scholarly journals Mechanical properties of magnetic gels containing rod-like composite particles

2019 ◽  
Vol 377 (2143) ◽  
pp. 20180218 ◽  
Author(s):  
Mariem M. Abrougui ◽  
Modesto T. Lopez-Lopez ◽  
Juan D. G. Duran
Keyword(s):  
Mechanical Properties ◽  
Magnetic Particles ◽  
Three Dimensional ◽  
Heterogeneous Systems ◽  
Soft Materials ◽  
Polymer Chains ◽  
Composite Particles ◽  
Magnetite Particles ◽  
Magneto Rheological ◽  
Mr Effect

Magnetic gels (ferrogels) are heterogeneous systems structured at the nanoscale that contains magnetic particles dispersed in three-dimensional networks of polymer chains. In the present work, the magnetic particles were synthesized with a core–shell structure, consisting of sepiolite particles covered by magnetite nanoparticles. These composite particles had a rod-like shape with a high aspect ratio. The obtained sepiolite–magnetite particles showed a high enough susceptibility and saturation magnetization. The magneto-rheological (MR) properties, and the intensity of the MR effect, of aqueous suspensions of the synthesized particles were studied. The particles, functionalized by adsorption of alginate molecules, were imbedded in alginate hydrogels to get homogeneous soft materials. The particles were linked to the polymer chains as the knots in a network and dominated in a great extent the mechanical properties of the materials. After determining the optimal compositions of the ferrogels, their viscoelastic properties were measured in the absence/presence of magnetic fields. The results pointed out that the MR effect provided by the clay–magnetite particles was considerably more intense than those achieved in ferrogels that contain spherical magnetic microparticles. Therefore, the imbedding of rod-shaped magnetic particles in hydrogels allows controlling the mechanical properties in a wider range than in conventional ferrogels. This article is part of the theme issue ‘Heterogeneous materials: metastable and non-ergodic internal structures’.

Study of the Performance of Practical Magneto-Rheological Elastomers

2012 ◽  
Vol 430-432 ◽  
pp. 1979-1983
Author(s):  
Wei Bang Feng ◽  
Xue Yang ◽  
Zhi Qiang Lv
Keyword(s):  
Magnetic Field ◽  
Mechanical Properties ◽  
Mechanical Property ◽  
Magnetic Properties ◽  
External Magnetic Field ◽  
Magnetic Particles ◽  
Poor Performance ◽  
Electrical And Magnetic Properties ◽  
Intelligent Material ◽  
Magneto Rheological

Magneto-rheological elastomer( MR elastomer) is an emerging intelligent material made up of macromolecule polymer and magnetic particles. While a promising wide application it has in the fields of warships vibration controlling for its controllable mechanical, electrical and magnetic properties by external magnetic field, design and application of devices based on it are facing great limitations imposed by its poor performance in mechanical properties and magneto effect. Aiming at developing a practical MR elastomer, a new confecting method was proposed in this paper. Then, following this new method and using a specificly designed solidifying matrix, an amido- polyester MR elastomer was developed with its mechanical property systemically explored.

Three-dimensional digital image correlation measurement of mechanical properties of soft materials

Meccanica ◽  
2014 ◽  
Vol 50 (2) ◽  
pp. 419-428 ◽  
Author(s):  
Wei-Chung Wang ◽  
Yu-An Chiang ◽  
Ken-Jen Yu ◽  
Yi-Chieh Ho ◽  
Hung-Tsan Shen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Three Dimensional ◽  
Soft Materials ◽  
Correlation Measurement ◽  
Image Correlation

scholarly journals Anisotropic magnetic hydrogels: design, structure and mechanical properties

2019 ◽  
Vol 377 (2143) ◽  
pp. 20180217 ◽  
Author(s):  
Cristina Gila-Vilchez ◽  
Mari C. Mañas-Torres ◽  
Rafael Contreras-Montoya ◽  
Miguel Alaminos ◽  
Juan D. G. Duran ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Biomedical Applications ◽  
Magnetic Particles ◽  
Precursor Solution ◽  
Polymer Chains ◽  
Cross Linking ◽  
Theme Issue ◽  
Design Structure ◽  
Internal Structures ◽  
Intrinsic Feature

Anisotropy is an intrinsic feature of most of the human tissues (e.g. muscle, skin or cartilage). Because of this, there has been an intense effort in the search of methods for the induction of permanent anisotropy in hydrogels intended for biomedical applications. The dispersion of magnetic particles or beads in the hydrogel precursor solution prior to cross-linking, in combination with applied magnetic fields, which gives rise to columnar structures, is one of the most recently proposed approaches for this goal. We have gone even further and, in this paper, we show that it is possible to use magnetic particles as actuators for the alignment of the polymer chains in order to obtain anisotropic hydrogels. Furthermore, we characterize the microstructural arrangement and mechanical properties of the resulting hydrogels. This article is part of a theme issue ‘Heterogeneous materials: metastable and non-ergodic internal structures’.

scholarly journals Polarized X-ray scattering measures molecular orientation in polymer-grafted nanoparticles

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Subhrangsu Mukherjee ◽  
Jason K. Streit ◽  
Eliot Gann ◽  
Kumar Saurabh ◽  
Daniel F. Sunday ◽  
...  
Keyword(s):  
Heterogeneous Systems ◽  
Soft Materials ◽  
Polymer Chains ◽  
Structural Motif ◽  
Density Region ◽  
Chain Orientation ◽  
X Ray ◽  
X Ray Scattering ◽  
Grafted Nanoparticles ◽  
Ray Scattering

AbstractPolymer chains are attached to nanoparticle surfaces for many purposes, including altering solubility, influencing aggregation, dispersion, and even tailoring immune responses in drug delivery. The most unique structural motif of polymer-grafted nanoparticles (PGNs) is the high-density region in the corona where polymer chains are stretched under significant confinement, but orientation of these chains has never been measured because conventional nanoscale-resolved measurements lack sensitivity to polymer orientation in amorphous regions. Here, we directly measure local chain orientation in polystyrene grafted gold nanoparticles using polarized resonant soft X-ray scattering (P-RSoXS). Using a computational scattering pattern simulation approach, we measure the thickness of the anisotropic region of the corona and extent of chain orientation within it. These results demonstrate the power of P-RSoXS to discover and quantify orientational aspects of structure in amorphous soft materials and provide a framework for applying this emerging technique to more complex, chemically heterogeneous systems in the future.

scholarly journals Development of a Spherical Model with a 3D Microchannel: An Application to Glaucoma Surgery

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 297
Author(s):  
Gallab ◽  
Omata ◽  
Harada ◽  
Mitsuishi ◽  
Sugimoto ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Three Dimensional ◽  
Spherical Model ◽  
Soft Materials ◽  
Glaucoma Surgery ◽  
Microfluidic Channels ◽  
Human Tissues ◽  
Surgical Simulator ◽  
Eye Model ◽  
Novice Surgeons

Three-dimensional (3D) microfluidic channels, which simulate human tissues such as blood vessels, are useful in surgical simulator models for evaluating surgical devices and training novice surgeons. However, animal models and current artificial models do not sufficiently mimic the anatomical and mechanical properties of human tissues. Therefore, we established a novel fabrication method to fabricate an eye model for use as a surgical simulator. For the glaucoma surgery task, the eye model consists of a sclera with a clear cornea; a 3D microchannel with a width of 200–500 µm, representing the Schlemm’s canal (SC); and a thin membrane with a thickness of 40–132 µm, representing the trabecular meshwork (TM). The sclera model with a clear cornea and SC was fabricated by 3D molding. Blow molding was used to fabricate the TM to cover the inner surface of the sclera part. Soft materials with controllable mechanical behaviors were used to fabricate the sclera and TM parts to mimic the mechanical properties of human tissues. Additionally, to simulate the surgery with constraints similar to those in a real operation, the eye model was installed on a skull platform. Therefore, in this paper, we propose an integration method for fabricating an eye model that has a 3D microchannel representing the SC and a membrane representing the TM, to develop a glaucoma model for training novice surgeons.

scholarly journals Laser reprogramming magnetic anisotropy in soft composites for reconfigurable 3D shaping

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Heng Deng ◽  
Kianoosh Sattari ◽  
Yunchao Xie ◽  
Ping Liao ◽  
Zheng Yan ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Phase Change ◽  
Composite Film ◽  
Magnetic Particles ◽  
Three Dimensional ◽  
Soft Materials ◽  
Magnetic Composite ◽  
Laser Writing ◽  
Soft Robots ◽  
Direct Laser

AbstractResponsive soft materials capable of exhibiting various three-dimensional (3D) shapes under the same stimulus are desirable for promising applications including adaptive and reconfigurable soft robots. Here, we report a laser rewritable magnetic composite film, whose responsive shape-morphing behaviors induced by a magnetic field can be digitally and repeatedly reprogrammed by a facile method of direct laser writing. The composite film is made from an elastomer and magnetic particles encapsulated by a phase change polymer. Once the phase change polymer is temporarily melted by transient laser heating, the orientation of the magnetic particles can be re-aligned upon change of a programming magnetic field. By the digital laser writing on selective areas, magnetic anisotropies can be encoded in the composite film and then reprogrammed by repeating the same procedure, thus leading to multimodal 3D shaping under the same actuation magnetic field. Furthermore, we demonstrated their functional applications in assembling multistate 3D structures driven by the magnetic force-induced buckling, fabricating multistate electrical switches for electronics, and constructing reconfigurable magnetic soft robots with locomotion modes of peristalsis, crawling, and rolling.

scholarly journals Enhanced mechanical properties of multiwalled carbon nanotubes/thermoplastic polyurethane nanocomposites

2019 ◽  
Vol 9 ◽  
pp. 184798041984085 ◽  
Author(s):  
P Kalakonda ◽  
S Banne ◽  
PB Kalakonda
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Composite Scaffold ◽  
Thermoplastic Polyurethane ◽  
Three Dimensional ◽  
Tensile Modulus ◽  
Polymer Nanocomposite ◽  
Polymer Chains ◽  
Multiwalled Carbon

Carbon nanotubes are considered to be ideal candidates for improving the mechanical properties of polymer nanocomposite scaffolds due to their higher surface area, mechanical properties of three-dimensional isotropic structure, and physical properties. In this study, we showed the improved mechanical properties prepared by backfilling of preformed hydrogels and aerogels of individually dispersed multiwalled carbon nanotubes (MWCNTs-Baytubes) and thermoplastic polyurethane. Here, we used the solution-based fabrication method to prepare the composite scaffold and observed an improvement in tensile modulus about 200-fold over that of pristine polymer at 19 wt% MWCNT loading. Further, we tested the thermal properties of composite scaffolds and observed that the nanotube networks suppress the mobility of polymer chains, the composite scaffold samples were thermally stable well above their decomposition temperatures that extend the mechanical integrity of a polymer well above its polymer melting point. The improved mechanical properties of the composite scaffold might be useful in smart material industry.

Biotemplated facile synthesis of three‐dimensional micro/nanoporous tin oxide: improving the flammable and mechanical properties of flexible PVC

2019 ◽  
Vol 14 (8) ◽  
pp. 828-830 ◽  
Author(s):  
Weihua Meng ◽  
Weihong Wu ◽  
Weiwei Zhang ◽  
Luyao Cheng ◽  
Yunhong Jiao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tin Oxide ◽  
Three Dimensional ◽  
Facile Synthesis

Analysis of magneto rheological elastomers for energy harvesting systems

2020 ◽  
Vol 64 (1-4) ◽  
pp. 439-446
Author(s):  
Gildas Diguet ◽  
Gael Sebald ◽  
Masami Nakano ◽  
Mickaël Lallart ◽  
Jean-Yves Cavaillé
Keyword(s):  
Magnetic Field ◽  
Energy Harvesting ◽  
Shear Strain ◽  
Magnetic Induction ◽  
Magnetic Particles ◽  
Homogeneous Magnetic Field ◽  
Electrical Signal ◽  
Harvesting Systems ◽  
Dc Bias ◽  
Magneto Rheological

Magneto Rheological Elastomers (MREs) are composite materials based on an elastomer filled by magnetic particles. Anisotropic MRE can be easily manufactured by curing the material under homogeneous magnetic field which creates column of particles. The magnetic and elastic properties are actually coupled making these MREs suitable for energy conversion. From these remarkable properties, an energy harvesting device is considered through the application of a DC bias magnetic induction on two MREs as a metal piece is applying an AC shear strain on them. Such strain therefore changes the permeabilities of the elastomers, hence generating an AC magnetic induction which can be converted into AC electrical signal with the help of a coil. The device is simulated with a Finite Element Method software to examine the effect of the MRE parameters, the DC bias magnetic induction and applied shear strain (amplitude and frequency) on the resulting electrical signal.

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