Jan 19, 2009
Sonochemical route to nanoparticle synthesis
Researchers at Nanjing University have recently developed sonochemical methods for the preparation of nanoparticles with controllable morphologies. Ultrasound has become an important tool for the synthesis of nanoparticles. When liquids are irradiated with ultrasonic irradiation, ultrasonic cavitation will form. Ultrasonic cavitation is concerned with the formation, growth, and implosive collapse of bubbles. Ultrasonic cavitation produces a variety of physical and chemical effects, such as high temperature (>5000 K), pressure (>20 MPa), and cooling rate (>1010 K s-1), which could provide a unique environment for chemical reactions under extreme conditions. The researchers’ work has demonstrated that ultrasound is a fine method in preparation of nanoparticles with controllable morphologies.
In a study published in Nanotechnology, PbWO4 nanostructures with different morphologies, such as dendritic, flowery, and star-like, have been synthesized via a sonochemical route. It has been proved that the ultrasonic irradiation plays a crucial role in the morphology of the product.
Zn(II)bis(1-(2-pyridylazo)-2-naphthol) (Zn(PAN)2) complex nanorods have been successfully synthesized via a sonochemical method. The formation of nanorods could be attributed to the inter-particle collision induced by the collapse of bubbles.
In their work, the researchers used a microemulsion system to successfully synthesize single-crystalline PbF2 nanorods via a sonochemical route. The ultrasonic irradiation has been proved to have an important effect on the final morphology of PbF2.
The high-speed microturbulence induced by ultrasonic irradiation could serve as nanoscale chiesels in the formation of pores. In the recent work published in Nanotechnology, porous Cu2O nanospheres have been successfully synthesized via a sonochemical route. It was found that the high-speed microturbulence could drive liquid into the nanospheres to produce pores.
 Xu L, Jiang L P and Zhu J J 2009 Nanotechnology 20 045605
 Xu K, Mao C J, Geng J and Zhu J J 2007 Nanotechnology 18 315604
 Pan H C, Liang F P, Mao C J and Zhu J J 2007 Nanotechnology 18 195606
 Geng J, Lv Y, Lu D J and Zhu J J 2006 Nanotechnology 17 2614
About the author
Prof. Dr. Jun-Jie Zhu is the Professor of Chemistry, and Vice Dean of School of Chemistry and Chemical Engineering, Nanjing University. Dr. Li-Ping Jiang is the Associate Professor of Chemistry, Nanjing University. Dr. Jun Geng has received the doctoral degree in Nanjing University, and is currently as an Associate Professor in Jiangsu Institute of Education. Dr. Hongcheng Pan has received the doctoral degree in Nanjing University, and is currently as a teacher in Guangxi Normal University. Mr. Ke Xu is the visiting scholar of Nanjing University, and the Associate Professor of Chemistry, West Anhui University. Mr. Lang Xu is the MS student at Nanjing University.