scholarly journals The effect of magnetic particles covering the droplets on the heating rate of Pickering emulsions in the AC magnetic field

2020 ◽  
Vol 320 ◽  
pp. 114388 ◽  
Author(s):  
Rafał Bielas ◽  
Tomasz Hornowski ◽  
Katarína Paulovičová ◽  
Michal Rajňák ◽  
Arkadiusz Józefczak
Keyword(s):  
Magnetic Field ◽  
Heating Rate ◽  
Magnetic Particles ◽  
Pickering Emulsions ◽  
Ac Magnetic Field

Effect of Diode-Laser and AC Magnetic Field of Bovine Serum Albumin Nanospheres Loaded with Phthalocyanine and Magnetic Particles

2011 ◽  
Vol 11 (4) ◽  
pp. 3604-3608 ◽  
Author(s):  
Andreza Ribeiro Simioni ◽  
Marcilene M. A. Rodrigues ◽  
Fernando L. Primo ◽  
Paulo C. Morais ◽  
Antonio Claudio Tedesco
Keyword(s):  
Magnetic Field ◽  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Diode Laser ◽  
Bovine Serum ◽  
Magnetic Particles ◽  
Ac Magnetic Field

scholarly journals Ultrasonic Studies of Emulsion Stability in the Presence of Magnetic Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
A. Józefczak ◽  
R. Wlazło
Keyword(s):  
Magnetic Field ◽  
Magnetic Nanoparticles ◽  
Acoustic Waves ◽  
Magnetic Particles ◽  
Emulsion Stability ◽  
High Energy ◽  
Pickering Emulsions ◽  
Ultrasound Waves ◽  
Acoustic Study ◽  
Magnetite Particles

Pickering emulsions are made of solid particle-stabilized droplets suspended in an immiscible continuous liquid phase. A magnetic emulsion can be obtained using magnetic particles. Solid magnetic nanoparticles are adsorbed strongly at the oil-water interface and are able to stabilize emulsions of oil and water. In this work emulsions stabilized by magnetite nanoparticles were obtained using high-energy ultrasound waves and a cavitation mechanism and, next, their stability in time was tested by means of acoustic waves with a low energy, without affecting the structure. An acoustic study showed high stability in time of magnetic emulsions stabilized by magnetite particles. The study also showed a strong influence of an external magnetic field, which can lead to changes of the emulsion properties. It is possible to control Pickering emulsion stability with the help of an external stimulus—a magnetic field.

HEATING RATE PREDICTION FOR INDUCTION WELDING MAGNETIC SUSCEPTORS

2021 ◽  
Author(s):  
ROMAIN G. MARTIN ◽  
CHRISTER JOHANSSON ◽  
JASON R. TAVARES ◽  
MARTINE DUBÉ
Keyword(s):  
Magnetic Field ◽  
Heating Rate ◽  
Surface Area ◽  
Magnetic Particles ◽  
Eddy Currents ◽  
Field Amplitude ◽  
Hysteresis Curve ◽  
Heating Rates ◽  
Electrically Conductive ◽  
Thermoplastic Matrix

Induction welding involves generating heat by applying an oscillating magnetic field, which produces eddy currents and Joule losses in an electrically-conductive material or hysteresis losses in a magnetic material. Most applications rely on eddy currents generation as composites are often made of electrically-conductive carbon fibres. However, in other applications, heat can be produced by a magnetic susceptor located at the weld interface of the parts to be joined. Composite films of magnetic particles dispersed in a thermoplastic matrix can serve as magnetic susceptors. Magnetic particles selection relies on various parameters that must be thoroughly defined beforehand. Firstly, the applied magnetic field amplitude and frequency is calculated, based on the generated current and the induction coil geometry. Secondly, the thermoplastic matrix is characterized, mainly with DSC measurements, to define its processing window. Finally, the magnetic properties of the particles are measured – for instance using a vibrating sample magnetometer (VSM) – to obtain the hysteresis curve for the applied field. The enclosed surface area of the hysteresis curve (i.e. absorbed energy density) is critical, as low hysteresis materials (i.e. soft magnets) will not dissipate enough heat, while high hysteresis materials (i.e. hard magnets) cannot be fully exploited as the saturation hysteresis is not reached within the used field amplitude. A methodology to approximate the hysteresis enclosed surface area with limited data is proposed, helping to anticipate the heating rate of a susceptor candidate material. Based on these parameters, the theoretical heating rates of three magnetic susceptor materials (magnetic particles of iron, nickel and magnetite) for induction welding are calculated. They are verified experimentally by comparing with the hysteresis analysis and by measuring the temperature evolution of samples made of polypropylene containing the magnetic particles.

scholarly journals The Effect of Particle Shell on Cooling Rates in Oil-in-Oil Magnetic Pickering Emulsions

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4783
Author(s):  
Rafał Bielas ◽  
Arkadiusz Józefczak
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Magnetic Particles ◽  
Surrounding Medium ◽  
Pickering Emulsions ◽  
Stable Particle ◽  
Heating And Cooling ◽  
Magnetic Heating ◽  
Potential Applications ◽  
The Magnetic Field

Pickering emulsions (particle-stabilized emulsions) are usually considered because of their unique properties compared to surfactant-stabilized emulsions including better stability against emulsion aging. However, the interesting feature of particle-stabilized emulsions could be revealed during their magnetic heating. When magnetic particles constitute a shell around droplets and the sample is placed in an alternating magnetic field, a temperature increase appears due to energy dissipation from magnetic relaxation and hysteresis within magnetic particles. We hypothesize that the solidity of the magnetic particle shell around droplets can influence the process of heat transfer from inside the droplet to the surrounding medium. In this way, particle-stabilized emulsions can be considered as materials with changeable heat transfer. We investigated macroscopically heating and cooling of oil-in-oil magnetic Pickering emulsions with merely packed particle layers and these with a stable particle shell. The change in stability of the shell was obtained here by using the coalescence of droplets under the electric field. The results from calorimetric measurements show that the presence of a stable particle shell caused a slower temperature decrease in samples, especially for lower intensities of the magnetic field. The retarded heat transfer from magnetic Pickering droplets can be utilized in further potential applications where delayed heat transfer is desirable.

Oil recovery method in ice conditions by means of magnetic field and finely dispersed magnetite

2020 ◽  
Vol 10 (5) ◽  
pp. 514-521
Author(s):  
Аlexander V. Salnikov ◽  
◽  
Аlexander А. Lyutoev ◽  
Mikhail A. Troshin ◽  
Arina V. Nikolaeva ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Oil Recovery ◽  
Magnetic Particles ◽  
Oil Spills ◽  
Solid Particles ◽  
Spherical Particles ◽  
Pickering Emulsions ◽  
Recovery Method ◽  
Oil Emulsion ◽  
Innovative Solution

The oil spill response using skimmer systems in the glacial seas continues to be relevant in world practice. A complex approach based on the combination of oil slick dispersion by solid fine magnetic particles and skimmer cleaning, the operative parts of which are equipped with metallic magnetized bristles, has been proposed as a promising and innovative solution. Application of finely dispersed magnetite – ferromagnetic spherical particles (iron oxides) as fine solid particles to create stable Pickering emulsions with formation of oil-ferromagnetic units is considered. Mathematical modeling has been performed to estimate the possibility of extraction of such oil-ferromagnetic units from water-oil emulsion under the influence of nonhomogeneous magnetic field created by magnetized steel bristles of skimmer operative parts. The results obtained confirmed the possibility of a practical application of the solution proposed by the authors to improve the efficiency of mechanical cleaning of oil spills in glacial seas.

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.

Effect of Magnetic Fields on the Resistance and Microstructure of Al-Cu Alloy during Solidification Processing

2011 ◽  
Vol 287-290 ◽  
pp. 2916-2920
Author(s):  
Chun Yan Ban ◽  
Peng Qian ◽  
Xu Zhang ◽  
Qi Xian Ba ◽  
Jian Zhong Cui
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Turning Points ◽  
Probe Method ◽  
Solidification Processing ◽  
Ac Magnetic Field ◽  
Dc Magnetic Field ◽  
Cu Alloy ◽  
The Difference ◽  
Good Agreement

The resistance of Al-21%Cu alloy under no magnetic field, DC magnetic field and AC magnetic field from liquid to solid was measured by a four-probe method. The difference of resistance versus temperature curves (R-T curves) was analyzed. It is found that the R-T curves of Al-21%Cu alloy are monotone decreasing and have two obvious turning points. Under DC magnetic field, the liquidus and solidus temperatures of the alloy both decrease, while under AC magnetic field, the liquidus and solidus temperatures both increase. There is a good agreement between the microstructure of quenching sample and R-T curves. The mechanism of the effect of magnetic fields was discussed.

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