STUDIES ON LEAD OXALATE CRYSTALLINE GROWTH

The synthesis of lead oxalate crystals was assayed under differing conditions. The main variable that determined the shape of the obtained crystals was the duration of the experiment. At short times (2 h) acicular dendritic crystals were obtained, whereas at long times (24 h) polyhedral crystals were formed. Anhydrous lead oxalate was obtained in all cases. The kinetics of lead oxalate crystal growth was studied. The experiments were performed at both decreasing supersaturation during the crystalline growth and under conditions where the range of oscillation of the supersaturation during the crystal growth process was automatically controlled without human intervention from potentiometric measurements. In all cases a crystal growth order superior to three was obtained. This must be interpreted by admitting that for all the studied supersaturations, a crystal growth mechanism through surface nucleation took place. © 1993 Academic Press, Inc.