Polymorphic Control of <i>α</i> and <i>β</i><scp>dl</scp>‐Methionine through Swift Cooling Crystallization Process

Abstract

Abstract Polymorphic control and crystal nucleation of α and β polymorphs of dl ‐methionine, an essential amino‐acid, is attained from saturated aqueous solution through swift cooling crystallization process by generating wide range of supersaturation (0.02 &lt; σ &lt; 2.19) in the temperature range of 323–274 K. The type of nucleation is very much supersaturation dependent: while lower supersaturation range (0.02 &lt; σ &lt; 0.08) prefers the stable β form, higher supersaturation range (1.20 &lt; σ &lt; 2.19) yields metastable α form. In situ optical microscopy and X‐ray diffraction analyses confirm the morphological and structural distinction of the grown polymorphs.

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