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Title: An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures

Abstract

Here, we report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmC aP A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterized and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.

Authors:
 [1];  [1];  [2];  [3];  [4];  [1];  [5];  [5];  [5];  [1];  [6]
  1. Kent State Univ., Kent, OH (United States). Liquid Crystal Inst., Chemical Physics Interdisciplinary Program
  2. Kent State Univ., Kent, OH (United States). Liquid Crystal Inst., Chemical Physics Interdisciplinary Program; Federal Univ. of Technology, Apucarana PR (Brazil). Dept. of Physics
  3. Kent State Univ., Kent, OH (United States). Dept. of Chemistry and Biochemistry
  4. Kent State Univ., Kent, OH (United States). Liquid Crystal Inst., Chemical Physics Interdisciplinary Program; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
  5. LG Display Co., Ltd., Wollong-myeon, Paju-si, Gyeonggi-do (South Korea)
  6. Kent State Univ., Kent, OH (United States). Liquid Crystal Inst., Chemical Physics Interdisciplinary Program; Kent State Univ., Kent, OH (United States). Dept. of Chemistry and Biochemistry
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1351644
Alternate Identifier(s):
OSTI ID: 1351645; OSTI ID: 1408427
Grant/Contract Number:
AC02-05CH11231; CHE-1263087
Resource Type:
Journal Article: Published Article
Journal Name:
ChemistryOpen
Additional Journal Information:
Journal Volume: 6; Journal Issue: 2; Journal ID: ISSN 2191-1363
Publisher:
ChemPubSoc Europe
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; antiferroelectric liquid crystal display; bent-core liquid crystals; optically isotropic; polar smectic; room-temperature switching

Citation Formats

Bergquist, Leah, Zhang, Cuiyu, Ribeiro de Almeida, Roberta R., Pellegrene, Brittany, Salamonczyk, Miroslaw, Kim, Matthew, Hwang, Jung-Im, Kim, Kyeong-Jin, Lee, Joun-Ho, Jákli, Antal, and Hegmann, Torsten. An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures. United States: N. p., 2017. Web. doi:10.1002/open.201600138.
Bergquist, Leah, Zhang, Cuiyu, Ribeiro de Almeida, Roberta R., Pellegrene, Brittany, Salamonczyk, Miroslaw, Kim, Matthew, Hwang, Jung-Im, Kim, Kyeong-Jin, Lee, Joun-Ho, Jákli, Antal, & Hegmann, Torsten. An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures. United States. doi:10.1002/open.201600138.
Bergquist, Leah, Zhang, Cuiyu, Ribeiro de Almeida, Roberta R., Pellegrene, Brittany, Salamonczyk, Miroslaw, Kim, Matthew, Hwang, Jung-Im, Kim, Kyeong-Jin, Lee, Joun-Ho, Jákli, Antal, and Hegmann, Torsten. Tue . "An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures". United States. doi:10.1002/open.201600138.
@article{osti_1351644,
title = {An Optically Isotropic Antiferroelectric Liquid Crystal (OI-AFLC) Display Mode Operating over a Wide Temperature Range using Ternary Bent-Core Liquid Crystal Mixtures},
author = {Bergquist, Leah and Zhang, Cuiyu and Ribeiro de Almeida, Roberta R. and Pellegrene, Brittany and Salamonczyk, Miroslaw and Kim, Matthew and Hwang, Jung-Im and Kim, Kyeong-Jin and Lee, Joun-Ho and Jákli, Antal and Hegmann, Torsten},
abstractNote = {Here, we report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmCaP A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterized and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.},
doi = {10.1002/open.201600138},
journal = {ChemistryOpen},
number = 2,
volume = 6,
place = {United States},
year = {Tue Feb 07 00:00:00 EST 2017},
month = {Tue Feb 07 00:00:00 EST 2017}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1002/open.201600138

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  • Here, we report on the synthesis and characterization of bent-core liquid crystal (LC) compounds and the preparation of mixtures that provide an optically isotropic antiferroelectric (OI-AFLC) liquid crystal display mode over a very wide temperature interval and well below room temperature. From the collection of compounds synthesized during this study, we recognized that several ternary mixtures displayed a modulated SmC aP A phase down to below -40 °C and up to about 100 °C on both heating and cooling, as well as optical tilt angles in the transformed state of approximately 45° (optically isotropic state). The materials were fully characterizedmore » and their liquid crystal as well as electro-optical properties analyzed by polarized optical microscopy, differential scanning calorimetry, synchrotron X-ray diffraction, dielectric spectroscopy, and electro-optical tests.« less
  • No abstract prepared.
  • We studied mixtures of the achiral bent-core mesogen NOBOW 1,3-phenylene bis[4-(4-9-alkoxyphenyliminonetyl)benzoates] (P-9-O-PIMB) and the small, rodlike liquid crystal 8CB using high-resolution synchrotron x-ray diffraction, freeze fracture transmission electron microscopy, and differential scanning calorimetry. NOBOW and 8CB mix in an isotropic state at high temperatures but phase separate at lower temperatures when NOBOW transforms into the B4 phase and forms chiral helical nanofilaments. In pure NOBOW, the nanofilaments are close packed but at moderate 8CB concentrations, they are separated by nanosized gaps filled by 8CB. At higher concentrations of 8CB, macroscopic phase separation occurs.
  • We report small angle x-ray scattering (SAXS) studies of isotropic, nematic, and smectic mesophases formed by binary mixtures of bent-core (BC) and rod-shaped (RS) molecules. While optical studies indicate that the components are fully miscible, SAXS reveals fascinating structures that are consistent with segregation on a nanoscopic scale. We find that tilted smectic clusters, which have been previously reported in both the nematic and isotropic states of the pure BC materials, are also present in mixtures with up to 50 wt% of the RS compound; this is consistent with previous dielectric and flexoelectric studies on such mixtures. Unexpectedly in thismore » concentration range the clusters are present in the isotropic and in the induced smectic phase range, as well as throughout the nematic phase. The results in the smectic phase also reveal complex layering phenomena, providing important insight into the interaction between bent and rod-shaped molecules. These studies will be crucial in the design of promising new functional nanomaterials.« less