Magnetic nanoparticles

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Magnetic nanoparticles are a class of nanoparticle which can be manipulated under the influence of a magnetic field. Such particles commonly consist of magnetic elements such as iron, nickel and cobalt and their chemical compounds. These particles have been the focus of much research recently because they possess attractive properties which could see potential use in catalysis ^[1], biomedicine ^[2], magnetic resonance imaging ^[3], data storage ^[4] and environmental remediation ^[5].

Contents 1 Properties 2 Synthesis 2.1 Co-precipitation 2.2 Thermal Decomposition 2.3 Microemulsion 3 Applications 3.1 Catalysis 3.2 Medical Diagnostics and Treatments 3.3 Magnetic Resonance Imaging 3.4 Data Storage 3.5 Water Treatment 4 References

[edit] Properties

The wide range of magnetic nanoparticles that have been synthesized has given rise to a variety of different physical and chemical properties largely depending on the synthesis method and chemical structure. In most cases, the particles range from 1 - 100 nm in size and display superparamagnetism ^[6].

[edit] Synthesis

The established methods of magnetic nanoparticle synthesis include:

[edit] Co-precipitation

Co-precipitation is a facile and convenient way to synthesize iron oxides (either Fe₃O₄ or γ-Fe₂O₃) from aqueous Fe²⁺/Fe³⁺ salt solutions by the addition of a base under inert atmosphere at room temperature or at elevated temperature. The size, shape, and composition of the magnetic nanoparticles very much depends on the type of salts used (e.g.chlorides, sulfates, nitrates), the Fe²⁺/Fe³⁺ ratio, the reaction temperature, the pH value and ionic strength of the media ^[7].

[edit] Thermal Decomposition

Monodisperse magnetic nanocrystals with smaller size can essentially be synthesized through the thermal decomposition of organometallic compounds in high-boiling organic solvents containing stabilizing surfactants ^[8].

[edit] Microemulsion

Using the microemulsion technique, metallic cobalt, cobalt/platinum alloys, and gold-coated cobalt/platinum nanoparticles have been synthesized in reverse micelles of cetyltrimethlyammonium bromide, using 1-butanol as the cosurfactant and octane as the oil phase ^[9].

[edit] Applications

A wide variety of applications have been envisaged for this class of particles these include:

[edit] Catalysis

[edit] Medical Diagnostics and Treatments

[edit] Magnetic Resonance Imaging

[edit] Data Storage

[edit] Water Treatment

[edit] References

1. ^ A.-H. Lu, W. Schmidt, N. Matoussevitch, H. Pnnermann, B.Spliethoff, B. Tesche, E. Bill, W. Kiefer, F. SchVth, Angew.Chem. 2004, 116, 4403; Angew. Chem. Int. Ed. 2004, 43, 4303.
2. ^ A. K. Gupta, M. Gupta, Biomaterials 2005, 26, 3995.
3. ^ S. Mornet, S. Vasseur, F. Grasset, P. Verveka, G. Goglio, A. Demourgues, J. Portier, E. Pollert, E. Duguet, Prog. Solid StateChem. 2006, 34, 237.
4. ^ T. Hyeon, Chem. Commun. 2003, 927
5. ^ D. W. Elliott, W.-X. Zhang, Environ. Sci. Technol. 2001, 35, 4922.
6. ^ A.-H. Lu, E. L. Salabas and F. Schüth, Angew. Chem., Int. Ed., 2007, 46,1222–1244
7. ^ A.-H. Lu, E. L. Salabas and F. Schüth, Angew. Chem., Int. Ed., 2007, 46,1222–1244
8. ^ A.-H. Lu, E. L. Salabas and F. Schüth, Angew. Chem., Int. Ed., 2007, 46,1222–1244
9. ^ A.-H. Lu, E. L. Salabas and F. Schüth, Angew. Chem., Int. Ed., 2007, 46,1222–1244

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