Brown's Chemistry Revision Notes
NANOCHEMISTRY - Nanoscience - Nanotechnology - Nanostructures
Part 2. NANOCHEMISTRY - an introduction
and potential applications
Alphabetical keyword index for
the nanoscience pages : Index of nanoscience pages
: boron nitride *
Buckminsterfullerenes-bucky balls *
carbon nanotubes * fat nanoparticles
* fluorographene *
graphene * health and
* liposomes *
nanoscale * nanoscience *
* nanotechnology *
problems in nanomaterial use *
silver nanoparticles *
safety issues * sunscreens-sunblockers *
Part 2. NANOCHEMISTRY
What is NANOCHEMISTRY?
Nanochemistry is a branch
of nanoscience, deals with
the chemical applications of nanomaterials in nanotechnology.
the study of the synthesis and characterisation of materials of nanoscale
Nanochemistry is a relatively
new branch of chemistry concerned with the unique properties associated
with assemblies of atoms or molecules of nanoscale (~1-100 nm), so the size
of nanoparticles lies somewhere between individual atoms or molecules (the
'building blocks') and larger assemblies of bulk material which we are more
There are physical and chemical techniques in
manipulating atoms to form molecules and nanoscale assemblies.
Physical techniques allow atoms
to be manipulated and positioned to specific requirements for a prescribed
chemical techniques arrange atoms in molecules using well characterised chemical reactions.
Nanochemistry is the science of tools, technologies, and methodologies for
novel chemical synthesis e.g. employing synthetic chemistry
to make nanoscale building blocks of desired (prescribed) shape, size, composition and
surface structure and possibly the potential to control
the actual self-assembly of these building blocks to various desirable size.
At this extremely small scale
level, quantum effects can be significant, fascinating and potentially
scientifically very rewarding innovative ways of carrying out chemical
reactions are possible.
The small size of nanoparticles
gives these particles 'unusual' structural and optical properties with
applications in catalysis, electrooptical devices etc.
As well as the huge numbers of
man-made nanoparticles structures being synthesised, there are naturally occurring
nanoparticle assemblies e.g. phospholipid vesicles, polypeptide micelle of
the iron storage protein, ferritin.
Nanoparticles are VERY tiny
aggregations of atoms BUT bigger than most molecules.
There is no strict dividing line
between nanoparticles and 'ordinary bulk' particles of a material such as
baking powder or grains of sand, BUT particle size matters! ...
... BECAUSE nanoparticles can display
properties significantly different from the bulk material and these
properties can be exploited for many different uses. If you compare the size of
nanoparticles to that of conventional industrially produced materials you
find they have novel uses such as sunscreens and many present future
Nanoparticles have a high
surface to volume ratio which has a dramatic effect on their properties
compared to non-nanoscale forms of the same material.
Pieces of gold are, fairly
obviously, gold-coloured, but gold nanoparticles are deep red or even black
when mixed with water. use?
Titanium dioxide is a white
solid used in house paint where plainly it reflects visible light. However,
titanium dioxide nanoparticles are so small that they do not reflect visible
light, so they cannot be seen and are used in sunblock creams because they
block harmful ultraviolet light from the Sun without appearing white on the
skin (as in TiO2 in paint).
Silver foil shows virtually no
reaction with dilute hydrochloric acid but nanoparticles of silver rapidly
react with hydrochloric acid because of the very large surface are to volume
ration (think of limestone lumps and very fine powder illustrates this effect
at the much larger non-nanoparticle level.
Nanotubes (more details of specific
examples on other pages), one of the most widespread studied and used
nanomaterials, consist of tiny cylinders of carbon (and other materials like
boron nitride), no wider than a strand of DNA with a wide range of properties
of great use to materials scientists. Nanotubes can be stronger than steel
with only 1/6th the weight. Some nanotubes are excellent
insulators, semiconductors or conduct electricity as well as
Incredibly, there are lots of varieties of nanotubes,
even for the same element or compound,
differing in size and atomic arrangement, which can have very different properties!
Therefore a wide range of nanomaterials are being developed for an even
wider range of applications and technological uses. See
carbon and boron nitride
to illustrate this point.
Applications of Nanoscience - with an
emphasis on NANOCHEMISTRY
Detailed examples of uses of
CHEMISTRY are discussed on separate pages
We are talking about the
manufacture of new catalysts, coatings, computer components, highly
selective sensors, lighter strong materials etc.
The large surface to volume
ratio will allow the development of new industrial catalysts.
Nanomaterials can be used to
make sensors that detect specific molecules.
Nanotubes can be fabricated into
strong and light materials, sometimes as composites with other
The increased reactivity
and small size of nanoparticles compared to larger ones are two important
factors which frequently crop up when
studying the function of
Nanoparticles have a high
surface are to volume ratio, this increases their rate of chemical
reaction (greater reactivity) and this also enhances their catalytic effect.
Nanomaterials can even be used
for such mundane-unexciting applications as in self-cleaning ovens and self-cleaning windows!,
but not mundane to domestic work in the home, but will it put window
cleaners out of business, I doubt it!
The work on
nanochemistry can include colloid chemistry.
Part 1. General introduction to nanoscience
and commonly used terms explained
Part 2. NANOCHEMISTRY - an introduction and potential
Uses of Nanoparticles of titanium(IV) oxide, fat and silver
From fullerenes & bucky balls to carbon nanotubes
Cubic and hexagonal boron nitride BN
Problems, issues and
implications associated with
see also INDEX
SMART MATERIALS PAGES
Keywords: uses applications carbon nanotubes nanoparticles nanochemistry nanomaterials nanoscale nanoscience nanosize-nanosized particles nanotubes