Radiation 2006. In association with the Polymer Division, Royal Australian Chemical Institute. Incorporating the 21st AINSE Radiation Chemistry Conference and the 18th Radiation Biology Conference, conference handbook

Full text: When sound wave is passed through a liquid medium, cavitation, commonly referred to the growth and violent collapse of microbubbles, is induced. The cavitation process can promote a wide range of chemical reactions, such as the synthesis of polymers and the production of metal nanoparticles. By sonicating a mixture of monomer/ water emulsion, polymer latex particles in the size range of 70 - 110nm could be produced. The sonochemical polymerization process is initiated by the reaction of primary radicals (H. and .Ho) with free monomer molecules. The physical effects, such as the shear forces generated during the bubble collapse, are responsible for the narrow size of the polymer particles produced. Ultrasonic irradiation can also be employed to prepare polymer/ metal nanocomposites. The primary and secondary reducing radicals generated during the ultrasonic irradiation of an aqueous solution could be used to reduce dissolved metal ions. These metal ions then agglomerate and produce metal nanoparticles. When this process is combined with the polymerization process, it enables the metal nanoparticles to be well dispersed within the polymer latex particles due to the physical effects caused by cavitation. Such nanocomposites have a wide range of applications in many fields such as optics, electronics and magnetism