Microemulsion Synthesis of Iron Core/Iron Oxide Shell Magnetic Nanoparticles and Their Physicochemical Properties

Abstract

Iron magnetic nanoparticles were synthesized under an inert atmosphere via the reaction between FeCl3 and NaBH4 in droplets of water in a microemulsion consisting of octane with cetyl trimethylammonium bromide and butanol as surfactants. A thin Fe3O4 layer was produced on the iron nanoparticles using slow, controlled oxidation at room temperature. A silica shell was deposited on the Fe3O4 using 3-aminopropyltrimethoxysilane following the method of Zhang et al. [Mater. Sci. Eng. C 30 (2010) 92–97]. The structure and chemistry of the resulting nanoparticles were studied using variety of methods and their magnetic properties were determined. The diameter of the iron core was typically 8–16 nm, while the thickness of the Fe3O4 shell was 2–3 nm. The presence of the silica layer was confirmed using Fourier transform infra-red spectroscopy and the number of NH2-groups on each nanoparticle was determined based on colorimetric tests using ortho-phthalaldehyde.

Magnetic nanoparticles with high specific absorption rate of electromagnetic energy at low field strength for hyperthermia therapy

“…8 A key characteristic of MNPs used for clinical hyperthermia is a high specific absorption rate (SAR), which depends on the MNPs' size, shape, composition, magnetic interaction, and concentration, as well as the applied magnetic field frequency and strength. [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] There are a number of types of MNPs available for hyperthermia therapy. [12][13][14]17,28,29 However, most existing MNPs require a high frequency or high AMF strength to deliver an adequate thermal dose to the tumor.…”

Magnetic Iron Oxide Nanoparticles: Synthesis, Characterization and Functionalization for Biomedical Applications in the Central Nervous System

“…The selected literature was classified into four main groups:Methods of synthesis of IONPs [13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56]Characterization of IONPs [57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,…”

“…Methods of synthesis of IONPs [13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56]…”

“…The microemulsion is a thermodynamically stable dispersion of two immiscible liquids in the presence of a surfactant, which forms a monolayer at the interface between oil and water, possibly exhibiting an ultralow interfacial tension [27]. In microemulsion, IONPs are typically synthetized by intramicellar nucleation and growth, following the standard procedure exemplified in Figure 3 [28]. The physicochemical properties of NPs prepared by such a technique essentially depend upon the choice of the surfactant.…”

Magnetic‐Nanoparticle‐Based Immunoassays‐on‐Chip: Materials Synthesis, Surface Functionalization, and Cancer Cell Screening

“…Naked metallic nanoparticles are chemically active and easily oxidized in air, which results in loss of magnetism and dispersibility . For example, it was shown that 8–16 nm Fe/Fe oxide core–shell particles show extraordinary saturation magnetization compared to other MNPs, but oxidize rapidly in water and especially in saline solution . Nanoparticles of Co or Co ferrites could be a good alternative to iron MNPs since they show better chemical stability in aquatic solutions.…”