Magnetoviscosity of Micronic Suspensions

Abstract

Rheological measurements are carried out on aqueous magnetic suspensions (10% ⩽ Φv ⩽ 30%) submitted to a low magnetic field. The suspended particles are micronic latex spheres made of very small ((10 ÷ 100) Å) grains of iron oxyde embedded in a polystyrene matrix. The suspension exhibit a strong increase of the apparent viscosity which is measured by capillary flow experiments. The rheological behaviour is interpreted on the basis of a Bingham model with a yield stress due to the fibrinated structure induced by the magnetic field.

Kinetic growth of field-oriented chains in dipolar colloidal solutions

“…The kinetic properties of the irreversible aggregation of particles has been the subject of great interest over the last decade [1][2][3]. In particular, several experimental and theoretical studies, as well as computer simulations have been devoted to understanding the behavior of colloidal suspensions of dipolar particles, the so-called electrorheological and magnetorheological fluids [4][5][6][7][8][9][10][11]. After applying an external electric or magnetic field, these suspensions experience a dramatic change in their rheological properties-i.e., a notable increase in the viscositywhich renders them particularly interesting systems from a technological point of view.…”

Recent progress on the simulation technology of magnetic fluid

“…阀模式下, 磁性液体处于Poiseuille流动状态, 如 图3(a)所示 [13] , 重点关注剪切率与壁面剪应力τ w 或压 强梯度 P ∇ 的关系. Bossis等人 [44] 用理论和实验的手 段研究了圆管中Bingham流体的Poiseuille流动, 得到 了管道内的平均剪切率和τ w 的关系: [13] ; (b) 细观示意图 [36] Figure 3 (Color online) Schematic diagram of magnetic fluid under valve mode. (a) From macroscopic view [13] ; (b) from mesoscopic view [36] 4 w app w w…”

Hydrodynamics on Charged Superparamagnetic Microparticles in Water Suspension: Effects of Low-Confinement Conditions and Electrostatics Interactions

“…For example, electro-rheological fluids (Fraden et al (1989)), magnetic holes (non-magnetic particles in a ferrofluid) (Cernak et al (2004);Helgesen et al (1990;1988);Skjeltorp (1983)), and magneto-rheological fluids and magnetic particles (Bacri et al (1993); Bossis et al (1990);Cernak (1994);Cernak et al (1991);Fermigier & Gast (1992); Melle et al (2001);Promislow et al (1994)). These studies focus their efforts in calculating the kinetic exponent z obtaining different values ranging z ∼ 0.4 − 0.7.…”