Nano is Greek for dwarf, and nanoscience deals with the study of molecular and atomic particles, a world that is measured in nanometers (billionths of a meter or 10-9). A nanometer is one billionth of a meter ( 10-9)
Study on Air-Water & Water-Water Heat Exchange in a Finned Tube Exchanger
Introduction to Nanotechnology
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Chapter One / General Introduction
“Justas the BritishIndustrial Revolution knocked handspinners and
handweavers out of business, nanotechnology will disrupt a slew of
multi-billion dollar companies and industries.”
– Lux Research, Inc. The Nanotech Report 2004
1.1. Introduction
The subject of nanotechnology is the science of the small. Nano is
Greek for dwarf, and nanoscience deals with the study of molecular and
atomic particles, a world that is measured in nanometers (billionths of a
meter or 10-9). A nanometer is one billionth of a meter ( 10-9). That’s
very small. At this scale, you are talking about the size of atoms and
molecules. To create a visual image of a nanometer, the width of your
nail on this finger is about 10 million nanometers across. To get a sense
of some other nano-scaled objects, the diameter of a human hair is
between 50,000 and 100,000 nanometers. A head of a pin is about a
million nanometers wide and it would take about 10 hydrogen atoms
end-to-end to span the length of one nanometer. The length of red blood
cell is approximately 7,000 nm wide and a water molecule is almost
0.3nm across. It is very small indeed Figure 1.1 and table 1.1 shows the
dimensions of different items.
Nanotechnology is the ability to observe measure, manipulate, assemble,
control and manufacture matter at the nanometer scale. People are
interested in the nanoscale because it is at this scale that the properties
of materials can be very different from those at a larger scale.
Nanoscience is a convergence of physics, chemistry, materials science
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and biology, which deals with the manipulation of materials at atomic,
molecular and macromolecular scales; nanotechnology is an emerging
engineering discipline that applies methods from nanoscience to create
products.
Figure 1.1 (a) Less than a nanometer, individual atoms is up to a few
angstroms, or up to a few tenths of a nanometer, in diameter.
(b) Nanometer, ten shoulder-to-shoulder hydrogen atoms. DNA
molecules are about 2.5 nanometers wide.
(c) A thousands of nanometers, biological cells, like these red blood
cells, have diameters in the range of thousands of nanometers.
Table 1.1 The dimension of some different items.
Dimensions (nm)
Items
1
Width of an Atom
2
The Width Across a DNA Molecule
5 – 50
Protein
75 – 100
Virus
800
The Width of a Dust Particle
1,000 – 10,000
Bacteria
10,000
White Blood Cell
100,000
The Width of a Hair
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or arrest the propagation of defects when the material is stressed, thus
giving it strength. If these grains can be made very small, or even
nanoscale in size, the interface area within the material greatly
increases, which enhances its strength. For example, nanocrystalline
nickel is as strong as hardened steel. Understanding surfaces and
interfaces is a key challenge for those working on nanomaterials, and
one where new imaging and analysis instruments are vital.