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Helical phases assembled from achiral molecules: Twist-bend nematic and helical filamentary B4 phases formed by mesogenic dimers. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2021.118180] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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2
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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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3
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Orientation Control of Helical Nanofilament Phase and Its Chiroptical Applications. CRYSTALS 2020. [DOI: 10.3390/cryst10080675] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Chiral liquid crystal phases show fascinating structural and optical properties due to their inherent helical characteristics. Among the various chiral liquid crystal phases, the helical nanofilament phase, made of achiral bent-shaped molecules, has been of keen research interest due to its unusual polar and chiral properties. This review is intended to introduce the recent progress in orientation control and its application to the helical nanofilament phase, which includes topographic confinement, photoalignment, and chiroptical applications such as photonic crystal and chirality sensor.
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Shadpour S, Nemati A, Salamończyk M, Prévôt ME, Liu J, Boyd NJ, Wilson MR, Zhu C, Hegmann E, Jákli AI, Hegmann T. Missing Link between Helical Nano- and Microfilaments in B4 Phase Bent-Core Liquid Crystals, and Deciphering which Chiral Center Controls the Filament Handedness. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2020; 16:e1905591. [PMID: 31885139 DOI: 10.1002/smll.201905591] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 11/18/2019] [Indexed: 06/10/2023]
Abstract
The range of possible morphologies for bent-core B4 phase liquid crystals has recently expanded from helical nanofilaments (HNFs) and modulated HNFs to dual modulated HNFs, helical microfilaments, and heliconical-layered nanocylinders. These new morphologies are observed when one or both aliphatic side chains contain a chiral center. Here, the following questions are addressed: which of these two chiral centers controls the handedness (helicity) and which morphology of the nanofilaments is formed by bent-core liquid crystals with tris-biphenyl diester core flanked by two chiral 2-octyloxy side chains? The combined results reveal that the longer arm of these nonsymmetric bent-core liquid crystals controls the handedness of the resulting dual modulated HNFs. These derivatives with opposite configuration of the two chiral side chains now feature twice as large dimensions compared to the homochiral derivatives with identical configuration. These results are supported by density functional theory calculations and stochastic dynamic atomistic simulations, which reveal that the relative difference between the para- and meta-sides of the described series of compounds drives the variation in morphology. Finally, X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) data also uncover the new morphology for B4 phases featuring p2/m symmetry within the filaments and less pronounced crystalline character.
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Affiliation(s)
- Sasan Shadpour
- Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242-0001, USA
| | - Ahlam Nemati
- Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242-0001, USA
| | | | - Marianne E Prévôt
- Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242-0001, USA
| | - Jiao Liu
- Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242-0001, USA
| | - Nicola J Boyd
- Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Mark R Wilson
- Department of Chemistry, Durham University, Durham, DH1 3LE, UK
| | - Chenhui Zhu
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Elda Hegmann
- Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242-0001, USA
- Department of Biological Sciences, Kent State University, Kent, OH, 44242-0001, USA
- Brain Health Research Institute, Kent State University, Kent, OH, 44242-0001, USA
| | - Antal I Jákli
- Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242-0001, USA
- Department of Physics and Astronomy, Kent State University, Kent, OH, 44242-0001, USA
| | - Torsten Hegmann
- Chemical Physics Interdisciplinary Program, Advanced Materials and Liquid Crystal Institute, Kent State University, Kent, OH, 44242-0001, USA
- Brain Health Research Institute, Kent State University, Kent, OH, 44242-0001, USA
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242-0001, USA
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Cui Y, Tao D, Huang X, Lu G, Feng C. Self-Assembled Helical and Twisted Nanostructures of a Preferred Handedness from Achiral π-Conjugated Oligo( p-phenylenevinylene) Derivatives. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3134-3142. [PMID: 30712352 DOI: 10.1021/acs.langmuir.8b04127] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The formation of chiral nanostructures from the self-assembly of achiral building blocks without external symmetry breaking inducing factors is believed to associate with the origin of chirality. Herein, we reported the synthesis and self-assembly of oligo( p-phenylenevinylene)- b-poly(ethylene glycol) (OPV3- b-PEG17, the subscripts represent the number of repeat unit of each block) in solution. We systematically examined the influence of solvent, heating temperature, and concentration of OPV3- b-PEG17 on the self-assembly of OPV3- b-PEG17 by UV/vis absorption and fluorescence spectrometry, circular dichroism technique, and transmission electron and atomic force microscopy. Interestingly, helical and twisted nanoribbons and nanotubes of a preferred handedness can be formed from achiral OPV3- b-PEG17 in the mixture of water/ethanol (v/v = 1/1) and the solution showed an obvious exciton-coupled bisignated signal, which indicated that symmetry breaking occurred during the formation of these nanostructures without external inducing factors. Our results showed that the occurrence of symmetry breaking is subtle to the experimental factors including solvent, heating temperature, and concentration of OPV3- b-PEG17. The directional π-π stacking along with steric repulsion between PEG domains should be the driving force for the formation of these chiral nanostructures. The occurrence of statistical fluctuations in the initial stage of self-assembly led to an accidental excess of helical or/and twisted structures, that is, symmetry breaking. Subsequently, the autocatalysis effect resulted in the formation of helical or/and twisted nanoribbons with a preferred handedness.
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Affiliation(s)
- Yinan Cui
- Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , People's Republic of China
| | - Daliao Tao
- Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , People's Republic of China
| | - Xiaoyu Huang
- Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , People's Republic of China
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials , Donghua University , 2999 North Renmin Road , Songjiang, Shanghai 201620 , People's Republic of China
| | - Guolin Lu
- Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , People's Republic of China
| | - Chun Feng
- Key Laboratory of Synthetic and Self-Assembly Chemistry for Organic Functional Molecules, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences , Chinese Academy of Sciences , 345 Lingling Road , Shanghai 200032 , People's Republic of China
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Busch M, Kityk AV, Piecek W, Hofmann T, Wallacher D, Całus S, Kula P, Steinhart M, Eich M, Huber P. A ferroelectric liquid crystal confined in cylindrical nanopores: reversible smectic layer buckling, enhanced light rotation and extremely fast electro-optically active Goldstone excitations. NANOSCALE 2017; 9:19086-19099. [PMID: 29199756 DOI: 10.1039/c7nr07273b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The orientational and translational order of a thermotropic ferroelectric liquid crystal (2MBOCBC) imbibed in self-organized, parallel, cylindrical pores with radii of 10, 15, or 20 nm in anodic aluminium oxide monoliths (AAO) are explored by high-resolution linear and circular optical birefringence as well as neutron diffraction texture analysis. The results are compared to experiments on the bulk system. The native oxidic pore walls do not provide a stable smectogen wall anchoring. By contrast, a polymeric wall grafting enforcing planar molecular anchoring results in a thermal-history independent formation of smectic C* helices and a reversible chevron-like layer buckling. An enhancement of the optical rotatory power by up to one order of magnitude of the confined compared to the bulk liquid crystal is traced to the pretransitional formation of helical structures at the smectic-A*-to-smectic-C* transformation. A linear electro-optical birefringence effect evidences collective fluctuations in the molecular tilt vector direction along the confined helical superstructures, i.e. the Goldstone phason excitations typical of the para-to-ferroelectric transition. Their relaxation frequencies increase with the square of the inverse pore radii as characteristic of plane-wave excitations and are two orders of magnitude larger than in the bulk, evidencing an exceptionally fast electro-optical functionality of the liquid-crystalline-AAO nanohybrids.
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Affiliation(s)
- Mark Busch
- Institute of Materials Physics and Technology, Hamburg University of Technology, 21073 Hamburg, Germany.
| | - Andriy V Kityk
- Institute of Materials Physics and Technology, Hamburg University of Technology, 21073 Hamburg, Germany. and Faculty of Electrical Engineering, Czestochowa University of Technology, 42-200 Czestochowa, Poland.
| | - Wiktor Piecek
- Military University of Technology, 00-908 Warsaw, Poland
| | - Tommy Hofmann
- Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany
| | - Dirk Wallacher
- Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany
| | - Sylwia Całus
- Faculty of Electrical Engineering, Czestochowa University of Technology, 42-200 Czestochowa, Poland.
| | | | - Martin Steinhart
- Institute for the Chemistry of New Materials, University Osnabrück, 49067 Osnabrück, Germany
| | - Manfred Eich
- Institute of Optical and Electronic Materials, Hamburg University of Technology, 21073 Hamburg, Germany and Institute of Materials Research, Helmholtz-Zentrum Geesthacht, 21502 Geesthacht, Germany
| | - Patrick Huber
- Institute of Materials Physics and Technology, Hamburg University of Technology, 21073 Hamburg, Germany.
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Ryu SH, Gim MJ, Lee W, Choi SW, Yoon DK. Switchable Photonic Crystals Using One-Dimensional Confined Liquid Crystals for Photonic Device Application. ACS APPLIED MATERIALS & INTERFACES 2017; 9:3186-3191. [PMID: 28029761 DOI: 10.1021/acsami.6b15361] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Photonic crystals (PCs) have recently attracted considerable attention, with much effort devoted to photonic bandgap (PBG) control for varying the reflected color. Here, fabrication of a modulated one-dimensional (1D) anodic aluminum oxide (AAO) PC with a periodic porous structure is reported. The PBG of the fabricated PC can be reversibly changed by switching the ultraviolet (UV) light on/off. The AAO nanopores contain a mixture of photoresponsive liquid crystals (LCs) with irradiation-activated cis/trans photoisomerizable azobenzene. The resultant mixture of LCs in the porous AAO film exhibits a reversible PBG, depending on the cis/trans configuration of azobenzene molecules. The PBG switching is reliable over many cycles, suggesting that the fabricated device can be used in optical and photonic applications such as light modulators, smart windows, and sensors.
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Affiliation(s)
- Seong Ho Ryu
- Graduate School of Nanoscience and Technology and KINC, KAIST , Daejeon 34141, Republic of Korea
| | - Min-Jun Gim
- Graduate School of Nanoscience and Technology and KINC, KAIST , Daejeon 34141, Republic of Korea
| | - Wonsuk Lee
- Graduate School of Nanoscience and Technology and KINC, KAIST , Daejeon 34141, Republic of Korea
| | - Suk-Won Choi
- Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University , Yongin 17104, Republic of Korea
| | - Dong Ki Yoon
- Graduate School of Nanoscience and Technology and KINC, KAIST , Daejeon 34141, Republic of Korea
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8
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From Sponges to Nanotubes: A Change of Nanocrystal Morphology for Acute-Angle Bent-Core Molecules. Angew Chem Int Ed Engl 2016. [DOI: 10.1002/ange.201604915] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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9
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From Sponges to Nanotubes: A Change of Nanocrystal Morphology for Acute-Angle Bent-Core Molecules. Angew Chem Int Ed Engl 2016; 55:12238-42. [DOI: 10.1002/anie.201604915] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 07/18/2016] [Indexed: 11/07/2022]
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10
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Ryu SH, Yoon DK. Molecular Orientation of Liquid Crystals on Topographic Nanopatterns. ACS APPLIED MATERIALS & INTERFACES 2016; 8:17707-17712. [PMID: 27322013 DOI: 10.1021/acsami.6b05568] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Controlling the orientation of building blocks in soft matter on the substrate has been a big challenge in material sciences. We have controlled the molecular orientation of liquid crystal (LC) materials on the porous anodic aluminum oxide (AAO) film having hexagonal pore arrays on the top surface. In our method, anchoring conditions can be varied by changing the pore size (Dp) and the porosity (P). As a proof-of-concept, the orientation of smectic A (SmA) structure at different anchoring conditions was successfully controlled in a sandwich cell consisting of AAO and a glass substrate, which has not been successfully controlled by conventional methods.
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Affiliation(s)
- Seong Ho Ryu
- Graduate School of Nanoscience and Technology and KINC, KAIST , Daejeon 34141, Republic of Korea
| | - Dong Ki Yoon
- Graduate School of Nanoscience and Technology and KINC, KAIST , Daejeon 34141, Republic of Korea
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11
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Kim H, Zep A, Ryu SH, Ahn H, Shin TJ, Lee SB, Pociecha D, Gorecka E, Yoon DK. Linkage-length dependent structuring behaviour of bent-core molecules in helical nanostructures. SOFT MATTER 2016; 12:3326-3330. [PMID: 26876379 DOI: 10.1039/c5sm03100a] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We studied the correlation between the molecular structure and the formation of helical nanofilaments (HNFs) of bent-core dimeric molecules with varying linkage lengths. To obtain precise structural data, a single domain of HNFs was prepared under physical confinement using porous 1D nanochannels, made up of anodic aluminium oxide films. Electron microscopy and grazing incidence X-ray diffraction were used to elucidate the linkage length-dependent formation of HNFs.
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Affiliation(s)
- Hanim Kim
- Graduate School of Nanoscience and Technology, KAIST, Daejeon 305-701, Republic of Korea.
| | - Anna Zep
- Department of Chemistry, University of Warsaw, Warsaw, 02-089, Poland.
| | - Seong Ho Ryu
- Graduate School of Nanoscience and Technology, KAIST, Daejeon 305-701, Republic of Korea.
| | - Hyungju Ahn
- Pohang Accelerator Laboratory, POSTECH, Pohang, 790-784, Republic of Korea
| | - Tae Joo Shin
- UNIST Central Research Facilities, UNIST, Ulsan 689-798, Republic of Korea
| | - Sang Bok Lee
- Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742, USA
| | - Damian Pociecha
- Department of Chemistry, University of Warsaw, Warsaw, 02-089, Poland.
| | - Ewa Gorecka
- Department of Chemistry, University of Warsaw, Warsaw, 02-089, Poland.
| | - Dong Ki Yoon
- Graduate School of Nanoscience and Technology, KAIST, Daejeon 305-701, Republic of Korea.
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