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Nanomaterials: An Introduction
Today, everybody is talking about nanomaterials, even advertisements for consumer
products use the prefix “nano” as a keyword for special features, and, indeed, very
many publications, books, and journals are devoted to this topic. Usually, such
publications are directed towards specialists such as physicists and chemists, and
the “classic” materials scientist encounters increasing problems in understanding
the situation. Moreover, those people who are interested in the subject but who have
no specific education in any of these fields have virtually no chance of understanding
the development of this technology. It is the aim of this book to fill this gap. The book
will focus on the special phenomena related to nanomaterials and attempt to provide
explanations that avoid – as far as possible – any highly theoretical and quantum
mechanical descriptions. The difficulties with nanomaterials arise from the fact that,
in contrast to conventional materials, a profound knowledge of materials science is
not sufficient. The cartoon shown in Figure 1.1 shows that nanomaterials lie at the
intersection of materials science, physics, chemistry, and – for many of the most
interesting applications – also of biology and medicine.
However, this situation is less complicated than it first appears to the observer, as
the number of additional facts introduced to materials science is not that large.
Nonetheless, the user of nanomaterials must accept that their properties demand a
deeper insight into their physics and chemistry. Whereas for conventional materials
the interface to biotechnology and medicine is related directly to the application, the
situation is different in nanotechnology, where biological molecules such as proteins
or DNA are also used as building blocks for applications outside of biology and
medicine.
So, the first question to be asked is: “What are nanomaterials?” There are two
definitions. The first – and broadest – definition states that nanomaterials are
materials where the sizes of the individual building blocks are less than 100 nm, at
least in one dimension. This definition is well suited for many research proposals,
where nanomaterials often have a high priority. The second definition is much more
restrictive and states that nanomaterials have properties that depend inherently on
the small grain size; as nanomaterials are usually quite expensive, such a restrictive
definition makes more sense. The main difference between nanotechnology and
conventional technologies is that the “bottom-up” approach (see below) is preferred
in nanotechnology, whereas conventional technologies usually use the “top-down”
Nanomaterials: An Introduction to Synthesis, Properties and Applications, Second Edition. Dieter Vollath.
Ó 2013 Wiley-VCH Verlag GmbH & Co. KGaA. Published 2013 by Wiley-VCH Verlag GmbH & Co. KGaA.
j1
Nanomaterials: An Introduction
Today, everybody is talking about nanomaterials, even advertisements for consumer
products use the prefix “nano” as a keyword for special features, and, indeed, very
many publications, books, and journals are devoted to this topic. Usually, such
publications are directed towards specialists such as physicists and chemists, and
the “classic” materials scientist encounters increasing problems in understanding
the situation. Moreover, those people who are interested in the subject but who have
no specific education in any of these fields have virtually no chance of understanding
the development of this technology. It is the aim of this book to fill this gap. The book
will focus on the special phenomena related to nanomaterials and attempt to provide
explanations that avoid – as far as possible – any highly theoretical and quantum
mechanical descriptions. The difficulties with nanomaterials arise from the fact that,
in contrast to conventional materials, a profound knowledge of materials science is
not sufficient. The cartoon shown in Figure 1.1 shows that nanomaterials lie at the
intersection of materials science, physics, chemistry, and – for many of the most
interesting applications – also of biology and medicine.
However, this situation is less complicated than it first appears to the observer, as
the number of additional facts introduced to materials science is not that large.
Nonetheless, the user of nanomaterials must accept that their properties demand a
deeper insight into their physics and chemistry. Whereas for conventional materials
the interface to biotechnology and medicine is related directly to the application, the
situation is different in nanotechnology, where biological molecules such as proteins
or DNA are also used as building blocks for applications outside of biology and
medicine.
So, the first question to be asked is: “What are nanomaterials?” There are two
definitions. The first – and broadest – definition states that nanomaterials are
materials where the sizes of the individual building blocks are less than 100 nm, at
least in one dimension. This definition is well suited for many research proposals,
where nanomaterials often have a high priority. The second definition is much more
restrictive and states that nanomaterials have properties that depend inherently on
the small grain size; as nanomaterials are usually quite expensive, such a restrictive
definition makes more sense. The main difference between nanotechnology and
conventional technologies is that the “bottom-up” approach (see below) is preferred
in nanotechnology, whereas conventional technologies usually use the “top-down”
Nanomaterials: An Introduction to Synthesis, Properties and Applications, Second Edition. Dieter Vollath.
Ó 2013 Wiley-VCH Verlag GmbH & Co. KGaA. Published 2013 by Wiley-VCH Verlag GmbH & Co. KGaA.
j1