Mechanism of Morphology Change on Synthesis of New AlPO4·H2O Crystal
- Paper number
IAC-05-A2.3.04
- Author
Prof. Chen Wanchun, Chinese Academy of Sciences, China
- Coauthor
Ms. Daodan Liu, China
- Coauthor
Prof. Yuren wang, China
- Year
2005
- Abstract
At the past decade, the experiments on crystal growth in space have been conducted by on boarding the International Space Station , Shen-Zhou (SZ-3) Spaceship, Russia MIR Station, US Space Shuttles, EURECA, Chinese Recoverable Satellite and Soviet rockets. Although the scientific results to today have been shown the benefits of experimentation under microgravity environment, there are still problems remaining further investigation in space and on the earth. Mechanism of morphology change on crystal growth is one of the topics. Since the numbers of space experiments are limited, the reports about influence of microgravity environment on crystal morphology are dispersed. For exampleA, on crystal growth of zeolite Beta, LiIO3 and ZnSe etc in space, no habit change was observed, the space-grown crystal had the same morphology as the terrestrial/control crystal. For Ce:Bi12SiO20 space experiment, the space-grown crystal had the smoother external surface than that one on the earth. For the space molecular sieve on ZSM-5, Mordenite and Offretite etc, the crystal morphology is markedly different in space and ground cases. At the present, the interpretation on the results of micro-gravity experiments is often hampered by the small amount of data available. With the intention of understanding the phenomena from the space experiments, we studied the mechanism of morphology change during synthesis process of AlPO4·H2O crystal. A new crystal of aluminophosphate, AlPO4·H2O is synthesized from three batches aqueous solution under hydrothermal conditions. The hydrothermal crystallization experiments were carried out in stainless steel autoclaves. The experimental results indicated that there are two different nucleation and growth processes: single crystal growth and aggregation solidification. We have used the Inductively Coupled Argon Plasma Spectroscopy (ICAP), X-ray Diffraction (XRD), Thermogravimetry (TG) and Differential Thermal Analysis (DTA) to identify the crystalline phases. The crystal morphologies were observed by Scanning Electronic Microscopy (SEM). Five types of crystal morphology were discovered which never seen before. The types of crystal habits are: 1) double pyramid; 2) hexagonal prism; 3) tetra-prism; 4) strip -type tetragonal prism; 5) plate-type tetragonal prism. This paper will reports the results on the mechanism of morphology change during synthesis process of AlPO4·H2O crystal.
- Abstract document
- Manuscript document
IAC-05-A2.3.04.pdf (🔒 authorized access only).
To get the manuscript, please contact IAF Secretariat.