1 Introduction 3
Figure 1.3 Chemical synthesis as bottom-up process. Bottom-up processes are characterized
by the use of atoms or molecules as educts. Products are particles, nanotubes or nanorods,
or layered structures.
Chemical
or physical
processes
s
t
c
u
d
o
r
P
s
t
c
u
d
E
ParƟcles
Nanorods
Nanotubes
Nanoplates
Atoms
Molecules
features are also called zero-, one-, or two-dimensional nanostructures. This is
graphically demonstrated in Figure 1.3. Bottom-up processes give tremendous
freedom in the composition of the resulting products; however, the number of
possible structures to be obtained is comparatively small. Ordered structures are
obtained by processes that are supplemented by self-organization of individual
particles. Often, top-down technologies are described as subtractive ones, in contrast to additive technologies describing bottom-up processes.
Figure 1.4 shows the size ranges of the different processes applied in nanotechnology. Certainly, there is a broad range of overlapping, between the top-down
and bottom-up technologies. Most interesting, there are improved top-down technologies, such as electron beam or X-ray lithography entering the size range typical
for nanotechnologies. These improved top-down technologies obtain increasing
importance, for example, in highly integrated electronic devices.
For industrial applications, the most important question is the price of the
product in relation to the properties. As far as the properties are comparable, in
most cases, nanomaterials and products applying nanomaterials are significantly
more expensive than conventional products. This becomes problematic in cases
where the increase in price is more pronounced than the improvement of the
properties due to the application of nanomaterials. Therefore, economically interesting applications of nanomaterials are found primarily in areas where properties
that are out of reach for conventional materials are demanded. Provided this condition is fulfilled, the price is no longer that important. However, in cases where
nanomaterials are in direct competition to well-established conventional technologies, the price is decisive. This fierce price competition is extremely difficult for a
young and expensive technology and may lead sometimes to severe, financial
Figure 1.3 Chemical synthesis as bottom-up process. Bottom-up processes are characterized
by the use of atoms or molecules as educts. Products are particles, nanotubes or nanorods,
or layered structures.
Chemical
or physical
processes
s
t
c
u
d
o
r
P
s
t
c
u
d
E
ParƟcles
Nanorods
Nanotubes
Nanoplates
Atoms
Molecules
features are also called zero-, one-, or two-dimensional nanostructures. This is
graphically demonstrated in Figure 1.3. Bottom-up processes give tremendous
freedom in the composition of the resulting products; however, the number of
possible structures to be obtained is comparatively small. Ordered structures are
obtained by processes that are supplemented by self-organization of individual
particles. Often, top-down technologies are described as subtractive ones, in contrast to additive technologies describing bottom-up processes.
Figure 1.4 shows the size ranges of the different processes applied in nanotechnology. Certainly, there is a broad range of overlapping, between the top-down
and bottom-up technologies. Most interesting, there are improved top-down technologies, such as electron beam or X-ray lithography entering the size range typical
for nanotechnologies. These improved top-down technologies obtain increasing
importance, for example, in highly integrated electronic devices.
For industrial applications, the most important question is the price of the
product in relation to the properties. As far as the properties are comparable, in
most cases, nanomaterials and products applying nanomaterials are significantly
more expensive than conventional products. This becomes problematic in cases
where the increase in price is more pronounced than the improvement of the
properties due to the application of nanomaterials. Therefore, economically interesting applications of nanomaterials are found primarily in areas where properties
that are out of reach for conventional materials are demanded. Provided this condition is fulfilled, the price is no longer that important. However, in cases where
nanomaterials are in direct competition to well-established conventional technologies, the price is decisive. This fierce price competition is extremely difficult for a
young and expensive technology and may lead sometimes to severe, financial