中国物理B ›› 2019, Vol. 28 ›› Issue (9): 98101-098101.doi: 10.1088/1674-1056/ab3445
• INTERDISCIPLINARY PHYSICS AND RELATED AREAS OF SCIENCE AND TECHNOLOGY • 上一篇 下一篇
Shuai Fang(房帅), Hong-An Ma(马红安), Long-Suo Guo(郭龙锁), Liang-Chao Chen(陈良超), Yao Wang(王遥), Lu-Yao Ding(丁路遥), Zheng-Hao Cai(蔡正浩), Jian Wang(王健), Xiao-Peng Jia(贾晓鹏)
Shuai Fang(房帅), Hong-An Ma(马红安), Long-Suo Guo(郭龙锁), Liang-Chao Chen(陈良超), Yao Wang(王遥), Lu-Yao Ding(丁路遥), Zheng-Hao Cai(蔡正浩), Jian Wang(王健), Xiao-Peng Jia(贾晓鹏)
摘要:
The properties of urea under high pressure and high temperature (HPHT) are studied using a China-type large volume cubic high-presentation apparatus (CHPA) (SPD-6×600). The samples are characterized by scanning electron microscopy (SEM), x-ray diffraction (XRD), and Raman spectroscopy. By directly observing the macroscopic morphology of urea with SEM, it is confirmed that the melting point of urea rises with the increase of pressure. The XRD patterns of urea residues derived under different pressures show that the thermal stability of urea also increases with the increase of pressure. The XRD pattern of the urea residue confirms the presence of C3H5N5O (ammeline) in the residue. A new peak emerges at 21.80°, which is different from any peak of all urea pyrolysis products under normal pressure. A more pronounced peak appears at 708 cm-1 in the Raman spectrum, which is produced by C-H off-plane bending. It is determined that the urea will produce a new substance with a C-H bond under HPHT, and the assessment of this substance requires further experiments.
中图分类号: (Diamond)