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Liu X, Debije MG, Heuts JPA, Schenning APHJ. Liquid-Crystalline Polymer Particles Prepared by Classical Polymerization Techniques. Chemistry 2021; 27:14168-14178. [PMID: 34320258 PMCID: PMC8596811 DOI: 10.1002/chem.202102224] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Indexed: 11/06/2022]
Abstract
Liquid-crystalline polymer particles prepared by classical polymerization techniques are receiving increased attention as promising candidates for use in a variety of applications including micro-actuators, structurally colored objects, and absorbents. These particles have anisotropic molecular order and liquid-crystalline phases that distinguish them from conventional polymer particles. In this minireview, the preparation of liquid-crystalline polymer particles from classical suspension, (mini-)emulsion, dispersion, and precipitation polymerization reactions are discussed. The particle sizes, molecular orientations, and liquid-crystalline phases produced by each technique are summarized and compared. We conclude with a discussion of the challenges and prospects of the preparation of liquid-crystalline polymer particles by classical polymerization techniques.
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Affiliation(s)
- Xiaohong Liu
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
| | - Michael G. Debije
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
| | - Johan P. A. Heuts
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
| | - Albert P. H. J. Schenning
- Department of Chemical Engineering and ChemistryEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
- Institute for Complex Molecular SystemsEindhoven University of TechnologyPO Box 5135600 MBEindhovenThe Netherlands
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2
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Liu X, Moradi MA, Bus T, Heuts JPA, Debije MG, Schenning APHJ. Monodisperse Liquid Crystalline Polymer Shells with Programmable Alignment and Shape Prepared by Seeded Dispersion Polymerization. Macromolecules 2021; 54:6052-6060. [PMID: 34276068 PMCID: PMC8280615 DOI: 10.1021/acs.macromol.1c00884] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Revised: 06/04/2021] [Indexed: 11/30/2022]
Abstract
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Monodisperse,
micrometer-sized liquid crystalline (LC) shells are
prepared by seeded dispersion polymerization. After polymerizing LC
monomer mixtures in the presence of non-crosslinked polymer seeds,
hollow LC polymer shells with programmable alignment and shape are
prepared by removing the seeds. The LC alignment in the LC polymer
shells can be easily manipulated by the polymer seeds, as a radial
alignment is observed with amorphous poly(phenyl methacrylate) seeds
and a bipolar alignment is observed with bipolar LC polymer seeds.
After removal of the seeds, the radially aligned samples give radially
aligned shells with small dimples. The resulting bipolar LC polymer
shells collapse into a biconcave shape. Polarized optical microscopy
and transmission electron microscopy indicate that the collapse occurs
at the defect points in the shell. In the case of a lower crosslink
density, LC polymer hollow shells with larger dimples are obtained,
resulting in cup-shaped polymer particles. Biconcave LC polymer shells
based on other LC mixtures have also been prepared, showing the versatility
of the seeded dispersion polymerization method.
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Affiliation(s)
- Xiaohong Liu
- Stimuli-responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands
| | - Mohammad-Amin Moradi
- Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands
| | - Tom Bus
- Stimuli-responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands
| | - Johan P A Heuts
- Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands.,Supramolecular Polymer Chemistry Group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Michael G Debije
- Stimuli-responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Albert P H J Schenning
- Stimuli-responsive Functional Materials and Devices, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, PO Box 513, 5600 MB Eindhoven, The Netherlands
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3
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Martinez AM, Cox LM, Killgore JP, Bongiardina NJ, Riley RD, Bowman CN. Permanent and reversibly programmable shapes in liquid crystal elastomer microparticles capable of shape switching. SOFT MATTER 2021; 17:467-474. [PMID: 33346289 DOI: 10.1039/d0sm01836h] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Reversibly programmable liquid crystal elastomer microparticles (LCEMPs), formed as a covalent adaptable network (CAN), with an average diameter of 7 μm ± 2 μm, were synthesized via a thiol-Michael dispersion polymerization. The particles were programmed to a prolate shape via a photoinitiated addition-fragmentation chain-transfer (AFT) exchange reaction by activating the AFT after undergoing compression. Due to the thermotropic nature of the AFT-LCEMPs, shape switching was driven by heating the particles above their nematic-isotropic phase transition temperature (TNI). The programmed particles subsequently displayed cyclable two-way shape switching from prolate to spherical when at low or high temperatures, respectively. Furthermore, the shape programming is reversible, and a second programming step was done to erase the prolate shape by initiating AFT at high temperature while the particles were in their spherical shape. Upon cooling, the particles remained spherical until additional programming steps were taken. Particles were also programmed to maintain a permanent oblate shape. Additionally, the particle surface was programmed with a diffraction grating, demonstrating programmable complex surface topography via AFT activation.
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Affiliation(s)
- Alina M Martinez
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA.
| | - Lewis M Cox
- Department of Mechanical Engineering, Montana State University, Culbertson Hall, 100, Bozeman, MT 59717, USA
| | - Jason P Killgore
- Applied Chemicals and Materials Division, National Institute of Standards and Technology, 325 Broadway, Boulder, CO 80305, USA
| | - Nicholas J Bongiardina
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA.
| | - Russell D Riley
- Department of Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA
| | - Christopher N Bowman
- Department of Materials Science and Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA. and Department of Chemical and Biological Engineering, University of Colorado Boulder, 596 UCB, Boulder, CO 80309, USA
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Liu X, Xu Y, Heuts JPA, Debije MG, Schenning APHJ. Monodisperse Liquid Crystal Network Particles Synthesized via Precipitation Polymerization. Macromolecules 2019; 52:8339-8345. [PMID: 31736513 PMCID: PMC6854653 DOI: 10.1021/acs.macromol.9b01852] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/18/2019] [Indexed: 01/29/2023]
Abstract
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The production of
liquid crystalline (LC) polymer particles with
a narrow size distribution on a large scale remains a challenge. Here,
we report the preparation of monodisperse, cross-linked liquid crystalline
particles via precipitation polymerization. This versatile and scalable
method yields polymer particles with a smectic liquid crystal order.
Although the LC monomers are randomly dissolved in solution, the oligomers
self-align and LC order is induced. For the polymerization, a smectic
LC monomer mixture consisting of cross-linkers and benzoic acid hydrogen-bonded
dimers is used. The average diameter of the particles increases at
higher polymerization temperatures and in better solvents, whereas
the monomer and initiator concentration have only minor impact on
the particle size. After deprotonating of the benzoic acid groups,
the particles show rapid absorption of a common cationic dye, methylene
blue. The methylene blue in the particles can be subsequently released
with the addition of Ca2+, while monovalent ions fail to
trigger the release. These results reveal that precipitation polymerization
is an attractive method to prepare functional LC polymer particles
of a narrow size distribution and on a large scale.
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Affiliation(s)
- Xiaohong Liu
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Yifei Xu
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Johan P A Heuts
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
| | - Michael G Debije
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands
| | - Albert P H J Schenning
- Stimuli-Responsive Functional Materials and Devices, Laboratory of Materials and Interface Chemistry and Center for Multiscale Electron Microscopy, and Supramolecular Polymer Chemistry group, Department of Chemical Engineering and Chemistry, Eindhoven University of Technology, 5600 MB Eindhoven, The Netherlands.,Institute for Complex Molecular Systems, Eindhoven University of Technology, P.O. Box 513, 5600 MB, Eindhoven, The Netherlands
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Imamura K, Yoshida H, Ozaki M. Field strength and frequency tunable, two-way rotation of liquid crystal micro-particles dispersed in a liquid crystal host. SOFT MATTER 2017; 13:4433-4440. [PMID: 28530008 DOI: 10.1039/c7sm00535k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Liquid crystal (LC) micro-particles are functional materials possessing anisotropies of LCs originating from their inner molecular alignment, and are fabricated by polymerizing pre-aligned rod-like molecules in the LC state. Here we demonstrate field strength and frequency tunable two-way rotation control of LC micro-particles in a LC host, and unravel its mechanism by theoretically calculating the contributing free energies. Cuboid-shaped micro-particles with inner molecular alignment along the long axis are fabricated via two-photon excited direct laser writing, and dispersed in a dual-frequency (DF) LC to be electrically driven by a voltage applied in the in-plane direction of the cell. Under an electric field, the particles rotate either clockwise or anticlockwise to align the inner molecular alignment parallel or perpendicular to the applied field; however, unlike conventional LCs, the rotation direction depends not only on the frequency, but also on the strength of the field. The complex motion is found to be the result of a delicate balance between the elastic energy of the host LC around the particle and the electrostatic energies of the host and the particle. Understanding complex rotational motion in LC/LC-particle composites is a step towards the development of advanced switching materials with superior performance.
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Affiliation(s)
- Koki Imamura
- Division of Electrical, Electronic and Information Engineering, Osaka University, 2-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
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Imamura K, Yoshida H, Ozaki M. Reversible switching of liquid crystal micro-particles in a nematic liquid crystal. SOFT MATTER 2016; 12:750-755. [PMID: 26514389 DOI: 10.1039/c5sm01956g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Liquid crystal micro-particles are functional materials possessing optical and dielectric anisotropies originating from the arrangement of rod-like molecules within the particles. Although they can be switched by an electric field, particles dispersed in isotropic hosts usually cannot return to their original state, because there is no restoration force acting on the particles. Here, we describe reversible switching of liquid crystal micro-particles by dispersing them in a nematic liquid crystal host. We fabricate square micro-particles with unidirectional molecular alignment and investigate their static and dynamic electro-optic properties by applying an in-plane electric field. The behavior of the micro-particles is well-described by the theoretical model we construct, making this study potentially useful for the development of liquid crystal-liquid crystal particle composites with engineered properties.
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Affiliation(s)
- Koki Imamura
- Division of Electrical, Electronic and Information Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Bera T, Freeman EJ, McDonough JA, Clements RJ, Aladlaan A, Miller DW, Malcuit C, Hegmann T, Hegmann E. Liquid Crystal Elastomer Microspheres as Three-Dimensional Cell Scaffolds Supporting the Attachment and Proliferation of Myoblasts. ACS APPLIED MATERIALS & INTERFACES 2015; 7:14528-35. [PMID: 26075811 DOI: 10.1021/acsami.5b04208] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We report that liquid crystal elastomers (LCEs), often portrayed as artificial muscles, serve as scaffolds for skeletal muscle cell. A simultaneous microemulsion photopolymerization and cross-linking results in nematic LCE microspheres 10-30 μm in diameter that when conjoined form a LCE construct that serves as the first proof-of-concept for responsive LCE muscle cell scaffolds. Confocal microscopy experiments clearly established that LCEs with a globular, porous morphology permit both attachment and proliferation of C2C12 myoblasts, while the nonporous elastomer morphology, prepared in the absence of a microemulsion, does not. In addition, cytotoxicity and proliferation assays confirm that the liquid crystal elastomer materials are biocompatible promoting cellular proliferation without any inherent cytotoxicity.
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Affiliation(s)
| | | | | | | | | | - Donald W Miller
- #Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 0T6, Canada
| | | | - Torsten Hegmann
- #Department of Pharmacology and Therapeutics, University of Manitoba, Winnipeg, MB R3E 0T6, Canada
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Ohm C, Kapernaum N, Nonnenmacher D, Giesselmann F, Serra C, Zentel R. Microfluidic Synthesis of Highly Shape-Anisotropic Particles from Liquid Crystalline Elastomers with Defined Director Field Configurations. J Am Chem Soc 2011; 133:5305-11. [DOI: 10.1021/ja1095254] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christian Ohm
- Institute of Organic Chemistry, University of Mainz, D-55128 Mainz, Germany
| | - Nadia Kapernaum
- Institute of Physical Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Dorothee Nonnenmacher
- Institute of Physical Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Frank Giesselmann
- Institute of Physical Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany
| | - Christophe Serra
- LIPHT-CNRS UMR 7165, University of Strasbourg, F-67087 Strasbourg Cedex 2, France
| | - Rudolf Zentel
- Institute of Organic Chemistry, University of Mainz, D-55128 Mainz, Germany
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Ohm C, Brehmer M, Zentel R. Liquid crystalline elastomers as actuators and sensors. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2010; 22:3366-87. [PMID: 20512812 DOI: 10.1002/adma.200904059] [Citation(s) in RCA: 561] [Impact Index Per Article: 40.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This review collects recent developments in the field of liquid crystalline elastomers (LCEs) with an emphasis on their use for actuator and sensor applications. Several synthetic pathways leading to crosslinked liquid crystalline polymers are discussed and how these materials can be oriented into liquid crystalline monodomains are described. By comparing the actuating properties of different systems, general structure-property relationships for LCEs are obtained. In the final section, how these materials can be turned into usable devices using different interdisciplinary techniques are described.
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Heinze P, Finkelmann H. Shear Deformation and Ferroelectricity in Chiral SmC* Main-chain Elastomers. Macromolecules 2010. [DOI: 10.1021/ma1002084] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Patrick Heinze
- Institut für Makromolekulare Chemie, Albert Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 31, 79104 Freiburg im Breisgau, Germany
| | - Heino Finkelmann
- Institut für Makromolekulare Chemie, Albert Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 31, 79104 Freiburg im Breisgau, Germany
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