Particles size distribution in diluted magnetic fluids

Dynamics of Magnetic Fluids in Crossed DC and AC Magnetic Fields

“…This conclusion agrees well with the data, which we obtained earlier in similar experiments [25] and in experiments on the diffusion and magnetophoresis of particles in magnetic fluids containing coarse particles [8,26]. The same results were reported [9] using the dynamic light scattering method. Sample No.…”

“…A comparison of the initial susceptibility of the base fluids (Table 1) with the Langevin susceptibility calculated by Equation (9) showed that the magneto dipole interactions led to an almost two-fold increase in the initial susceptibility. The magnetic properties of diluted samples directly used in the experiments are shown in Table 2.…”

“…Equation (2) The case using diluted solutions was of interest to the analysis because it can demonstrate the influence of particle polydispersity on the magnitude of the signal. The interparticle interactions and Nanomaterials 2019, 9,1711 3 of 17 demagnetization fields can be neglected and the magnetization curve is described by the superposition of the Langevin functions:…”

“…In Figure 6, the vertical dashed line is used to denote the maximum diameter xmax ≈ 20-25 nm of magnetite particles, which were still observable in an electron microscope in highly stable magnetic fluids and powders obtained by the chemical precipitation method [9,10,[29][30][31][32]. In real solutions, particles with magnetic cores of large diameter are absent, since the concentration of iron salts in Let us consider the problem of particle size distribution in magnetic fluids in more detail.…”

“…In this work, we consider the crossed-field method as the tool for obtaining information about the biggest particles contained in a ferrofluid. The coarse fraction leads to the formation of nanoscale (tens of nanometers [8][9][10]) and drop-like (microns and tens of microns [11][12][13][14]) aggregates, and fluid separation into weakly and strongly concentrated phases.…”