Formation and development of Nanochemistry

Introduction.Formation and development of Nanochemistry. Nanoparticle as a structural unit of new substances and materials with unusual properties. Classification of nanoparticles. Properties of nanoparticles.

Objectives:

Ø To explain formation and development of Nanochemistry.

Ø To give an overview about Nanoparticle as a structural unit of new substances and materials with unusual properties.

Ø To organize nanoparticles according different criteria.

Ø To explain briefly properties of nanoparticles.

The development of Nanotechnology comes from the proposals of Richard Feynman, who is considered the father of "nanoscience", Nobel Prize in Physics, who in 1959 proposed to manufacture products based on a rearrangement of atoms and molecules. The great physicist wrote an article that analyzed how computers working with individual atoms could consume very little energy and achieve surprising speeds.

Nanotechnology is one of the most promising areas of modern science and technology with great economic and social impact. It works with extremely small elements such as one millionth of a millimeter and even more. For this, the human being has had to develop techniques that allow him to even manipulate matter atom by atom.

The nanotechnology revolution is associated, on the one hand, with "molecular fabrication" whose viability would have a huge impact on our lives, economies, countries and society in general soon. Among the effects, they highlight their potential impacts on medicine, biology, the environment, computing, construction and so on.

Formation and development of Nanochemistry

The term “nano” refers to the metric prefix 10^-9. It means one billionth of something. “Nano” can be recognized to any unit of measure. For example, you may report a very small mass in nanograms or the amount of liquid in one cell in terms of nanoliters.

So, what is nanoscience? Nanoscience is the study of structures and materials on the scale of nanometers. To give you an idea of how long a nanometer is, this printed page is about 75,000 nanometers thick. When structures are made small enough—in the nanometer size range—they can take on interesting and useful properties.

With Nanoscience being the study of phenomena and manipulation of materials at atomic, molecular and macromolecular scales, where properties differ significantly from those at a larger scale and Nanotechnology being a device or machine, product or process, based upon individuals or multiple integrated nanoscale components, then What is Nanochemistry?

In its broad test terms, the defining feature of Nanochemistry is the utilization of synthetic chemistry to make nanoscale building blocks of different size and shape, composition and surface structure, charge and functionality. These building blocks may be useful in their own right or in a self-assembly construction process, spontaneous, directed by templates or guided by chemically or lithographically defined surface patterns. They may form architectures that perform an intelligent function and portend a particular use.

Nanoparticle is a structural unit of new substances and materials. It can be defined as particles with at least one of their three - dimensional sizes in the range of 1– ∼100 nm (1 nm=10^-9 m). This is between the size of atoms or molecules and bulk materials. Within this size range, they can usually consist of 10–10,000 atoms. First, let us clarify the terms. Various terms that describe the nanosized particles have been adopted in the literature. The term is sometimes based on just the size, sometimes based on the physical property of the particles, and sometimes based on the shape of the particles. The term nanoparticle is obviously the most widely used one, and it is safe to say that this term encompasses most of the nanosized particles regardless of their physical property, size, and shape. Also, nanoparticles can be in either an amorphous or crystalline state. Nanoparticle refers to both states. When the crystalline state is considered, the term nanocrystal is preferred.

The terms cluster or nanocluster are also frequently used. Some of the literature uses these words as equivalent to or as replacements for nanoparticle. They are sometimes used to refer even to the aggregates of colloidal particles. This seems not to be a problem, as long as they are meant to represent the particles of the nanometer range. However, cluster is originally adopted to define the size range of atomic aggregates whose optical transition is not dependent on the number of atoms. As we will discuss later, the optical properties of nanoparticles are strongly dependent on their size. Hence, once the optical properties show variation in changes in size, the term cluster had better not be used to replace the term nanoparticle.