Solution-Mediated Transformation of α to β l-Glutamic Acid:  Rate Enhancement Due to Secondary Nucleation

• Published in: Crystal growth & design Vol. 4; no. 5; pp. 1061 - 1068
• Main Authors: Ferrari, Elena S, Davey, Roger J
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Washington,DC American Chemical Society 01.09.2004
• Subjects: Condensed matter: structure, mechanical and thermal properties; Crystalline state (including molecular motions in solids); Crystallographic aspects of phase transformations; pressure effects; Equations of state, phase equilibria, and phase transitions; Exact sciences and technology; General studies of phase transitions; Nucleation; Physics; Structure of solids and liquids; crystallography; Glutamic acid; Scanning electron microscopy; Raman spectra; Nucleation; Ultraviolet spectra; Composition effect; Evaporation; Infrared spectra; Experimental study; Optical microscopy; Monocrystals; Saturated solution; Crystal growth from solutions; Fourier transform spectra; Organic compounds; Polymorphism
• ISSN: 1528-7483; 1528-7505
• DOI: 10.1021/cg0342112

The ability to control the transformation process between polymorphs of crystalline materials is critical to ensure that the correct form is produced, and hence it is essential to learn which experimental factors affect this transformation reaction. In this contribution, the kinetics of the polymorphic transformation between metastable and stable forms of l-glutamic acid was studied using a number of techniques:  optical microscopy, FT-IR, Raman and UV spectroscopy. The effects of solution composition and in particular process scale were investigated. The role of secondary nucleation in which the surface of one polymorph acts as a template for the nucleation of another form is highlighted in this paper.