A Safer Nanotechnology

Nanotechnology has blossomed for over a decade as evidenced by the growing number of applications of nanomaterials. Environmental implications are an important consideration when developing new materials and researchers in Saudi Arabia have developed a more environment friendly way to make nanomaterials from zinc oxide.¹ Their approach avoids using toxic volatile organic solvents and allows them to make zinc oxide nanorods for medical and other uses in nothing more than hot water. 

Zinc oxide is used in food products such as breakfast cereals as a source of dietary zinc, in dentistry and cosmetics, sunscreens, antiseptics, and other products. It has also been developed into sensor materials for gas detection and in biosensors. However, its use in nanotechnology relies on volatile organic compounds (VOCs) for producing the necessary particles, which are ca 100 nm across.  

The new approach, developed by a team lead by Abdullah Mohammed Asiri of the King Abdul-Aziz University, in Jeddah, Saudi Arabia, uses sonochemistry - a technique in which high frequency ultrasound is used to initiate physical changes in a substance. The researchers added zinc powder to water, blasted this mixture with ultrasound, and then heated it to 200°C for 24 hours. Using X-ray and field emission electron microscopy, the team confirmed that their technique produces uniform nanorods that are just 30-100 nm across.