Dynamic moduli of magneto-sensitive elastomers: a coarse-grained network model

Ivaneyko, Dmytro; Toshchevikov, Vladimir; Saphiannikova, Marina

doi:10.1039/c5sm01761k

Cited by 46 publications

(35 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Then, as m is slowly increased, this symmetry is broken and E zz (m) decreases, whereas E xx (m) and E yy (m) increase identically, as expected by the unbroken x ↔ y symmetry. Moreover, all moduli show to lowest order in m a quadratic behavior, as demanded by the necessary m → −m symmetry [59], see Fig. 7 (c).…”

Section: A Static Modulimentioning

confidence: 83%

Dynamic elastic moduli in magnetic gels: Normal modes and linear response

Pessot

Löwen

Menzel

2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

In the perspective of developing smart hybrid materials with customized features, ferrogels and magnetorheological elastomers allow a synergy of elasticity and magnetism. The interplay between elastic and magnetic properties gives rise to a unique reversible control of the material behavior by applying an external magnetic field. Albeit few works have been performed on the time-dependent properties so far, understanding the dynamic behavior is the key to model many practical situations, e.g., applications as vibration absorbers. Here we present a way to calculate the frequency-dependent elastic moduli based on the decomposition of the linear response to an external stress in normal modes. We use a minimal three-dimensional dipole-spring model to theoretically describe the magnetic and elastic interactions on the mesoscopic level. Specifically, the magnetic particles carry permanent magnetic dipole moments and are spatially arranged in a prescribed way, before they are linked by elastic springs. An external magnetic field aligns the magnetic moments. On the one hand, we study regular lattice-like particle arrangements to compare with previous results in the literature. On the other hand, we calculate the dynamic elastic moduli for irregular, more realistic particle distributions. Our approach measures the tunability of the linear dynamic response as a function of the particle arrangement, the system orientation with respect to the external magnetic field, as well as the magnitude of the magnetic interaction between the particles. The strength of the present approach is that it explicitly connects the relaxational modes of the system with the rheological properties as well as with the internal rearrangement of the particles in the sample, providing new insight into the dynamics of these remarkable materials.

show abstract

Section: A Static Modulimentioning

confidence: 83%

Dynamic elastic moduli in magnetic gels: Normal modes and linear response

Pessot

Löwen

Menzel

2016

The Journal of Chemical Physics

View full text Add to dashboard Cite

show abstract

“…Starting on the microscale, at most a few individual polymer chains are resolved by coarsegrained bead-spring models [17][18][19]. In still more reduced mesoscopic dipole-spring models, the elasticity of the matrix is directly represented by effective spring-like interactions between the particles, combined with long-ranged magnetic dipolar interactions between them [20][21][22][23][24]. More explicit approaches treat the matrix directly by continuum elasticity theory, yet at the price of reduced accessible overall particle numbers [25][26][27][28].…”

Section: Introductionmentioning

confidence: 99%

Driving self-assembly and emergent dynamics in colloidal suspensions by time-dependent magnetic fields

2013

View full text Add to dashboard Cite

In this review we discuss recent research on driving self-assembly of magnetic particle suspensions subjected to alternating magnetic fields. The variety of structures and effects that can be induced in such systems is remarkably broad due to the large number of variables involved. The alternating field can be uniaxial, biaxial or triaxial, the particles can be spherical or anisometric, and the suspension can be dispersed throughout a volume or confined to a soft interface. In the simplest case the field drives the static or quasistatic assembly of unusual particle structures, such as sheets, networks and open-cell foams. More complex, emergent collective behaviors evolve in systems that can follow the time-dependent field vector. In these cases energy is continuously injected into the system and striking flow patterns and structures can arise. In fluid volumes these include the formation of advection and vortex lattices. At air-liquid and liquid-liquid interfaces striking dynamic particle assemblies emerge due to the particle-mediated coupling of the applied field to surface excitations. These out-of-equilibrium interface assemblies exhibit a number of remarkable phenomena, including self-propulsion and surface mixing. In addition to discussing various methods of driven self-assembly in magnetic suspensions, some of the remarkable properties of these novel materials are described.

show abstract

“…III is exact concerning the treatment of the elastic polymer matrix. In previous approaches, simplified spring-like interactions had been introduced to model the matrix elasticity [18,27,42,44,48,50,[68][69][70][71]. We now argue that in the present highly symmetric and simplified set-up the reduction to effective harmonic spring-like interactions is exact within the framework of linear elasticity theory.…”

Section: Mapping Onto Reduced Dipole-spring Modelsmentioning

confidence: 71%

Reversible magnetomechanical collapse: virtual touching and detachment of rigid inclusions in a soft elastic matrix

et al. 2018

View full text Add to dashboard Cite

Soft elastic composite materials containing particulate rigid inclusions in a soft elastic matrix are candidates for developing soft actuators or tunable damping devices. The possibility to reversibly drive the rigid inclusions within such a composite together to a close-to-touching state by an external stimulus would offer important benefits. Then, a significant tuning of the mechanical properties could be achieved due to the resulting mechanical hardening. For a long time, it has been argued whether a virtual touching of the embedded magnetic particles with subsequent detachment can actually be observed in real materials, and if so, whether the process is reversible. Here, we present experimental results that demonstrate this phenomenon in reality. Our system consists of two paramagnetic nickel particles embedded at finite initial distance in a soft elastic polymeric gel matrix. Magnetization in an external magnetic field tunes the magnetic attraction between the particles and drives the process. We quantify our experimental results by different theoretical tools, i.e., explicit analytical calculations in the framework of linear elasticity theory, a projection onto simplified dipole-spring models, as well as detailed finite-element simulations. From these different approaches, we conclude that in our case the cycle of virtual touching and detachment shows hysteretic behavior due to the mutual magnetization between the paramagnetic particles. Our results are important for the design and construction of reversibly tunable mechanical damping devices. Moreover, our projection on dipole-spring models allows the formal connection of our description to various related systems, e.g., magnetosome filaments in magnetotactic bacteria.

show abstract

Dynamic moduli of magneto-sensitive elastomers: a coarse-grained network model

Cited by 46 publications

References 57 publications

Dynamic elastic moduli in magnetic gels: Normal modes and linear response

Dynamic elastic moduli in magnetic gels: Normal modes and linear response

Driving self-assembly and emergent dynamics in colloidal suspensions by time-dependent magnetic fields

Reversible magnetomechanical collapse: virtual touching and detachment of rigid inclusions in a soft elastic matrix

Contact Info

Product

Resources

About