Study On The Impact Of Ultrasound On Crystallization Mechanism Of C₆H₉N₃O₃

The characteristics and applications of ultrasound, and thermodynamic and kinetics properties of the crystallization were summarized. The effect of ultrasound on the crystallization of C₆H₉N₃O₃ aqueous solution has been systematically investigated. The metastable zone width, induction time and crystal size of C₆H₉N₃O₃ were emphasized. The mechanism of the process of crystallization with ultrasound was theoretically analyzed in this paper.The metstable zone width and induction time of nucleation were measured in the cooling crystallization of C₆H₉N₃O₃ with ultrasound and stirring. Compared the metstable zone width and induction time under ultrasound with those under stirring, the advantages and microscopic mechanism of ultrasonic effect have been analyzed. By comparing the crystals insonated with that stirred, the factors of influencing crystal size distribution and crystal yield were analyzed on thermodynamics.In order to explore the effect of ultrasonic cavitation on solution nucleation, we observed the distribution of ferrite particles in water imposed by ultrasonic cavitation, vibration and stir separately. It was found that the ultrasonic cavitation and stirring could enhance the diffusion coefficients of liquor more than ultrasonic vibration. The induction time of nucleation was also measured under above three actions. We analyzed the mechanism of nucleation of C₆H₉N₃O₃ aqueous solution insonated. It is concluded that the ultrasonic cavitation and vibration prompt nucleation and the former was better. The crystals of C₆H₉N₃O₃ under cavitation and vibration have smaller and more even size than those under stirring. This indicates that the vibration is the most important factor influencing the crystalline of C₆H₉N₃O₃.