12.2.1 Nanoparticle
These are the particles having the size range from 1 to 100 nm. They are considered
to be smaller than the cells and similar to the proteins size. On the basis of the
applications, there are many different types of nanoparticles, which can be divided
into four main groups: carbon-based, metal-based, dendrimers, and composites
(Tambe Patil 2005).
12.2.2 Carbon-based Nanomaterials
These nanomaterials are mainly in the shape of the hollow spheres, ellipsoids, or
tubes mostly composed of carbon. Further on the basis of the shape they are
classified in two structures i.e., fullerenes and nanotubes. Spherical and ellipsoidal
nanomaterials are called as fullerenes and the cylindrical nanomaterials are called as
nanotubes. These nanomaterials have multiple properties such as improved coatings,
stronger and lighter materials and are mainly used in electronics (United States
Environmental Protection Agency 2007).
12.2.3 Carbon Nanotubes
These are the graphite sheets which are rolled up into tubes having the bonds at the end
of the sheet and form the bonds near the tubes. They have the diameter of 2 nm and
length of 100 pm, and are used for making the one-dimensional structures called as
nanowires. These nanotubes are formed by the methods of laser evaporation, carbon
arc methods and chemical vapor deposition (Poole Jr and Owens 2003). Apart from
this, they have been used in sustainable environment and green technologies which
include waste water treatment, air pollution monitoring, biotechnologies, renewable
energy technologies, and green nanocomposites (Attar and Ranveer 2015).
12.2.4 Metal-based Nanomaterials
These are the nanomaterials having the smaller size with high surface area and are
used for functionalization and stability. There are many nanomaterials which are
metal based used for embodying the quantum dots, nano gold, nano silver, and metal
oxides, such as titanium dioxide, etc.
12.2.5 Quantum Dots
A quantum dot is a semiconductor crystal which is tightly packed and is made up of
hundreds to thousands of atoms. Its size varies from few nanometers to few hundred
nanometers. They have different conductive properties because of their different size
as a result of which their optical properties also get changed (United States
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These are the particles having the size range from 1 to 100 nm. They are considered
to be smaller than the cells and similar to the proteins size. On the basis of the
applications, there are many different types of nanoparticles, which can be divided
into four main groups: carbon-based, metal-based, dendrimers, and composites
(Tambe Patil 2005).
12.2.2 Carbon-based Nanomaterials
These nanomaterials are mainly in the shape of the hollow spheres, ellipsoids, or
tubes mostly composed of carbon. Further on the basis of the shape they are
classified in two structures i.e., fullerenes and nanotubes. Spherical and ellipsoidal
nanomaterials are called as fullerenes and the cylindrical nanomaterials are called as
nanotubes. These nanomaterials have multiple properties such as improved coatings,
stronger and lighter materials and are mainly used in electronics (United States
Environmental Protection Agency 2007).
12.2.3 Carbon Nanotubes
These are the graphite sheets which are rolled up into tubes having the bonds at the end
of the sheet and form the bonds near the tubes. They have the diameter of 2 nm and
length of 100 pm, and are used for making the one-dimensional structures called as
nanowires. These nanotubes are formed by the methods of laser evaporation, carbon
arc methods and chemical vapor deposition (Poole Jr and Owens 2003). Apart from
this, they have been used in sustainable environment and green technologies which
include waste water treatment, air pollution monitoring, biotechnologies, renewable
energy technologies, and green nanocomposites (Attar and Ranveer 2015).
12.2.4 Metal-based Nanomaterials
These are the nanomaterials having the smaller size with high surface area and are
used for functionalization and stability. There are many nanomaterials which are
metal based used for embodying the quantum dots, nano gold, nano silver, and metal
oxides, such as titanium dioxide, etc.
12.2.5 Quantum Dots
A quantum dot is a semiconductor crystal which is tightly packed and is made up of
hundreds to thousands of atoms. Its size varies from few nanometers to few hundred
nanometers. They have different conductive properties because of their different size
as a result of which their optical properties also get changed (United States
12 Management of Waste Using Nanotechnology
257