Table 1.
Summary of the most common techniques used for the production of MNPs
| Year | Production technique | Size | Characterization | Functionalization agent | Outcome |
|---|---|---|---|---|---|
| 201150 | Solvo-thermal method to synthesize nanohybrids (Ag cores and Fe3O4 shell) | NR | TEM: surface of Ag is coated by Fe3O4. XRD: confirms the formation of the hybrids. SEM: indicates roughness on the surface of the Ag. |
Ag core coated by Fe3O4 | The deposition of Fe3O4 increases the stability of Ag; improves its solubility |
| 201151 | Microwave irradiation (2.45 GHz) method | Stoichiometric WO3 with dispersed elongated sphere-like morphology with dimensions of 70–110 nm in length and 40–80 nm in width | XRD: sharp and strong peaks at the PEG-assistedsample. TEM: WO3–PEG consisted of well separated, elongated spheres composed of nanoparticles. |
WO3 coated by PEG | The results showed that the PEG-assisted samples had high sensitivity and good selectivity when compared to surfactant-free samples |
| 201152 | Coprecipitation method and calcined at 500°C and 800°C | 20.4 nm to 29.3 nm; depends on the temperature that the calcinations was taking place | XRD: samples calcined at 500°C; peaks are rather broad, while for the samples calcined at 800°C, much sharper peaks. TEM: particles are generally rounded in shape. |
NR | NR |
| 201153 | Spray gelation-based method | 811±162 nm to 94l±2 nm | DLS: particle size to be in the range of 811±162 nm to 94l±2 nm. SEM: spherical shapes with relatively smooth surfaces. |
Functionalized by PEG | Improve water dispersability and distribution of MNPs |
| 201154 | Thermal decomposition | 8 nm | FTIR confirms successful functionalization. TEM: γ-PGA-coated MnFe2O4 nanoparticles intend to randomly suspend in aqueous sol. |
γ-PGA | γ-PGA was used for the convenient phase transfer of MnFe2O4 nanoparticles dispersed in organic solvents into aqueous sol |
| 201155 | Solvo–thermal route | 60 nm | TEM: reveals that the magnetite nanoparticles have a nearly uniform size of about 60 nm and a spherical shape. | Coated with Au | Generate good biocompatibility, magnetic response, and optical properties |
| 201156 | The Ag–Fe3O4 bi-component nanoparticles were synthesized via a hydrothermal process | 40 nm | XRD: broad diffraction peaks. SEM: shape and the high yield of bracelet-like nanoring. TEM: particles are mainly bracelet-like nanorings, and most of these nanorings are enclosed by the other one. |
NR | NR |
| 201057 | Coprecipitation | 10–12 nm | TEM: Fe3O4/HA had uniform particle distribution. XRD: Fe3O4 MNPs were not changed after modification with HA. FTIR: successful modification of HA on the Fe3O4 surface. |
Fe3O4 MNPs coated by HA | (Fe3O4/HA) were highly efficient in decomposing H2O2 to produce large amounts of hydroxyl radicals |
| 201058 | Bacterial fermentation | 13.l±0.8 nm | TEM: extracellular magnetites exhibited good monodispersity | NR | NR |
| 200759 | Synthesis of iron oxide nanoparticles of narrow size distribution on polysaccharides | 30–35 nm | X-ray: iron oxide particles are not sufficiently crystalline in the absence of the template. SEM: uniform particles when chitosan template was employed. |
NR | NR |
| 200760 | 1 M of FeCl3 · 6H2O (>99%) was mixed with 2 M of FeCl2 · 4H2O (>99%) at the ratio of 2:1 | NR | TEM: well dispersed iron oxide image. FTIR: vibrational feature at 1,628 cm−1 is found and assigned to the C–N stretching motion. |
Betaine hydrochloride was dissolved in the solution containing Fe3o4 by stirring | Improve the water dispersablity and the stability of Fe3O4 |
| 200461 | Thermal decomposition | 6–30 nm | TEM: high quality of the nanocrystals. XRD: magnetite crystal structure of nanocrystals. |
Generation of iron carboxylate salts through dissolution of iron oxides in oleic acid | Solubility improved |
| 200462 | Narrow size distribution | Average diameter: 25.3 nm | XRD: microtac used to measure the magnetic particle size distribution. DLS: used to measure the diameter. |
Dextran was added to coat the surface of the magnetic Fe3O4 nano particles | Enhance the biocompatibility of the magnetic Fe3O4 nanoparticles |
| 200463 | Coprecipitation of ferrous and ferric salts solution | 40–50 nm | TEM and AFM studies showed that the particles are spherical in shape with a core–shell structure. | PEG used for labeling the MNPs | Coated particles with PEG resulted in increased blood circulation time |
Abbreviations: NR, not reported; TEM, transmission electron microscopy; XRD, X-ray diffraction; PEG, polyethylene glycol; DLS, dynamic light scattering; FTIR, Fourier transform infrared spectroscopy; γ-PGA, poly(γ-glutamic acid); HA, humic acid; MNPs, magnetic nanoparticles; AFM, atomic force microscopy; SEM, scanning electron microscope.