ABSTRACT
Nanotechnology, which has been heralded as the next great technological revolution, is the engineering or manipulation of matter at or near the atomic level [1,2]; essentially, nanotechnology is building objects atom by atom and molecule by molecule. A key building block of this technological eld are nanoparticles [3]. Nanoparticles are de ned as particles with a diameter, or dimension, between 1 and 100 nm (nanometers). For reference, a nanometer is one billionth of a meter (10−9 m). In comparison, a human hair is approximately 80,000 nm in diameter, while a water molecule is only 0.3 nm across. Nanoparticles are in fact a class of particles of speci c size more commonly referred to as colloids [4]. ey have unique properties that distinguish them from other larger bulk materials having similar chemical compositions. ese unique properties are largely attributed to the size e ect phenomena [2]. As particle size approaches or decreases below 100 nm, the surface area-to-mass ratio increases dramatically, meaning that the bulk of a particle’s atoms are at the surface. is makes nanoparticles highly surface reactive. Another size e ect is that quantum e ects become much more signi cant for nanoparticles, which a ects their optical, electrical, and magnetic properties [2,5].
