The Effect of Additives on Glycine Crystal Growth Kinetics

✍ Scribed by Li Li; David Lechuga-Ballesteros; Beth A. Szkudlarek; Naı́r Rodrı́guez-Hornedo

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 554 KB
• Volume: 168
• Category: Article
• ISSN: 0021-9797
• DOI: 10.1006/jcis.1994.1387

✦ Synopsis

The effect of (\alpha)-amino acids ("tailor-made" additives) on the morphology and nucleation of glycine crystals was studied in batch experiments, and the effect of L-leucine on glycine crystal growth kinetics was investigated in flow cell experiments at constant supersaturation. From dissolution and growth experiments in a flow cell system, L-leucine was found to adsorb onto the ((0 \overline{1} 0)) face of glycine crystals and to inhibit the growth of that face, modifying the crystal habit. At high t--leucine concentrations ( (>8 \mathrm{mg} / \mathrm{ml}) ), the growth rate of the ((010),(011)), and (01I) faces was faster than that in the absence of additive. This may be the result of the effect L-leucine has on the crystal/solution interfacial tension and on the aggregation of glycine in solution. Oriented nucleation and growth of glycine crystals on the ( (0 \overline{1} 0) ) face were observed. This may be a consequence of multilayer (\mathrm{L})-leucine adsorption onto the ( (0 \overline{\mathrm{I}} 0) ) face, which provides a template for nucleation and growth of glycine twinned crystals about the ( (0 \overline{\mathbf{1}} \mathbf{0}) ) basal plane. 1994 Academic Press, Inc.