Abstract
Ultrasound can generate acoustic cavitations, which is the formation and violent collapse of micro bubbles or gas cavities within a liquid. The collapse of the cavities generates the energy for chemical and mechanical effects. The temperature and pressure generated from the collapse in water have been estimated to be over 5000 K and 2000 atm, respectively, which is high enough to dissociate water molecules into primary hydrogen radicals (H・) and hydroxyl radicals (OH・) in cavitation bubble. Hydrogen peroxide (H_2O_2) is formed by the recombination of hydroxyl radicals (OH・) during the sonolysis of aqueous solution. These facts indicate that one-step synthesizes of nanoparticles and polymer in the form of composite can be possible in aqueous solution using ultrasonic irradiation. In this work, we report a successful one-pot synthesis of Au-NPs/PPy nanocomposite by using ultrasonic irradiation. Hybrid nanocomoposite composed of gold nanoparticles (Au-NPs) and polypyrrole (PPy) was prepared by ultrasonic irradiation of aqueous HAuCl_4 and pyrrole solution in the presence of stabilizer such as poly(N-vinyl-2-pyrrolidone) (PVP).
