The effect of additive aggregation state on controlling crystallization. Crystallization of L-asparagine monohydrate in the presence of carboxylic acid functionality additives

Cooper, S.J.

Abstract

L-Asparagine monohydrate crystals grown from 100-300% supersaturated solutions in the presence of 1-20 mg ml(-1) polyacrylic acid exhibit a needle-like morphology, instead of their normal prismatic morphology. A similar effect is observed for crystals grown in octanoic acid emulsions. In contrast, no growth modification is observed for L-asparagine monohydrate crystals grown in 20 mg ml(-1) sodium polyacrylate, sodium octanoate and propanoic acid. Polyamido amine (PAMAM) dendrimers (generations -0.5, 1.5, 3.5 and 4.5) end-capped with carboxylate groups also exhibit no growth inhibitory effect at 20 mg ml(-1), even after acidification to pH 2.8. The ability of the carboxylic acid functionality to potentially act as a growth inhibitor for L-asparagine when in solution, or emulsion droplets, is contrasted with the L-asparagine crystallization promotion produced by carboxylic acid films spread at the air- water interface.

Citation

Cooper, S. (2001). The effect of additive aggregation state on controlling crystallization. Crystallization of L-asparagine monohydrate in the presence of carboxylic acid functionality additives. CrystEngComm, art. no.-56

• Journal Article Type: Article
• Publication Date: 2001
• Journal: CrystEngComm
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Issue: 56
• Pages: art. no.-56
• Publisher URL: <Go to ISI>://000172699500001