Acoustic wave in a suspension of magnetic nanoparticle with sodium oleate coating

Abstract

The ultrasonic propagation in the water-based magnetic fluid with doubled layered surfactant shell was studied. The measurements were carried out both in the presence as well as in the absence of the external magnetic field. The thickness of the surfactant shell was evaluated by comparing the mean size of magnetic grain extracted from magnetization curve with the mean hydrodynamic diameter obtained from differential centrifugal sedimentation method. The thickness of surfactant shell was used to estimate volume fraction of the particle aggregates consisted of magnetite grain and surfactant layer. From the ultrasonic velocity measurements in the absence of the applied magnetic field, the adiabatic compressibility of the particle aggregates was determined. In the external magnetic field, the magnetic fluid studied in this article becomes acoustically anisotropic, i.e., velocity and attenuation of the ultrasonic wave depend on the angle between the wave vector and the direction of the magnetic field. The results of the ultrasonic measurements in the external magnetic field were compared with the hydrodynamic theory of Ovchinnikov and Sokolov (velocity) and with the internal chain dynamics model of Shliomis, Mond and Morozov (attenuation).

Study of Structural Changes of Water-Based Magnetic-Fluid by Acoustic Spectroscopy

“…The mean diameter of a magnetic nanoparticle (Fe 3 O 4 ) and its standard deviations equal to d m = 6.23 ± 0.07 nm and σ m = 2.72 ± 0.03 nm. The hydrodynamic size distribution of magnetic nanoparticles coated with oleate sodium in suspension was determined by differential centrifugal sedimentation and the mean hydrodynamic diameter and its standard deviation is d = 27.7 ± 0.3 nm and σ = 24.1 ± 0.3 nm [6]. The coupling constant for the sample studied is λ = 1.18.…”

“…The result of these interactions is new structures, which are dependent mainly on the value of applied magnetic field and type of magnetic fluid. The acoustic spectroscopy is very useful for the study of these structural changes in the external magnetic field and better information about types of structures can be obtained from the study of the anisotropy of acoustic attenuation [1][2][3][4][5][6][7].…”

N-Acetylcysteine-Loaded Magnetic Nanoparticles for Magnetic Resonance Imaging

“…The magnetization curve allows us to determine the magnetic core diameter (D MAG ) by fitting to the Langevin function as well [26]. Figure 4B displays the magnetization curves fitted by the Langevin function (red line) and corresponding magnetic core particle size distribution with mean D MAG .…”

The Effect of Sonication on Acoustic Properties of Biogenic Ferroparticle Suspension

“…Magnetisation measurements of the prepared magnetosome suspensions were carried out by Superconducting Quantum Interference Device (SQUID) Magnetometer of Quantum Design (Józefczak et al, 2014). The dependence of magnetisation on the magnetic field ( Fig.…”