Acta Chim Slov. 2020 Sep;67(3):842-852.
This work assesses the effects of various amino acids, including serine, alanine, methionine, and proline, on calcium tartrate tetrahydrate (CTT) crystals. The crystallization experiments were performed in batch mode at 25 °C, pH 9 with three amino acid concentrations. The CTT crystals were characterized by XRD, FTIR, SEM, particle size and zeta poten-tial analysis. All of the amino acids used in this study were found to significantly affect the surface electrical charge, size, and morphology of the obtained crystals. In addition, the thermal decomposition of the produced crystals obtained in pure media was examined and the obtained data were used to investigate the decomposition kinetics of the crystals with the help of three different model-free kinetic methods, namely Flynn-Wall-Ozawa (FWO), Kissinger-Akahira-Sunose (KAS), and Starink. The average activation energy of the crystals for the first, second, third, and fourth stages using the FWO, KAS, and Starink methods was calculated to be 91.0, 158.0, 249.1, and 224.8 kJ/mol; 89.6, 155.9, 250.7, and 221.1 kJ/mol; 88.6, 156.8, 250.5, and 220.4 kJ/mol, respectively. Thus, the results of this work are useful for selecting CTT mor-phology modifiers and explaining the decomposition kinetics of CTT crystals.
这项工作评估了各种氨基酸（包括丝氨酸、丙氨酸、蛋氨酸和脯氨酸）对酒石酸氢钙四水合物（CTT）晶体的影响。结晶实验在 25°C、pH9 下以三种氨基酸浓度进行分批操作。通过 XRD、FTIR、SEM、粒度和zeta 电位分析对 CTT 晶体进行了表征。研究中使用的所有氨基酸都被发现显著影响了所得晶体的表面电荷、大小和形态。此外，还研究了在纯介质中获得的晶体的热分解，并利用三种不同的无模型动力学方法（Flynn-Wall-Ozawa（FWO）、Kissinger-Akahira-Sunose（KAS）和 Starink）获得的数据来研究晶体的分解动力学。使用 FWO、KAS 和 Starink 方法计算晶体第一、第二、第三和第四阶段的平均活化能分别为 91.0、158.0、249.1 和 224.8 kJ/mol；89.6、155.9、250.7 和 221.1 kJ/mol；88.6、156.8、250.5 和 220.4 kJ/mol。因此，这项工作的结果有助于选择 CTT 形态改性剂并解释 CTT 晶体的分解动力学。
