scholarly journals Effect of Mould Orientation on the Field-Dependent Properties of MR Elastomers under Shear Deformation

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3273
Author(s):  
Muntaz Hana Ahmad Khairi ◽  
Saiful Amri Mazlan ◽  
Ubaidillah ◽  
Nur Azmah Nordin ◽  
Siti Aishah Abdul Aziz ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Shear Deformation ◽  
Silicone Oil ◽  
Dynamic Properties ◽  
Industrial Applications ◽  
Shear Direction ◽  
Air Gaps ◽  
Field Dependent ◽  
Pass Through ◽  
Mr Effect

In this study, magnetorheological elastomer (MRE) was fabricated using an electromagnetic device with a new configuration mold at the orientation of 0°, 45° and 90°. This new curing concept enhanced the alignment of carbonyl iron particles (CIPs) within the silicone matrix in the presence of silicone oil (SO) during solidifying, by eliminating air gaps to prevent magnetic flux losses. Using a mold made of steel, which is a magnetic material, the mold functions as a guide for concentrated magnetic flux of 0.315 T to pass through the MRE sample. Scanning electron microscopy (SEM) was used to observe the surface morphology of the fabricated MRE samples particularly the alignment of the CIPs. The field-dependent dynamic properties of the MREs were measured using a rheometer. The analysis implied that the effectiveness of the MRE operating under shear deformation with this curing concept provided the highest magneto-induced modulus of 1.01 MPa when a 45° orientation mold is used, with relative magnetorheological (MR) effect value up to 918%, followed by 0° mold orientation with 0.79 MPa magneto-induced modulus and 646% relative MR effect. The high modulus properties offered by this MRE are believed to be potentially useful in industrial applications where a high range of stiffness is required particularly in the shear direction.

scholarly journals Enhancement of Particle Alignment Using Silicone Oil Plasticizer and Its Effects on the Field-Dependent Properties of Magnetorheological Elastomers

2019 ◽  
Vol 20 (17) ◽  
pp. 4085 ◽  
Author(s):  
Khairi ◽  
Fatah ◽  
Mazlan ◽  
Ubaidillah ◽  
Nordin ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Closed Loop ◽  
Silicone Oil ◽  
Dynamic Properties ◽  
Field Dependent ◽  
The Matrix ◽  
Industry Applications ◽  
Particle Alignment ◽  
Strain Sweep

The existing mold concept of fabricating magnetorheological elastomer (MRE) tends to encounter several flux issues due to magnetic flux losses inside the chamber. Therefore, this paper presents a new approach for enhancing particle alignment through MRE fabrication as a means to provide better rheological properties. A closed-loop mold, which is essentially a fully guided magnetic field inside the chamber, was designed in order to strengthen the magnetic flux during the curing process with the help of silicone oil (SO) plasticizers. The oil serves the purpose of softening the matrix. Scanning electron microscopy (SEM) was used to observe the surface morphology of the fabricated MRE samples. The field-dependent dynamic properties of the MREs were measured several ways using a rheometer, namely, strain sweep, frequency sweep, and magnetic field sweep. The analysis implied that the effectiveness of the MRE was associated with the use of the SO, and the closed-loop mold helped enhance the absolute modulus up to 0.8 MPa. The relative magnetorheological (MR) effects exhibited high values up to 646%. The high modulus properties offered by the MRE with SO are believed to be potentially useful in industry applications, particularly as vibration absorbers, which require a high range of stiffness.

scholarly journals Mechanical properties of bulk Sylgard 184 and its extension with silicone oil

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Moučka ◽  
M. Sedlačík ◽  
J. Osička ◽  
V. Pata
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Ambient Temperature ◽  
Oil Content ◽  
Silicone Oil ◽  
Polymer System ◽  
Industrial Applications ◽  
Curing Temperature ◽  
Rotational Rheometer ◽  
Oil Concentration

AbstractDue to its simple curing and very good mechanical properties, Sylgard 184 belongs to the most widely and frequently used silicones in many industrial applications such as microfluidics and microengineering. On top of that its mechanical properties are further controllable through the curing temperature, which may vary from ambient temperature up to 200 °C; the lower the curing temperature the lower the mechanical properties (Johnston et al. in J Micromech Microeng 24:7, 2014. 10.1088/0960-1317/24/3/035017). However, certain specialised application may require even a softer binder than the low curing temperature allows for. In this study we show that this softening can be achieved with the addition of silicone oil into the Sylgard 184 system. To this end a series of Sylgard 184 samples with varying silicone oil concentrations were prepared and tested (tensile test, rotational rheometer) in order to determine how curing temperature and silicone oil content affect mechanical properties. Curing reaction of the polymer system was found to observe 2nd order kinetics in all cases, regardless the oil concentration used. The results suggest that within the tested concentration range the silicone oil addition can be used to soften commercial silicone Sylgard 184.

scholarly journals High-Speed impact experiment for evaluation of magnetorheological fluid’s shock-absorption performance

2018 ◽  
Vol 183 ◽  
pp. 04008
Author(s):  
Yuya Mitani ◽  
Takahiro Yano ◽  
Takuyoh Hagi ◽  
Keiko Watanabe ◽  
Koji Fukudome
Keyword(s):  
Kinematic Viscosity ◽  
High Speed ◽  
Silicone Oil ◽  
Tap Water ◽  
Shock Absorption ◽  
Mr Fluid ◽  
High Speed Impact ◽  
Smart Fluids ◽  
Absorption Performance ◽  
Mr Effect

Magnetorheological (MR) fluids are categorized as smart fluids, which are made of small iron particles suspended in carrier fluids such as silicone oil. The presence of a magnetic field will instantaneously increase the viscosity of the MR fluid, also known as the MR effect. The application of the MR fluid as viscous dampers to automobiles and buildings has shown excellent performance in shock absorption. To expand the practical application of the MR fluid, various evaluations of shock-absorption performance under high-loading conditions are needed. Therefore, we decided to investigate its performance in high-speed impact conditions. Impact experiments were conducted in different liquids—tap water, two types of silicone oils with different kinematic viscosities, and an MR fluid—and it was investigated how the properties of each liquid affect the shock-absorption performance. Accordingly, it was found that kinematic viscosity and compressibility affect shock-absorption performance. The kinematic viscosity did not affect the speed attenuation of the projectile. Furthermore, it was found that the compressibility affected the pressure wave generated by the entry of a projectile into the liquid.

scholarly journals Evaluation of Parallel-Series Configurations of Two-Phase Partitioning Biotrickling Filtration and Biotrickling Filtration for Treating Styrene Gas-Phase Emissions

2020 ◽  
Vol 12 (17) ◽  
pp. 6740 ◽  
Author(s):  
Pau San-Valero ◽  
Javier Álvarez-Hornos ◽  
Pablo Ferrero ◽  
Josep M. Penya-Roja ◽  
Paula Marzal ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Silicone Oil ◽  
Sharp Decrease ◽  
Complete Removal ◽  
Industrial Applications ◽  
Biotrickling Filter ◽  
Gaseous Emissions ◽  
Two Phase ◽  
Phase Partitioning ◽  
In Series

The removal of styrene from industrial representative gaseous emissions was studied using two reactors connected in series: a two-phase partitioning biotrickling filter (TPPB-BTF) and a conventional biotrickling filter (BTF). The system was operated under industrial conditions, which included steady and transient conditions and intermittent spraying. Silicone oil was used in the TPPB-BTF with a quantity as low as 25 mL L−1, promoting a faster start-up compared to the BTF. By working at a styrene loading of 30 g m−3 h−1, nearly complete removal efficiency (RE) was obtained. In addition, the removal was not adversely impacted by using non-steady emission patterns such as overnight shutdowns (97% RE) and oscillating concentrations (95% RE), demonstrating its viability for industrial applications. After 2 months from inoculation, two additional configurations (reverse series BTF + TPPB-BTF and parallel) were tested, showing the series configuration as the best approach to consistently achieve RE > 95%. After 51 days of operation, high throughput sequencing revealed a sharp decrease in the bacterial diversity. In both reactors, the microorganisms belonging to the Comamonadaceae family were predominant and other styrene degraders such as Pseudomonadaceae proliferated preferably in the first reactor.

scholarly journals Material Characterization of Magnetorheological Elastomers with Corroded Carbonyl Iron Particles: Morphological Images and Field-dependent Viscoelastic Properties

2019 ◽  
Vol 20 (13) ◽  
pp. 3311 ◽  
Author(s):  
Siti Aishah Binti Abdul Aziz ◽  
Saiful Amri Mazlan ◽  
Nur Azmah Nordin ◽  
Nor Azlin Nazira Abd Rahman ◽  
U Ubaidillah ◽  
...  
Keyword(s):  
Carbonyl Iron ◽  
Matrix Material ◽  
Rheological Characteristics ◽  
Iron Particles ◽  
Ambient Conditions ◽  
X Ray ◽  
Field Dependent ◽  
Mr Effect

High temperatures and humidity could alter the field-dependent rheological properties of MR materials. These environmental phenomena may accelerate the deterioration processes that will affect the long-term rheological reliability of MR materials such as MR elastomer (MRE). This study therefore attempts to investigate the field-dependent rheological characteristics of MRE with corroded carbonyl iron particles (CIPs). The corroded CIPs were treated with hydrochloric acid (HCl) as a way of providing realistic environments in gauging the CIPs reaction towards the ambient conditions. The corroded CIPs along with silicone rubber as a matrix material were used in the fabrication of the MRE samples. To observe the effect of HCl treatment on the CIPs, the morphological observations of MREs with non-corroded and corroded CIPs were investigated via field emission scanning electron microscopy (FESEM), energy-dispersive x-ray spectroscopy (EDX) and x-ray diffractometer (XRD). In addition, the magnetic properties were examined through the vibrating sample magnetometer (VSM), while the field-dependent rheological characteristics such as the storage modulus of MRE with the corroded CIPs were also tested and compared with the non-corroded CIPs. The results showed that the corroded CIPs possessed hydrangea-like structures. In the meantime, it was identified that a sudden reduction of up to 114% of the field-dependent MR effect of MRE with the corroded CIPs was observed as a result of the weakened interfacial bonding between the CIPs and the silicon in the outer layers of the CIPs structure.

Vibration Analysis of Continuous Systems by Dynamic Discretization

1980 ◽  
Vol 102 (2) ◽  
pp. 391-398 ◽  
Author(s):  
B. Downs
Keyword(s):  
Power Series ◽  
Shear Deformation ◽  
Vibration Analysis ◽  
Dynamic Properties ◽  
Mass Matrix ◽  
Continuous System ◽  
Mode Shapes ◽  
Continuous Systems ◽  
Stress Distributions ◽  
Equivalent Mass

An equivalent mass matrix may be defined, for a segment of a continuous system, as one which retains precisely the dynamic properties of the original segment in discretized form. Dynamic Discretization, which makes use of a particular form of Stodola iteration, progressively generates the equivalent mass matrix in ascending powers of frequency squared, whilst simultaneously generating deformation functions in a similar power series. The method is quasi-static and readily copes with shear deformation, rotary inertia and quite complex segment geometry. Accurate vibration analysis in terms of frequencies, mode shapes and corresponding stress distributions is achieved using an extremely coarse system subdivision for a variety of geometries.

scholarly journals Glassy Carbon: A Promising Material for Micro- and Nanomanufacturing

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1857 ◽  
Author(s):  
Swati Sharma
Keyword(s):  
Glassy Carbon ◽  
Carbon Material ◽  
Large Scale ◽  
Solid Phase ◽  
Three Dimensional ◽  
Industrial Applications ◽  
Degradation Temperature ◽  
Pass Through ◽  
Semi Solid ◽  
Device Research

When certain polymers are heat-treated beyond their degradation temperature in the absence of oxygen, they pass through a semi-solid phase, followed by the loss of heteroatoms and the formation of a solid carbon material composed of a three-dimensional graphenic network, known as glassy (or glass-like) carbon. The thermochemical decomposition of polymers, or generally of any organic material, is defined as pyrolysis. Glassy carbon is used in various large-scale industrial applications and has proven its versatility in miniaturized devices. In this article, micro and nano-scale glassy carbon devices manufactured by (i) pyrolysis of specialized pre-patterned polymers and (ii) direct machining or etching of glassy carbon, with their respective applications, are reviewed. The prospects of the use of glassy carbon in the next-generation devices based on the material’s history and development, distinct features compared to other elemental carbon forms, and some large-scale processes that paved the way to the state-of-the-art, are evaluated. Selected support techniques such as the methods used for surface modification, and major characterization tools are briefly discussed. Barring historical aspects, this review mainly covers the advances in glassy carbon device research from the last five years (2013–2018). The goal is to provide a common platform to carbon material scientists, micro/nanomanufacturing experts, and microsystem engineers to stimulate glassy carbon device research.

Electroviscoelastic Properties in ER Gel of Disperse System under DC Electric Field

2002 ◽  
Vol 16 (17n18) ◽  
pp. 2433-2439 ◽  
Author(s):  
R. HANAOKA ◽  
S. TAKATA ◽  
H. FUJITA ◽  
T. FUKAMI ◽  
K. SAKURAI ◽  
...  
Keyword(s):  
Field Strength ◽  
Electric Field ◽  
Disperse System ◽  
Fine Particles ◽  
Silicone Oil ◽  
Dynamic Properties ◽  
Low Frequencies ◽  
Hydrosilylation Reaction ◽  
Microscopical Method ◽  
Dc Electric Field

The silicone oil-based electrorheological (ER) gel containing the non-aqueous fine particles was newly created in the present study. After these particles were dispersed at 30wt.% in the dimethylsilicone oil, the ER gel was produced by the hydrosilylation reaction in the mixture of the modified silicone oil. The reaction could considerably be promoted by heating at 90°C. The behavior of particles in the ER gel was observed by a microscopical method. When an electric field was applied to the ER gel, the gap between the electrodes was bridged by the chains of particles arranged in the direction of the electric field. The dynamic properties of the ER gel were also examined under the applied dc electric field up to 2kV/mm using the oscillating rheometer with the low frequencies of 1Hz or less. Consequently, it is shown that the electroviscoelastic effect of the gel can be controlled by the electric field strength.

Shear Deformation and Texture Evolution in Al Alloys Processed for One Pass by ECAP

2008 ◽  
Vol 584-586 ◽  
pp. 679-684 ◽  
Author(s):  
Marco J. Starink ◽  
Shun Cai Wang ◽  
Xiao Guang Qiao ◽  
Nong Gao ◽  
Hans Jørgen Roven ◽  
...  
Keyword(s):  
Shear Deformation ◽  
Texture Evolution ◽  
Shear Plane ◽  
Al Alloys ◽  
Coarse Grained ◽  
Al Alloy ◽  
Shear Direction ◽  
Crystallographic Slip ◽  
Slip Planes ◽  
Low Strength

The evolution of texture and deformation in the grains during one pass of equal-channel angular pressing (ECAP) was examined for fine grained high strength and low strength Al alloys and a coarse grained low strength Al alloy. The materials were analysed using electron back-scatter diffraction (EBSD). The results are consistent with the materials responding to the intense macroscopic shear stress by deformation of individual grains through movement of dislocations on one or more of the slip crystallographic slip planes {hkl} that are favourably oriented, combined with the rotation of grains to directions that bring main crystallographic slip planes parallel to the macroscopic shear direction and crystallographic slip directions <uvw> parallel to two main shear directions. Contrary to reports claiming up to 4 slip systems are activated, it was observed that only the {111}<110> and {001}<110> shear systems are activated. Macroscopic shear deformation occurs on two shear planes: the main shear plane (MSP), equivalent to the simple shear plane, and a secondary shear plane which is perpendicular to the MSP.

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