Synthesis of dl-Alanine Mesocrystals with a Hollow Morphology

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• 作者：Dana D. Medina ; Yitzhak Mastai
• 刊名：Crystal Growth & Design
• 出版年：2008
• 出版时间：October 1, 2008
• 年：2008
• 卷：8
• 期：10
• 页码：3646-3651
• 全文大小：247K
• 年卷期：v.8,no.10(October 1, 2008)
• ISSN：1528-7505

文摘

The crystallization of dl-alanine from water/alcohol supersaturated solutions results in the precipitation of a racemic compound displaying a needlelike hollow morphology, in contrast to the needlelike crystals grown from pure aqueous solutions. This unusual morphology is explained by assuming that the supersaturated solutions crystallized rapidly to create dl-alanine nanocrystals that assemble to give mesoscale crystals. The resulting dl-alanine crystals are characterized by a range of techniques such as X-ray diffraction, scanning electron microscopy, micro-Raman, and differential scanning calorimetry. The kinetics was studied by light scattering and ion-solution conductivity. These measurements revealed that these superstructures of dl-alanine mesocrystals consist of three-dimensional dl-alanine nanocrystals. Finally, a mechanism for the formation of dl-alanine mesocrystals with a hollow morphology is proposed.