scholarly journals Preparation of Magnetic Hybrid Microspheres with Well-Defined Yolk-Shell Structure

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Yuan Zhao ◽  
Tao Chen ◽  
Shaofa Sun ◽  
Long Zhao
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
External Magnetic Field ◽  
Magnetic Particles ◽  
Suspension Polymerization ◽  
Magnetic Microspheres ◽  
Vibrating Sample Magnetometry ◽  
Efficient Route ◽  
Magnetic Bioseparation ◽  
Tga Analysis

A facile and efficient route was reported to prepare a kind of yolk-shell magnetic hybrid microspheres by suspension polymerization and calcinations method. The morphology, structure, and composition of the magnetic microspheres were characterized by FTIR, XRD, TEM, SEM, and TGA analysis. The vibrating-sample magnetometry (VSM) results clearly showed that the magnetic particles were superparamagnetic with saturation magnetization of 32.82 emu/g which makes the microcomposites easily controlled by an external magnetic field. The results revealed that the magnetic hybrid microspheres might have important applications in magnetic bioseparation and drug delivery.

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.

scholarly journals Magnetic micropump embedded in contact lens for on-demand drug delivery

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Cong Wang ◽  
Jungyul Park
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
External Magnetic Field ◽  
Drug Release ◽  
Contact Lens ◽  
Tear Film ◽  
Check Valve ◽  
Drug Diffusion ◽  
On Demand ◽  
The Magnetic Field

AbstractIn this paper, we report a thin magnetic micropump embedded in contact lens, which is capable of on-demand one-directional drug delivery. The proposed micropump can be actuated by the external magnetic field whenever needed without the need of battery. A micro check valve was integrated with the micropump for one-directional drug delivery from the micropump to the post-lens tear film. With actuation of the external magnetic field, the micro check valve is opened, and on-demand drug release can be realized. On the contrary, without an external magnetic field, the micro check valve is closed, and the undesired drug diffusion can be prevented. Through the control of the strength and the frequency of the magnetic field pulse, on-demand drug release and controlled dose can be realized.

scholarly journals Biomagnetic Recovery and Bioaccumulation of Selenium Granules in Magnetotactic Bacteria

2016 ◽  
Vol 82 (13) ◽  
pp. 3886-3891 ◽  
Author(s):  
Masayoshi Tanaka ◽  
William Knowles ◽  
Rosemary Brown ◽  
Nicole Hondow ◽  
Atsushi Arakaki ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Particles ◽  
Magnetotactic Bacteria ◽  
Selenium Nanoparticles ◽  
Water Remediation ◽  
Polluted Water ◽  
Contaminated Water ◽  
Elemental Selenium ◽  
Cell Recovery

ABSTRACTUsing microorganisms to remove waste and/or neutralize pollutants from contaminated water is attracting much attention due to the environmentally friendly nature of this methodology. However, cell recovery remains a bottleneck and a considerable challenge for the development of this process. Magnetotactic bacteria are a unique group of organisms that can be manipulated by an external magnetic field due to the presence of biogenic magnetite crystals formed within their cells. In this study, we demonstrated an account of accumulation and precipitation of amorphous elemental selenium nanoparticles within magnetotactic bacteria alongside and independent of magnetite crystal biomineralization when grown in a medium containing selenium oxyanion (SeO32−). Quantitative analysis shows that magnetotactic bacteria accumulate the largest amount of target molecules (Se) per cell compared with any other previously reported nonferrous metal/metalloid. For example, 2.4 and 174 times more Se is accumulated than Te taken up into cells and Cd2+adsorbed onto the cell surface, respectively. Crucially, the bacteria with high levels of Se accumulation were successfully recovered with an external magnetic field. The biomagnetic recovery and the effective accumulation of target elements demonstrate the potential for application in bioremediation of polluted water.IMPORTANCEThe development of a technique for effective environmental water remediation is urgently required across the globe. A biological remediation process of waste removal and/or neutralization of pollutant from contaminated water using microorganisms has great potential, but cell recovery remains a bottleneck. Magnetotactic bacteria synthesize magnetic particles within their cells, which can be recovered by a magnetic field. Herein, we report an example of accumulation and precipitation of amorphous elemental selenium nanoparticles within magnetotactic bacteria independent of magnetic particle synthesis. The cells were able to accumulate the largest amount of Se compared to other foreign elements. More importantly, the Se-accumulating bacteria were successfully recovered with an external magnetic field. We believe magnetotactic bacteria confer unique advantages of biomagnetic cell recovery and of Se accumulation, providing a new and effective methodology for bioremediation of polluted water.

Targeting Magnetic Nanoparticles in High Magnetic Fields for Drug Delivery Purposes

2004 ◽  
Vol 820 ◽  
Author(s):  
Ramazan Asmatulu ◽  
Richard.O. Claus ◽  
Judy S. Riffle ◽  
Michael Zalich
Keyword(s):  
Magnetic Field ◽  
Drug Delivery ◽  
Magnetic Nanoparticles ◽  
Magnetic Fields ◽  
Magnetic Particles ◽  
Guidance System ◽  
Test Results ◽  
Test Parameters ◽  
Magnetic Guidance ◽  
The Magnetic Field

AbstractBiodegradable magnetic nanoparticles were synthesized using Poly(L-Lactic Acid) and magnetite nanoparticles (∼14 nm) at different dosages, and then these nanaoparticles (nanocomposites) and pure magnetic particles were targeted in external magnetic fields by changing the test parameters. The magnetic field test results showed that magnetic saturation, fluid speed, magnetic field distance and particle size were extremely effective for a magnetic guidance system that is needed for an effective drug delivery approach. Thus, it is assumed that such nanoparticles can carry drugs (chemotherapy) to be able to cure cancer tumors as well as many other diseases.

Effect of Magnetic Field on the Distribution and Orientation of Magnetic Particles in Co-injection Moulding

2008 ◽  
Vol 24 (4) ◽  
pp. 227-237 ◽  
Author(s):  
E.O. Ogur ◽  
M.C. Davis ◽  
V. Goodship ◽  
G.F. Smith
Keyword(s):  
Magnetic Field ◽  
Image Analysis ◽  
External Magnetic Field ◽  
Injection Moulding ◽  
Magnetic Particles ◽  
Magnetic Field Gradient ◽  
Analysis Techniques ◽  
Drag Forces ◽  
Nickel Particles ◽  
Image Analysis Techniques

This paper presents a study of the effect of an external magnetic field on the distribution and orientation of magnetic particles in co-injection moulding. The orientation of the magnetic particles was determined using optical microscopy and image analysis techniques. The external magnetic field was placed in the tool cavity and used to magnetize the particles and to generate the necessary magnetic field gradient to manipulate them. The ferromagnetic nickel particles remained magnetic enough to overcome the strong drag forces imposed on them by the polymeric fluid matrix and to be orientated by the permanent magnet in the tool.

scholarly journals Experimental Investigation of Magnetic Particle Movement in Two-Phase Vertical Flow under an External Magnetic Field Using 2D LIF-PIV

2020 ◽  
Vol 10 (11) ◽  
pp. 3976
Author(s):  
Changje Lee ◽  
Yong-Seok Choi
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Magnetic Particles ◽  
Magnetic Particle ◽  
Two Phase Flow ◽  
Scattered Light ◽  
Laser Sheet ◽  
Phase Flow ◽  
Particle Movement ◽  
Two Phase

In this study, we experimentally investigated magnetic particle movement in two-phase flow under an external magnetic field. According to Faraday’s law, the alignment of a magnet is important for power generation. For high generation, it is important to understand how magnetic particles move in two-phase flow. The rotationality could be determined by observing a single particle; however, this is impossible due to the flow conditions. In this study, we estimated nonrotationality based on the vorticity. To eliminate scattered light and improve the signal-to-noise ratio, the laser-induced fluorescence particle image velocimetry technique was used. The solenoid nozzle has a hydraulic diameter of 3 mm. Its surface is covered with a coil with a diameter of 0.3 mm. The average diameter of a magnetic particle is 1.2 μm. The excitation and emission wavelengths are 532 and 612 nm, respectively. A thin laser sheet setup was configured. The laser sheet was illuminated on both sides to prevent shadows. The images were captured at 200 μm away from the wall and center of the nozzle. To estimate the decrease in vorticity, the theoretical and single-phase non-magnetic and magnetic particles are compared. The vorticity of magnetic particles is reduced by the external magnetic field.

Effect of the Concentration of the Magnetic Particles in the Ferrooil on its Dynamic’s Viscosity Changes in an External Magnetic Field

2015 ◽  
Vol 220-221 ◽  
pp. 324-327 ◽  
Author(s):  
Marcin Frycz ◽  
Wojciech Horak
Keyword(s):  
Magnetic Field ◽  
External Magnetic Field ◽  
Tribological Properties ◽  
Dynamic Viscosity ◽  
Magnetic Particles ◽  
Magnetic Polarity ◽  
Journal Bearings ◽  
Physical Conditions ◽  
Viscosity Changes

There is presented an effect of the changes of the concentration of magnetic particles included in the ferrooil on the dynamic viscosity in the presence of external magnetic field in this paper. The study was conducted in the context of temperature’s changes. In that way, the influence of external physical conditions of ferrooil’s employment was also taken into account. Ferrooil’s dynamic viscosity changes significantly alter the tribological properties and thus its usefulness as a lubricant of the sliding journal bearings. Due to the fact that the ferrooil demonstrates strong magnetic polarity in the presence of an external magnetic field, it is possible to control the viscosity by means of an external magnetic field just by changing the intensity as well as by changing of the concentration of magnetic particles.The paper presents, in the form of graphs, the changes of ferrooil’s dynamic viscosity as a function of temperature and concentration of magnetic particles. The results of research were also subjected to analysis.

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