Intensification of synthesis of zirconium dioxide using ultrasound: Effect of amplitude variation

Nanosize zirconium dioxide has been synthesized from zirconyl nitrate using the conventional approach as well as ultrasound assisted precipitation method for understanding the process intensification. Also, the effect of amplitude of irradiation (input power varied from 7.6 W (20% amplitude) to 82.1 W (70% amplitude)) on tetragonal phase content, percentage crystallinity, crystallite size, thermal and morphological properties of the obtained nano-ZrO2 has been studied. The samples synthesized at low (20%), mid-range (40%) and high (70%) amplitudes have been calcinated at a constant temperature of 500 °C. The effect of ultrasound power input on the obtained yields has also been investigated. The use of ultrasound increased the yields as compared to the conventional approach though the enhanced power input was observed to have marginal effect on the yields. All the important properties were significantly affected by the power dissipation levels which decide the cavitational activity in the reactor and it has been established that optimum power input is necessary to achieve significant intensification in terms of the desired properties for the final product. 40% amplitude, corresponding to 27 W, was found to be optimum for getting maximum tetragonal content for zirconia with higher thermal stability over the range of 400 to 600 °C.