Abstract： Crystallization of aqueous glycin solution with acetone as the anti-solvent is studied to examine the effects of ultrasound on crystal size and habit. With ultrasound excitations, the solution experiences cavitation, first nucleation, second nucleation, crystal growth, fragmentation, etc. Introducing ultrasound at different times or for different durations will have different influences on the crystallization distribution. If ultrasound is introduced for a short time before the onset of homogeneous nucleation to induce nucleation, one will obtain larger crystals, whereas if the ultrasound is introduced at or after the onset of homogeneous nucleation, smaller crystals will be obtained. If ultrasound is used in the growth stage, the crystals will also be small because the crystals will be fragmented by ultrasound.
2007, Vol. 7 
