Investigation of the surface tension of water-based Fe3O4 magnetic fluids under magnetic field: The effect of surfactants

2021 ◽  
Vol 33 (12) ◽  
pp. 122013
Author(s):  
Qianqian Chen ◽  
Decai Li ◽  
Zhifan Yang ◽  
Zhengyan Xue ◽  
Jiangtao Hao ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Magnetic Fluids ◽  
Water Based

Ferrohydrodynamic Capillary Convection

2018 ◽  
Vol 11 (2) ◽  
Author(s):  
Francisco J. Arias ◽  
Salvador A. De Las Heras
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Concentration Gradient ◽  
Deductive Reasoning ◽  
Marangoni Convection ◽  
Marangoni Effect ◽  
Magnetic Fluids ◽  
Homogeneous Magnetic Field ◽  
Gradient Field ◽  
Two Fluids

Abstract In this work, consideration is given to capillary convection on ferrofluids from the concentration gradient induced when a nonhomogeneous magnetic field is applied. It is known that mass transfer along an interface between two fluids can appear due to a gradient of the surface tension in the so-called Marangoni effect (or Gibbs–Marangoni effect). Because the surface tension is both thermal and concentration dependent, Marangoni convection can be induced by either a thermal or a concentration gradient, where in the former case, it is generally referred as thermocapillary convection. Now, it has been theoretically and experimentally demonstrated that a ferrofluid under the action of a non-homogeneous magnetic field can induce a concentration gradient of suspended magnetic nanoparticles, and also the effect of Fe3O4 nanoparticles on the surface tension has been measured. Therefore, by deductive reasoning and taking into account the above mentioned facts, it is permissible to infer ferrohydrodynamic capillary convection on magnetic fluids under the presence of a magnetic gradient field. Utilizing a simplified physical model, the phenomenon was investigated and it was found that ferrohydrodynamic-Marangoni convection could be induced with particle size in the range up to 10 nm, which is the range of magnetic fluids to escape magnetic agglomeration.

Investigation on Magnetoviscous Effects of Water-Based Magnetic Fluid

2018 ◽  
Vol 281 ◽  
pp. 906-911
Author(s):  
Zhi Li Zhang ◽  
Nan Nan Di ◽  
Le Bai ◽  
Yang Yang ◽  
De Cai Li
Keyword(s):  
Magnetic Field ◽  
Magnetic Fluid ◽  
Magnetic Fluids ◽  
Magnetic Nanomaterials ◽  
Precipitation Method ◽  
Two Phase ◽  
Field Function ◽  
Carrier Liquid ◽  
Water Based ◽  
Co Precipitation

Magnetic fluid or called ferro-fluid is such kind of magnetic nanomaterials, which is stable of solid-liquid two phase colloidal solution composited by magnetic nanoparticles coated by surfactant and highly disperse in a carrier liquid. The basis of magnetic fluid widely applied mainly is due to their unique magnetic properties and rheological properties, which enable its action as intelligent control materials in the magnetic field so as to achieve the goal of magnetic liquid dynamic seal, magnetic damping vibration and so on. In our recent research, the water-based magnetic fluid was synthesized using a co-precipitation method and its magnetorheological properties were studied. During the process, the magnetorheological properties of stable water-based magnetic fluids were determined by magnetic rheometer. The results show that the shear-thinning behavior of magnetic fluids was observed both in the absence and presence of magnetic field. However, there was a remarkable magnetoviscous effect with magnetic field function and the unexpected variation of shear stress was related to the chain aggregation. Furthermore, the constitutive equation of water-based magnetic fluid at a low magnetic field was discussed.

Water Electrolysis Process in Water-Based Magnetic Fluids Under Non-uniform Magnetic Field

2018 ◽  
Vol 2018 (0) ◽  
pp. OS12-5
Author(s):  
Yuhiro IWAMOTO ◽  
Kotaro CHIMURA ◽  
Hitoshi MIYAO ◽  
Yasushi IDO ◽  
Shigeru TAKAGI
Keyword(s):  
Magnetic Field ◽  
Uniform Magnetic Field ◽  
Water Electrolysis ◽  
Magnetic Fluids ◽  
Electrolysis Process ◽  
Water Based

Separation and Recycling Non-Magnetic Metals from the Shredded Automobiles Scrap with Magnetic Fluids

2011 ◽  
Vol 233-235 ◽  
pp. 470-475
Author(s):  
Hui Ping Shao ◽  
Tao Lin ◽  
Ji Luo ◽  
Zhi Meng Guo
Keyword(s):  
Magnetic Field ◽  
Software Package ◽  
Magnetic Fluids ◽  
Analysis Software ◽  
Element Analysis ◽  
Field System ◽  
Water Based ◽  
The Magnetic Field ◽  
Nonmagnetic Metals ◽  
Chemical Coprecipitation Method

It is important to separate the nonmagnetic metals from shredded automobiles scraps efficiently. The research relates in general to the separation of non-magnetic metals automatically on the basis of the different density of the magnetic fluids in a magnetic field. A water-based magnetic fluid was prepared with a chemical coprecipitation method by using ultrasonic in dispersing process. The magnetic field system was design and simulated by a finite element analysis software package, ANSYS 8.1. Separation tests were performed on the mixtures of aluminum, zinc, copper and lead with various scrap size and shape using the water-based magnetic fluids.

Strong Magnetic Field Effect on Surface Tension Associated with an Interfacial Magnetic Pressure

2012 ◽  
Vol 116 (33) ◽  
pp. 17676-17681 ◽  
Author(s):  
Z.H.I. Sun ◽  
X. Guo ◽  
M. Guo ◽  
C. Li ◽  
J. Vleugels ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Strong Magnetic Field ◽  
Field Effect ◽  
Magnetic Field Effect ◽  
Magnetic Pressure

scholarly journals Kelvin-Helmholtz discontinuity in two superposed viscous conducting fluids in a horizontal magnetic field

2008 ◽  
Vol 12 (3) ◽  
pp. 103-110 ◽  
Author(s):  
Aiyub Khan ◽  
Neha Sharma ◽  
P.K. Bhatia
Keyword(s):  
Magnetic Field ◽  
Surface Tension ◽  
Growth Rate ◽  
Unstable Mode ◽  
Two Dimensional ◽  
Horizontal Magnetic Field ◽  
Streaming Velocity ◽  
The Stability ◽  
Conducting Fluids ◽  
Streaming Motion

The Kelvin-Helmholtz discontinuity in two superposed viscous conducting fluids has been investigated in the taking account of effects of surface tension, when the whole system is immersed in a uniform horizontal magnetic field. The streaming motion is assumed to be two-dimensional. The stability analysis has been carried out for two highly viscous fluid of uniform densities. The dispersion relation has been derived and solved numerically. It is found that the effect of viscosity, porosity and surface tension have stabilizing influence on the growth rate of the unstable mode, while streaming velocity has a destabilizing influence on the system.

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