid crystals consisting of inorganic crystalline mesogens. Nanosheet colloids of photocatalytically active semiconducting oxides can exhibit unusual photoresponses that are not observed for organic liquid crystals. This review summarizes experimental work on the phase behavior of the nanosheet colloids as well as photochemical reactions observed in the clay and semiconducting nanosheets system.
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Affiliation(s)
- Teruyuki Nakato
- Division of Bio-Applications and Systems Engineering (BASE), Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei-shi, Tokyo 184-8588, Japan
- Author to whom correspondence should be addressed; E-Mail: ; Tel./Fax: +81-42-388-7344
| | - Nobuyoshi Miyamoto
- Department of Life, Environment, and Materials Science, Faculty of Engineering, Fukuoka Institute of Technology, 3-30-1 Wajiro-higashi, Higashi-ku, Fukuoka-shi, Fukuoka 811-0295, Japan; E-Mail:
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21
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Trukhina Y, Jungblut S, van der Schoot P, Schilling T. Osmotic compression of droplets of hard rods: A computer simulation study. J Chem Phys 2009; 130:164513. [DOI: 10.1063/1.3117924] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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