Brown's Chemistry Revision Notes
NANOCHEMISTRY - Nanoscience - Nanotechnology - Nanostructures
Uses of nanoparticles of titanium(IV) oxide, fat and silver
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 *
Uses of nanoparticles of titanium(IV) oxide (titanium dioxide,
How does titanium dioxide
protect us from uv light? What does titanium dioxide do in sun creams?
In the cosmetics industry the use of nanosized particles in creams etc is increasing,
because of the small particle size, they can be more easily absorbed
through the skin, as in moisturisers.
Titanium dioxide, TiO2, is a white
powder and a good reflector of visible light and most commonly encountered as a brilliant white pigment in paint.
However, it also used in the
cosmetic and skincare products industry as a pigment, thickener, moisturiser
and used in sunscreens as a uv absorber.
Titanium dioxide is a good uv
light absorber and is effective as many organic molecules used as uv
absorbers in many commercial sun creams.
Nanoparticles of titanium
dioxide are incorporated into 'sun blockers', though the particles have to
be specially coated (*) to avoid skin irritation problems from using
such titanium dioxide based sunscreens.
As well as being a good uv
absorber (90% absorbed, 10% scattered), nanosized titanium dioxide particles have
2nd another advantage.
TiO2 particles are smaller than
the wavelength of light and are therefore too small to see, and when used
in sunscreen creams they are transparent to light rather than opaque, so the
skin looks a more natural colour nanochemistry meets human aesthetics!
A good example of where particle
size matter, and the tiny size of titanium dioxide particles gives it this
Note in passing that
nanoparticles of zinc oxide are also used in sunscreens.
Note - titanium dioxide in the
form of anatase crystals can be converted into nanotubes 10-20 nm in
diameter - but I don't their potential uses?
What are nanoparticles of
silver? What size are they? What can we do with nanoparticles of silver?
Silver has always been used as a
catalyst to speed up specific reactions in the chemical industry to improve
By using nanoparticles of silver (35-120 nm in size)
the effectiveness of the catalyst is greatly improved because the surface
area of nanosized silver is so much greater than the larger particles
Its a good example of the 'surface area' rates-kinetic
factor for reactions involving a solid catalyst or reactant.
Nanoparticles of silver are
being used in anti-bacterial and anti-fungal agents in biotechnology,
bioengineering, the textile industry, water treatment and disinfecting
surfaces in the home or hospitals etc.
Bactericide and fungicide
formulations are being developed to include nanoparticles e.g. of silver,
because of their powerful ability to kill bacteria and other organisms.
Because of their antibacterial
and antifungal properties, potential uses of silver nanoparticles include
bone cement, surgical instruments, surgical masks and wound dressings.
There is an advantage (at least
at the moment!) in using nanoparticles of silver in antibacterial agents,
because many bacteria are evolving into strains which are resistant to many
antibiotics rendering the ineffective in fighting infections, but so far
bacteria don't seem to be resistant to nano-silver formulations!
Nanoparticles of silver are also
used in optics and electronics - important applications but not much, if
any, chemistry involved?
Some cosmetics contain 'liposomes',
which are fatty nanoparticles .
Nanoparticles of fatty-like
molecules have great potential in the pharmaceutical
industry to deliver tiny doses of medicines directly into cells.
Other examples of the use of nanoparticles and
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
liposomes fat sunscreens-sunblockers titanium dioxide silver nanoparticles TiO2 Revising for KS4 Science IGCSE/O level/GCSE
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