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Wang L, Urbas AM, Li Q. Nature-Inspired Emerging Chiral Liquid Crystal Nanostructures: From Molecular Self-Assembly to DNA Mesophase and Nanocolloids. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1801335. [PMID: 30160812 DOI: 10.1002/adma.201801335] [Citation(s) in RCA: 157] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 05/17/2018] [Indexed: 05/22/2023]
Abstract
Liquid crystals (LCs) are omnipresent in living matter, whose chirality is an elegant and distinct feature in certain plant tissues, the cuticles of crabs, beetles, arthropods, and beyond. Taking inspiration from nature, researchers have recently devoted extensive efforts toward developing chiral liquid crystalline materials with self-organized nanostructures and exploring their potential applications in diverse fields ranging from dynamic photonics to energy and safety issues. In this review, an account on the state of the art of emerging chiral liquid crystalline nanostructured materials and their technological applications is provided. First, an overview on the significance of chiral liquid crystalline architectures in various living systems is given. Then, the recent significant progress in different chiral liquid crystalline systems including thermotropic LCs (cholesteric LCs, cubic blue phases, achiral bent-core LCs, etc.) and lyotropic LCs (DNA LCs, nanocellulose LCs, and graphene oxide LCs) is showcased. The review concludes with a perspective on the future scope, opportunities, and challenges in these truly advanced functional soft materials and their promising applications.
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Affiliation(s)
- Ling Wang
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
| | - Augustine M Urbas
- Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH, 45433, USA
| | - Quan Li
- Liquid Crystal Institute and Chemical Physics Interdisciplinary Program, Kent State University, Kent, OH, 44242, USA
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2
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Singh S, Singh H, Tandon P, Chakraborty N, Rao NVS, Ayala AP. Study of Cr→SmA phase transition and hydrogen bonding in four-ring bent-core liquid crystal. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 178:142-150. [PMID: 28182984 DOI: 10.1016/j.saa.2017.01.067] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 01/21/2017] [Accepted: 01/27/2017] [Indexed: 06/06/2023]
Abstract
A newly designed asymmetrical four-ring bent-core compound (4'-n-decyloxyphenylazo)-phenyl-4-yl-3-[N-(4'-n-octadecyloxy-2-hydroxybenzylidene) amino]-2-methyl benzoate exhibiting liquid crystalline behavior was synthesized and characterized. The thermal and textural morphology were studied using differential scanning calorimetry and polarizing optical microscopy, respectively. The study of hydrogen bonding and dynamics of the phase transition has been performed at the molecular level using temperature dependent Fourier transform infrared (FTIR) spectroscopy. The spectral analysis of OH, CH2/CH3, CO, and CN stretching vibrational bands revealed clear signatures of Cr→SmA phase transition at 125°C. Density functional theory has been adopted for the geometry optimization and conformational study of the monomer using the B3LYP/6-31G(d) method. The conformational analysis has been performed to predict the most stable conformer along with the possible conformers using one-dimensional potential energy scan employing the same level of theory. The combination of experimental findings and theoretical analysis helped to understand the mechanism of phase transitions at the molecular level.
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Affiliation(s)
- Swapnil Singh
- Department of Physics, University of Lucknow, Lucknow 226007, India
| | - Harshita Singh
- Department of Physics, University of Lucknow, Lucknow 226007, India
| | - Poonam Tandon
- Department of Physics, University of Lucknow, Lucknow 226007, India.
| | | | - N V S Rao
- Chemistry Department, Assam University, Silchar 788011, Assam, India
| | - A P Ayala
- Departamento de Física, Universidade Federal do Ceará, C.P. 6030, 60.455-900 Fortaleza, CE, Brazil
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3
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Gowda A, Roy A, Kumar S. Synthesis and mesomorphic properties of novel Schiff base liquid crystalline EDOT derivatives. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2016.11.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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4
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Alaasar M, Prehm M, Tschierske C. Helical Nano-crystallite (HNC) Phases: Chirality Synchronization of Achiral Bent-Core Mesogens in a New Type of Dark Conglomerates. Chemistry 2016; 22:6583-97. [DOI: 10.1002/chem.201505016] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2015] [Indexed: 12/20/2022]
Affiliation(s)
- Mohamed Alaasar
- Institute of Chemistry; Martin Luther University Halle-Wittenberg; Kurt Mothes Str. 2 06120 Halle (Saale) Germany), Fax
- Department of Chemistry; Faculty of Science; Cairo University; Giza Egypt
| | - Marko Prehm
- Institute of Chemistry; Martin Luther University Halle-Wittenberg; Kurt Mothes Str. 2 06120 Halle (Saale) Germany), Fax
| | - Carsten Tschierske
- Institute of Chemistry; Martin Luther University Halle-Wittenberg; Kurt Mothes Str. 2 06120 Halle (Saale) Germany), Fax
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5
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Ivšić T, Vinković M, Baumeister U, Mikleušević A, Lesac A. Towards understanding the NTB phase: a combined experimental, computational and spectroscopic study. RSC Adv 2016. [DOI: 10.1039/c5ra26078g] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Combined studies support the hierarchical model for the NTB phase that involves formation of embryonic self-assembly of the propeller-shaped dimeric molecules with syn-parallel orientation in the isotropic melt.
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Affiliation(s)
- Trpimir Ivšić
- Division of Organic Chemistry and Biochemistry
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
| | | | - Ute Baumeister
- Institute of Chemistry
- Physical Chemistry
- Martin Luther University Halle-Wittenberg
- 06120 Halle
- Germany
| | - Ana Mikleušević
- Division of Organic Chemistry and Biochemistry
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
| | - Andreja Lesac
- Division of Organic Chemistry and Biochemistry
- Ruđer Bošković Institute
- 10000 Zagreb
- Croatia
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6
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Alaasar M, Prehm M, Tschierske C. Mirror symmetry breaking in fluorinated bent-core mesogens. RSC Adv 2016. [DOI: 10.1039/c6ra18482k] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
New fluorinated bent-core liquid crystals exhibiting helical nano-crystallite phases composed of chiral domains with opposite handedness and polar smcetic phases.
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Affiliation(s)
- Mohamed Alaasar
- Institute of Chemistry
- Martin Luther University Halle-Wittenberg
- D-06120 Halle (Saale)
- Germany
- Department of Chemistry
| | - Marko Prehm
- Institute of Chemistry
- Martin Luther University Halle-Wittenberg
- D-06120 Halle (Saale)
- Germany
| | - Carsten Tschierske
- Institute of Chemistry
- Martin Luther University Halle-Wittenberg
- D-06120 Halle (Saale)
- Germany
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Alaasar M, Poppe S, Dong Q, Liu F, Tschierske C. Mirror symmetry breaking in cubic phases and isotropic liquids driven by hydrogen bonding. Chem Commun (Camb) 2016; 52:13869-13872. [DOI: 10.1039/c6cc08226b] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Achiral hydrogen bonded rod-like complexes with four nonequally distributed terminal alkyl chains form a chirality synchronized isotropic liquid conglomerate as well as a conglomerate type chiral cubic phase.
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Affiliation(s)
- Mohamed Alaasar
- Institute of Chemistry
- Martin Luther University Halle-Wittenberg
- D-06120 Halle
- Germany
- Department of Chemistry
| | - Silvio Poppe
- Institute of Chemistry
- Martin Luther University Halle-Wittenberg
- D-06120 Halle
- Germany
| | - Qingshu Dong
- State Key Laboratory for Mechanical Behavior of Materials
- Xi’an Jiaotong University
- Xi’an 710049
- P. R. China
| | - Feng Liu
- State Key Laboratory for Mechanical Behavior of Materials
- Xi’an Jiaotong University
- Xi’an 710049
- P. R. China
| | - Carsten Tschierske
- Institute of Chemistry
- Martin Luther University Halle-Wittenberg
- D-06120 Halle
- Germany
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Tschierske C, Ungar G. Mirror Symmetry Breaking by Chirality Synchronisation in Liquids and Liquid Crystals of Achiral Molecules. Chemphyschem 2015; 17:9-26. [DOI: 10.1002/cphc.201500601] [Citation(s) in RCA: 131] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Indexed: 01/05/2023]
Affiliation(s)
- Carsten Tschierske
- Institute of Chemistry, Organic Chemistry; Martin Luther University Halle-Wittenberg; Kurt-Mothes Str. 2 06120 Halle/Saale Germany
| | - Goran Ungar
- Department of Physics; Zhejiang Sci-Tech University; Xiasha College Park 310018 Hangzhou China
- Department of Materials Science and Engineering; University of Sheffield; Sheffield S1 3JD Sheffield UK
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Alaasar M, Prehm M, Brautzsch M, Tschierske C. Dark conglomerate phases of azobenzene derived bent-core mesogens - relationships between the molecular structure and mirror symmetry breaking in soft matter. SOFT MATTER 2014; 10:7285-7296. [PMID: 25095778 DOI: 10.1039/c4sm01255k] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
New 4-bromoresorcinol based bent-core molecules with peripheral fluoro substituted azobenzene wings have been synthesized and the liquid crystalline self-assembly was investigated by differential scanning calorimetry (DSC), optical polarizing microscopy (POM), electro-optic studies and X-ray diffraction (XRD). A new type of optically isotropic mesophase composed of chiral domains with opposite handedness (dark conglomerate phases, DC phases) is observed, which for some homologues with medium alkyl chain length is stable down to ambient temperature. It is proposed that these DC phases are formed by helical twisted nano-domains of limited size and composed of the crystallized aromatic cores which are separated by the disordered alkyl chains. This structure is distinct from the previously known soft helical nano-filament phases (HNF phases, B4 phases) formed by extended crystalline nano-filaments and also distinct from the fluid sponge phases composed of deformed fluid layers. Comparison with related bent-core molecules having H, F, Cl, I, CH3 and CN groups in the 4-position at the resorcinol core, either with or without additional peripheral fluorines, provided information about the effects of these substituents on the tendency to form DC phases. Based on these relationships and by comparison with the minimum energy conformations obtained by DFT calculations a hypothesis is provided for the formation of DC phases depending on the molecular structure.
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Affiliation(s)
- Mohamed Alaasar
- Institute of Chemistry, Martin Luther University Halle-Wittenberg, Kurt Mothes Str. 2, D-06120 Halle (Saale), Germany.
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Martínez-González JA, Chapela GA, Quintana-H J. Spontaneous chiral resolution in two-dimensional systems of patchy particles. J Chem Phys 2014; 140:194505. [PMID: 24852548 DOI: 10.1063/1.4876575] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Short ranged potentials and their anisotropy produce spontaneous chiral resolution in a two dimensional model of patchy particles introduced in this paper. This model could represent an equimolar binary mixture (racemic mixture) of two kinds of chiral molecules (enantiomers) adsorbed to a bi-dimensional domain where only lateral short ranged interactions are present. Most racemic mixtures undergo chiral resolution due to their spatial anisotropy, the combined effect of long range forces and the thermodynamic conditions. The patchy particles are modeled as a hard disk and four different bonding sites located to produce chirality. Phase behavior and structural properties are analysed using Discontinuous Molecular Dynamics in the canonical ensemble. When the four patchy particles are separated by the angles {60°, 120°, 60°, 120°}, spontaneous chiral resolution is produced, given by the formation of homochiral clusters, if started from the corresponding racemic mixture. Gel behavior is also obtained in all the systems for low temperatures and low densities.
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Affiliation(s)
- J A Martínez-González
- Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 México D.F., Mexico
| | - G A Chapela
- Departamento de Física, Universidad Autónoma Metropolitana-Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 México D.F., Mexico
| | - J Quintana-H
- Instituto de Química, Universidad Nacional Autónoma de México - Apdo. Postal 70213, 04510 Coyoacán, México D.F., Mexico
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Gleeson HF, Kaur S, Görtz V, Belaissaoui A, Cowling S, Goodby JW. The nematic phases of bent-core liquid crystals. Chemphyschem 2014; 15:1251-60. [PMID: 24700653 PMCID: PMC4257080 DOI: 10.1002/cphc.201400014] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Indexed: 11/07/2022]
Abstract
Over the last ten years, the nematic phases of liquid crystals formed from bent-core structures have provoked considerable research because of their remarkable properties. This Minireview summarises some recent measurements of the physical properties of these systems, as well as describing some new data. We concentrate on oxadiazole-based materials as exemplars of this class of nematogens, but also describe some other bent-core systems. The influence of molecular structure on the stability of the nematic phase is described, together with progress in reducing the nematic transition temperatures by modifications to the molecular structure. The physical properties of bent-core nematic materials have proven difficult to study, but patterns are emerging regarding their optical and dielectric properties. Recent breakthroughs in understanding the elastic and flexoelectric behaviour are summarised. Finally, some exemplars of unusual electric field behaviour are described.
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Affiliation(s)
- Helen F Gleeson
- [a] Prof. H. F. Gleeson, Dr. S. Kaur School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL (UK) E-mail:
| | - Sarabjot Kaur
- [a] Prof. H. F. Gleeson, Dr. S. Kaur School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL (UK) E-mail:
| | - Verena Görtz
- Department of ChemistryUniversity of York, Heslington, York YO10 5DD (UK)
- Department of ChemistryLancaster University, Lancaster LA1 4YB (UK)
| | - Abdel Belaissaoui
- Department of ChemistryUniversity of York, Heslington, York YO10 5DD (UK)
| | - Stephen Cowling
- Department of ChemistryUniversity of York, Heslington, York YO10 5DD (UK)
| | - John W Goodby
- Department of ChemistryUniversity of York, Heslington, York YO10 5DD (UK)
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Paul MK, Kalita G, Laskar AR, Debnath S, Gude V, Sarkar DD, Mohiuddin G, Varshney SK, Nandiraju Rao V. Synthesis and mesomorphic behaviour of achiral four-ring unsymmetrical bent-core liquid crystals: Nematic phases. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.06.044] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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13
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Tschierske C. Entwicklung struktureller Komplexität durch Selbstorganisation in flüssigkristallinen Systemen. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201300872] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Tschierske C. Development of structural complexity by liquid-crystal self-assembly. Angew Chem Int Ed Engl 2013; 52:8828-78. [PMID: 23934786 DOI: 10.1002/anie.201300872] [Citation(s) in RCA: 354] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2013] [Indexed: 11/09/2022]
Abstract
Since the discovery of the liquid-crystalline state of matter 125 years ago, this field has developed into a scientific area with many facets. This Review presents recent developments in the molecular design and self-assembly of liquid crystals. The focus is on new exciting soft-matter structures distinct from the usually observed nematic, smectic, and columnar phases. These new structures have enhanced complexity, including multicompartment and cellular structures, periodic and quasiperiodic arrays of spheres, and new emergent properties, such as ferroelctricity and spontaneous achiral symmetry-breaking. Comparisons are made with developments in related fields, such as self-assembled monolayers, multiblock copolymers, and nanoparticle arrays. Measures of structural complexity used herein are the size of the lattice, the number of distinct compartments, the dimensionality, and the logic depth of the resulting supramolecular structures.
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Affiliation(s)
- Carsten Tschierske
- Institut für Chemie, Organische Chemie, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle Saale, Germany.
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Alaasar M, Prehm M, Nagaraj M, Vij JK, Tschierske C. A liquid crystalline phase with uniform tilt, local polar order and capability of symmetry breaking. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2013; 25:2186-2191. [PMID: 23427137 DOI: 10.1002/adma.201205180] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Indexed: 06/01/2023]
Abstract
A new liquid crystalline (LC) phase with uniform tilt, local polar order and capability of symmetry breaking is found for a bent-core mesogen combining a 4-cyanoresorcinol unit with two azobenzene wings. The combination of local polar order and long range synclinic tilt in this SmC(s)P(R) phase leads, under special conditions, to macroscopic domains with opposite chirality, though the molecules themselves are achiral.
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Affiliation(s)
- Mohamed Alaasar
- Department of Chemistry, Faculty of Science, Cairo University, Giza, Egypt.
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Alaasar M, Prehm M, Tschierske C. A new room temperature dark conglomerate mesophase formed by bent-core molecules combining 4-iodoresorcinol with azobenzene units. Chem Commun (Camb) 2013; 49:11062-4. [DOI: 10.1039/c3cc45938a] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Peroukidis SD, Vanakaras AG, Photinos DJ. Molecular simulation of hierarchical structures in bent-core nematic liquid crystals. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:010702. [PMID: 21867106 DOI: 10.1103/physreve.84.010702] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Indexed: 05/31/2023]
Abstract
The structure of nematic liquid crystals formed by bent-core mesogens (BCMs) is studied in the context of Monte Carlo simulations of a simple molecular model that captures the symmetry, shape, and flexibility of achiral BCMs. The results indicate the formation of (i) clusters exhibiting local smectic order, orthogonal or tilted, with strong in-layer polar correlations and antiferroelectric juxtaposition of successive layers and (ii) large homochiral domains through the helical arrangement of the tilted smectic clusters, while the orthogonal clusters produce achiral (untwisted) nematic states.
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