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S A, V S D, More P, Pujala RK, Dhara S. Electrophoretic propulsion of matchstick-shaped magnetodielectric particles in the presence of external magnetic fields in a nematic liquid crystal. SOFT MATTER 2024; 20:535-545. [PMID: 38126395 DOI: 10.1039/d3sm01382k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2023]
Abstract
Synthesis of micro- and nanoparticles of pre-designed shape and surface properties is an integral part of soft and synthetic active matter. We report synthesis of matchstick-shaped (MS) magnetodielectric particles and demonstrate their potential as active agents with field-controllable trajectories in a nematic liquid crystal (NLC). The MS particles with homeotropic anchoring in NLCs align either parallel or perpendicular to the director depending on the dipolar or quadrupolar director distortions. When subjected to transverse electric and magnetic fields, the particles experience electric and magnetic torques trying to align them in the respective field directions. At equilibrium, the long axis is tilted at an angle with respect to the director. The change in orientation alters the surrounding elastic distortion, which results in unbalanced electroosmotic flows. These flows provide the necessary impetus for propelling the particles in various directions with different velocities depending on their orientations.
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Affiliation(s)
- Archana S
- School of Physics, University of Hyderabad, Hyderabad-500046, India.
| | - Devika V S
- School of Physics, University of Hyderabad, Hyderabad-500046, India.
| | - Prasanna More
- Department of Physics, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh, 517507, India
| | - Ravi Kumar Pujala
- Department of Physics, Indian Institute of Science Education and Research (IISER) Tirupati, Tirupati, Andhra Pradesh, 517507, India
| | - Surajit Dhara
- School of Physics, University of Hyderabad, Hyderabad-500046, India.
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Benke D, Feller T, Krüsmann M, Neuhöfer AM, Ganster F, Karg M, Retsch M. Prolate spheroidal polystyrene nanoparticles: matrix assisted synthesis, interface properties, and scattering analysis. SOFT MATTER 2023; 19:9006-9016. [PMID: 37966805 DOI: 10.1039/d3sm01002c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2023]
Abstract
Shape-anisotropic colloids are increasingly attracting attention for the fabrication of nano- and mesostructured materials. Polymer-based prolate spheroids are typically accessible through a two-step fabrication procedure comprising the synthesis of monodisperse particles of initially spherical shape and their stretching into elongated, ellipsoidal-like objects. The particle stretching is conducted within a matrix polymer, most commonly polyvinylalcohol, which allows heating beyond the glass transition temperature of the polymer particles, e.g. polystyrene. Here, we investigate various aspects of the synthesis and their consequences for the resulting colloids. Loading the stretching matrix with a high amount of polymer particles results in small particle clusters, which are separated during the mechanical stretching step. At the same time, the matrix polymer physisorbs at the particle surface which can be removed via a rigorous work-up procedure. Overall, this process allows for a precise adjustment of the aspect ratio of the prolate spheroids with a small size distribution and retained electrostatic stabilization. We analyse these particles with a range of microscopic and scattering techniques, including depolarized dynamic light scattering that gives access to the rotational diffusion coefficients.
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Affiliation(s)
- Dominik Benke
- Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany.
| | - Tanja Feller
- Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany.
| | - Marcel Krüsmann
- Chair of Colloids and Nano Optics, Heinrich-Heine-University Düsseldorf, D-40225 Düsseldorf, Germany
| | - Anna M Neuhöfer
- Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany.
| | - Friederike Ganster
- Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany.
| | - Matthias Karg
- Chair of Colloids and Nano Optics, Heinrich-Heine-University Düsseldorf, D-40225 Düsseldorf, Germany
| | - Markus Retsch
- Department of Chemistry, Chair of Physical Chemistry 1, University Bayreuth, Germany.
- Bavarian Polymer Institute, Bayreuth Center for Colloids and Interfaces, Bavarian Center for Battery Technology (BayBatt), Universitätsstraße 30, 95447 Bayreuth, Germany
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Schwenker E, Jiang W, Spreadbury T, Ferrier N, Cossairt O, Chan MK. EXSCLAIM!: Harnessing materials science literature for self-labeled microscopy datasets. PATTERNS (NEW YORK, N.Y.) 2023; 4:100843. [PMID: 38035197 PMCID: PMC10682750 DOI: 10.1016/j.patter.2023.100843] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 01/31/2023] [Accepted: 08/21/2023] [Indexed: 12/02/2023]
Abstract
This work introduces the EXSCLAIM! toolkit for the automatic extraction, separation, and caption-based natural language annotation of images from scientific literature. EXSCLAIM! is used to show how rule-based natural language processing and image recognition can be leveraged to construct an electron microscopy dataset containing thousands of keyword-annotated nanostructure images. Moreover, it is demonstrated how a combination of statistical topic modeling and semantic word similarity comparisons can be used to increase the number and variety of keyword annotations on top of the standard annotations from EXSCLAIM! With large-scale imaging datasets constructed from scientific literature, users are well positioned to train neural networks for classification and recognition tasks specific to microscopy-tasks often otherwise inhibited by a lack of sufficient annotated training data.
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Affiliation(s)
- Eric Schwenker
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA
- Department of Materials Science and Engineering, Northwestern University, Evanston, IL 60208, USA
| | - Weixin Jiang
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA
- Department of Computer Science, Northwestern University, Evanston, IL 60208, USA
| | - Trevor Spreadbury
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA
- Department of Computer Science, Northwestern University, Evanston, IL 60208, USA
| | - Nicola Ferrier
- Mathematics and Computer Science, Argonne National Laboratory, Argonne, IL 60439, USA
| | - Oliver Cossairt
- Department of Computer Science, Northwestern University, Evanston, IL 60208, USA
| | - Maria K.Y. Chan
- Center for Nanoscale Materials, Argonne National Laboratory, Argonne, IL 60439, USA
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4
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Yao X, Zhang L, Chen JZY. Defect patterns of two-dimensional nematic liquid crystals in confinement. Phys Rev E 2022; 105:044704. [PMID: 35590543 DOI: 10.1103/physreve.105.044704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 03/23/2022] [Indexed: 06/15/2023]
Abstract
A two-dimensional or quasi-two-dimensional nematic liquid crystal refers to a surface-confined system. When such a system is further confined by external line boundaries or excluded from internal line boundaries, the nematic directors form a deformed texture that may display defect points or defect lines, for which winding numbers can be clearly defined. Here, a particular attention is paid to the case when the liquid crystal molecules prefer to form a boundary nematic texture in parallel to the wall surface (i.e., following the homogeneous boundary condition). A general theory, based on geometric argument, is presented for the relationship between the sum of all winding numbers in the system (the total winding number) and the type of confinement angles and curved segments. The conclusion is validated by comparing the theoretical defect rule with existing nematic textures observed experimentally and theoretically in recent years.
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Affiliation(s)
- Xiaomei Yao
- Beijing International Center for Mathematical Research, Peking University, Beijing 100871, China
| | - Lei Zhang
- Beijing International Center for Mathematical Research, Peking University, Beijing 100871, China
| | - Jeff Z Y Chen
- Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario, Canada, N2L 3G1
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Aya S, Kougo J, Araoka F, Haba O, Yonetake K. Nontrivial topological defects of micro-rods immersed in nematics and their phototuning. Phys Chem Chem Phys 2022; 24:3338-3347. [PMID: 35060569 DOI: 10.1039/d1cp03363h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Combinations of different geometries and surface anchoring conditions give rise to the diversity of topological structures in nematic colloid systems. Tuning these parameters in a single system offers possibilities for observing the evolution of the topological transformation and for manipulating colloids through topological forces. Here we investigate the nontrivial topological properties of micro-rods dispersed in nematic liquid crystals through experimental observation and computer simulation. The topological variation is driven by photodynamically changing the surface anchoring using azobenzene-based surface-commander molecules, the majority of which are localized on both the substrates and the surface of micro-rods. By comparing experimental and simulation results, we show previously unidentified topological properties of the two-body LC-rod-colloid system. Moreover, unlike the traditional photoresponsive liquid crystal systems, the localization of azobenzene molecules on the surfaces makes it possible to change only the direction of the surface orientation, not disordering of the bulk structures. The results assist in the development of photo-driven micro-robotics in fluids.
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Affiliation(s)
- Satoshi Aya
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Molecular Science and Engineering, South China University of Technology, Guangzhou 510640, China. .,Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Junichi Kougo
- South China Advanced Institute for Soft Matter Science and Technology (AISMST), School of Molecular Science and Engineering, South China University of Technology, Guangzhou 510640, China. .,Guangdong Provincial Key Laboratory of Functional and Intelligent Hybrid Materials and Devices, South China University of Technology, Guangzhou 510640, China
| | - Fumito Araoka
- RIKEN Center for Emergent Matter Science (CEMS), 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Osamu Haba
- Graduate School of Organic Materials Science, Yamagata University, Yonezawa 992-8510, Yamagata, Japan
| | - Koichiro Yonetake
- Graduate School of Organic Materials Science, Yamagata University, Yonezawa 992-8510, Yamagata, Japan
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Ettinger S, Dietrich CF, Mishra CK, Miksch C, Beller DA, Collings PJ, Yodh AG. Rods in a lyotropic chromonic liquid crystal: emergence of chirality, symmetry-breaking alignment, and caged angular diffusion. SOFT MATTER 2022; 18:487-495. [PMID: 34851348 DOI: 10.1039/d1sm01209f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
In lyotropic chromonic liquid crystals (LCLCs), twist distortion of the nematic director costs much less energy than splay or bend distortion. This feature leads to novel mirror-symmetry breaking director configurations when the LCLCs are confined by interfaces or contain suspended particles. Spherical colloids in an aligned LCLC nematic phase, for example, induce chiral director perturbations ("twisted tails"). The asymmetry of rod-like particles in an aligned LCLC offer a richer set of possibilities due to their aspect ratio (α) and mean orientation angle (〈θ〉) between their long axis and the uniform far-field director. Here we report on the director configuration, equilibrium orientation, and angular diffusion of rod-like particles with planar anchoring suspended in an aligned LCLC. Video microscopy reveals, counterintuitively, that two-thirds of the rods have an angled equilibrium orientation (〈θ〉 ≠ 0) that decreases with increasing α, while only one-third of the rods are aligned (〈θ〉 = 0). Polarized optical video-microscopy and Landau-de Gennes numerical modeling demonstrate that the angled and aligned rods are accompanied by distinct chiral director configurations. Angled rods have a longitudinal mirror plane (LMP) parallel to their long axis and approximately parallel to the substrate walls. Aligned rods have a transverse and longitudinal mirror plane (TLMP), where the transverse mirror plane is perpendicular to the rod's long axis. Effectively, the small twist elastic constant of LCLCs promotes chiral director configurations that modify the natural tendency of rods to orient along the far-field director. Additional diffusion experiments confirm that rods are angularly confined with strength that depends on α.
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Affiliation(s)
- Sophie Ettinger
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Clarissa F Dietrich
- Institute of Physical Chemistry, University of Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany
| | - Chandan K Mishra
- Discipline of Physics, Indian Institute of Technology (IIT) Gandhinagar, Palaj, Gandhinagar, Gujarat 382355, India
| | - Cornelia Miksch
- Max Planck Institute of Intelligent Systems, Heisenbergstr. 3, 70569 Stuttgart, Germany
| | - Daniel A Beller
- Department of Physics, University of California, Merced, CA, 95343, USA
| | - Peter J Collings
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA.
- Department of Physics and Astronomy, Swarthmore College, Swarthmore, PA, 19081, USA
| | - A G Yodh
- Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA, 19104, USA.
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M MR, Pujala RK, Paladugu S, Dhara S. Interactions of charged microrods in chiral nematic liquid crystals. Phys Rev E 2021; 104:014706. [PMID: 34412267 DOI: 10.1103/physreve.104.014706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 07/02/2021] [Indexed: 11/07/2022]
Abstract
We study the pair interaction of charged silica microrods in chiral nematic liquid crystals and show that the microrods with homeotropic surface anchoring form a bound state due to the competing effect of electrostatic (Coulomb) and elastic interactions. The robustness of the bound state is demonstrated by applying external electrical and mechanical forces that perturbs their equilibrium position as well as orientation. In the bound state we have measured the correlated thermal fluctuations of the position, using two-particle cross-correlation spectroscopy that uncovers their hydrodynamic interaction. These findings reveal unexplored aspects of liquid-crystal dispersions which are important for understanding the assembly and dynamics of nano- and microparticles in chiral nematic liquid crystals.
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Affiliation(s)
- Muhammed Rasi M
- School of Physics, University of Hyderabad, Hyderabad 500046, India
| | - Ravi Kumar Pujala
- Department of Physics, Indian Institute of Science Education and Research, Tirupati, Andhra Pradesh 517507, India
| | - Sathyanarayana Paladugu
- Department of Physics, Indian Institute of Science Education and Research, Tirupati, Andhra Pradesh 517507, India
| | - Surajit Dhara
- School of Physics, University of Hyderabad, Hyderabad 500046, India
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Zhang B, Martens K, Kneer L, Funck T, Nguyen L, Berger R, Dass M, Kempter S, Schmidtke J, Liedl T, Kitzerow HS. DNA Origami Nano-Sheets and Nano-Rods Alter the Orientational Order in a Lyotropic Chromonic Liquid Crystal. NANOMATERIALS (BASEL, SWITZERLAND) 2020; 10:E1695. [PMID: 32872176 PMCID: PMC7560128 DOI: 10.3390/nano10091695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/21/2020] [Accepted: 08/24/2020] [Indexed: 12/28/2022]
Abstract
Rod-like and sheet-like nano-particles made of desoxyribonucleic acid (DNA) fabricated by the DNA origami method (base sequence-controlled self-organized folding of DNA) are dispersed in a lyotropic chromonic liquid crystal made of an aqueous solution of disodium cromoglycate. The respective liquid crystalline nanodispersions are doped with a dichroic fluorescent dye and their orientational order parameter is studied by means of polarized fluorescence spectroscopy. The presence of the nano-particles is found to slightly reduce the orientational order parameter of the nematic mesophase. Nano-rods with a large length/width ratio tend to preserve the orientational order, while more compact stiff nano-rods and especially nano-sheets reduce the order parameter to a larger extent. In spite of the difference between the sizes of the DNA nano-particles and the rod-like columnar aggregates forming the liquid crystal, a similarity between the shapes of the former and the latter seems to be better compatible with the orientational order of the liquid crystal.
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Affiliation(s)
- Bingru Zhang
- Faculty of Science, Department of Chemistry, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany; (B.Z.); (J.S.)
| | - Kevin Martens
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Luisa Kneer
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Timon Funck
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Linh Nguyen
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Ricarda Berger
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Mihir Dass
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Susanne Kempter
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Jürgen Schmidtke
- Faculty of Science, Department of Chemistry, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany; (B.Z.); (J.S.)
| | - Tim Liedl
- Faculty of Physics, Ludwig-Maximilians-University, Geschwister-Scholl-Platz 1, 80539 Munich, Germany; (K.M.); (L.K.); (T.F.); (L.N.); (R.B.); (M.D.); (S.K.); (T.L.)
| | - Heinz-S. Kitzerow
- Faculty of Science, Department of Chemistry, University of Paderborn, Warburger Straße 100, 33098 Paderborn, Germany; (B.Z.); (J.S.)
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Zhang C, Ge Y, Huo X, Xue J, Li K, Zhang Y, Miao Z. Studies on electro‐optical properties of polymer matrix/LC/ITO nanoparticles composites. POLYM ADVAN TECHNOL 2019. [DOI: 10.1002/pat.4795] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Cuihong Zhang
- Key Laboratory of Organic Polymer Photoelectric Materials, School of ScienceXijing University Xi'an China
- Department of Materials Science and Engineering, College of EngineeringPeking University Beijing China
| | - Yuan Ge
- Key Laboratory of Organic Polymer Photoelectric Materials, School of ScienceXijing University Xi'an China
| | - Xiaoping Huo
- Key Laboratory of Organic Polymer Photoelectric Materials, School of ScienceXijing University Xi'an China
| | - Jing Xue
- Key Laboratory of Organic Polymer Photoelectric Materials, School of ScienceXijing University Xi'an China
| | - Kexuan Li
- Key Laboratory of Organic Polymer Photoelectric Materials, School of ScienceXijing University Xi'an China
| | - Yongming Zhang
- Key Laboratory of Organic Polymer Photoelectric Materials, School of ScienceXijing University Xi'an China
| | - Zongcheng Miao
- Key Laboratory of Organic Polymer Photoelectric Materials, School of ScienceXijing University Xi'an China
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