Example of Nanomaterials

7/30/2019 Example of Nanomaterials

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Example of Nanomaterials

As the world is advancing, there are many nanomaterials that being produces and engineered.

Nanomaterials is also a new step in the evolution of understanding and utilization of materials.

Example of nanomaterials are carbon nanotube, nanoparticle, metal rubber, quantum dots,

nanopores and many more.

Nanotechnology, shortened to "nanotech", is the study of the controlling of matter on an atomic

and molecular scale. Generally nanotechnology deals with structures of the size 100 nanometers or

smaller in at least one dimension, and involves developing materials or devices within that size.

Nanotechnology range is very wide from the smallest particles that cannot be seen by naked eye to

the the food you ate and clothes you wear.


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1. Carbon Nanotubes

Background

Carbon nanotubes are carbon sheets rolled to form either a

seamless cylinder, known as single-walled carbon

nanotubes (SWCNTs), or many cylinders stacked one

inside the other, known as multi-walled carbon

nanotubes (MWCNTs). The lengths of these tubes

generally range from several hundred nanometers (nm) to

several micrometers (m), though tubes in the millimetre

range have also been reported. Their diameter is dependent on the number of walls and is usually

less than 100 nm.

As a result of their good physical and chemical properties such as the strongest and stiffest materials

yet discovered in terms of tensile strength and elastic modulus respectively and good

electr ical and thermal conductor, carbon nanotubes have potential use in a variety of industrial

and biomedical applications including:

catalysts

biosensors

composite materials with improved mechanical and electrical properties, and

drug carriers.

2.

Nanoparticles


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In nanotechnology, a nanoparticle is defined as a small object that behaves as a whole unit in terms

of its transport and properties. It is further classified according to size: in terms of diameter.

Particles in the nano range are being

investigated for a number of applications, like:

wear resistance, scratch protection, blocking of

light. A good example of this last application is

the blocking of ultraviolet light by zinc oxide

particles for cosmetics. The blocking power is

directly related to particle size, size

distribution, particle loading and the dispersion.

Other application examples of nanoparticles are:

Filter media. The active component is an alumina (AlOOH) fiber two nanometers in diameter.

The nano alumina fiber is highly electropositive, and will attract and retain particles.

Silver has long been known to inhibit oxygen exchange, effectively killing bacteria. Nanosilver

has been demonstrated to enhance that effect, and is

currently being used in wound dressings for

critical-burn victims.

Other nanoparticles can be used as pharmaceutical

carriers to specifically deliver disease-fighting

drugs to afflicted body areas, thus minimizing

secondary effects.

In fuel cells perovskites are being discussed as

electrode materials for use as cathodes.

Specifically the high surface area and the high ionic

conductivity of the material is of interest.

3. Quantum Dots

A semiconductor whose excitons are confined in all three

spatial dimensions. Basically a single electron trapped


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inside a cage of atoms and when the dot is exposed to a pulse of light at the right time and

wavelength, the electron is raised to an exited state. Thus when the electron fall back to its ground

state, these dots then have the ability to glow. Quantum dots are a special class of materials known

as semiconductor. Quantum dots are very special because they are so small that 4,000,000 dots

take up 2cm. At these small sizes quantum dots enable never before seen appications to science

and technology. New markets and applications emerges as we continue to innovate, works and

master the quantum dot technology.

Now the researchers are trying to harnest quantum dots full potential. Many application

used is based on quantum dots such as:-

used for LED

memory storage

solar cells and

disease

In the near future there will be a foldable wide screen TV, or a truly foldable phone, right in your

pocket, instead of paint, you have walls which are screens that can display movies or tv shows,

walls that can change colours to your mood, and help you get to sleep, and a newspaper that

actually only on a single surface.

4. Nanoshell

A type of spherical nanoparticle consisting of

a dielectric core which is covered by a

thin metallic shell (usually gold). Nanoshells possess

highly favorable optical and chemical properties for

biomedical imaging and therapeutic applications. In


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addition, nanoshells offer other advantages over conventional organic dyes including improved

optical properties.

Nanoshells designed to absorb various wavelengths of light (the six vials on the right), including

infrared (vial at far right) compared to gold colloid (far left).

Nanoshell properties is chemically inert and water-soluble, can be used as efficient catalysts, forms

stable dispersions and also non-magnetic; therefore they can be useful in biological applications.

5. Metal Rubber

A self-assembled nanocomposite material that combines the high electrical conductivity of metals

with the low mechanical modulus of elastomers. This metal rubber also flexible, indestructible

material that can be heated, frozen, washed or doused with jet fuel, and still retain its electricity-

conducting properties.


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A process called self-assembly is used by chemists and engineers to make this rubber metal. The

material is repeatedly dipped into positively charged and negatively charged solutions. The

positive and negative charges bond, forming layers that conduct electricity.

Metal rubber is used for:

bendy, electrically charged aircraft wings

body armor

durable electronic sensors

artificial muscles

wearable computers and

abuse-resistant, flexible circuits, like cell phones

6. Nanopores


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Nanoporous materials area class of compounds that contain a regular ordered framework possessing pores

on the nanoscale. The collection includes mainly natural or synthetic zeolites. There are many types of

nanopores such as biological nanopores, solid-state nanopores, and hybrid nanopores.

Nanopore analysis is an emerging technique that involves using a voltage to drive molecules

through a nanoscale pore in a membrane between two electrolytes, and monitoring how the ionic

current through the nanopore changes as single molecules pass through it. Using this approach,

many application can be used such as DNA sequencing, transport of various ions, detect target

molecules at very low concentrations from very small sample volumes, simultaneously screen

panels of biomarkers or genes and eliminate cumbersome amplification and conversion steps.

Reference

1.

Nanoparticles, Gunter Schmidt Edition, Wiley-VCH, 2004.

2. Lewis, L. N. Chem. Rev. (Washington, D.C.) 1993, 93, 2693.

3. Iqbal, S. & Bashir, R. Nanopores: Sensing and Fundamental Biological Interactions

(Springer, 2011).


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4. Brongersma, M. L. Nanoshells: Gifts in a Gold Wrapper.Nature

Materials 2, 296-297 (2003).

Example of Nanomaterials

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