The word composite means “made of two or more various parts.” (Jean –Marie Berthelot). “A composite is a combination of two or more varied materials that are mixed in an effective and exertive way to get the most excellent properties of both.” Nanocomposite material is fabricated by a matrix and a reinforcement consisting of fibers. The matrix itself composed of a resin and filler, by reducing the production cost we get the improve results with better characteristics. The system behaves as a heterogenous and constructed as a combination of a matrix and reinforcement. This reinforcement gives them a greater mechanical performance, whereas the role of the matrix is to transmit to the fiber to the external mechanical load and protect the fibers against external attack. The composite material depends upon:

FUNDAMENTAL CONCEPTS OF NANOSCIENCE AND NANOTECHNOLOGY
Rimsha Zia
Rimsha Zia

Fundamental Concepts of Nano Science and Nanotechnology

Nanotechnology is science, engineering, and technology operated at the nanoscale, that ranges up to 100 nanometers.

“Nanoscience and nanotechnology are the study and application of extremely small things and can be used across all the other science fields, such as chemistry, biology, physics, materials science, and engineering”.

The beginning of nanotechnology and nanoscience introduced with allocution entitled “There’s Plenty of Room at the Bottom” by physicist Richard Feynman at an American Physical Society meeting at the California Institute of Technology (Caltech) on December 29, 1959, going before the term nanotechnology was used. Feynman described a process in which scientists would be able to manipulate or fabricate as well as they can control individual atoms and molecules. The evolution of nanotechnology was rise in 1981 by the development of scanning electron microscope so we can able to see an individual atom.

It is difficult to visualized or conceptualized that how small nanotechnology is. One nanometer is a billionth of a meter, or 10-9 of meters.

Here are a few examples:

  • There are 25,400,000 nanometers in an inch

  • A sheet of newspaper is about 100,000 nanometers thick

  • If a marble piece were a nanometer, then one meter would be the size of the Earth.

  • Everything on Earth is made up of atoms such that clothes we wear, houses we live in, and all other different items we used in our daily life

FUNDAMENTAL CONCEPTS OF NANOSCIENCE AND NANOTECHNOLOGY 1

In nanoscience we are now able to see an individual atom with the help of these tool microscopes which are AFM and STM, comparing with the last century we were unable to visualize the single atom with naked eye or by using high school microscopes.

 

Nano based materials:

We classify Nano based structure as below:

Nano porous materials

Nano composites

Nanotube

 

Nano porous materials:

Materials having pores in a diameter at nano level, they have 2D structure like CNTs, inorganic nanotubes, nanobelts.

Nanotube:

A nanotube is a nanoscale material that has a tube-like structure as it can see as layers rolled up. They are of two types, single layered or multi layered. Most common nanotube is carbon nanotube and other are boron nanotube and halides.

Nanocomposites:

The word composite means “made of two or more various parts.” (Jean –Marie

Berthelot). “A composite is a combination of two or more varied materials that are mixed in an effective and exertive way to get the most excellent properties of both.”

Nanocomposite material is fabricated by a matrix and a reinforcement consisting of fibers. The matrix itself composed of a resin and filler, by reducing the production cost we get the improve results with better characteristics. The system behaves as a heterogenous and constructed as a combination of a matrix and reinforcement. This reinforcement gives them a greater mechanical performance, whereas the role of the matrix is to transmit to the fiber to the external mechanical load and protect the fibers against external attack. The composite material depends upon:

 

  • High mechanical characteristics

  • Good thermal stability

  • Cost

  • Resistance to corrosion

FUNDAMENTAL CONCEPTS OF NANOSCIENCE AND NANOTECHNOLOGY 2

Properties of nanomaterials:

Properties of nanomaterials depends on their chemistry and the arrangement of building blocks of atoms. As in nano size the properties of a bulk material becomes changed as converted in to nanosized, the bulk material can behave as a conductor while single atom is not.

Size effect:

Shrinking their size from bulk to nano sized material their properties goes changed. The surface area of the material becomes wider, so it is stated that the surface to volume ratio is wider at nanoscale.

Interface effect:

By changing their sizes, high percentage of atoms will be on the surface of a material.

Magnetic properties:

In bulk form gold and platinum behaves as non-magnetic material, reducing their size at nano level, they show magnetic properties. The material having magnetic properties at nano level are further used in many fields like turbo magnetic beads are used in treating or purifying the contaminated water, imaging MRI, and in storage devices.

Optical properties:

Shifting of colors by reducing sizes is included in their properties, that is gold bulk form shift its color from gold to red at nano level. This property is being in used in photo catalyst, photo emission and photo conductivity.

FUNDAMENTAL CONCEPTS OF NANOSCIENCE AND NANOTECHNOLOGY 3

 Classification of nanostructure materials:

The classification of nanostructured materials depends upon their dimensions.

 

Zero dimension (0-D)

One dimension (1-D)

Two dimensions (2-D)

Three dimensions (3-D)

 

Zero Dimension (0-D):

Materials in which all the three dimensions are measured at nano level. Zero dimension are greater than 100nm.

The common features of 0-D are,

They can be crystalline, amorphous or polycrystalline.

They are made up of single or multi-chemical element.

They can be existing in the metallic, ceramic or polymeric.

 

One dimension(1-D):

Length is the measure of one-dimension materials. This leads to needle like shaped nano materials like nano tubes, nanorods and nanowires. 1-D Shaped materials can be;

Chemically pure or impure.

Standalone materials or having some composite relation with other material.

 

Two dimensions (2-D):

Materials having two-dimension (length and width) properties are known to be 2 -D materials at nano levels. For example, nano films, nanolayers, nano coating.

Can be used as a single layered or also in multi layered structures.

These 2-D materials are deposited on a substrate (silicon wafers)

 

Three-dimensions (3-D):

Materials are not restricted to any dimension at nano scale (length, width, height, volume) etc. their ranges are up to 100 nanometers. e-g bundles of nanowires and nanotubes

 

Composed of multiple arrangement in the crystal

Having different orientations

FUNDAMENTAL CONCEPTS OF NANOSCIENCE AND NANOTECHNOLOGY 4
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