Magnetic measurements on frozen ferrofluids as a method for estimating the magnetoviscous effect

Abstract

Magnetic measurements on frozen ferrofluids with and without significant structure formation in an applied magnetic field have been performed. The results of these investigations were compared with the magnetic field dependent rheological properties for two different kinds of ferrofluids. Magnetic experiments performed similarly to conventional field cooled-field warming magnetic tests show the contribution of magnetic domain blocking and structure reorganization to the rheology of ferrofluids. Our efforts have shown the possibility of giving an estimate of the magnetoviscous effect by considering the temperature dependence of the magnetization of a frozen sample.

Preparation and rheological studies of uncoated and PVA-coated magnetite nanofluid

“…Rheology is a major subject of investigating the flow and deformation of materials can be monitored by the application of a field, either magnetic or electric. Most studies have been focused on measurement of field-induced effects in FFs under shear flow [35][36][37], and shear stress versus shear rate [38][39][40]. Focusing on the change of fluid's viscous behavior due to the action of an appropriate magnetic field seems to be the most prominent effect and accounts as a challenging topic in FF research.…”

Thermal convection thresholds in a Oldroyd magnetic fluid

“…An important application of ferrofluids lies in the biomedicine area where the carrier liquid is blood [2][3][4][5][6] which is known to have also special rheological proprieties [7][8][9]. In addition, when a magnetic field is applied, the ferrofluid can exhibit additional rheological properties such as magneto-viscosity, adhesion properties, non-Newtonian behavior, among others [10][11][12][13][14][15][16][17][18][19][20]. Hence, a detailed study of viscoelastic magnetic fluids is quite important and in order.…”

Relaxation dynamics of the rheological properties of ferrofluids

“…Sample 1 (AP G513A) is a magnetite based fluid considered in [7,8] and sample 2 (V S1 − 017) is a cobalt based fluid characterized in [9]. In contrast to sample 1 the magnetic particles in sample 2 are large enough to form significant structures in the presence of a magnetic field.…”