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Marin O, Alesker M, Guttman S, Gershinsky G, Edri E, Shpaisman H, Guerra RE, Zitoun D, Deutsch M, Sloutskin E. Self-faceting of emulsion droplets as a route to solid icosahedra and other polyhedra. J Colloid Interface Sci 2019; 538:541-545. [DOI: 10.1016/j.jcis.2018.11.111] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 11/29/2018] [Accepted: 11/30/2018] [Indexed: 12/25/2022]
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2
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Hatch HW, Mahynski NA, Murphy RP, Blanco MA, Shen VK. Monte Carlo simulation of cylinders with short-range attractions. AIP ADVANCES 2018; 8:095210. [PMID: 32855837 PMCID: PMC7448613 DOI: 10.1063/1.5040252] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 09/03/2018] [Indexed: 05/21/2023]
Abstract
Cylindrical or rod-like particles are promising materials for the applications of fillers in nanocomposite materials and additives to control rheological properties of colloidal suspensions. Recent advances in particle synthesis allows for cylinders to be manufactured with short-ranged attractions to study the gelation as a function of packing fraction, aspect ratio and attraction strength. In order to aid in the analysis of small-angle scattering experiments of rod-like particles, computer simulation methods were used to model these particles with specialized Monte Carlo algorithms and tabular superquadric potentials. The attractive interaction between neighboring rods increases with the amount of locally-accessible surface area, thus leading to patchy-like interactions. We characterize the clustering and percolation of cylinders as the attractive interaction increases from the homogenous fluid at relatively low attraction strength, for a variety of aspect ratios and packing fractions. Comparisons with the experimental scattering results are also presented, which are in agreement.
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Affiliation(s)
- Harold W. Hatch
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Nathan A. Mahynski
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Ryan P. Murphy
- Center for Neutron Science and Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, USA
| | - Marco A. Blanco
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland 20850, USA
| | - Vincent K. Shen
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
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Liber SR, Indech G, van der Wee EB, Butenko AV, Kodger TE, Lu PJ, Schofield AB, Weitz DA, van Blaaderen A, Sloutskin E. Axial Confocal Tomography of Capillary-Contained Colloidal Structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:13343-13349. [PMID: 29043816 DOI: 10.1021/acs.langmuir.7b03039] [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
Confocal microscopy is widely used for three-dimensional (3D) sample reconstructions. Arguably, the most significant challenge in such reconstructions is posed by the resolution along the optical axis being significantly lower than in the lateral directions. In addition, the imaging rate is lower along the optical axis in most confocal architectures, prohibiting reliable 3D reconstruction of dynamic samples. Here, we demonstrate a very simple, cheap, and generic method of multiangle microscopy, allowing high-resolution high-rate confocal slice collection to be carried out with capillary-contained colloidal samples in a wide range of slice orientations. This method, realizable with any common confocal architecture and recently implemented with macroscopic specimens enclosed in rotatable cylindrical capillaries, allows 3D reconstructions of colloidal structures to be verified by direct experiments and provides a solid testing ground for complex reconstruction algorithms. In this paper, we focus on the implementation of this method for dense nonrotatable colloidal samples, contained in complex-shaped capillaries. Additionally, we discuss strategies to minimize potential pitfalls of this method, such as the artificial appearance of chain-like particle structures.
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Affiliation(s)
- Shir R Liber
- Physics Department and Bar-Ilan Institute of Nanotechnology & Advanced Materials, Bar-Ilan University , Ramat-Gan 5290002, Israel
| | - Ganit Indech
- Physics Department and Bar-Ilan Institute of Nanotechnology & Advanced Materials, Bar-Ilan University , Ramat-Gan 5290002, Israel
| | - Ernest B van der Wee
- Soft Condensed Matter, Debye Institute for NanoMaterials Science, Utrecht University , Princetonplein 1, 3584 CC Utrecht, The Netherlands
| | - Alexander V Butenko
- Physics Department and Bar-Ilan Institute of Nanotechnology & Advanced Materials, Bar-Ilan University , Ramat-Gan 5290002, Israel
| | - Thomas E Kodger
- Physical Chemistry and Soft Matter, Wageningen University & Research , Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Peter J Lu
- Department of Physics and SEAS, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Andrew B Schofield
- The School of Physics and Astronomy, University of Edinburgh , Edinburgh EH9 3FD, U.K
| | - David A Weitz
- Department of Physics and SEAS, Harvard University , Cambridge, Massachusetts 02138, United States
| | - Alfons van Blaaderen
- Soft Condensed Matter, Debye Institute for NanoMaterials Science, Utrecht University , Princetonplein 1, 3584 CC Utrecht, The Netherlands
| | - Eli Sloutskin
- Physics Department and Bar-Ilan Institute of Nanotechnology & Advanced Materials, Bar-Ilan University , Ramat-Gan 5290002, Israel
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Heymans S, Schilling T. Elastic properties of the nematic phase in hard ellipsoids of short aspect ratio. Phys Rev E 2017; 96:022708. [PMID: 28950529 DOI: 10.1103/physreve.96.022708] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Indexed: 06/07/2023]
Abstract
We present a Monte Carlo simulation study of suspensions of hard ellipsoids of revolution. Based on the spatial fluctuations of the orientational order, we have computed the Frank elastic constants for prolate and oblate ellipsoids and compared them to the affine transformation model. The affine transformation model predicts the right order of magnitude of the twist and bend constant but not of the splay constant. In addition, we report the observation of a stable nematic phase at an aspect ratio as low as 2.5.
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Affiliation(s)
- S Heymans
- Université du Luxembourg, Theory of Soft Condensed Matter, Physics and Materials Sciences Research Unit, L-1511 Luxembourg, Luxembourg
| | - T Schilling
- Institute of Physics, University of Freiburg, Hermann-Herder-Strasse 3, D-79104 Freiburg, Germany
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LaMarche CQ, Miller AW, Liu P, Leadley S, Hrenya CM. How nano-scale roughness impacts the flow of grains influenced by capillary cohesion. AIChE J 2017. [DOI: 10.1002/aic.15830] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Casey Q. LaMarche
- Dept. of Chemical and Biological Engineering; University of Colorado at Boulder; Boulder CO 80309
| | - Andrew W. Miller
- Dept. of Chemical and Biological Engineering; University of Colorado at Boulder; Boulder CO 80309
| | - Peiyuan Liu
- Dept. of Chemical and Biological Engineering; University of Colorado at Boulder; Boulder CO 80309
| | - Stuart Leadley
- Dow Corning Europe SA, Rue Jules Bordet, Parc Industriel de Seneffe - Zone C; B-7180 Seneffe Belgium
| | - Christine M. Hrenya
- Dept. of Chemical and Biological Engineering; University of Colorado at Boulder; Boulder CO 80309
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Photo-Crosslinkable Colloids: From Fluid Structure and Dynamics of Spheres to Suspensions of Ellipsoids. Gels 2016; 2:gels2040029. [PMID: 30674159 PMCID: PMC6318651 DOI: 10.3390/gels2040029] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 11/03/2016] [Accepted: 11/07/2016] [Indexed: 11/16/2022] Open
Abstract
Recently-developed photo-crosslinkable PMMA (polymethylmethacrylate) colloidal spheres are a highly promising system for fundamental studies in colloidal physics and may have a wide range of future technological applications. We synthesize these colloids and characterize their size distribution. Their swelling in a density- and index- matching organic solvent system is demonstrated and we employ dynamic light scattering (DLS), as also the recently-developed confocal differential dynamic microscopy (ConDDM), to characterize the structure and the dynamics of a fluid bulk suspension of such colloids at different particle densities, detecting significant particle charging effects. We stretch these photo-crosslinkable spheres into ellipsoids. The fact that the ellipsoids are cross-linked allows them to be fluorescently stained, permitting a dense suspension of ellipsoids, a simple model of fluid matter, to be imaged by direct confocal microscopy.
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Gurin P, Varga S, Odriozola G. Anomalous structural transition of confined hard squares. Phys Rev E 2016; 94:050603. [PMID: 27967070 DOI: 10.1103/physreve.94.050603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Indexed: 06/06/2023]
Abstract
Structural transitions are examined in quasi-one-dimensional systems of freely rotating hard squares, which are confined between two parallel walls. We find two competing phases: one is a fluid where the squares have two sides parallel to the walls, while the second one is a solidlike structure with a zigzag arrangement of the squares. Using transfer matrix method we show that the configuration space consists of subspaces of fluidlike and solidlike phases, which are connected with low probability microstates of mixed structures. The existence of these connecting states makes the thermodynamic quantities continuous and precludes the possibility of a true phase transition. However, thermodynamic functions indicate strong tendency for the phase transition and our replica exchange Monte Carlo simulation study detects several important markers of the first order phase transition. The distinction of a phase transition from a structural change is practically impossible with simulations and experiments in such systems like the confined hard squares.
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Affiliation(s)
- Péter Gurin
- Institute of Physics and Mechatronics, University of Pannonia, P.O. Box 158, Veszprém H-8201, Hungary
| | - Szabolcs Varga
- Institute of Physics and Mechatronics, University of Pannonia, P.O. Box 158, Veszprém H-8201, Hungary
| | - Gerardo Odriozola
- Area de Física de Procesos Irreversibles, División de Ciencias Básicas e Ingeniería, Universidad Autónoma Metropolitana-Azcapotzalco, Av. San Pablo 180, 02200 CD México, Mexico
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