Types of Nano Particles

Nano particles have l0⁶ atoms or less, their properties differ from those of the same atoms bonded together to form bulk materials. First, it is necessary to define what we mean by a nano particle.

Nano particles themselves had been around and studied long before the words were coined. For example, many of the beautiful colors of stained-glass windows are a result of the presence of small metal oxide clusters in the glass, having a size comparable to the wavelength of light.

Particles of different sizes scatter different wavelengths of light, imparting different colors to the glass. Small colloidal particles of silver are a part of the process of image formation in photography. Water at ambient temperature consists of clusters of hydrogen-bonded water molecules. Nano particles are generally considered to be a number of atoms or molecules bonded together with a radius of < l00 nm.

A nano meter is l0^-9 m, so particles having a radius of about 510008, can be considered to be nano particles. Some of the types of Nano particles are discussed as follows.

Nano Wires

Nanowires can be defined as structures that have a thickness or diameter constrained to tens of nanometers or less and an unconstrained length. At these scales, quantum mechanical effects are important which coined the term "quantum wires".Many different types of nanowires exist, including metallic (e.g., Ni, Pt, Au), semiconducting (e.g., Si, InP, GaN, etc.), and insulating (e.g., SiO₂, TiO₂). Molecular nanowires are composed of repeating molecular units either organic (e.g. DNA) or inorganic (e.g. Mo₆S_9-xI_x).

Nano rods

In nanotechnology, nanorods are one morphology of nanoscale objects. Each of their dimensions range from 1–100 nm. They may be synthesized from metals or semiconducting materials. Standard aspect ratios (length divided by width) are 3-5. Nanorods are produced by direct chemical synthesis.

Quantum Dots

Quantum Dots are semiconductor nano crystals that are so small that they are consider dimensionless. Quantum Dots range for 2-20nm (10-50 atoms) in diameter. Some quantum dots are small regions of one material buried in another with a larger band gap