Ferrofluids: Synthetic Strategies, Stabilization, Physicochemical Features, Characterization, and Applications

Abstract

Ferrofluids (FFs) or magnetic nanofluids are incredible smart materials consisting of ultrafine magnetic nanoparticles suspended in a liquid carrier medium, which exhibit both fluidity and magnetic controllability. Studies involving the dynamics and physicochemical properties of these magnetic nanofluids are an interdisciplinary area of research attracting researchers from different fields of science and technology. Herein, a comprehensive Review on the different aspects of FF research is presented. First, the synthesis and stabilization of various types of FFs are discussed followed by their physicochemical features such as polydispersity, magnetic behavior, dipolar interactions, formation of chainlike aggregates, and long‐range ordering. The Review also details the rheological and thermal properties, dynamic instabilities, phase behavior, and particle assemblies in FFs to form complex multipolar geometries, photonic nanostructures, labyrinth structures, thin films, and droplets. Many important characterization techniques for probing FF properties are also briefly discussed, and the numerous innovative applications and future prospects of FFs are outlined.

Side‐Viewing Endoscopic Raman Spectroscopy for Angle‐Resolved Analysis of Luminal Organs

“…The magnet rotor is magnetized along the radial direction of the tube (perpendicular to the axial direction of the rotor) and rotates as a result of dynamic switching of the electromagnetic fields created by the stator coils. A controlled amount of ferrofluid, a colloidal liquid comprised of ferromagnetic nanoparticles suspended in a carrier fluid, is applied to the rotor to serve as its bearing inside the stator tube. This fluid accumulates on both poles of the magnet rotor (Figure b) to achieve two important functions: 1) The fluid creates a magnetic pressure in the gap spacing between the rotor surface and the tube's inner walls, levitating the rotor against the walls to maintain its position on the tube's axis without requiring a complex mechanical means for radial alignment, and 2) the fluid behaves as a self‐sustained lubricant on the rotor to allow for its low‐friction rotation within the stator tube.…”

Pengukuran Sampel Magnetik Cair dengan Vibrating Sample Magnetometer (Vsm)

“…Secara umum ferrofluid didefinisikan sebagai suspensi koloid stabil dari nanopartikel magnetik yang tersebar dalam medium cair. Bahan ini mempunyai aplikasi yang luas mulai dari aplikasi sebagai pelumas pada sistem mekanis hingga aplikasi di bidang biomedis sebagai bahan pengontras MRI serta sebagai agen hipertermi [1] [2]. Berbagai aplikasi ini mengeksplor beberapa sifat ferrofluid terutama sifat mudah-alir dan mudah-kendali nya dengan memanfaatkan medan http://journal2.um.ac.id/index.php/jpse EISSN: 2541-2485 magnet luar [3].…”

Aggregation of superparamagnetic iron oxide nanoparticles in dilute aqueous dispersions: Effect of coating by double-hydrophilic block polyelectrolyte

“…A c c e p t e d M a n u s c r i p t 3 In this article, we compare the aggregation behavior of iron oxide SPION coated by a bilayer of oleate (oleate-SPION) and the SPION provided with an additional layer of cationic block polyelectrolyte poly[(3,5-bis(trimethylammoniummethyl)-4-hydroxystyrene iodide]-block-poly(ethylene oxide) [19,20] (QNPHOS-PEO/oleate-SPION) that were prepared by coassembly of QNPHOS-PEO with the negatively charged oleate-SPION. The nanoparticles and their aggregates are characterized on the lengthscales from 1 nm to tens of μm using transmission electron microscopy, atomic force microscopy and light scattering techniques including small-angle light scattering.…”

“…Superparamagnetic iron oxide nanoparticles (SPION) of magnetite (Fe 3 O 4 ) or maghemite (γ-Fe 2 O 3 ) [1][2][3] have been extensively studied in connection with their applications in technology as magnetic fluids [4] or in medicine as systems for magnetic hyperthermia therapy [5], targeted drug delivery systems [6,7] or as contrast agents for magnetic resonance imaging [6,7]. In these applications, it is essential to obtain stable aqueous dispersions of SPION.…”