1
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Cruickshank E. The Emergence of a Polar Nematic Phase: A Chemist's Insight into the Ferroelectric Nematic Phase. Chempluschem 2024; 89:e202300726. [PMID: 38452282 DOI: 10.1002/cplu.202300726] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 02/20/2024] [Accepted: 03/07/2024] [Indexed: 03/09/2024]
Abstract
The discovery of a new polar nematic phase; the ferroelectric nematic, has generated a great deal of excitement in the field of liquid crystals. To date there have been around 150 materials reported exhibiting the ferroelectric nematic phase, in general, following three key archetypal structures with these compounds known as RM734, DIO and UUQU-4N. In this review, the relationship between the molecular structure and the stability of the ferroelectric nematic, NF, phase will be described from a chemist's perspective. This will look to highlight the wide variety of functionalities which have been incorporated into these archetypal structures and how these changes influence the transition temperatures of the mesophases present. The NF phase appears to be stabilised particularly by reducing the length of terminal alkyl chains present and adding fluorines laterally along the length of the molecular backbone. This review will look to introduce the background of the ferroelectric nematic phase before then showing the molecular structures of a range of materials which exhibit the phase, describing their structure-property relationships and therefore giving an up-to-date account of the literature for this fascinating new mesophase.
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Affiliation(s)
- Ewan Cruickshank
- School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen, AB10 7GJ, UK
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2
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Jarosik A, Nádasi H, Schwidder M, Manabe A, Bremer M, Klasen-Memmer M, Eremin A. Fluid fibers in true 3D ferroelectric liquids. Proc Natl Acad Sci U S A 2024; 121:e2313629121. [PMID: 38513103 PMCID: PMC10990086 DOI: 10.1073/pnas.2313629121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Accepted: 02/08/2024] [Indexed: 03/23/2024] Open
Abstract
We demonstrate an exceptional ability of a high-polarization 3D ferroelectric liquid to form freely suspended fluid fibers at room temperature. Unlike fluid threads in modulated smectics and columnar phases, where translational order is a prerequisite for forming liquid fibers, recently discovered ferroelectric nematic forms fibers with solely orientational molecular order. Additional stabilization mechanisms based on the polar nature of the mesophase are required for this. We propose a model for such a mechanism and show that these fibers demonstrate an exceptional nonlinear optical response and exhibit electric field-driven instabilities.
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Affiliation(s)
- Alexander Jarosik
- Department of Nonlinear Phenomena, Institute of Physics, Otto von Guericke University, Magdeburg39106, Germany
| | - Hajnalka Nádasi
- Department of Nonlinear Phenomena, Institute of Physics, Otto von Guericke University, Magdeburg39106, Germany
| | - Michael Schwidder
- Department Industrial Chemistry, Institute of Chemistry, Otto von Guericke University, Magdeburg39106, Germany
| | | | | | | | - Alexey Eremin
- Department of Nonlinear Phenomena, Institute of Physics, Otto von Guericke University, Magdeburg39106, Germany
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3
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Marchenko AA, Kapitanchuk OL, Lopatina YY, Nazarenko KG, Senenko AI, Katsonis N, Nazarenko VG, Lavrentovich OD. Polar Self-Organization of Ferroelectric Nematic-Liquid-Crystal Molecules on Atomically Flat Au(111) Surface. PHYSICAL REVIEW LETTERS 2024; 132:098101. [PMID: 38489655 DOI: 10.1103/physrevlett.132.098101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 12/15/2023] [Accepted: 01/26/2024] [Indexed: 03/17/2024]
Abstract
Understanding nanoscale mechanisms responsible for the recently discovered ferroelectric nematics can be helped by direct visualization of self-assembly of strongly polar molecules. Here, we report on scanning tunneling microscopy studies of monomolecular layers of a ferroelectric nematic liquid crystal on a reconstructed Au(111) surface. The monolayers are obtained by deposition from a solution at ambient conditions. The adsorbed ferroelectric nematic molecules self-assemble into regular rows with tilted orientation, resembling a layered structure of a smectic C. Remarkably, each molecular dipole in this architecture is oriented along the same direction giving rise to polar ferroelectric ordering.
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Affiliation(s)
- Alexandr A Marchenko
- Institute of Physics of the National Academy of Sciences of Ukraine, 46 Nauki Avenue, Kyiv 03028, Ukraine
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Oleksiy L Kapitanchuk
- Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, 14-B Metrologichna Street, Kyiv 03143, Ukraine
| | - Yaroslava Yu Lopatina
- Institute of Physics of the National Academy of Sciences of Ukraine, 46 Nauki Avenue, Kyiv 03028, Ukraine
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Kostiantyn G Nazarenko
- Institute of Organic Chemistry of the National Academy of Sciences of Ukraine, 5 Academician Kukhar St., Kyiv 02660, Ukraine
- Ukraine Enamine Ltd., 78 Winston Churchill St., Kyiv 02094, Ukraine
| | - Anton I Senenko
- Institute of Physics of the National Academy of Sciences of Ukraine, 46 Nauki Avenue, Kyiv 03028, Ukraine
| | - Nathalie Katsonis
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Vassili G Nazarenko
- Institute of Physics of the National Academy of Sciences of Ukraine, 46 Nauki Avenue, Kyiv 03028, Ukraine
- Institute of Physical Chemistry, PAS, Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Oleg D Lavrentovich
- Advanced Materials and Liquid Crystal Institute, Department of Physics, Materials Science Graduate Program, Kent State University, Kent, Ohio 44242, USA
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4
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Nacke P, Manabe A, Klasen-Memmer M, Chen X, Martinez V, Freychet G, Zhernenkov M, Maclennan JE, Clark NA, Bremer M, Giesselmann F. New examples of ferroelectric nematic materials showing evidence for the antiferroelectric smectic-Z phase. Sci Rep 2024; 14:4473. [PMID: 38396051 DOI: 10.1038/s41598-024-54832-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Accepted: 02/16/2024] [Indexed: 02/25/2024] Open
Abstract
We present a new ferroelectric nematic material, 4-((4'-((trans)-5-ethyloxan-2-yl)-2',3,5,6'-tetrafluoro-[1,1'-biphenyl]-4-yl)difluoromethoxy)-2,6-difluorobenzonitrile (AUUQU-2-N) and its higher homologues, the molecular structures of which include fluorinated building blocks, an oxane ring, and a terminal cyano group, all contributing to a large molecular dipole moment of about 12.5 D. We observed that AUUQU-2-N has three distinct liquid crystal phases, two of which were found to be polar phases with a spontaneous electric polarization Ps of up to 6 µC cm-2. The highest temperature phase is a common enantiotropic nematic (N) exhibiting only field-induced polarization. The lowest-temperature, monotropic phase proved to be a new example of the ferroelectric nematic phase (NF), evidenced by a single-peak polarization reversal current response, a giant imaginary dielectric permittivity on the order of 103, and the absence of any smectic layer X-ray diffraction peaks. The ordinary nematic phase N and the ferroelectric nematic phase NF are separated by an antiferroelectric liquid crystal phase which has low permittivity and a polarization reversal current exhibiting a characteristic double-peak response. In the polarizing light microscope, this antiferroelectric phase shows characteristic zig-zag defects, evidence of a layered structure. These observations suggest that this is another example of the recently discovered smectic ZA (SmZA) phase, having smectic layers with the molecular director parallel to the layer planes. The diffraction peaks from the smectic layering have not been observed to date but detailed 2D X-ray studies indicate the presence of additional short-range structures including smectic C-type correlations in all three phases-N, SmZA and NF-which may shed new light on the understanding of polar and antipolar order in these phases.
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Affiliation(s)
- Pierre Nacke
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany
| | - Atsutaka Manabe
- Display Solutions, Merck Electronics KGaA, 64293, Darmstadt, Germany
- Individual researcher (Since 01.01.22), 64625, Bensheim, Germany
| | | | - Xi Chen
- Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO, 80309, USA
| | - Vikina Martinez
- Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO, 80309, USA
| | - Guillaume Freychet
- Brookhaven National Laboratory, National Synchrotron Light Source-II, Upton, NY, 11973, USA
| | - Mikhail Zhernenkov
- Brookhaven National Laboratory, National Synchrotron Light Source-II, Upton, NY, 11973, USA
| | - Joseph E Maclennan
- Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO, 80309, USA
| | - Noel A Clark
- Department of Physics and Soft Materials Research Center, University of Colorado, Boulder, CO, 80309, USA
| | - Matthias Bremer
- Display Solutions, Merck Electronics KGaA, 64293, Darmstadt, Germany
| | - Frank Giesselmann
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569, Stuttgart, Germany.
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5
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Parton-Barr C, Gleeson HF, Mandle RJ. Room-temperature ferroelectric nematic liquid crystal showing a large and diverging density. SOFT MATTER 2024; 20:672-680. [PMID: 38164818 DOI: 10.1039/d3sm01282d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2024]
Abstract
The ferroelectric nematic phase (NF) is a recently discovered phase of matter in which the orientational order of the conventional nematic liquid crystal state is augmented with polar order. Atomistic simulations suggest that the polar NF phase would be denser than conventional nematics owing to contributions from polar order. Using an oscillating U-tube densitometer, we obtain detailed temperature-dependent density values for a selection of conventional liquid crystals with excellent agreement with earlier reports. Having demonstrated the validity of our method, we then record density as a function of temperature for M5, a novel room-temperature ferroelectric nematic material. We present the first experimental density data for a NF material as well as density data for a nematic that has not previously been reported. We find that the room-temperature NF material shows a large (>1.3 g cm-3) density at all temperatures studied, notably including phases without polar order. An increase in density at phase transitions is observed. The magnitude of the increase for the intermediate-to-ferroelectric nematic (NX-NF) transition is an order of magnitude smaller than the isotropic-nematic (I-N) transition. We then probe potential consequences that may result from an elevated density through measurement of the refractive indices (no and ne). The navg of M5 is compared with 5CB and polar smectic liquid crystals. We observe how the highly polar nature of the system counteracts the effects of an increase in density. With knowledge of experimental density, we are able to derive an approximation that yields the polar order parameter, 〈P1〉, from polarisation measurements. Present results may be typical of ferroelectric nematic materials, potentially guiding material development, and is especially relevant for informing ongoing studies into this emerging class of materials.
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Affiliation(s)
| | - Helen F Gleeson
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
| | - Richard J Mandle
- School of Physics and Astronomy, University of Leeds, Leeds, LS2 9JT, UK
- School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK.
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6
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Erkoreka A, Mertelj A, Huang M, Aya S, Sebastián N, Martinez-Perdiguero J. Collective and non-collective molecular dynamics in a ferroelectric nematic liquid crystal studied by broadband dielectric spectroscopy. J Chem Phys 2023; 159:184502. [PMID: 37947513 DOI: 10.1063/5.0173813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2023] [Accepted: 10/23/2023] [Indexed: 11/12/2023] Open
Abstract
A great deal of effort has been recently devoted to the study of dielectric relaxation processes in ferroelectric nematic liquid crystals, yet their interpretation remains unclear. In this work, we present the results of broadband dielectric spectroscopy experiments of a prototypical ferroelectric nematogen in the frequency range 10 Hz-110 MHz at different electrode separations and under the application of DC bias fields. The results evidence a complex behavior in all phases due to the magnitude of polar correlations in these systems. The observed modes have been assigned to different relaxation mechanisms based on existing theoretical frameworks.
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Affiliation(s)
- Aitor Erkoreka
- Department of Physics, Faculty of Science and Technology, University of the Basque Country UPV/EHU, Bilbao, Spain
| | | | - Mingjun Huang
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Molecular Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, China
| | - Satoshi Aya
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Molecular Science and Engineering, South China University of Technology, Guangzhou, China
- Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, China
| | | | - Josu Martinez-Perdiguero
- Department of Physics, Faculty of Science and Technology, University of the Basque Country UPV/EHU, Bilbao, Spain
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7
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Karcz J, Rychłowicz N, Czarnecka M, Kocot A, Herman J, Kula P. Enantiotropic ferroelectric nematic phase in a single compound. Chem Commun (Camb) 2023. [PMID: 37937977 DOI: 10.1039/d3cc04296k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
The ferroelectric nematic phase became the centre of interest of scientists because of its unique physical properties. The uniqueness of this particular phase results in its monotropic character in all known NF materials. Here we present the very first example of a compound with an enantiotropic ferroelectric nematic phase. Compound 3JK is complementary with already well known NF materials, i.e. RM734 and DIO and is characterized by moderately high dielectric anisotropy.
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Affiliation(s)
- Jakub Karcz
- Institute of Chemistry, Faculty of Advanced Technologies and Chemistry, Military University of Technology, ul. gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
| | - Natan Rychłowicz
- Institute of Chemistry, Faculty of Advanced Technologies and Chemistry, Military University of Technology, ul. gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
| | - Małgorzata Czarnecka
- Faculty of Electrical Engineering, Automatics, Computer Science and Biomedical Engineering, AGH University of Science and Technology, al. Adama Mickiewicza 30, 30-059 Cracow, Poland
| | - Antoni Kocot
- Institute of Materials Engineering, Faculty of Science and Technology, University of Silesia, ul. 75 Pułku Piechoty, 41-500 Chorzów, Poland
| | - Jakub Herman
- Institute of Chemistry, Faculty of Advanced Technologies and Chemistry, Military University of Technology, ul. gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
| | - Przemysław Kula
- Institute of Chemistry, Faculty of Advanced Technologies and Chemistry, Military University of Technology, ul. gen. S. Kaliskiego 2, 00-908 Warsaw, Poland.
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8
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Ortega J, Folcia CL, Etxebarria J. Second harmonic generation in anisotropic stratified media: a generalization of the Berreman method and its application to photonic materials. OPTICS EXPRESS 2023; 31:36966-36980. [PMID: 38017835 DOI: 10.1364/oe.497447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 10/09/2023] [Indexed: 11/30/2023]
Abstract
We have developed a numerical method for calculating the second-harmonic generation (SHG) generated by an anisotropic material whose optical properties present an arbitrary modulation in one dimension. The method is based on the Berreman 4 × 4 matrix formalism, which is generalized to include nonlinear optical phenomena. It can be used under oblique incidences of the input beam, and is valid even when the SHG frequency is close to photonic bands, where the usual slowly-varying-amplitude approximation breaks down. As an example of application, we have studied the SHG performance of ferroelectric and helielectric fluids. The obtained results indicate that the present procedure may contribute to improving the structural design and enlarging the variety of nonlinear optical materials for application in optical devices.
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9
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Cruickshank E, Rybak P, Majewska MM, Ramsay S, Wang C, Zhu C, Walker R, Storey JMD, Imrie CT, Gorecka E, Pociecha D. To Be or Not To Be Polar: The Ferroelectric and Antiferroelectric Nematic Phases. ACS OMEGA 2023; 8:36562-36568. [PMID: 37810647 PMCID: PMC10552116 DOI: 10.1021/acsomega.3c05884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 08/30/2023] [Indexed: 10/10/2023]
Abstract
We report two new series of compounds that show the ferroelectric nematic, NF, phase in which the terminal chain length is varied. The longer the terminal chain, the weaker the dipole-dipole interactions of the molecules are along the director and thus the lower the temperature at which the axially polar NF phase is formed. For homologues of intermediate chain lengths, between the non-polar and ferroelectric nematic phases, a wide temperature range nematic phase emerges with antiferroelectric character. The size of the antiparallel ferroelectric domains critically increases upon transition to the NF phase. In dielectric studies, both collective ("ferroelectric") and non-collective fluctuations are present, and the "ferroelectric" mode softens weakly at the N-NX phase transition because the polar order in this phase is weak. The transition to the NF phase is characterized by a much stronger lowering of the mode relaxation frequency and an increase in its strength, and a typical critical behavior is observed.
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Affiliation(s)
- Ewan Cruickshank
- Department
of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE, U.K.
| | - Paulina Rybak
- Faculty
of Chemistry, University of Warsaw, ul. Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Magdalena M. Majewska
- Faculty
of Chemistry, University of Warsaw, ul. Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Shona Ramsay
- Department
of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE, U.K.
| | - Cheng Wang
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Chenhui Zhu
- Advanced
Light Source, Lawrence Berkeley National
Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Rebecca Walker
- Department
of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE, U.K.
| | - John M. D. Storey
- Department
of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE, U.K.
| | - Corrie T. Imrie
- Department
of Chemistry, School of Natural and Computing Sciences, University of Aberdeen, Aberdeen AB24 3UE, U.K.
| | - Ewa Gorecka
- Faculty
of Chemistry, University of Warsaw, ul. Zwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Damian Pociecha
- Faculty
of Chemistry, University of Warsaw, ul. Zwirki i Wigury 101, 02-089 Warsaw, Poland
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10
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Szydlowska J, Majewski P, Čepič M, Vaupotič N, Rybak P, Imrie CT, Walker R, Cruickshank E, Storey JMD, Damian P, Gorecka E. Ferroelectric Nematic-Isotropic Liquid Critical End Point. PHYSICAL REVIEW LETTERS 2023; 130:216802. [PMID: 37295101 DOI: 10.1103/physrevlett.130.216802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 04/18/2023] [Indexed: 06/12/2023]
Abstract
A critical end point above which an isotropic phase continuously evolves into a polar (ferroelectric) nematic phase with an increasing electric field is found in a ferroelectric nematic liquid crystalline material. The critical end point is approximately 30 K above the zero-field transition temperature from the isotropic to nematic phase and at an electric field of the order of 10 V/μm. Such systems are interesting from the application point of view because a strong birefringence can be induced in a broad temperature range in an optically isotropic phase.
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Affiliation(s)
- Jadwiga Szydlowska
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Pawel Majewski
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Mojca Čepič
- Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
- Department of Physics and Technical Studies, Faculty of Education, University of Ljubljana, Kardeljeva ploščad 16, 1000 Ljubljana, Slovenia
| | - Nataša Vaupotič
- Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, Koroška 160, 2000 Maribor, Slovenia
| | - Paulina Rybak
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Corrie T Imrie
- Department of Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE, United Kingdom
| | - Rebecca Walker
- Department of Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE, United Kingdom
| | - Ewan Cruickshank
- Department of Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE, United Kingdom
| | - John M D Storey
- Department of Chemistry, University of Aberdeen, Old Aberdeen AB24 3UE, United Kingdom
| | - Pociecha Damian
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland
| | - Ewa Gorecka
- Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02-089 Warsaw, Poland
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11
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Sebastián N, Lovšin M, Berteloot B, Osterman N, Petelin A, Mandle RJ, Aya S, Huang M, Drevenšek-Olenik I, Neyts K, Mertelj A. Polarization patterning in ferroelectric nematic liquids via flexoelectric coupling. Nat Commun 2023; 14:3029. [PMID: 37230977 DOI: 10.1038/s41467-023-38749-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023] Open
Abstract
The recently discovered ferroelectric nematic liquids incorporate to the functional combination of fluidity, processability and anisotropic optical properties of nematic liquids, an astonishing range of physical properties derived from the phase polarity. Among them, the remarkably large values of second order optical susceptibility encourage to exploit these new materials for non-linear photonic applications. Here we show that photopatterning of the alignment layer can be used to structure polarization patterns. To do so, we take advantage of the flexoelectric effect and design splay structures that geometrically define the polarization direction. We demonstrate the creation of periodic polarization structures and the possibility of guiding polarization by embedding splay structures in uniform backgrounds. The demonstrated capabilities of polarization patterning, open a promising new route for the design of ferroelectric nematic based photonic structures and their exploitation.
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Affiliation(s)
| | - Matija Lovšin
- Jožef Stefan Institute, Ljubljana, Slovenia
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Brecht Berteloot
- Liquid Crystals and Photonics Group, ELIS Department, Ghent University, Ghent, Belgium
| | - Natan Osterman
- Jožef Stefan Institute, Ljubljana, Slovenia
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Andrej Petelin
- Jožef Stefan Institute, Ljubljana, Slovenia
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Richard J Mandle
- School of Physics and Astronomy, University of Leeds, Leeds, UK
- School of Chemistry, University of Leeds, Leeds, UK
| | - Satoshi Aya
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, China
- Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, China
| | - Mingjun Huang
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, China
- Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, China
| | - Irena Drevenšek-Olenik
- Jožef Stefan Institute, Ljubljana, Slovenia
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
| | - Kristiaan Neyts
- Liquid Crystals and Photonics Group, ELIS Department, Ghent University, Ghent, Belgium
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12
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Tufaha N, Cruickshank E, Pociecha D, Gorecka E, Storey JM, Imrie CT. Molecular Shape, Electronic Factors, and the Ferroelectric Nematic Phase: Investigating the Impact of Structural Modifications. Chemistry 2023; 29:e202300073. [PMID: 36807424 PMCID: PMC10962687 DOI: 10.1002/chem.202300073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 02/14/2023] [Accepted: 02/16/2023] [Indexed: 02/22/2023]
Abstract
The synthesis and characterisation of two series of low molar mass mesogens, the (4-nitrophenyl) 2-alkoxy-4-(4-methoxybenzoyl)oxybenzoates (NT3.m) and the (3-fluoro-4-nitrophenyl) 2-alkoxy-4-(4-methoxybenzoyl)oxybenzoates (NT3F.m), are reported in order to investigate the effect of changing the position of a lateral alkoxy chain from the methoxy-substituted terminal ring to the central phenyl ring in these two series of materials based on RM734. All members of the NT3.m series exhibited a conventional nematic phase, N, which preceded the ferroelectric nematic phase, NF , whereas all the members of the NT3F.m series exhibited direct NF -I transitions except for NT3F.1 which also exhibited an N phase. These materials cannot be described as wedge-shaped, yet their values of the ferroelectric nematic-nematic transition temperature, TN F N ${{_{{\rm N}{_{{\rm F}}}{\rm N}}}}$ , exceed those of the corresponding materials with the lateral alkoxy chain located on the methoxy-substituted terminal ring. In part, this may be attributed to the effect that changing the position of the lateral alkoxy chain has on the electronic properties of these materials, specifically on the electron density associated with the methoxy-substituted terminal aromatic ring. The value of TNI decreased with the addition of a fluorine atom ortho to the nitro group in NT3F.1, however, the opposite behaviour was found when the transition temperatures of the NF phase were compared which are higher for the NT3F.m series. This may reflect a change in the polarity and polarizability of the NT3F.m series compared to the NT3.m series. Therefore, it is suggested that, rather than simply promoting a tapered shape, the role of the lateral chain in inhibiting anti-parallel associations and its effect on the electronic properties of the molecules are the key factors in driving the formation of the NF phase.
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Affiliation(s)
- Naila Tufaha
- Department of ChemistryUniversity of AberdeenOld AberdeenAB24 3UEUK
| | - Ewan Cruickshank
- Department of ChemistryUniversity of AberdeenOld AberdeenAB24 3UEUK
| | - Damian Pociecha
- Faculty of ChemistryUniversity of Warsawul. Zwirki i Wigury 10102-089WarsawPoland
| | - Ewa Gorecka
- Faculty of ChemistryUniversity of Warsawul. Zwirki i Wigury 10102-089WarsawPoland
| | - John M.D. Storey
- Department of ChemistryUniversity of AberdeenOld AberdeenAB24 3UEUK
| | - Corrie T. Imrie
- Department of ChemistryUniversity of AberdeenOld AberdeenAB24 3UEUK
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13
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Mrukiewicz M, Perkowski P, Karcz J, Kula P. Ferroelectricity in a nematic liquid crystal under a direct current electric field. Phys Chem Chem Phys 2023; 25:13061-13071. [PMID: 37114748 DOI: 10.1039/d3cp00714f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
We investigated the electrical properties of the liquid crystal compound 4-(4-nitrophenoxycarbonyl)phenyl 2,4-dimethoxybenzoate, known as RM734, exhibiting a ferroelectric nematic phase. The influence of alternating (AC) and direct (DC) current electric fields on the switching process of the polarization vector and dielectric constant of planarly aligned ferronematic and nematic phases were examined. The decrease of the real part of electric permittivity in the ferronematic phase and the creation of a ferroelectric order in the nematic phase under a DC field were demonstrated. The analysis of the results reveals the latching of the ferroelectric state. The applied DC field created a ferroelectric mode in the nematic phase. A new model of collective and molecular relaxations considering the domain structure of the ferronematic phase was proposed. The temperature and DC field dependence of dielectric properties was shown. Spontaneous polarization was measured using the field reversal technique. The spontaneous polarization value reaches the maximum at a fixed temperature.
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Affiliation(s)
- Mateusz Mrukiewicz
- Institute of Applied Physics, Military University of Technology, 2 Kaliskiego, 00-908 Warsaw, Poland.
| | - Paweł Perkowski
- Institute of Applied Physics, Military University of Technology, 2 Kaliskiego, 00-908 Warsaw, Poland.
| | - Jakub Karcz
- Institute of Chemistry, Military University of Technology, 2 Kaliskiego, 00-908 Warsaw, Poland
| | - Przemysław Kula
- Institute of Chemistry, Military University of Technology, 2 Kaliskiego, 00-908 Warsaw, Poland
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14
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Máthé MT, Farkas B, Péter L, Buka Á, Jákli A, Salamon P. Electric field-induced interfacial instability in a ferroelectric nematic liquid crystal. Sci Rep 2023; 13:6981. [PMID: 37117269 PMCID: PMC10147939 DOI: 10.1038/s41598-023-34067-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Accepted: 04/24/2023] [Indexed: 04/30/2023] Open
Abstract
Studies of sessile droplets and fluid bridges of a ferroelectric nematic liquid crystal in externally applied electric fields are presented. It is found that above a threshold, the interface of the fluid with air undergoes a fingering instability or ramification, resembling to Rayleigh-type instability observed in charged droplets in electric fields or circular drop-type instabilities observed in ferromagnetic liquids in magnetic field. The frequency dependence of the threshold voltage was determined in various geometries. The nematic director and ferroelectric polarization direction was found to point along the tip of the fingers that appear to repel each other, indicating that the ferroelectric polarization is essentially parallel to the director. The results are interpreted in connection to the Rayleigh and circular drop-type instabilities.
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Affiliation(s)
- Marcell Tibor Máthé
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest, 1525, Hungary
- Eötvös Loránd University, P.O. Box 32, 1518, Budapest, Hungary
| | - Bendegúz Farkas
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest, 1525, Hungary
- Eötvös Loránd University, P.O. Box 32, 1518, Budapest, Hungary
| | - László Péter
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest, 1525, Hungary
| | - Ágnes Buka
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest, 1525, Hungary
| | - Antal Jákli
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest, 1525, Hungary.
- Materials Sciences Graduate Program and Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA.
- Department of Physics, Kent State University, Kent, OH, 44242, USA.
| | - Péter Salamon
- Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, P.O. Box 49, Budapest, 1525, Hungary.
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15
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Yadav N, Panarin YP, Jiang W, Mehl GH, Vij JK. Spontaneous mirror symmetry breaking and chiral segregation in the achiral ferronematic compound DIO. Phys Chem Chem Phys 2023; 25:9083-9091. [PMID: 36919840 DOI: 10.1039/d3cp00357d] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
Abstract
An achiral compound, DIO, known to exhibit three nematic phases namely N, NX and NF, is studied by polarizing microscopy and electro-optics for different surface conditions in confinement. The high temperature N phase assigned initially as a conventional nematic phase, shows two additional unusual features: the optical activity and the linear electro-optic response related to the polar nature of this phase. An appearance of chiral domains is explained by the spontaneous symmetry breaking arising from the saddle-splay elasticity and followed by the formation of helical domains of the opposite chirality. This is the first example of helical segregation observed in calamitic non-chiral molecules in the nematic phase. As reported previously, the ferronematic NF shows strong polar azimuthal surface interaction energy which stabilizes a homogeneous structure in planar aligned LC cells rubbed parallel and exhibits a twisted structure in cells with antiparallel buffing. The transmission spectra are simulated using Berreman's 4 × 4 matrix method. The observed agreement between the experimental and the simulated spectra quantitatively confirms the presence of twisted structures in antiparallel rubbed cells.
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Affiliation(s)
- Neelam Yadav
- Department of Electronic and Electrical Engineering, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
| | - Yuri P Panarin
- Department of Electrical and Electronic Engineering, TU Dublin, Dublin 7, Ireland
| | - Wanhe Jiang
- Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
| | - Georg H Mehl
- Department of Chemistry, University of Hull, Hull, HU6 7RX, UK
| | - Jagdish K Vij
- Department of Electronic and Electrical Engineering, Trinity College Dublin, The University of Dublin, Dublin 2, Ireland.
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16
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Yadav N, Panarin YP, Vij JK, Jiang W, Mehl GH. Two mechanisms for the formation of ferronematic phase in DIO as studied by dielectric spectroscopy. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2023]
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17
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Kumari P, Basnet B, Wang H, Lavrentovich OD. Ferroelectric nematic liquids with conics. Nat Commun 2023; 14:748. [PMID: 36765061 PMCID: PMC9918734 DOI: 10.1038/s41467-023-36326-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 01/23/2023] [Indexed: 02/12/2023] Open
Abstract
Spontaneous electric polarization of solid ferroelectrics follows aligning directions of crystallographic axes. Domains of differently oriented polarization are separated by domain walls (DWs), which are predominantly flat and run along directions dictated by the bulk translational order and the sample surfaces. Here we explore DWs in a ferroelectric nematic (NF) liquid crystal, which is a fluid with polar long-range orientational order but no crystallographic axes nor facets. We demonstrate that DWs in the absence of bulk and surface aligning axes are shaped as conic sections. The conics bisect the angle between two neighboring polarization fields to avoid electric charges. The remarkable bisecting properties of conic sections, known for millennia, play a central role as intrinsic features of liquid ferroelectrics. The findings could be helpful in designing patterns of electric polarization and space charge.
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Affiliation(s)
- Priyanka Kumari
- grid.258518.30000 0001 0656 9343Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242 USA ,grid.258518.30000 0001 0656 9343Materials Science Graduate Program, Kent State University, Kent, OH 44242 USA
| | - Bijaya Basnet
- grid.258518.30000 0001 0656 9343Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242 USA ,grid.258518.30000 0001 0656 9343Materials Science Graduate Program, Kent State University, Kent, OH 44242 USA
| | - Hao Wang
- grid.258518.30000 0001 0656 9343Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242 USA
| | - Oleg D. Lavrentovich
- grid.258518.30000 0001 0656 9343Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH 44242 USA ,grid.258518.30000 0001 0656 9343Materials Science Graduate Program, Kent State University, Kent, OH 44242 USA ,grid.258518.30000 0001 0656 9343Department of Physics, Kent State University, Kent, OH 44242 USA
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18
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Perera K, Saha R, Nepal P, Dharmarathna R, Hossain MS, Mostafa M, Adaka A, Waroquet R, Twieg RJ, Jákli A. Ferroelectric nematic droplets in their isotropic melt. SOFT MATTER 2023; 19:347-354. [PMID: 36597812 DOI: 10.1039/d2sm01395a] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The isotropic to ferroelectric nematic liquid transition was theoretically studied over one hundred years ago, but its experimental studies are rare. Here we present experimental results and theoretical considerations of novel electromechanical effects of ferroelectric nematic liquid crystal droplets coexisting with the isotropic melt. We find that the droplets have flat pancake-like shapes that are thinner than the sample thickness as long as there is room to increase the lateral droplet size. In the center of the droplets a wing-shaped defect with low birefringence is present that moves perpendicular to a weak in-plane electric field, and then extends and splits in two at higher fields. Parallel to the defect motion and extension, the entire droplet drifts along the electric field with a speed that is independent of the size of the droplet and is proportional to the amplitude of the electric field. After the field is increased above 1 mV μm-1 the entire droplet gets deformed and oscillates with the field. These observations led us to determine the polarization field and revealed the presence of a pair of positive and negative bound electric charges due to divergences of polarization around the defect volume.
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Affiliation(s)
- Kelum Perera
- Department of Physics, Kent State University, Kent OH, 44242, USA.
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
| | - Rony Saha
- Department of Physics, Kent State University, Kent OH, 44242, USA.
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
| | - Pawan Nepal
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
| | - Rohan Dharmarathna
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
| | - Md Sakhawat Hossain
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
- Materials Science Graduate Program, Kent State University, Kent OH, 44242, USA
| | - Md Mostafa
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
- Materials Science Graduate Program, Kent State University, Kent OH, 44242, USA
| | - Alex Adaka
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
- Materials Science Graduate Program, Kent State University, Kent OH, 44242, USA
| | - Ronan Waroquet
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
| | - Robert J Twieg
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH 44242, USA
| | - Antal Jákli
- Department of Physics, Kent State University, Kent OH, 44242, USA.
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent OH, 44242, USA
- Materials Science Graduate Program, Kent State University, Kent OH, 44242, USA
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19
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Thoen J, Cordoyiannis G, Jiang W, Mehl GH, Glorieux C. Phase transitions study of the liquid crystal DIO with a ferroelectric nematic, a nematic, and an intermediate phase and of mixtures with the ferroelectric nematic compound RM734 by adiabatic scanning calorimetry. Phys Rev E 2023; 107:014701. [PMID: 36797863 DOI: 10.1103/physreve.107.014701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 12/21/2022] [Indexed: 06/18/2023]
Abstract
High-resolution calorimetry has played a significant role in providing detailed information on phase transitions in liquid crystals. In particular, adiabatic scanning calorimetry (ASC), capable of providing simultaneous information on the temperature dependence of the specific enthalpy h(T) and on the specific heat capacity c_{p}(T), has proven to be an important tool to determine the order of transitions and render high-resolution information on pretransitional thermal behavior. Here we report on ASC results on the compound 2,3',4',5'-tetrafluoro[1,1'-biphenyl]-4-yl 2,6-difluoro-4-(5-propyl-1,3-dioxan-2-yl) benzoate (DIO) and on mixtures with 4-[(4-nitrophenoxy)carbonyl]phenyl 2,4-dimethoxybenzoate (RM734). Both compounds exhibit a low-temperature ferroelectric nematic phase (N_{F}) and a high-temperature paraelectric nematic phase (N). However, in DIO these two phases are separated by an intermediate phase (N_{x}). From the detailed data of h(T) and c_{p}(T), we found that the intermediate phase was present in all the mixtures over the complete composition range, albeit with strongly decreasing temperature width for that phase with decreasing mole fraction of DIO (x_{DIO}). The x_{DIO} dependence on the transition temperatures for both transitions could be well described by a quadratic function. Both these transitions were weakly first order. The true latent heat of the N_{x}-N transition of DIO was as low as L=0.0075±0.0005J/g and L=0.23±0.03J/g for the N_{F}-N_{x} transition, which is about twice the previously reported value of 0.115 J/g for the N_{F}-N transition in RM734. In the mixtures both transition latent heats decrease gradually with decreasing x_{DIO}. At all the N_{x}-N transitions pretransition fluctuation effects are absent and these transitions are purely but very weakly first order. As in RM734 the transition from the N_{F} to the higher-temperature phase exhibits substantial pretransitional behavior, in particular, in the high-temperature phase. Power-law analysis of c_{p}(T) resulted in an effective critical exponent α=0.88±0.1 for DIO and this value decreased in the mixtures with decreasing x_{DIO} toward α=0.50±0.05 reported for RM734. Ideal mixture analysis of the phase diagram was consistent with ideal mixture behavior provided the total transition enthalpy change was used in the analysis.
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Affiliation(s)
- J Thoen
- Laboratory for Soft Matter and Biophysics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
| | - G Cordoyiannis
- Condensed Matter Physics Department, Jožef Stefan Institute, 1000 Ljubljana, Slovenia
| | - W Jiang
- Department of Chemistry, University of Hull, Hull HU6 7RX, United Kingdom
| | - G H Mehl
- Department of Chemistry, University of Hull, Hull HU6 7RX, United Kingdom
| | - C Glorieux
- Laboratory for Soft Matter and Biophysics, Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium
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20
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Yang J, Zou Y, Tang W, Li J, Huang M, Aya S. Spontaneous electric-polarization topology in confined ferroelectric nematics. Nat Commun 2022; 13:7806. [PMID: 36528675 PMCID: PMC9759571 DOI: 10.1038/s41467-022-35443-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
Topological textures have fascinated people in different areas of physics and technologies. However, the observations are limited in magnetic and solid-state ferroelectric systems. Ferroelectric nematic is the first liquid-state ferroelectric that would carry many possibilities of spatially-distributed polarization fields. Contrary to traditional magnetic or crystalline systems, anisotropic liquid crystal interactions can compete with the polarization counterparts, thereby setting a challenge in understating their interplays and the resultant topologies. Here, we discover chiral polarization meron-like structures, which appear during the emergence and growth of quasi-2D ferroelectric nematic domains. The chirality can emerge spontaneously in polar textures and can be additionally biased by introducing chiral dopants. Such micrometre-scale polarization textures are the modified electric variants of the magnetic merons. Both experimental and an extended mean-field modelling reveal that the polarization strength plays a dedicated role in determining polarization topology, providing a guide for exploring diverse polar textures in strongly-polarized liquid crystals.
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Affiliation(s)
- Jidan Yang
- grid.79703.3a0000 0004 1764 3838South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640 China
| | - Yu Zou
- grid.79703.3a0000 0004 1764 3838South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640 China
| | - Wentao Tang
- grid.79703.3a0000 0004 1764 3838South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640 China
| | - Jinxing Li
- grid.79703.3a0000 0004 1764 3838South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640 China
| | - Mingjun Huang
- grid.79703.3a0000 0004 1764 3838South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640 China ,grid.79703.3a0000 0004 1764 3838Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, 510640 China
| | - Satoshi Aya
- grid.79703.3a0000 0004 1764 3838South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou, 510640 China ,grid.79703.3a0000 0004 1764 3838Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou, 510640 China
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21
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Zavvou E, Klasen-Memmer M, Manabe A, Bremer M, Eremin A. Polarisation-driven magneto-optical and nonlinear-optical behaviour of a room-temperature ferroelectric nematic phase. SOFT MATTER 2022; 18:8804-8812. [PMID: 36354279 DOI: 10.1039/d2sm01298g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Nematics with a broken polar symmetry are one of the fascinating recent discoveries in the field of soft matter. High spontaneous polarisation and the fluidity of the ferroelectric nematic NF phase make such materials attractive for future applications and interesting for fundamental research. Here, we explore the polar and mechanical properties of a room-temperature ferroelectric nematic and its behaviour in a magnetic field. We show that NF is much less susceptible to the splay deformation than to the twist. The strong splay rigidity can be attributed to the electrostatic self-interaction of polarisation avoiding the polarisation splay.
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Affiliation(s)
- Evangelia Zavvou
- Otto von Guericke University Magdeburg, Institute of Physics, Dept. Nonlinear Phenomena, Magdeburg, Germany.
- Department of Physics, University of Patras, 26504, Patras, Greece
| | | | | | | | - Alexey Eremin
- Otto von Guericke University Magdeburg, Institute of Physics, Dept. Nonlinear Phenomena, Magdeburg, Germany.
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22
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Cruickshank E, Walker R, Storey JMD, Imrie CT. The effect of a lateral alkyloxy chain on the ferroelectric nematic phase. RSC Adv 2022; 12:29482-29490. [PMID: 36320775 PMCID: PMC9562421 DOI: 10.1039/d2ra05628c] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 10/06/2022] [Indexed: 11/05/2022] Open
Abstract
The synthesis and characterisation of two series of low molar mass liquid crystals, the 4-[(4-nitrophenoxy)carbonyl]phenyl 2-alkoxy-4-methoxybenzoates (series 5-m) and the 4-[(3-fluoro-4-nitrophenoxy)carbonyl]phenyl 2-alkoxy-4-methoxybenzoates (series 6-m) are reported in order to explore the effects of a lateral alkyloxy chain on the formation and stability of the recently discovered ferroelectric nematic phase. In both series m, the number of carbon atoms in the lateral chain, is varied from one to nine. The two series differ by the addition of a fluorine substituent in the 6-m series. 5-1 is the extensively studied ferroelectric nematogen RM734. All the members of the 5-m series exhibited both a conventional nematic, N, and ferroelectric nematic, NF, phase, whereas all the members of the 6-m series exhibit a direct NF-I transition with the exception of 6-1 that also exhibits a N phase. The replacement of a hydrogen atom by a fluorine atom reduces the nematic-isotropic transition temperature, T NI, whereas the ferroelectric nematic-nematic, or isotropic, transition temperature, T NFN/I, increases. This is interpreted in terms of the reduced structural anisotropy associated with the larger fluorine atom whereas the increase in the stability of the NF phase reflects changes in polarity and polarizability. The dependence of T NI and T NFN/I on m in both series is similar, and these initially decrease on increasing m but converge to limiting values on further increasing m. This suggests that the lateral alkyloxy chain may adopt conformations in which it lies along the major axis of the mesogenic unit.
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Affiliation(s)
- Ewan Cruickshank
- Department of Chemistry, University of AberdeenOld AberdeenAB24 3UEUK
| | - Rebecca Walker
- Department of Chemistry, University of AberdeenOld AberdeenAB24 3UEUK
| | - John M. D. Storey
- Department of Chemistry, University of AberdeenOld AberdeenAB24 3UEUK
| | - Corrie T. Imrie
- Department of Chemistry, University of AberdeenOld AberdeenAB24 3UEUK
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23
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Pociecha D, Walker R, Cruickshank E, Szydlowska J, Rybak P, Makal A, Matraszek J, Wolska JM, Storey JM, Imrie CT, Gorecka E. Intrinsically chiral ferronematic liquid crystals: An inversion of the helical twist sense at the chiral nematic – Chiral ferronematic phase transition. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.119532] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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24
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Sebastián N, Čopič M, Mertelj A. Ferroelectric nematic liquid-crystalline phases. Phys Rev E 2022; 106:021001. [PMID: 36109969 DOI: 10.1103/physreve.106.021001] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Indexed: 06/15/2023]
Abstract
Recent experimental realization of ferroelectric nematic liquid crystalline phases stimulated material development and numerous experimental studies of these phases, guided by their fundamental and applicative interest. In this Perspective, we give an overview of this emerging field by linking history and theoretical predictions to a general outlook of the development and properties of the materials exhibiting ferroelectric nematic phases. We will highlight the most relevant observations to date, e.g., giant dielectric permittivity values, polarization values an order of magnitude larger than in classical ferroelectric liquid crystals, and nonlinear optical coefficients comparable with several ferroelectric solid materials. Key observations of anchoring and electro-optic behavior will also be examined. The collected contributions lead to a final discussion on open challenges in materials development, theoretical description, experimental explorations, and possible applications of the ferroelectric phases.
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Affiliation(s)
| | - Martin Čopič
- J. Stefan Institute, SI-1000 Ljubljana, Slovenia
- University of Ljubljana, Faculty of Mathematics and Physics, Ljubljana, Slovenia
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25
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Mandle RJ. A new order of liquids: polar order in nematic liquid crystals. SOFT MATTER 2022; 18:5014-5020. [PMID: 35776092 DOI: 10.1039/d2sm00543c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Given the widespread adoption of display technology based on nematic liquid crystals, the discovery of new nematic phases at thermodynamic equilibrium, although extremely rare, generates much excitement. The remarkable discovery polar order and giant ferroelectric polarisation in a nematic fluid is a watershed moment in soft matter research, and is one of the most important discoveries in the 150 year history of liquid crystals. After a brief introduction to this emerging field, we present the current state-of-the art in terms of understanding the molecular origins of this phase, before exploring how molecular structure underpins the incidence of this phase, as well as exploring future directions.
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Affiliation(s)
- Richard J Mandle
- School of Physics and Astronomy, University of Leeds, UK, LS2 9JT
- School of Chemistry, University of Leeds, UK, LS2 9HT.
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26
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Basnet B, Rajabi M, Wang H, Kumari P, Thapa K, Paul S, Lavrentovich MO, Lavrentovich OD. Soliton walls paired by polar surface interactions in a ferroelectric nematic liquid crystal. Nat Commun 2022; 13:3932. [PMID: 35798735 PMCID: PMC9262936 DOI: 10.1038/s41467-022-31593-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Accepted: 06/24/2022] [Indexed: 11/09/2022] Open
Abstract
Surface interactions are responsible for many properties of condensed matter, ranging from crystal faceting to the kinetics of phase transitions. Usually, these interactions are polar along the normal to the interface and apolar within the interface. Here we demonstrate that polar in-plane surface interactions of a ferroelectric nematic NF produce polar monodomains in micron-thin planar cells and stripes of an alternating electric polarization, separated by \documentclass[12pt]{minimal}
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\begin{document}$${180}^{{{{{{\rm{o}}}}}}}$$\end{document}180o domain walls, in thicker slabs. The surface polarity binds together pairs of these walls, yielding a total polarization rotation by \documentclass[12pt]{minimal}
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\begin{document}$${360}^{{{{{{\rm{o}}}}}}}$$\end{document}360o. The polar contribution to the total surface anchoring strength is on the order of 10%. The domain walls involve splay, bend, and twist of the polarization. The structure suggests that the splay elastic constant is larger than the bend modulus. The \documentclass[12pt]{minimal}
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\begin{document}$${360}^{{{{{{\rm{o}}}}}}}$$\end{document}360o pairs resemble domain walls in cosmology models with biased vacuums and ferromagnets in an external magnetic field. Surface interactions are usually polar along the normal to the interface and apolar within the interface. Here, the authors find that polar in-plane surface interactions produce domain structures in the bulk of a ferroelectric nematic liquid crystal.
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Affiliation(s)
- Bijaya Basnet
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA.,Materials Science Graduate Program, Kent State University, Kent, OH, 44242, USA
| | - Mojtaba Rajabi
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA.,Department of Physics, Kent State University, Kent, OH, 44242, USA
| | - Hao Wang
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| | - Priyanka Kumari
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA.,Materials Science Graduate Program, Kent State University, Kent, OH, 44242, USA
| | - Kamal Thapa
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA.,Department of Physics, Kent State University, Kent, OH, 44242, USA
| | - Sanjoy Paul
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA
| | - Maxim O Lavrentovich
- Department of Physics and Astronomy, University of Tennessee, Knoxville, TN, 37996, USA
| | - Oleg D Lavrentovich
- Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242, USA. .,Materials Science Graduate Program, Kent State University, Kent, OH, 44242, USA. .,Department of Physics, Kent State University, Kent, OH, 44242, USA.
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27
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Wide Nematogenic Azomethine/Ester Liquid Crystals Based on New Biphenyl Derivatives: Mesomorphic and Computational Studies. Molecules 2022; 27:molecules27134150. [PMID: 35807398 PMCID: PMC9268434 DOI: 10.3390/molecules27134150] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/18/2022] [Accepted: 06/25/2022] [Indexed: 02/04/2023] Open
Abstract
The thermal stability and mesomorphic behavior of a new biphenyl azomethine liquid crystal homologues series, (E)-4-(([1,1′-biphenyl]-4-ylmethylene)amino)phenyl 4-(alkoxy)benzoate, In, were investigated. The chemical structures of the synthesized compounds were characterized using FT-IR, NMR, and elemental analyses. Differential scanning calorimetry (DSC) and polarized optical microscopy were employed to evaluate the mesomorphic characteristics of the designed homologues. The examined homologues possessed high thermal stability and broad nematogenic temperature ranges. Furthermore, the homologues were covered by enantiotropic nematic phases. The experimental measurements of the mesomorphic behavior were substantiated by computational studies using the density functional theory (DFT) approach. The reactivity parameters, dipole moments, and polarizability of the studied molecules are discussed. The theoretical calculations demonstrated that as the chain length increased, the polarizability of the studied series increased; while it did not significantly affect the HOMO–LUMO energy gap and other reactivity descriptors, the biphenyl moiety had an essential impact on the stability of the possible geometries and their thermal as well as physical parameters.
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28
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Song Y, Li J, Xia R, Xu H, Zhang X, Lei H, Peng W, Dai S, Aya S, Huang M. Development of emergent ferroelectric nematic liquid crystals with highly fluorinated and rigid mesogens. Phys Chem Chem Phys 2022; 24:11536-11543. [PMID: 35506891 DOI: 10.1039/d2cp01110g] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The emerging ferroelectric nematic liquid crystals have been attracting broader interests in new liquid crystal physics and their unique material properties. One big challenge for the ferroelectric nematic research is to enrich the material choice, which is now limited to RM734 and DIO families as representatives, in sharp contrast to the enormously diverse variety of the traditional apolar nematic liquid crystals. Here, we report a design of novel ferroelectric nematic materials with highly fluorinated and rigid mesogens. Noteworthily, they show distinct chemical structural features compared with previous aromatic ester-based molecules. The ferroelectric nematic phase was identified and confirmed through rigorous experiments. The bulk polarization was found to become purely along the long axis director, creating giant dielectric anisotropy. This work demonstrates a great potential for expanding ferroelectric nematic material diversity and will accelerate the corresponding application research and technology innovation.
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Affiliation(s)
- Yaohao Song
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Jinxing Li
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Runli Xia
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Hao Xu
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Xinxin Zhang
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Huanyu Lei
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Weifeng Peng
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Shuqi Dai
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China.
| | - Satoshi Aya
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China. .,Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Mingjun Huang
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Emergent Soft Matter, South China University of Technology, Guangzhou 510640, China. .,Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou 510640, China
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29
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Nishikawa H, Sano K, Araoka F. Anisotropic fluid with phototunable dielectric permittivity. Nat Commun 2022; 13:1142. [PMID: 35241651 PMCID: PMC8894468 DOI: 10.1038/s41467-022-28763-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 02/11/2022] [Indexed: 11/24/2022] Open
Abstract
Dielectric permittivity, a measure of polarisability, is a fundamental parameter that dominates various physical phenomena and properties of materials. However, it remains a challenge to control the dielectric permittivity of materials reversibly over a large range. Herein, we report an anisotropic fluid with photoresponsive dielectric permittivity (200 < ε < 18,000) consisting of a fluorinated liquid-crystalline molecule (96 wt%) and an azobenzene-tethered phototrigger (4 wt%). The reversible trans-cis isomerisation of the phototrigger under blue and green light irradiation causes a switch between two liquid-crystalline phases that exhibit different dielectric permittivities, with a rapid response time (<30 s) and excellent reversibility (~100 cycles). This anisotropic fluid can be used as a flexible photovariable capacitor that, for example, allows the reversible modulation of the sound frequency over a wide range (100 < f < 8500 Hz) in a remote manner using blue and green wavelengths. Light stimuli are widely used to control material properties, yet it remains challenging to reversibly photocontrol the dielectric permittivity. Nishikawa et al. achieve this goal in an anisotropic fluid via its liquid crystal phase transition induced by isomerization of an azobenzene-tethered phototrigger.
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Affiliation(s)
- Hiroya Nishikawa
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
| | - Koki Sano
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan. .,JST PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan. .,Department of Chemistry and Materials, Faculty of Textile Science and Technology, Shinshu University, 3-15-1 Tokida, Ueda, Nagano, 386-8567, Japan.
| | - Fumito Araoka
- RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan.
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