A significant nanoparticle discovery that came to light in 1991 was carbon nanotubes. Where buckyballs are round, nanotubes are cylinders that haven’t folded around to create a sphere. Carbon nanotubes are composed of carbon atoms linked in hexagonal shapes, with each carbon atom covalently bonded to three other carbon atoms. Carbon nanotubes have diameters as small as 1 nm and lengths up to several centimeters. Although, like buckyballs, carbon nanotubes are strong, they are not brittle. They can be bent, and when released, they will spring back to their original shape. The strongest, lightest and most conductive material known Carbon nanotubes (CNTs) are tubular cylinders of carbon atoms that have extraordinary mechanical, electrical, thermal, optical and chemical properties At the individual tube level, these unique structures exhibit: 200X the strength and 5X the elasticity of steel; 5X the electrical conductivity (\"ballistic transport\"), 15X the thermal conductivity and 1,000X the current capacity of copper; at almost half the density of aluminum. As a carbon based product, CNTs have almost none of of environmental or physical degradation issues common to metals—thermal expansion and contraction, corrosion and sensitivity to radiation—all of which result in greater system failure in performance-sensitive applications in aerospace and defense, aviation, automotive, energy and consumer products. CNTs typically have diameters ranging from ‹1 nanometer (nm) up to 50 nm—a nanometer is one thousand millionth of a meter. Typical CNT lengths are several microns—several thousand nanometers long; by contrast, Nanocomp\'s produced fibers are measured in millimeters—thousands of times longer than all other commercially produced CNTs. In the powdery format offered by all CNT producers (but for NTI), applications are limited to the properties possible by this form factor—e.g. additive active ingredients in semiconductors, liquid crystal displays (LCDs), sensors, and other uses in which these powders add some level of functional performance. Due to its fiber length and its form factors, NTI delivers strength and conductivity unlike any other commercial CNT producer, and so can address a much broader array of applications for which its material rivals copper and aluminum in conductivity, and steel, aluminum, carbon fibers and glass composites where strength and lightweight matter. Further, the Company\'s macro forms (sheets, tapes, conductors and yarns) are comprised of CNTs that are too long to be inhaled or absorbed by the skin; for this reason, NTI believes it produces the safest CNT commercial products on the market. NTI\'s sheets, tapes, conductors and yarn products have been classified by the Environmental Protection Agency (EPA) as \"articles, \"not\" particles and so--unlike all commercial producers of CNT particles--are not subject to more stringent oversight as a potentially toxic or hazardous material. . Wavelength Versus Physical Dimension.

1. A significant nanoparticle discovery that came to light in 1991 was carbon nanotubes. Where
buckyballs are round, nanotubes are cylinders that haven’t folded around to create a sphere.
Carbon nanotubes are composed of carbon atoms linked in hexagonal shapes, with each carbon
atom covalently bonded to three other carbon atoms. Carbon nanotubes have diameters as small
as 1 nm and lengths up to several centimeters. Although, like buckyballs, carbon nanotubes are
strong, they are not brittle. They can be bent, and when released, they will spring back to their
original shape.
The strongest, lightest and most conductive material known
Carbon nanotubes (CNTs) are tubular cylinders of carbon atoms that have extraordinary
mechanical, electrical, thermal, optical and chemical properties At the individual tube level,
these unique structures exhibit: 200X the strength and 5X the elasticity of steel; 5X the electrical
conductivity ("ballistic transport"), 15X the thermal conductivity and 1,000X the current
capacity of copper; at almost half the density of aluminum. As a carbon based product, CNTs
have almost none of of environmental or physical degradation issues common to
metals—thermal expansion and contraction, corrosion and sensitivity to radiation—all of which
result in greater system failure in performance-sensitive applications in aerospace and defense,
aviation, automotive, energy and consumer products.
CNTs typically have diameters ranging from ‹1 nanometer (nm) up to 50 nm—a nanometer is
one thousand millionth of a meter. Typical CNT lengths are several microns—several thousand
nanometers long; by contrast, Nanocomp's produced fibers are measured in
millimeters—thousands of times longer than all other commercially produced CNTs. In the
powdery format offered by all CNT producers (but for NTI), applications are limited to the
properties possible by this form factor—e.g. additive active ingredients in semiconductors, liquid
crystal displays (LCDs), sensors, and other uses in which these powders add some level of
functional performance.
Due to its fiber length and its form factors, NTI delivers strength and conductivity unlike any
other commercial CNT producer, and so can address a much broader array of applications for
which its material rivals copper and aluminum in conductivity, and steel, aluminum, carbon
fibers and glass composites where strength and lightweight matter. Further, the Company's
macro forms (sheets, tapes, conductors and yarns) are comprised of CNTs that are too long to be
inhaled or absorbed by the skin; for this reason, NTI believes it produces the safest CNT
commercial products on the market. NTI's sheets, tapes, conductors and yarn products have
been classified by the Environmental Protection Agency (EPA) as "articles, "not" particles and
so--unlike all commercial producers of CNT particles--are not subject to more stringent oversight
as a potentially toxic or hazardous material.

2. . Wavelength Versus Physical Dimension
For electromagnetic radiation with a wavelength of nanometers, one is in the X-ray range of the
spectrum. Therefore, any technology with nanometer feature sizes is bound to be in the limit that
the device size is much less than the wavelength.
DC Versus AC Eelectronic Properties
In the case of electronic properties of systems, there is another important wavelength, and that is
the quantummechanical wavelength of the electron. At dc it is well known that when conductors
are made at this scale the dc electronic properties are very different than larger conductors. Since
the wavelength of electrons in metals and semiconductors is in the range 0.1–10 nm, this
presents an important issue for dc properties of electronic devices. By and large, the physical
principles that govern these device operations at dc have been fairly well laid out and understood
by the device physics research community.[5] These concepts include, for example, the
quantization of electrical conductance in units of e2 h , and the concept of single-electron
transistors, based on the large energy it takes to add a single electron to a system with a very
small capacitance
Nanoantenna
A separate topic is the interaction of such systems with microwave radiation (e.g., plane waves).
Until recently, very little was known about this at all. For example, if a nanotube is fabricated
that is one free-space wavelength long, what will its radiation impedance be, what will the
radiation pattern look like, how will the antenna resistive losses affect its properties, and what
will the scattering properties be like? The answers to these questions are unknown for all but the
very simplest of geometries, that of a dipole antenna geometry.
SINGLE-WALLED NANOTUBES (SWNT) A SWNT is formed by wrapping a single sheet of
graphite (graphene- Fig.1(a)), seamlessly, into tubular forms (Fig. 1(b)).It is interesting to note
that graphene, by itself, can be characterized as either a zero-gap semiconductor or a metal, since
the density of states (DOS) is zero at the Fermi energy (EF), and imparts those properties to a
nanotube.It is also well known that the fundamental conducting properties of a graphene tubule
depend on the nature of wrapping (chirality) and the diameter (typically, SWNTs have diameters
in the range21 0.4 nm–2 nm).
Doping Characteristics of Nanotubes
For semiconducting SWNTs, in the absence of impurities or defects (doping), the Fermi energy
(EF) is taken to be at a reference value of zero.However, for a realistic graphene based nanotube
a finite doping is inevitable due to the presence of adsorbates, from the ambient, which would
cause charge transfer.In that case, the EF is either <0 (for hole doping, electron transfer from the
NT—p type) or >0 (for electron doping, electron transfer to the NT—
n type).The effects of temperature also have to be taken into consideration i.e., (i) kBT >EF or

3. (ii) kBT
Solution
A significant nanoparticle discovery that came to light in 1991 was carbon nanotubes. Where
buckyballs are round, nanotubes are cylinders that haven’t folded around to create a sphere.
Carbon nanotubes are composed of carbon atoms linked in hexagonal shapes, with each carbon
atom covalently bonded to three other carbon atoms. Carbon nanotubes have diameters as small
as 1 nm and lengths up to several centimeters. Although, like buckyballs, carbon nanotubes are
strong, they are not brittle. They can be bent, and when released, they will spring back to their
original shape.
The strongest, lightest and most conductive material known
Carbon nanotubes (CNTs) are tubular cylinders of carbon atoms that have extraordinary
mechanical, electrical, thermal, optical and chemical properties At the individual tube level,
these unique structures exhibit: 200X the strength and 5X the elasticity of steel; 5X the electrical
conductivity ("ballistic transport"), 15X the thermal conductivity and 1,000X the current
capacity of copper; at almost half the density of aluminum. As a carbon based product, CNTs
have almost none of of environmental or physical degradation issues common to
metals—thermal expansion and contraction, corrosion and sensitivity to radiation—all of which
result in greater system failure in performance-sensitive applications in aerospace and defense,
aviation, automotive, energy and consumer products.
CNTs typically have diameters ranging from ‹1 nanometer (nm) up to 50 nm—a nanometer is
one thousand millionth of a meter. Typical CNT lengths are several microns—several thousand
nanometers long; by contrast, Nanocomp's produced fibers are measured in
millimeters—thousands of times longer than all other commercially produced CNTs. In the
powdery format offered by all CNT producers (but for NTI), applications are limited to the
properties possible by this form factor—e.g. additive active ingredients in semiconductors, liquid
crystal displays (LCDs), sensors, and other uses in which these powders add some level of
functional performance.
Due to its fiber length and its form factors, NTI delivers strength and conductivity unlike any
other commercial CNT producer, and so can address a much broader array of applications for
which its material rivals copper and aluminum in conductivity, and steel, aluminum, carbon
fibers and glass composites where strength and lightweight matter. Further, the Company's
macro forms (sheets, tapes, conductors and yarns) are comprised of CNTs that are too long to be
inhaled or absorbed by the skin; for this reason, NTI believes it produces the safest CNT
commercial products on the market. NTI's sheets, tapes, conductors and yarn products have
been classified by the Environmental Protection Agency (EPA) as "articles, "not" particles and

4. so--unlike all commercial producers of CNT particles--are not subject to more stringent oversight
as a potentially toxic or hazardous material.
. Wavelength Versus Physical Dimension
For electromagnetic radiation with a wavelength of nanometers, one is in the X-ray range of the
spectrum. Therefore, any technology with nanometer feature sizes is bound to be in the limit that
the device size is much less than the wavelength.
DC Versus AC Eelectronic Properties
In the case of electronic properties of systems, there is another important wavelength, and that is
the quantummechanical wavelength of the electron. At dc it is well known that when conductors
are made at this scale the dc electronic properties are very different than larger conductors. Since
the wavelength of electrons in metals and semiconductors is in the range 0.1–10 nm, this
presents an important issue for dc properties of electronic devices. By and large, the physical
principles that govern these device operations at dc have been fairly well laid out and understood
by the device physics research community.[5] These concepts include, for example, the
quantization of electrical conductance in units of e2 h , and the concept of single-electron
transistors, based on the large energy it takes to add a single electron to a system with a very
small capacitance
Nanoantenna
A separate topic is the interaction of such systems with microwave radiation (e.g., plane waves).
Until recently, very little was known about this at all. For example, if a nanotube is fabricated
that is one free-space wavelength long, what will its radiation impedance be, what will the
radiation pattern look like, how will the antenna resistive losses affect its properties, and what
will the scattering properties be like? The answers to these questions are unknown for all but the
very simplest of geometries, that of a dipole antenna geometry.
SINGLE-WALLED NANOTUBES (SWNT) A SWNT is formed by wrapping a single sheet of
graphite (graphene- Fig.1(a)), seamlessly, into tubular forms (Fig. 1(b)).It is interesting to note
that graphene, by itself, can be characterized as either a zero-gap semiconductor or a metal, since
the density of states (DOS) is zero at the Fermi energy (EF), and imparts those properties to a
nanotube.It is also well known that the fundamental conducting properties of a graphene tubule
depend on the nature of wrapping (chirality) and the diameter (typically, SWNTs have diameters
in the range21 0.4 nm–2 nm).
Doping Characteristics of Nanotubes
For semiconducting SWNTs, in the absence of impurities or defects (doping), the Fermi energy
(EF) is taken to be at a reference value of zero.However, for a realistic graphene based nanotube
a finite doping is inevitable due to the presence of adsorbates, from the ambient, which would
cause charge transfer.In that case, the EF is either <0 (for hole doping, electron transfer from the

5. NT—p type) or >0 (for electron doping, electron transfer to the NT—
n type).The effects of temperature also have to be taken into consideration i.e., (i) kBT >EF or
(ii) kBT