aA non-toxic and environmentally friendly way to make tiny nanorods of zinc
oxide has been developed for the first time by researchers in Saudi Arabia.
The approach, described in the current issue of the International
Journal of Nanoparticles, could allow the nanorods to be used safely in
medical and for other applications.
Zinc oxide has many uses when fabricated as nanoparticles and nanorods, just
100 nanometers in diameter. In such as nanoscopic form, it can be used in food
products, such as breakfast cereals as a source of zinc, a necessary nutrient.
It can also be used in dentistry and cosmetic ointments, creams, and lotions
to protect against sunburn and skin damage caused by ultraviolet light.
Zinc oxide can also act as a sensor for detecting changes in electric current
due to absorption of gas molecules and so be used for gas leak warning devices.
In electronics, the same material has wrought a revolution in lasers and light
emitting diodes (LEDs). And as a biosensor, it can be used as a biomimic membrane
to immobilize and modify biomolecules.
Now, M.A. Shah and M.S. Al-Shahry of the King Khalid University, in Abha, and
A.M. Asiri of the King Abdul-Aziz University, in Jeddah, Saudi Arabia, have
discovered a safe and biocompatible route for the synthesis of zinc oxide nano
rods. Their route is based on the simple reaction of water and zinc powder at
a relatively low temperature. "Since water is regarded as a benign solvent
and non-toxic, the product (nanorods) could be used safely for biomedical and
other applications," Shah says.
The approach is versatile for making different kinds of zinc oxide nanostructures
and critically avoids the use of toxic organic solvents altogether. In the new
approach, zinc powder is added to water, blasted with ultrasound for few minutes
and then warmed at a temperature of 200 Celsius for 24 hours. The team has used
the analytical techniques of X-ray and field emission electron microscopy to
reveal the structure of the product.
The researchers found that they can produce uniform nanorods of 30 to 100 nanometers.
They have also found that they can use pure water in what they say is a "simple
and straightforward approach…suitable for large scale production."
The proposed method is novel, rapid, economical, environmentally benign, and
produces no pollutants, Shah adds.
Posted August 19th, 2009
