1
|
Urano R, Watanabe K, Chen K, Liang X, Kawai M, Mitsumata T. Particle mobility and macroscopic magnetorheological effects for polyurethane magnetic elastomers. SOFT MATTER 2024; 20:4456-4465. [PMID: 38780303 DOI: 10.1039/d4sm00193a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2024]
Abstract
The relationship between the particle mobility and magnetorheological effect was investigated for polyurethane magnetic elastomers containing carbonyl iron particles with various cross-linking densities or plasticizer concentrations. The storage modulus at 0 mT increased and the on-field modulus at 500 mT decreased with the cross-linking density. The critical magnetic field where the storage modulus starts to rise up increased with the cross-linking density, indicating that the movement of magnetic particles is depressed by the cross-linking points of the polyurethane network. Magnetic elastomers with various plasticizer concentrations revealed that the storage modulus at 0 mT decreased and the on-field modulus at 500 mT increased with the plasticizer concentration. The critical magnetic field decreased with increasing plasticizer concentration, indicating that a dense polyurethane network prevents magnetic particles from moving. It was found that the change in the modulus due to the magnetic field can be scaled by the storage modulus at 0 mT as well as the critical magnetic field. Thus, there is a certain correlation between the macroscopic modulus of elasticity (storage modulus at 0 mT) and the microscopic mobility of magnetic particles reflected in the critical magnetic field.
Collapse
Affiliation(s)
- Rio Urano
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
| | - Kaito Watanabe
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
| | - Kejun Chen
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
| | - Xiandun Liang
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
| | - Mika Kawai
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
| | - Tetsu Mitsumata
- Graduate School of Science and Technology, Niigata University, Niigata 950-2181, Japan.
| |
Collapse
|
2
|
Nadzharyan TA, Kramarenko EY. Effects of Filler Anisometry on the Mechanical Response of a Magnetoactive Elastomer Cell: A Single-Inclusion Modeling Approach. Polymers (Basel) 2023; 16:118. [PMID: 38201782 PMCID: PMC10780330 DOI: 10.3390/polym16010118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 12/21/2023] [Accepted: 12/27/2023] [Indexed: 01/12/2024] Open
Abstract
A finite-element model of the mechanical response of a magnetoactive elastomer (MAE) volume element is presented. Unit cells containing a single ferromagnetic inclusion with geometric and magnetic anisotropy are considered. The equilibrium state of the cell is calculated using the finite-element method and cell energy minimization. The response of the cell to three different excitation modes is studied: inclusion rotation, inclusion translation, and uniaxial cell stress. The influence of the magnetic properties of the filler particles on the equilibrium state of the MAE cell is considered. The dependence of the mechanical response of the cell on the filler concentration and inclusion anisometry is calculated and analyzed. Optimal filler shapes for maximizing the magnetic response of the MAE are discussed.
Collapse
|
3
|
Kriegl R, Kravanja G, Hribar L, Čoga L, Drevenšek-Olenik I, Jezeršek M, Kalin M, Shamonin M. Microstructured Magnetoactive Elastomers for Switchable Wettability. Polymers (Basel) 2022; 14:polym14183883. [PMID: 36146027 PMCID: PMC9503804 DOI: 10.3390/polym14183883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/11/2022] [Accepted: 09/14/2022] [Indexed: 12/02/2022] Open
Abstract
We demonstrate the control of wettability of non-structured and microstructured magnetoactive elastomers (MAEs) by magnetic field. The synthesized composite materials have a concentration of carbonyl iron particles of 75 wt.% (≈27 vol.%) and three different stiffnesses of the elastomer matrix. A new method of fabrication of MAE coatings on plastic substrates is presented, which allows one to enhance the response of the apparent contact angle to the magnetic field by exposing the particle-enriched side of MAEs to water. A magnetic field is not applied during crosslinking. The highest variation of the contact angle from (113 ± 1)° in zero field up to (156 ± 2)° at about 400 mT is achieved in the MAE sample with the softest matrix. Several lamellar and pillared MAE structures are fabricated by laser micromachining. The lateral dimension of surface structures is about 50 µm and the depth varies between 3 µm and 60 µm. A systematic investigation of the effects of parameters of laser processing (laser power and the number of passages of the laser beam) on the wetting behavior of these structures in the absence and presence of a magnetic field is performed. In particular, strong anisotropy of the wetting behavior of lamellar structures is observed. The results are qualitatively discussed in the framework of the Wenzel and Cassie–Baxter models. Finally, directions of further research on magnetically controlled wettability of microstructured MAE surfaces are outlined. The obtained results may be useful for the development of magnetically controlled smart surfaces for droplet-based microfluidics.
Collapse
Affiliation(s)
- Raphael Kriegl
- East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule (OTH) Regensburg, Seybothstr. 2, 93053 Regensburg, Germany
- Correspondence: (R.K.); (M.S.)
| | - Gaia Kravanja
- Laboratory for Laser Techniques, Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, SI-1000 Ljubljana, Slovenia
| | - Luka Hribar
- Laboratory for Laser Techniques, Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, SI-1000 Ljubljana, Slovenia
| | - Lucija Čoga
- Laboratory for Tribology and Interface Nanotechnology, Faculty of Mechanical Engineering, University of Ljubljana, Bogišićeva 8, SI-1000 Ljubljana, Slovenia
| | - Irena Drevenšek-Olenik
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, SI-1000 Ljubljana, Slovenia
- Department of Complex Matter, J. Stefan Institute, Jamova 39, SI-1000 Ljubljana, Slovenia
| | - Matija Jezeršek
- Laboratory for Laser Techniques, Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, SI-1000 Ljubljana, Slovenia
| | - Mitjan Kalin
- Laboratory for Tribology and Interface Nanotechnology, Faculty of Mechanical Engineering, University of Ljubljana, Bogišićeva 8, SI-1000 Ljubljana, Slovenia
| | - Mikhail Shamonin
- East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule (OTH) Regensburg, Seybothstr. 2, 93053 Regensburg, Germany
- Correspondence: (R.K.); (M.S.)
| |
Collapse
|
4
|
Lovšin M, Brandl D, Glavan G, Belyaeva IA, Cmok L, Čoga L, Kalin M, Shamonin M, Drevenšek-Olenik I. Reconfigurable Surface Micropatterns Based on the Magnetic Field-Induced Shape Memory Effect in Magnetoactive Elastomers. Polymers (Basel) 2021; 13:polym13244422. [PMID: 34960973 PMCID: PMC8708412 DOI: 10.3390/polym13244422] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Revised: 12/10/2021] [Accepted: 12/14/2021] [Indexed: 11/20/2022] Open
Abstract
A surface relief grating with a period of 30 µm is embossed onto the surface of magnetoactive elastomer (MAE) samples in the presence of a moderate magnetic field of about 180 mT. The grating, which is represented as a set of parallel stripes with two different amplitude reflectivity coefficients, is detected via diffraction of a laser beam in the reflection configuration. Due to the magnetic-field-induced plasticity effect, the grating persists on the MAE surface for at least 90 h if the magnetic field remains present. When the magnetic field is removed, the diffraction efficiency vanishes in a few minutes. The described effect is much more pronounced in MAE samples with larger content of iron filler (80 wt%) than in the samples with lower content of iron filler (70 wt%). A simple theoretical model is proposed to describe the observed dependence of the diffraction efficiency on the applied magnetic field. Possible applications of MAEs as magnetically reconfigurable diffractive optical elements are discussed. It is proposed that the described experimental method can be used as a convenient tool for investigations of the dynamics of magnetically induced plasticity of MAEs on the micrometer scale.
Collapse
Affiliation(s)
- Matija Lovšin
- Department of Complex Matter, J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; (M.L.); (L.C.)
| | - Dominik Brandl
- East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule (OTH) Regensburg, Seybothstr. 2, 93053 Regensburg, Germany; (D.B.); (G.G.); (I.A.B.); (M.S.)
| | - Gašper Glavan
- East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule (OTH) Regensburg, Seybothstr. 2, 93053 Regensburg, Germany; (D.B.); (G.G.); (I.A.B.); (M.S.)
| | - Inna A. Belyaeva
- East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule (OTH) Regensburg, Seybothstr. 2, 93053 Regensburg, Germany; (D.B.); (G.G.); (I.A.B.); (M.S.)
| | - Luka Cmok
- Department of Complex Matter, J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; (M.L.); (L.C.)
| | - Lucija Čoga
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia; (L.Č.); (M.K.)
| | - Mitjan Kalin
- Faculty of Mechanical Engineering, University of Ljubljana, Aškerčeva 6, 1000 Ljubljana, Slovenia; (L.Č.); (M.K.)
| | - Mikhail Shamonin
- East Bavarian Centre for Intelligent Materials (EBACIM), Ostbayerische Technische Hochschule (OTH) Regensburg, Seybothstr. 2, 93053 Regensburg, Germany; (D.B.); (G.G.); (I.A.B.); (M.S.)
| | - Irena Drevenšek-Olenik
- Department of Complex Matter, J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia; (M.L.); (L.C.)
- Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana, Slovenia
- Correspondence:
| |
Collapse
|