1
|
Junot G, Cebers A, Tierno P. Collective hydrodynamic transport of magnetic microrollers. Soft Matter 2021; 17:8605-8611. [PMID: 34614055 DOI: 10.1039/d1sm00653c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We investigate the collective transport properties of microscopic magnetic rollers that propel close to a surface due to a circularly polarized, rotating magnetic field. The applied field exerts a torque to the particles, which induces a net rolling motion close to a surface. The collective dynamics of the particles result from the balance between magnetic dipolar interactions and hydrodynamic ones. We show that, when hydrodynamics dominate, i.e. for high particle spinning, the collective mean velocity linearly increases with the particle density. In this regime we analyse the clustering kinetics, and find that hydrodynamic interactions between the anisotropic, elongated particles, induce preferential cluster growth along a direction perpendicular to the driving one, leading to dynamic clusters that easily break and reform during propulsion.
Collapse
Affiliation(s)
- Gaspard Junot
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Barcelona, Spain.
| | - Andrejs Cebers
- MMML Lab, Department of Physics, University of Latvia, Jelgavas-3, Riga, LV-1004, Latvia
| | - Pietro Tierno
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, Barcelona, Spain.
- Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, Barcelona, Spain
- Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, 08028, Barcelona, Spain
| |
Collapse
|
2
|
Belovs M, Livanovics R, Cebers A. Hydrodynamic synchronization of pairs of puller type magnetotactic bacteria in a high frequency rotating magnetic field. Soft Matter 2019; 15:1627-1632. [PMID: 30672559 DOI: 10.1039/c8sm02118j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ensembles of magnetotactic bacteria are known to interact hydrodynamically and form swarms under the influence of external magnetic fields. We describe the synchronization of puller type magnetotactic bacteria in a rotating magnetic field by representing the bacteria as hydrodynamic force dipoles. Numerical simulations show that at moderate values of the hydrodynamic interaction parameter large ensembles of asynchronously rotating bacteria randomly eject propagating doublets of synchronized bacteria. We quantitatively analyze the dynamics of the doublets and show that an important role in the formation of these propagating structures is played by the parameters characterizing the possible trajectories of a single bacterium in a rotating magnetic field.
Collapse
Affiliation(s)
- Mihails Belovs
- MMML Lab, Department of Physics, University of Latvia, Zellu 23, Riga, Latvia.
| | | | | |
Collapse
|
3
|
Massana-Cid H, Martinez-Pedrero F, Cebers A, Tierno P. Orientational dynamics of fluctuating dipolar particles assembled in a mesoscopic colloidal ribbon. Phys Rev E 2017; 96:012607. [PMID: 29347116 DOI: 10.1103/physreve.96.012607] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Indexed: 06/07/2023]
Abstract
We combine experiments and theory to investigate the dynamics and orientational fluctuations of ferromagnetic microellipsoids that form a ribbonlike structure due to attractive dipolar forces. When assembled in the ribbon, the ellipsoids display orientational thermal fluctuations with an amplitude that can be controlled via application of an in-plane magnetic field. We use video microscopy to investigate the orientational dynamics in real time and space. Theoretical arguments are used to derive an analytical expression that describes how the distribution of the different angular configurations depends on the strength of the applied field. The experimental data are in good agreement with the developed model for all the range of field parameters explored. Understanding the role of fluctuations in chains composed of dipolar particles is important not only from a fundamental point of view, but it may also help understanding the stability of such structures against thermal noise, which is relevant in microfluidics and laboratory-on-a-chip applications.
Collapse
Affiliation(s)
- Helena Massana-Cid
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Fernando Martinez-Pedrero
- Departamento de Química Física I, Universidad Complutense de Madrid, Ciudad Universitaria, 28040, Madrid, Spain
| | - Andrejs Cebers
- Faculty of Physics and Mathematics, University of Latvia, Zellu 23, LV-1002
| | - Pietro Tierno
- Departament de Física de la Matèria Condensada, Universitat de Barcelona, 08028 Barcelona, Spain
- Universitat de Barcelona Institute of Complex Systems (UBICS), Universitat de Barcelona, 08028 Barcelona, Spain
- Institut de Nanociència i Nanotecnologia, IN2 UB, Universitat de Barcelona, 08028 Barcelona, Spain
| |
Collapse
|
4
|
Martinez-Pedrero F, Cebers A, Tierno P. Orientational dynamics of colloidal ribbons self-assembled from microscopic magnetic ellipsoids. Soft Matter 2016; 12:3688-95. [PMID: 26936015 DOI: 10.1039/c5sm02823j] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We combine experiments and theory to investigate the orientational dynamics of dipolar ellipsoids, which self-assemble into elongated ribbon-like structures due to the presence of a permanent magnetic moment, perpendicular to the long axis in each particle. Monodisperse hematite ellipsoids are synthesized via the sol-gel technique and arrange into ribbons in the presence of static or time-dependent magnetic fields. We find that under an oscillating field, the ribbons reorient perpendicular to the field direction, in contrast with the behaviour observed under a static field. This observation is explained theoretically by treating a chain of interacting ellipsoids as a single particle with orientational and demagnetizing field energy. The model allows us to describe the orientational behaviour of the chain and captures well its dynamics at different strengths of the actuating field. The understanding of the complex dynamics and assembly of anisotropic magnetic colloids is a necessary step for controlling the structure formation, which has direct applications in different fluid-based microscale technologies.
Collapse
Affiliation(s)
- Fernando Martinez-Pedrero
- Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain. and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, 08028, Barcelona, Spain
| | - Andrejs Cebers
- Faculty of Physics and Mathematics, University of Latvia, Zellu 23, LV-1002, Riga, Latvia
| | - Pietro Tierno
- Departament d'Estructura i Constituents de la Matèria, Universitat de Barcelona, 08028, Barcelona, Spain. and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, 08028, Barcelona, Spain
| |
Collapse
|
5
|
Chevry L, Sampathkumar NK, Cebers A, Berret JF. Magnetic wire-based sensors for the microrheology of complex fluids. Phys Rev E Stat Nonlin Soft Matter Phys 2013; 88:062306. [PMID: 24483443 DOI: 10.1103/physreve.88.062306] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Indexed: 05/05/2023]
Abstract
We propose a simple microrheology technique to evaluate the viscoelastic properties of complex fluids. The method is based on the use of magnetic wires of a few microns in length submitted to a rotational magnetic field. In this work, the method is implemented on a surfactant wormlike micellar solution that behaves as an ideal Maxwell fluid. With increasing frequency, the wires undergo a transition between a steady and a hindered rotation regime. The study shows that the average rotational velocity and the amplitudes of the oscillations obey scaling laws with well-defined exponents. From a comparison between model predictions and experiments, the rheological parameters of the fluid are determined.
Collapse
Affiliation(s)
- L Chevry
- Matière et Systèmes Complexes, UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet 10 rue Alice Domon et Léonie Duquet, F-75205 Paris, France
| | - N K Sampathkumar
- Matière et Systèmes Complexes, UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet 10 rue Alice Domon et Léonie Duquet, F-75205 Paris, France
| | - A Cebers
- Department of Theoretical Physics, University of Latvia, Zellu 8, Riga LV-1002, Latvia
| | - J-F Berret
- Matière et Systèmes Complexes, UMR 7057 CNRS Université Denis Diderot Paris-VII, Bâtiment Condorcet 10 rue Alice Domon et Léonie Duquet, F-75205 Paris, France
| |
Collapse
|
6
|
Huisman EM, Wen Q, Wang YH, Cruz K, Kitenbergs G, Erglis K, Zeltins A, Cebers A, Janmey PA. Gelation of semiflexible polyelectrolytes by multivalent counterions. Soft Matter 2011; 7:7257-7261. [PMID: 22267963 PMCID: PMC3262026 DOI: 10.1039/c1sm05553d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Filamentous polyelectrolytes in aqueous solution aggregate into bundles by interactions with multivalent counterions. These effects are well documented by experiment and theory. Theories also predict a gel phase in isotropic rodlike polyelectrolyte solutions caused by multivalent counterion concentrations much lower than those required for filament bundling. We report here the gelation of Pf1 virus, a model semiflexible polyelectrolyte, by the counterions Mg(2+), Mn(2+) and spermine(4+). Gelation can occur at 0.04% Pf1 volume fraction, which is far below the isotropic-nematic transition of 0.7% for Pf1 in monovalent salt. Unlike strongly crosslinked gels of semiflexible polymers, which stiffen at large strains, Pf1 gels reversibly soften at high strain. The onset strain for softening depends on the strength of interaction between counterions and the polyelectrolyte. Simulations show that the elasticity of counterion crosslinked gels is consistent with a model of semiflexible filaments held by weak crosslinks that reversibly rupture at a critical force.
Collapse
Affiliation(s)
- Elisabeth M Huisman
- Universiteit Leiden, Instituut-Lorentz, Postbus 9506, NL-2300 RA Leiden, The Netherlands
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Levental I, Cebers A, Janmey PA. Combined electrostatics and hydrogen bonding determine intermolecular interactions between polyphosphoinositides. J Am Chem Soc 2008; 130:9025-30. [PMID: 18572937 DOI: 10.1021/ja800948c] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Membrane lipids are active contributors to cell function as key mediators in signaling pathways controlling cell functions including inflammation, apoptosis, migration, and proliferation. Recent work on multimolecular lipid structures suggests a critical role for lipid organization in regulating the function of both lipids and proteins. Of particular interest in this context are the polyphosphoinositides (PPI's), especially phosphatidylinositol (4,5) bisphosphate (PIP 2). The cellular functions of PIP 2 are numerous but the organization of PIP 2 in the inner leaflet of the plasma membrane, as well as the factors controlling targeting of PIP 2 to specific proteins, remains poorly understood. To analyze the organization of PIP 2 in a simplified planar system, we used Langmuir monolayers to study the effects of subphase conditions on monolayers of purified naturally derived PIP 2 and other anionic or zwitterionic phospholipids. We report a significant molecular area expanding effect of subphase monovalent salts on PIP 2 at biologically relevant surface densities. This effect is shown to be specific to PIP 2 and independent of subphase pH. Chaotropic agents (e.g., salts, trehalose, urea, temperature) that disrupt water structure and the ability of water to mediate intermolecular hydrogen bonding also specifically expanded PIP 2 monolayers. These results suggest a combination of water-mediated hydrogen bonding and headgroup repulsion in determining the organization of PIP 2, and may contribute to an explanation for the unique functionality of PIP 2 compared to other anionic phospholipids.
Collapse
Affiliation(s)
- Ilya Levental
- Institute for Medicine and Engineering, Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
| | | | | |
Collapse
|
8
|
Pauchard L, Elias F, Boltenhagen P, Cebers A, Bacri JC. When a crack is oriented by a magnetic field. Phys Rev E Stat Nonlin Soft Matter Phys 2008; 77:021402. [PMID: 18352026 DOI: 10.1103/physreve.77.021402] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Indexed: 05/26/2023]
Abstract
Upon drying, colloidal suspensions undergo a phase transformation from a "liquid" to a "gel" state. With further solvent evaporation, tensile stresses develop in the gel, which ultimately leads to fractures. These generally manifest themselves in regular cracking patterns which reflect the physical conditions of the drying process. Here we show experimentally and theoretically how, in the case of a drying droplet of magnetic colloid (ferrofluid), an externally applied magnetic field modifies the stress in the gel and therefore the crack patterns. We find that the analysis of the shape of the cracks allows one to estimate the value of the gel Young's modulus just before the crack nucleation.
Collapse
Affiliation(s)
- L Pauchard
- Laboratoire Matière et Systèmes Complexes, Universitè Paris 7, CNRS UMR 7057, France
| | | | | | | | | |
Collapse
|
9
|
Mériguet G, Cousin F, Dubois E, Boué F, Cebers A, Farago B, Perzynski R. What Tunes the Structural Anisotropy of Magnetic Fluids under a Magnetic Field? J Phys Chem B 2006; 110:4378-86. [PMID: 16509738 DOI: 10.1021/jp0558573] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the present study, the structure of monophasic ionic magnetic fluids under a static magnetic field is explored. In these aqueous electrostatically stabilized ferrofluids, we vary both the isotropic interparticle interactions and the anisotropic dipolar magnetic interaction by tuning the ionic strength and the size of the nanoparticles. Small angle neutron scattering measurements carried out on nanoparticles dispersed in light water exhibit miscellaneous 2D nuclear patterns under a magnetic field with various q-dependent anisotropies. In this nondeuterated solvent where the magnetic scattering is negligible, this anisotropy originates from an anisotropy of the structure of the dispersions. Both the low q region and the peak of the structure factor can be anisotropic. On the scale of the interparticle distance, the structure is better defined in the direction perpendicular to the field. In the thermodynamic limit (q-->0), the model previously described in ref 10 matches the data without any fitting parameters: the interparticle interaction is more repulsive in the direction parallel to the magnetic field. At low q, the amplitude of the anisotropy of the pattern is governed by the ratio of two interaction parameters: the reduced parameter of the anisotropic magnetic dipolar interaction, gamma/Phi, over the isotropic interaction parameter, , in zero field, which is proportional to the second virial coefficient.
Collapse
Affiliation(s)
- Guillaume Mériguet
- Laboratoire Liquides Ioniques et Interfaces Chargées, UPMC, UMR CNRS-UPMC-ESPCI 7612, case 51, 4 place Jussieu, 75252 Paris Cedex 05, France
| | | | | | | | | | | | | |
Collapse
|
10
|
Wilhelm C, Cebers A, Bacri JC, Gazeau F. Deformation of intracellular endosomes under a magnetic field. Eur Biophys J 2003; 32:655-60. [PMID: 12811432 DOI: 10.1007/s00249-003-0312-0] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2003] [Revised: 04/25/2003] [Accepted: 04/25/2003] [Indexed: 10/26/2022]
Abstract
We present a non-invasive method to monitor the membrane tension of intracellular organelles using a magnetic field as an external control parameter. By exploiting the spontaneous endocytosis of anionic colloidal ferromagnetic nanoparticles, we obtain endosomes possessing a superparamagnetic lumen in eukaryotic cells. Initially flaccid, the endosomal membrane undulates because of thermal fluctuations, restricted in zero field by the resting tension and the curvature energy of the membrane. When submitted to a uniform magnetic field, the magnetized endosomes elongate along the field, resulting in the flattening of the entropic membrane undulations. The quantification of the endosome deformation for different magnetic fields allows in situ measurement of the resting tension and the bending stiffness of the membrane enclosing the intracellular organelle.
Collapse
Affiliation(s)
- C Wilhelm
- Laboratoire des Milieux Désordonnés et Hétérogènes, UMR7603, and FR2438 CNRS Matière et Systèmes Complexes, Université Pierre et Marie Curie, Tour 13, Case 86, 4 place Jussieu, 75005 Paris, France
| | | | | | | |
Collapse
|
11
|
Ménager C, Meyer M, Cabuil V, Cebers A, Bacri JC, Perzynski R. Magnetic phospholipid tubes connected to magnetoliposomes: Pearling instability induced by a magnetic field. Eur Phys J E Soft Matter 2002; 7:325-337. [PMID: 27638164 DOI: 10.1140/epje/i2001-10094-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We propose here a method to modify the membrane tension of phospholipid tubes with an applied magnetic field. The tubes are connected to giant liposomes capping the tubes at both ends. Tubes and liposomes are all filled with a magnetic fluid. The tension of the tube membrane is tuned by the deformation of the ending liposomes under the applied field. We modelize the magnetoliposome deformation and we are then able to describe the tube evolution. At low magnetic fields, the tube remains at equilibrium with a cylindrical shape and a uniform radius. It responds to an increase of membrane tension by a diameter reduction. Above a magnetic-field threshold, the cylindrical shape becomes unstable with respect to a pearling deformation. The tube shape then selected by the system is an unduloid, with a constant mean curvature equal to C 0, the spontaneous curvature of the membrane.
Collapse
Affiliation(s)
- C Ménager
- Laboratoire LI2C, Equipe Colloıdes Inorganiques, Université Pierre et Marie Curie, Case 63, UMR 7612, 4 place Jussieu, 75252 Paris Cedex 05, France, Paris Cedex, France
| | - M Meyer
- Laboratoire LI2C, Equipe Colloıdes Inorganiques, Université Pierre et Marie Curie, Case 63, UMR 7612, 4 place Jussieu, 75252 Paris Cedex 05, France, Paris Cedex, France
| | - V Cabuil
- Laboratoire LI2C, Equipe Colloıdes Inorganiques, Université Pierre et Marie Curie, Case 63, UMR 7612, 4 place Jussieu, 75252 Paris Cedex 05, France, Paris Cedex, France
| | - A Cebers
- Institute of Physics, University of Latvia, Salaspils-1, LV-2169, Latvia, Latvia, Latvia
| | - J-C Bacri
- Laboratoire LMDH, Université Pierre et Marie Curie, Université Denis Diderot, Case 78, 4 place Jussieu, 75252 Paris Cedex 05, France, Paris Cedex, France
| | - R Perzynski
- Laboratoire LMDH, Université Pierre et Marie Curie, Université Denis Diderot, Case 78, 4 place Jussieu, 75252 Paris Cedex 05, France, Paris Cedex, France
| |
Collapse
|
12
|
Gazeau F, Dubois E, Bacri JC, Boué F, Cebers A, Perzynski R. Anisotropy of the structure factor of magnetic fluids under a field probed by small-angle neutron scattering. Phys Rev E Stat Nonlin Soft Matter Phys 2002; 65:031403. [PMID: 11909053 DOI: 10.1103/physreve.65.031403] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2001] [Indexed: 11/07/2022]
Abstract
Small-angle neutron scattering is used to measure the two-dimensional diffraction pattern of a monophasic magnetic colloid, under an applied magnetic field. This dipolar system presents in zero field a fluidlike structure. It is well characterized by an interaction parameter K(0)(T) proportional to the second virial coefficient, which is here positive, expressing a repulsion of characteristic length kappa-10. Under the field a strong anisotropy is observed at the lowest q vectors. The length kappa-10 remains isotropic, but the interaction parameter K(T) becomes anisotropic due to the long-range dipolar interaction. However, the system remains stable, the interaction being repulsive in all directions. Thus we do not observe any chaining of the nanoparticles under magnetic field. On the contrary, the revealed structure of our anisotropic colloid is a lowering of the concentration fluctuations along the field while the fluidlike structure, observed without field, is roughly preserved perpendicularly to the field. It expresses a strong anisotropy of the Brownian motion of the nanoparticles in the solution under applied field.
Collapse
Affiliation(s)
- F Gazeau
- Laboratoire des Milieux Désordonnés et Hétérogènes, UPMC Case 78, 4, Place Jussieu, 75252 Paris Cedex 05, France
| | | | | | | | | | | |
Collapse
|
13
|
Sandre O, Ménager C, Prost J, Cabuil V, Bacri JC, Cebers A. Shape transitions of giant liposomes induced by an anisotropic spontaneous curvature. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 62:3865-3870. [PMID: 11088905 DOI: 10.1103/physreve.62.3865] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/1999] [Revised: 05/25/2000] [Indexed: 05/23/2023]
Abstract
We explore how a magnetic field breaks the symmetry of an initially spherical giant liposome filled with a magnetic colloid. The condition of rotational symmetry along the field axis leads either to a prolate or to an oblate ellipsoid. We demonstrate that an electrostatic interaction between the nanoparticles and the membrane triggers the shape transition.
Collapse
Affiliation(s)
- O Sandre
- Laboratoire Milieux Désordonnés et Hétérogènes, UMR 7603 Centre National de la Recherche Scientifique/Université Pierre et Marie Curie, Université Denis Diderot, Tour 13, Case 78, 4 place Jussieu, 75252 Paris Cedex 05, France
| | | | | | | | | | | |
Collapse
|
14
|
Cebers A. Instabilities of concentration stripe patterns in ferrocolloids. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 2000; 61:700-8. [PMID: 11046313 DOI: 10.1103/physreve.61.700] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/1999] [Indexed: 11/07/2022]
Abstract
Equations describing the kinetics of the phase separation in ferrocolloids in a Hele-Shaw cell under the action of a rotating magnetic field are proposed. Numerical simulation on the basis of a pseudospectral technique demonstrates that upon the action of a rotating field on a magnetic colloid which undergoes the phase separation a periodical system of stripes parallel to the plane of a rotating magnetic field stripes is created. The period of a structure found numerically satisfactorily corresponds to the one calculated on the basis of the energy minimum. Thus, the undulation instability leading to the formation of chevron structures takes place if the tangential component of a rotating magnetic field is eliminated, whereas the normal component is increased at the same time. If during the development of the undulation deformations of a concentration pattern the magnetic Bond number is large enough the secondary instabilities may occur leading to the fingering of stripes to bring about merging and break-up of stripes. It is shown that an increase in the magnetic Bond number leads to the onset of the instability at the boundaries between the regions with homogeneous orientation of stripes as well as to formation of the characteristic hairpin patterns.
Collapse
Affiliation(s)
- A Cebers
- Institute of Physics, University of Latvia, Salaspils-1, LV-2169, Latvia
| |
Collapse
|
15
|
Cebers A, Drikis I. 2D shape relaxation dynamics in amphiphile monolayers. Colloid Polym Sci 1997. [DOI: 10.1007/bf01188941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
Gazeau F, Heegaard BM, Bacri J, Cebers A, Perzynski R. Magnetic fluid under vorticity: Free precession decay of magnetization and optical anisotropy. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1996; 54:3672-3675. [PMID: 9965516 DOI: 10.1103/physreve.54.3672] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
|
17
|
Flament C, Lacis S, Bacri J, Cebers A, Neveu S, Perzynski R. Measurements of ferrofluid surface tension in confined geometry. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1996; 53:4801-4806. [PMID: 9964808 DOI: 10.1103/physreve.53.4801] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
18
|
Bacri J, Cebers A, Bourdon A, Demouchy G, Heegaard BM, Kashevsky B, Perzynski R. Transient grating in a ferrofluid under magnetic field: Effect of magnetic interactions on the diffusion coefficient of translation. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1995; 52:3936-3942. [PMID: 9963866 DOI: 10.1103/physreve.52.3936] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
19
|
|
20
|
Bacri JC, Cebers A, Bourdon A, Demouchy G, Heegaard BM, Perzynski R. Forced Rayleigh experiment in a magnetic fluid. Phys Rev Lett 1995; 74:5032-5035. [PMID: 10058666 DOI: 10.1103/physrevlett.74.5032] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|
21
|
Bacri J, Cebers A, Dabadie J, Perzynski R. Roll-rectangle transition in the magnetic fluid Faraday instability. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1994; 50:2712-2715. [PMID: 9962311 DOI: 10.1103/physreve.50.2712] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
|
22
|
Wang H, Zhu Y, Boyd C, Luo W, Cebers A, Rosensweig RE. Periodic branched structures in a phase-separated magnetic colloid. Phys Rev Lett 1994; 72:1929-1932. [PMID: 10055740 DOI: 10.1103/physrevlett.72.1929] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
|