1
|
One-pot synthesis of 1,2,4-oxadiazoles from chalcogen amino acid derivatives under microwave irradiation. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
|
2
|
Vita F, Adamo FC, Pisani M, Francescangeli O. Nanostructure of Unconventional Liquid Crystals Investigated by Synchrotron Radiation. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1679. [PMID: 32859117 PMCID: PMC7558469 DOI: 10.3390/nano10091679] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 07/27/2020] [Accepted: 08/12/2020] [Indexed: 11/30/2022]
Abstract
The macroscopic properties of novel liquid crystal (LC) systems-LCs with unconventional molecular structure as well as conventional LCs in unconventional geometries-directly descend from their mesoscopic structural organization. While X-ray diffraction (XRD) is an obvious choice to investigate their nanoscale structure, conventional diffractometry is often hampered by experimental difficulties: the low scattering power and short-range positional order of the materials, resulting in weak and diffuse diffraction features; the need to perform measurements in challenging conditions, e.g., under magnetic and/or electric fields, on thin films, or at high temperatures; and the necessity to probe micron-sized volumes to tell the local structural properties from their macroscopic average. Synchrotron XRD allows these problems to be circumvented thanks to the superior diffraction capabilities (brilliance, q-range, energy and space resolution) and advanced sample environment available at synchrotron beamlines. Here, we highlight the potentiality of synchrotron XRD in the field of LCs by reviewing a selection of experiments on three unconventional LC systems: the potentially biaxial and polar nematic phase of bent-core mesogens; the very high-temperature nematic phase of all-aromatic LCs; and polymer-dispersed liquid crystals. In all these cases, synchrotron XRD unveils subtle nanostructural features that are reflected into macroscopic properties of great interest from both fundamental and technological points of view.
Collapse
Affiliation(s)
| | | | | | - Oriano Francescangeli
- Dipartimento di Scienze e Ingegneria della Materia, dell’Ambiente ed Urbanistica, Università Politecnica delle Marche, via Brecce Bianche, 60131 Ancona, Italy; (F.V.); (F.C.A.); (M.P.)
| |
Collapse
|
3
|
Lyu X, Xiao A, Shi D, Li Y, Shen Z, Chen EQ, Zheng S, Fan XH, Zhou QF. Liquid crystalline polymers: Discovery, development, and the future. POLYMER 2020. [DOI: 10.1016/j.polymer.2020.122740] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
4
|
Liu K, Shen Y, Li X, Zhang Y, Quan Y, Cheng Y. Strong CPL of achiral liquid crystal fluorescent polymer via the regulation of AIE-active chiral dopant. Chem Commun (Camb) 2020; 56:12829-12832. [DOI: 10.1039/d0cc05523a] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Strong CPL induced by ternary polymer dispersed cholesteric liquid crystals (PD-CLCs) can deliver a new strategy for designing excellent CPL materials.
Collapse
Affiliation(s)
- Kerui Liu
- Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- China
| | - Yihao Shen
- Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- China
| | - Xiaojing Li
- Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- China
| | - Yu Zhang
- Key Laboratory of High Performance Polymer Material and Technology of Ministry of Education
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- China
| | - Yiwu Quan
- Key Laboratory of High Performance Polymer Material and Technology of Ministry of Education
- Department of Polymer Science and Engineering, School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- China
| | - Yixiang Cheng
- Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory of Advanced Organic Materials
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210023
- China
| |
Collapse
|
5
|
|
6
|
Evidence of both unusual dielectric mode at low frequencies and the co-existence of antiferroelectric, ferroelectric and paraelectric phases in a novel antiferroelectric liquid crystals mixture. J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.09.055] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
7
|
Torgova S, Sreenilayam SP, Panarin YP, Francescangeli O, Vita F, Vij JK, Pozhidaev E, Minchenko M, Ferrero C, Strigazzi A. Short bent-core molecules: X-ray, polarization, dielectricity, texture and electro-optics investigations. Phys Chem Chem Phys 2017; 19:22946-22956. [PMID: 28813044 DOI: 10.1039/c7cp03561f] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Bent-core liquid crystals based on 1,2,4-oxadiazole as a central unit have been the first mesogens to exhibit a ferroelectric response in the nematic phase. This behavior has been widely recognized as due to the presence of smectic-like polar cybotactic clusters permeating the nematic phase. Unfortunately, these compounds exhibited rather high melting points, about 120 °C, due to the presence of four benzene rings in the molecules. Here we describe the synthesis and physical characterization of a new series of BC mesogens, featuring the same bent core as the previous compounds but shorter outer substituents. By keeping only two benzene rings, we were able to lower the melting points to about 70 °C. However, while X-ray diffraction and dielectric spectroscopy measurements confirm the cybotactic nature of the nematic phase of these compounds, polarization and electro-optical measurements ascribe their polar response to flexoelectricity rather than to spontaneous polarization. Finally, texture investigation suggests the biaxiality of the nematic phase, which is indicated also by conoscopic measurements. These results are important for recognizing size and rigidity limitations in designing bent-core liquid crystal molecules suitable for applications.
Collapse
Affiliation(s)
- S Torgova
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Leninsky Pr. 53, Moscow, 119991, Russia
| | - S P Sreenilayam
- Department of Electronic and Electrical Engineering, Trinity College, Dublin 2, Ireland
| | - Yu P Panarin
- Department of Electronic and Electrical Engineering, Trinity College, Dublin 2, Ireland and School of Electrical and Electronic Engineering, Dublin Institute of Technology, Dublin, Ireland
| | - O Francescangeli
- Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio and CNISM, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - F Vita
- Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio and CNISM, Università Politecnica delle Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - J K Vij
- Department of Electronic and Electrical Engineering, Trinity College, Dublin 2, Ireland
| | - E Pozhidaev
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Leninsky Pr. 53, Moscow, 119991, Russia
| | - M Minchenko
- P.N. Lebedev Physical Institute of the Russian Academy of Sciences, Leninsky Pr. 53, Moscow, 119991, Russia
| | - C Ferrero
- European Synchrotron Radiation Facility, Bôite Postale 220, 38043 Grenoble Cedex, France
| | - A Strigazzi
- Department of Applied Science and Technology, Physics Institute of Condensed Matter and Complex Systems, CNISM, Politecnico di Torino, Torino, Italy. and National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Moscow, Russia
| |
Collapse
|
8
|
Narayanan T, Wacklin H, Konovalov O, Lund R. Recent applications of synchrotron radiation and neutrons in the study of soft matter. CRYSTALLOGR REV 2017. [DOI: 10.1080/0889311x.2016.1277212] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
| | - Hanna Wacklin
- European Spallation Source ERIC, Lund, Sweden
- Physical Chemistry, Lund University, Lund, Sweden
| | | | - Reidar Lund
- Department of Chemistry, University of Oslo, Blindern, Oslo, Norway
| |
Collapse
|
9
|
Kaur S, Punjani V, Mohiuddin G, Pal SK. Orthogonal smectic and nematic ordering in three-ring polar bent-core molecules with anti-parallel arrangement. NEW J CHEM 2017. [DOI: 10.1039/c7nj00272f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Three-ring based BLCs exhibiting orthogonal smectic and nematic phases with antiparallel arrangement as derived from SCXRD and X-ray scattering results.
Collapse
Affiliation(s)
- Supreet Kaur
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manauli-140306
- India
| | - Vidhika Punjani
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manauli-140306
- India
| | - Golam Mohiuddin
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manauli-140306
- India
| | - Santanu Kumar Pal
- Department of Chemical Sciences
- Indian Institute of Science Education and Research (IISER) Mohali
- Manauli-140306
- India
| |
Collapse
|
10
|
Arakawa Y, Sasaki Y, Igawa K, Tsuji H. Hydrogen bonding liquid crystalline benzoic acids with alkylthio groups: phase transition behavior and insights into the cybotactic nematic phase. NEW J CHEM 2017. [DOI: 10.1039/c7nj00282c] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel class of hydrogen bonding liquid crystalline benzoic acids with alkylthio groups was established and their phase transition behavior was investigated in detail.
Collapse
Affiliation(s)
- Yuki Arakawa
- Department of Environmental and Life Sciences
- Graduate School of Engineering
- Toyohashi University of Technology
- Toyohashi
- Japan
| | - Yukito Sasaki
- Department of Environmental and Life Sciences
- Graduate School of Engineering
- Toyohashi University of Technology
- Toyohashi
- Japan
| | - Kazunobu Igawa
- Institute for Materials Chemistry and Engineering
- Kyushu University
- Fukuoka 816-8580
- Japan
| | - Hideto Tsuji
- Department of Environmental and Life Sciences
- Graduate School of Engineering
- Toyohashi University of Technology
- Toyohashi
- Japan
| |
Collapse
|
11
|
Chen W, Zhu Y, Cui F, Liu L, Sun Z, Chen J, Li Y. GPU-Accelerated Molecular Dynamics Simulation to Study Liquid Crystal Phase Transition Using Coarse-Grained Gay-Berne Anisotropic Potential. PLoS One 2016; 11:e0151704. [PMID: 26986851 PMCID: PMC4795799 DOI: 10.1371/journal.pone.0151704] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 03/02/2016] [Indexed: 12/26/2022] Open
Abstract
Gay-Berne (GB) potential is regarded as an accurate model in the simulation of anisotropic particles, especially for liquid crystal (LC) mesogens. However, its computational complexity leads to an extremely time-consuming process for large systems. Here, we developed a GPU-accelerated molecular dynamics (MD) simulation with coarse-grained GB potential implemented in GALAMOST package to investigate the LC phase transitions for mesogens in small molecules, main-chain or side-chain polymers. For identical mesogens in three different molecules, on cooling from fully isotropic melts, the small molecules form a single-domain smectic-B phase, while the main-chain LC polymers prefer a single-domain nematic phase as a result of connective restraints in neighboring mesogens. The phase transition of side-chain LC polymers undergoes a two-step process: nucleation of nematic islands and formation of multi-domain nematic texture. The particular behavior originates in the fact that the rotational orientation of the mesogenes is hindered by the polymer backbones. Both the global distribution and the local orientation of mesogens are critical for the phase transition of anisotropic particles. Furthermore, compared with the MD simulation in LAMMPS, our GPU-accelerated code is about 4 times faster than the GPU version of LAMMPS and at least 200 times faster than the CPU version of LAMMPS. This study clearly shows that GPU-accelerated MD simulation with GB potential in GALAMOST can efficiently handle systems with anisotropic particles and interactions, and accurately explore phase differences originated from molecular structures.
Collapse
Affiliation(s)
- Wenduo Chen
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Youliang Zhu
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Fengchao Cui
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Lunyang Liu
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Zhaoyan Sun
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Jizhong Chen
- State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| | - Yunqi Li
- Key Laboratory of Synthetic Rubber & Laboratory of Advanced Power Sources, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, 5625 Renmin Street, Changchun, PR China
| |
Collapse
|
12
|
Pace A, Buscemi S, Piccionello AP, Pibiri I. Recent Advances in the Chemistry of 1,2,4-OxadiazolesaaDedicated to Professor Nicolò Vivona on the occasion of his 75th birthday. ADVANCES IN HETEROCYCLIC CHEMISTRY 2015. [DOI: 10.1016/bs.aihch.2015.05.001] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
13
|
Ahmed Z, Welch C, Mehl GH. The design and investigation of the self-assembly of dimers with two nematic phases. RSC Adv 2015. [DOI: 10.1039/c5ra18118f] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Non-symmetric nematic dimers are designed and investigated by OPM, DSC and XRD; assembly models for the Nx phase are developed.
Collapse
Affiliation(s)
- Z. Ahmed
- Department of Chemistry
- University of Hull
- UK
| | - C. Welch
- Department of Chemistry
- University of Hull
- UK
| | - G. H. Mehl
- Department of Chemistry
- University of Hull
- UK
| |
Collapse
|
14
|
Francescangeli O, Vita F, Samulski ET. The cybotactic nematic phase of bent-core mesogens: state of the art and future developments. SOFT MATTER 2014; 10:7685-7691. [PMID: 25133629 DOI: 10.1039/c4sm01256a] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The molecular clustering observed in the fluid nematic phase of nonlinear liquid crystal molecules underlies exaggerated field effects that portend unique technological advances in next-generation liquid crystal displays. However, the detailed nature of the molecular organization within the clusters and the temporal and spatial persistence of the organization remain unclear. Herein we review the evolution of structural studies of this unique nematic phase. The mounting experimental evidence points to a converging picture of the microscopic nature of this relatively new class of liquid crystals.
Collapse
Affiliation(s)
- Oriano Francescangeli
- Dipartimento di Scienze e Ingegneria della Materia, dell'Ambiente ed Urbanistica and CNISM, Università Politecnica delle Marche, Via Brecce Bianche, 60131, Ancona, Italy.
| | | | | |
Collapse
|