THE PHASE-TRANSFORMATION OF CAFFEINE - INVESTIGATION BY DYNAMIC X-RAY-DIFFRACTION AND EMANATION THERMAL-ANALYSIS

被引：29

作者：

EPPLE, M

CAMMENGA, HK

SARGE, SM

DIEDRICH, R

BALEK, V

机构：

[1] TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST PHYS & THEORET CHEM,D-38106 BRAUNSCHWEIG,GERMANY

[2] TECH UNIV CAROLO WILHELMINA BRAUNSCHWEIG,INST PHARMACEUT TECHNOL,D-38106 BRAUNSCHWEIG,GERMANY

[3] NUCL RES INST,CR-25068 PRAGUE,CZECH REPUBLIC

来源：

THERMOCHIMICA ACTA | 1995年 / 250卷 / 01期

关键词：

CAFFEINE; ETA; PHASE TRANSFORMATION; SEM; TXRD;

D O I：

10.1016/0040-6031(94)01958-J

中图分类号：

O414.1 [热力学];

学科分类号：

摘要：

The solid-solid phase transformation of caffeine has been studied with time- and temperature-resolved X-ray powder diffractometry (TXRD) and with emanation thermal analysis (ETA). The phase transformation of caffeine at 141 degrees C has been followed by heating a sample of the low-temperature phase. After cooling again, the high-temperature phase converts only slowly back into the low-temperature phase. This transformation needs weeks or months at room temperature to complete. With TXRD, it was possible to study this slow transformation in situ at elevated temperatures. A nucleation-controlled transformation mechanism appears likely.

引用

页码：29 / 39

页数：11

共 14 条

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