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Chougale S, Romeis D, Saphiannikova M. Magneto-Mechanical Enhancement of Elastic Moduli in Magnetoactive Elastomers with Anisotropic Microstructures. MATERIALS 2022; 15:ma15020645. [PMID: 35057361 PMCID: PMC8780743 DOI: 10.3390/ma15020645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Revised: 01/11/2022] [Accepted: 01/12/2022] [Indexed: 12/15/2022]
Abstract
Magnetoactive elastomers (MAEs) have gained significant attention in recent years due to their wide range of engineering applications. This paper investigates the important interplay between the particle microstructure and the sample shape of MAEs. A simple analytical expression is derived based on geometrical arguments to describe the particle distribution inside MAEs. In particular, smeared microstructures are considered instead of a discrete particle distribution. As a consequence of considering structured particle arrangements, the elastic free energy is anisotropic. It is formulated with the help of the rule of mixtures. We show that the enhancement of elastic moduli arises not only from the induced dipole–dipole interactions in the presence of an external magnetic field but also considerably from the change in the particle microstructure.
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Kostrov SA, Dashtimoghadam E, Keith AN, Sheiko SS, Kramarenko EY. Regulating Tissue-Mimetic Mechanical Properties of Bottlebrush Elastomers by Magnetic Field. ACS APPLIED MATERIALS & INTERFACES 2021; 13:38783-38791. [PMID: 34348460 DOI: 10.1021/acsami.1c12860] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
We report on a new class of magnetoactive elastomers (MAEs) based on bottlebrush polymer networks filled with carbonyl iron microparticles. By synergistically combining solvent-free, yet supersoft polymer matrices, with magnetic microparticles, we enable the design of composites that not only mimic the mechanical behavior of various biological tissues but also permit contactless regulation of this behavior by external magnetic fields. While the bottlebrush architecture allows to finely tune the matrix elastic modulus and strain-stiffening, the magnetically aligned microparticles generate a 3-order increase in shear modulus accompanied by a switch from a viscoelastic to elastic regime as evidenced by a ca. 10-fold drop of the damping factor. The developed method for MAE preparation through solvent-free coinjection of bottlebrush melts and magnetic particles provides additional advantages such as injection molding of various shapes and uniform particle distribution within MAE composites. The synergistic combination of bottlebrush network architecture and magnetically responsive microparticles empowers new opportunities in the design of actuators and active vibration insulation systems.
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Affiliation(s)
- Sergei A Kostrov
- Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russian Federation
- A.N. Nesmeyanov Institute for Organoelement Compounds, Russian Academy of Sciences, 119991 Moscow, Russian Federation
| | - Erfan Dashtimoghadam
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill 27599, United States
| | - Andrew N Keith
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill 27599, United States
| | - Sergei S Sheiko
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill 27599, United States
| | - Elena Yu Kramarenko
- Faculty of Physics, Lomonosov Moscow State University, 119991 Moscow, Russian Federation
- A.N. Nesmeyanov Institute for Organoelement Compounds, Russian Academy of Sciences, 119991 Moscow, Russian Federation
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Field-Induced Transversely Isotropic Shear Response of Ellipsoidal Magnetoactive Elastomers. MATERIALS 2021; 14:ma14143958. [PMID: 34300876 PMCID: PMC8306654 DOI: 10.3390/ma14143958] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 07/09/2021] [Accepted: 07/12/2021] [Indexed: 12/11/2022]
Abstract
Magnetoactive elastomers (MAEs) claim a vital place in the class of field-controllable materials due to their tunable stiffness and the ability to change their macroscopic shape in the presence of an external magnetic field. In the present work, three principal geometries of shear deformation were investigated with respect to the applied magnetic field. The physical model that considers dipole-dipole interactions between magnetized particles was used to study the stress-strain behavior of ellipsoidal MAEs. The magneto-rheological effect for different shapes of the MAE sample ranging from disc-like (highly oblate) to rod-like (highly prolate) samples was investigated along and transverse to the field direction. The rotation of the MAE during the shear deformation leads to a non-symmetric Cauchy stress tensor due to a field-induced magnetic torque. We show that the external magnetic field induces a mechanical anisotropy along the field direction by determining the distinct magneto-mechanical behavior of MAEs with respect to the orientation of the magnetic field to shear deformation.
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Ikeda J, Kurihara T, Ogura K, Akama S, Kawai M, Mitsumata T. Flowability of Gel-Matrix and Magnetorheological Response for Carrageenan Magnetic Hydrogels. Gels 2021; 7:56. [PMID: 34066471 PMCID: PMC8162321 DOI: 10.3390/gels7020056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 05/01/2021] [Accepted: 05/02/2021] [Indexed: 01/22/2023] Open
Abstract
The relationship between rheological features in the absence of a magnetic field and magnetic response was investigated for κ-carrageenan magnetic hydrogels containing carbonyl iron particles. The concentration of carrageenan was varied from 1.0 to 5.0 wt%, while the concentration of carbonyl iron was kept at 70 wt%. The magnetic response revealed that the change in storage modulus ΔG' decreased inversely proportional to the carrageenan concentration. A characteristic strain γ1 where G' equals to G″ was seen in a strain range of 10-3. It was found that ΔG' was inversely proportional to the characteristic stress at γ1. Another characteristic strain γ2 where the loss tangent significantly increased was also analyzed. Similar to the behavior of γ1, ΔG' was inversely proportional to γ2. The characteristic stresses at γ1 and γ2 were distributed at 80-720 Pa and 40-310 Pa, respectively. It was revealed that a giant magnetorheology higher than 1 MPa can be observed when the characteristic stresses at γ1 and γ2 are below approximately 240 Pa and 110 Pa, respectively.
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Affiliation(s)
| | | | | | | | | | - Tetsu Mitsumata
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan; (J.I.); (T.K.); (K.O.); (S.A.); (M.K.)
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Romeis D, Saphiannikova M. A Cascading Mean-Field Approach to the Calculation of Magnetization Fields in Magnetoactive Elastomers. Polymers (Basel) 2021; 13:polym13091372. [PMID: 33922333 PMCID: PMC8122822 DOI: 10.3390/polym13091372] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/19/2021] [Accepted: 04/19/2021] [Indexed: 01/23/2023] Open
Abstract
We consider magnetoactive elastomer samples based on the elastic matrix and magnetizable particle inclusions. The application of an external magnetic field to such composite samples causes the magnetization of particles, which start to interact with each other. This interaction is determined by the magnetization field, generated not only by the external magnetic field but also by the magnetic fields arising in the surroundings of interacting particles. Due to the scale invariance of magnetic interactions (O(r−3) in d=3 dimensions), a comprehensive description of the local as well as of the global effects requires a knowledge about the magnetization fields within individual particles and in mesoscopic portions of the composite material. Accordingly, any precise calculation becomes technically infeasible for a specimen comprising billions of particles arranged within macroscopic sample boundaries. Here, we show a way out of this problem by presenting a greatly simplified, but accurate approximation approach for the computation of magnetization fields in the composite samples. Based on the dipole model to magnetic interactions, we introduce the cascading mean-field description of the magnetization field by separating it into three contributions on the micro-, meso-, and macroscale. It is revealed that the contributions are nested into each other, as in the Matryoshka’s toy. Such a description accompanied by an appropriate linearization scheme allows for an efficient and transparent analysis of magnetoactive elastomers under rather general conditions.
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Vaganov MV, Borin DY, Odenbach S, Raikher YL. Magnetic Response of Magnetoactive Elastomers with Allowance for Slippage at the Particle‐Matrix Interfaces. ADVANCED THEORY AND SIMULATIONS 2021. [DOI: 10.1002/adts.202000327] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Mikhail V. Vaganov
- Institute of Continuous Media Mechanics Russian Academy of Sciences Ural Branch Perm 614013 Russia
| | - Dmitry Yu. Borin
- Institute of Mechatronic Engineering TU Dresden Dresden 01069 Germany
| | - Stefan Odenbach
- Institute of Mechatronic Engineering TU Dresden Dresden 01069 Germany
| | - Yuriy L. Raikher
- Institute of Continuous Media Mechanics Russian Academy of Sciences Ural Branch Perm 614013 Russia
- Institute of Natural Sciences and Mathematics Ural Federal University Ekaterinburg 620002 Russia
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Large-Scale Shape Transformations of a Sphere Made of a Magnetoactive Elastomer. Polymers (Basel) 2020; 12:polym12122933. [PMID: 33302589 PMCID: PMC7763455 DOI: 10.3390/polym12122933] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/03/2020] [Accepted: 12/06/2020] [Indexed: 02/06/2023] Open
Abstract
Magnetostriction effect, i.e., deformation under the action of a uniform applied field, is analyzed to detail for a spherical sample of a magnetoactive elastomer (MAE). A close analogy with the field-induced elongation of spherical ferrofluid droplets implies that similar characteristic effects viz. hysteresis stretching and transfiguration into a distinctively nonellipsoidal bodies, should be inherent to MAE objects as well. The absence until now of such studies seems to be due to very unfavorable conclusions which follow from the theoretical estimates, all of which are based on the assumption that a deformed sphere always retains the geometry of ellipsoid of revolution just changing its aspect ratio under field. Building up an adequate numerical modelling tool, we show that the ‘ellipsoidal’ approximation is misleading beginning right from the case of infinitesimal field strengths and strain increments. The results obtained show that the above-mentioned magnetodeformational effect should distinctively manifest itself in the objects made of quite ordinary MAEs, e.g., composites on the base of silicone cautchouc filled with micron-size carbonyl iron powder.
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Borin D, Stepanov G. Magneto-mechanical properties of elastic hybrid composites. PHYSICAL SCIENCES REVIEWS 2020. [DOI: 10.1515/psr-2019-0126] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Abstract
The paper gives an overview of tunable elastic magnetic composites based on silicon rubber matrix highly filled with a magnetic soft and hard filler. The magnetic soft phase, which is represented by iron microparticles, allows active control of the physical properties of the composites, while the magnetically hard phase (e.g. neodymium–iron–boron alloy microparticles) is mainly responsible for passive adjustment of the composite. The control is performed by the application of an external magnetic field in situ, and passive adjustment is performed by means of pre-magnetization in order to change material remanent magnetization, i.e. the initial state. The potential and limits of active control and passive tuning of these composites in terms of their magneto-mechanical behavior are presented and discussed.
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Affiliation(s)
- Dmitry Borin
- Institute of Mechatronic Engineering, Technische Universität Dresden , Dresden , 01062 Germany
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Stolbov OV, Sánchez PA, Kantorovich SS, Raikher YL. Magnetostriction in elastomers with mixtures of magnetically hard and soft microparticles: effects of nonlinear magnetization and matrix rigidity. PHYSICAL SCIENCES REVIEWS 2020. [DOI: 10.1515/psr-2020-0009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
In this contribution, a magnetoactive elastomer (MAE) of mixed content, i.e., a polymer matrix filled with a mixture of magnetically soft and magnetically hard spherical particles, is considered. The object we focus on is an elementary unit of this composite, for which we take a set consisting of a permanent spherical micromagnet surrounded by an elastomer layer filled with magnetically soft microparticles. We present a comparative treatment of this unit from two essentially different viewpoints. The first one is a coarse-grained molecular dynamics simulation model, which presents the composite as a bead-spring assembly and is able to deliver information of all the microstructural changes of the assembly. The second approach is entirely based on the continuum magnetomechanical description of the system, whose direct yield is the macroscopic field-induced response of the MAE to external field, as this model ignores all the microstructural details of the magnetization process. We find that, differing in certain details, both frameworks are coherent in predicting that a unit comprising magnetically soft and hard particles may display a nontrivial reentrant (prolate/oblate/prolate) axial deformation under variation of the applied field strength. The flexibility of the proposed combination of the two complementary frameworks enables us to look deeper into the manifestation of the magnetic response: with respect to the magnetically soft particles, we compare the linear regime of magnetization to that with saturation, which we describe by the Fröhlich–Kennelly approximation; with respect to the polymer matrix, we analyze the dependence of the reentrant deformation on its rigidity.
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Affiliation(s)
- Oleg V. Stolbov
- Laboratory of Physics and Mechanics of Soft Matter , Institute of Continuous Media Mechanics, Russian Academy of Sciences (Ural Branch) , Perm , Russia
| | - Pedro A. Sánchez
- Institute of Natural Sciences and Mathematics , Ural Federal University , Ekaterinburg , Russia
- Wolfgang Pauli Institute , University of Vienna , Vienna , Austria
| | - Sofia S. Kantorovich
- Institute of Natural Sciences and Mathematics , Ural Federal University , Ekaterinburg , Russia
- Faculty of Physics, Computational and Soft Matter Physics , University of Vienna , Vienna , Austria
- Research Platform MMM , University of Vienna , Vienna , Austria
| | - Yuriy L. Raikher
- Laboratory of Physics and Mechanics of Soft Matter , Institute of Continuous Media Mechanics, Russian Academy of Sciences (Ural Branch) , Perm , Russia
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Romeis D, Kostrov SA, Kramarenko EY, Stepanov GV, Shamonin M, Saphiannikova M. Magnetic-field-induced stress in confined magnetoactive elastomers. SOFT MATTER 2020; 16:9047-9058. [PMID: 32915184 DOI: 10.1039/d0sm01337d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We present a theoretical approach for calculating the state of stress induced by a uniform magnetic field in confined magnetoactive elastomers of arbitrary shape. The theory explicitly includes the magnetic field generated by magnetizable spherical inclusions in the sample interior assuming a non-linear magnetization behavior. The initial spatial distribution of particles and its change in an external magnetic field are considered. This is achieved by the introduction of an effective demagnetizing factor where both the sample shape and the material microstructure are taken into account. Theoretical predictions are fitted to the stress data measured using a specifically designed experimental setup. It is shown that the theory enables the quantification of the effect of material microstructure upon introducing a specific microstructural factor and its derivative with respect to the extensional strain in the undeformed state. The experimentally observed differences between isotropic and anisotropic samples, compliant and stiff elastomer matrices are explained.
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Affiliation(s)
- D Romeis
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany
| | - S A Kostrov
- Faculty of Physics, Lomonosov Moscow State University, Moscow 119991, Russia
| | - E Yu Kramarenko
- A. N. Nesmeyanov Institute of Organoelement Compounds of Russian Academy of Sciences, Moscow 119991, Russia
| | - G V Stepanov
- State Scientific Center of the Russian Federation, Institute of Chemistry and Technology of Organoelement Compounds, Moscow 111123, Russia
| | - M Shamonin
- East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule (OTH) Regensburg, 93053 Regensburg, Germany
| | - M Saphiannikova
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany
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Rubowitz A, Ayalon A, Roy PK, Shoval S, Legchenkova I, Bormashenko E. Study of wetting of the animal retinas by Water and organic liquids and its Implications for ophthalmology. Colloids Surf B Biointerfaces 2020; 195:111265. [PMID: 32739770 DOI: 10.1016/j.colsurfb.2020.111265] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 07/16/2020] [Accepted: 07/19/2020] [Indexed: 10/23/2022]
Abstract
Interfacial properties of the animal retinas are reported. Wetting of the retina-retinal pigment epithelium-choroid-sclera tissues of cow, sheep, and pig eyes by water, silicone and castor oil was explored experimentally. Both water and silicone oils demonstrated complete wetting of the retina, regardless of the viscosity of the silicone oil, whereas the castor oil demonstrated a partial wetting regime. Similar wetting regimes were observed for sheep, cow and pig retinas. The intact surface of animal retina was found to be both hydrophilic and oleophilic. Wetting experiments with double sandwich oil/water layers were performed. Water demonstrated stronger affinity to the retina than silicone and castor oils, and eventually replaced the oils at the liquid/retina interface. We conclude that aqueous solutions continuously secreted in the living eye may displace silicone oil from the retinal surface and contribute to retinal re-detachment. Study of dynamics of wetting of the animal retina by water and organic oils is reported. The exponent describing the dynamics of spreading of the castor oil is lower than that predicted by the Tanner law. Castor oil may provide more effective tamponade than silicone oil.
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Affiliation(s)
- Alexander Rubowitz
- Retina Service, Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel; Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Anfisa Ayalon
- Retina Service, Department of Ophthalmology, Meir Medical Center, Kfar Saba, Israel
| | - Pritam Kumar Roy
- Engineering Faculty, Chemical Engineering Department, Ariel University, 407000, P.O.B. 3, Ariel, Israel; Engineering Faculty, Industrial Engineering and Management Department, Ariel University, P. O. B. 3, 407000 Ariel, Israel
| | - Shraga Shoval
- Engineering Faculty, Industrial Engineering and Management Department, Ariel University, P. O. B. 3, 407000 Ariel, Israel
| | - Irina Legchenkova
- Engineering Faculty, Chemical Engineering Department, Ariel University, 407000, P.O.B. 3, Ariel, Israel
| | - Edward Bormashenko
- Engineering Faculty, Chemical Engineering Department, Ariel University, 407000, P.O.B. 3, Ariel, Israel.
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Kostrov SA, Gorodov VV, Sokolov BO, Muzafarov AM, Kramarenko EY. Low-Modulus Elastomeric Matrices for Magnetoactive Composites with a High Magnetic Field Response. POLYMER SCIENCE SERIES A 2020. [DOI: 10.1134/s0965545x20040082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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