An Introduction To Nanotechnology

1 nanometre = 10^-9 meter. Hence, 10 nanometre = 10^-9 meter

Nanoscience involves the study of matter whose at least one of the dimension is 1nm – 100nm or less.

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Between two carbon atoms covalent bonds are formed by sharing of electrons. The covalent bonds may be single, double, and triple bonds.

Fullerene is a carbon based molecule which is in the form of hollow sphere, ellipsoid or tube. Mass Spectrograph Experiment indicates that Fullerene is made up of 60 Carbon Atoms arranged in dome-shaped hollow sphere also known as “bucky ball” as they resemble a football

The carbon nanotubes have good thermal conductivity along their length. Thermal conductivity of standard SWNT along its, length is 3500.

Nanoscience is the study of atoms, molecules, and objects whose at least one of the dimensions is 1nm – 100nm or less.

Nanomaterials are light and strong due to this property, they are applied in security. Examples are Damascus steel with carbon nanoparticles were present on the surface of Tipu Sultan’s sword and use of nano-lead compound for their eye makeup by ancient Egyptians.

(a) Scanning tunnelling microscope

(b) Atomic force microscope

Carbon Nanobuds are recently discovered material which is obtained by combining allotropes of carbon nanotubes and fullerenes. In the new material the Fullerene-like buds are bonded covalently to the outer sidewalls of carbon-nanotube thus having useful properties of both fullerenes and carbon nanotubes

•Carbon Nanotube are recently derived allotrope of carbon in which the “Fullerene” buds are attached to the outer part of the carbon nanotubes through covalent bond thus having the properties of both Fullerenes and Nanotubes.

•Carbon nanotubes are known to carry electric current of 10⁹ ampere per cm² cross section of the tube which is 1000 times more than conducting copper metal. MWNT also able to show superconductivity up to the temperature of 12K.

The four energy sectors where nanotechnology is useful are given below:

(a) Biofuel as renewable energy :- They are the renewable sources of energy which will be useful in near future as fossil fuels are getting exhausted

(b) Fusion power:- Nano technology can play a vital role in generating energy from Nuclear Fission

(c) Concentrated solar power:- Solar power will be important in Future as it is untapped source of energy

(d) Nanowire battery:- Nanotechnology can be used in future to make batteries which have better performance than those in present

The areas related to nanotechnology are:

(a) Nanocomposite:-Can be used for construction of materials with enhanced physical properties

(b) Metallic nanotubes:-Have huge potential in Medical Field for bone drafting as well as in Automobile Industry

(c) Synthesis and characterization:- Nanoparticles are used as fillers in Polymers to enhance its physical properties

(d) Nanotubes and bucky-balls:-BuckyBalls can combine with nanotubes to form cost-effective solar cells

(e) Bio and carbonic Nano-sensors :- Biosensors are being used for detection of various diseases like cancer, diabetes with high specificity and sensitivity

(f)For Drug Delivery:- Nanotechnology can be used for drug delivery to parts of body where the oral or intravenous are not able to reach such as the brain

(g) For Making Medical Devices:-Nanotechnology is being used increasingly to make implants with nanocoating as well as materials mimicking natural tissues.

I. A parameter that determines functioning of a nanomaterial is the surface area (SA) to volume (V) ratio.

II. The greater the surface area of the nanomaterial, greater is the reactivity.

III. Due to difference in surface area to volume ratio different materials show different physical properties at the nanoscale.

IV. The size and shapes of all nanostructures are dependent on their physical properties.

V. Due to large surface area to volume ratio, friction and striking effects are prominent in nanomaterials.

I. Carbon forms complex molecules by binding to other elements such as hydrogen, oxygen and nitrogen forming covalent bonds.

II. The examples of formed complex molecules like nucleic acids (DNA and RNA), proteins, enzymes, carbohydrates.

III. Proteins are made of long chains amino acids. Proteins are structural units of living organisms.

IV. Strong cohesion is responsible for most stable biochemical compounds.

I. The tensile strength of carbon nanotube is very large as compared to many bulky materials.

II. The tensile strength is the result of the covalent sp² bonds between carbon-carbon atoms. But, under excessive tensile strain nanotubes display permanent deformations.

III. When compared to their tensile strength compressive strength is low.

IV. Nanotubes are much softer along radial directions permitting bending like rubber tube.

I. The carbon nanotubes are good conductor of heat (thermal) along with their length.

II. Thermal conductivity of standard SWNT along its, length is 3500 and for copper the same is 385 at room temperature.

III. Carbon insulators are good insulators along the axis of the tube. The thermal stability in vacuum is up to 3100K and 1000K in air.

I. Nanotechnology can change the healthcare sector for the next generation. For examples, nano-devices are cheaper and gives fast diagnostics and drug applications. They are accurate and precise diagnosis improves medical treatment.

II. With the help of nanotechnology system, can measure hundreds of complicated factors simultaneously, avoiding the risk of losing samples waiting days for lab results, and lab mess-ups.

III. Nano filters are able to remove the smallest of known viruses. Nano technologically made, antimicrobial coating is another promising area for preventing diseases.

IV. Nanotechnology can help to design certain drugs that very difficult to manufacture because of structural constraints by using a controlled manufacturing system at the atomic and molecular level.

I. The aim of nanotechnology is to design nanostructures and nanoparticles for specific applications.

II. It follows a bottom-up approach and requires special techniques to manufacture nanomaterials.

III. The physical properties of nanostructures are dependent on their size and shape.

IV. The functioning of a nanomaterial is based on the surface area (SA) to volume (V) ratio.

V. Greater the SA/V ratio, greater is the reactivity of such materials. Therefore, the same material shows different physical properties at the nanoscale.

VI. Further, large SA/V ratio; the friction and sticking property of such materials is large.

VII. The laws of quantum mechanics determine the forces among nanomaterials. Thus, Nanotechnology plays by different rules.’

I. Bucky balls are composed of carbon atoms linked to three other carbon atoms by covalent bonds.

II. The carbon atoms are connected in the same pattern of hexagons and pentagons you find on a soccer ball.

III. The most common bucky-ball contains 60 carbon atoms and is sometimes called C₆₀.Other sizes of bucky balls range from those containing 20 carbon atoms to those containing more than 100 carbon atoms.

IV. The covalent bond between carbon atoms make bucky balls very strong, and the carbon atoms readily form covalent bonds with a variety of other atoms.

V. Bucky balls are used in composites to strengthen material.

VI. Bucky balls are very good electron acceptors. They accept loose electrons from other materials.

VII. It increases the efficiency of solar cells in transforming sunlight into electricity due to its property of good electron acceptor.

I. Carbon nanotubes are allotropes of carbon such as fullerenes, having cylindrical nanostructure.

II. They are bucky balls with closing ends which form tube-like structures.

III. The carbon nanotube derived from a bucky ball is also called ‘bucky tube’.

IV. Nanotubes can be found with either closed-ends or open- ends.

V. Nanotubes with single cylinder called Single Walled Nanotube (SWNT).

VI. Nanotube with multiple concentric nano-cylinders are Multi-Walled Nanotube (MWNT).

The importance of nanotechnology are mentioned below:

I. Nano-devices are cheap, good and they are functionally very efficient in diagnosis and drug applications.

II. Their accurate and precise diagnosis improves medical treatment.

III. They have tuneable electrical and optical properties due to nanomaterial. They can interchange electricity and light with minimum energy loss.

IV. Nanomaterials have found large applications in the field of defence due to lighter yet stronger mechanical properties.

V. They are used to construct light and strong baffle tanks; space crafts, bridges, cranks, etc.

VI. Researchers have shown that ultra-fast calculators can be made with the help of nanotechnology.