Chapter 5 - Nanoparticles

Abstract

Synthesis of materials in the nanosize such as nanoparticles makes it possible to control several properties such as their shape and stability. Magnetic nanoparticles, in particular, have a more advanced technology and more applications due to their physical and chemical properties compared to all other types of nanoparticles. There are many kinds of magnetic nanoparticles based on their different source such as metals, rare earth metals, oxidation of metallic nanoparticles, and magnetic alloys. The most commonly used metal oxides in synthesizing magnetic nanoparticles are Fe, Co, Mg, and Mn with their alloy compounds. Moreover, the main methods to synthesize magnetic nanoparticles are Co-precipitation, thermal decomposition, and microemulsion. In general, the production of metallic nanoparticles can be categorized into two different kinds: top–down and bottom–up. Polymer matrices are embedded with metal in order to provide materials that possess the unique properties arising from nanoscopic size and shapes of metal clusters (e.g., semiconductors). The use of clay with polymer materials would provide significant advantages in the physical properties compared to polymers alone. Cell separation and drug delivery are applications of magnetic nanoparticles. Metal nanoparticles have recently been found to be applicable in catalysis as well as gold nanoparticles (based on enzymatic biosensor). The incorporation of these nanoparticles into polymer matrices has shown great potential for photovoltaic cells, LEDs, tunable lasers, biologically active tags, and diagnostic devices.