Crystallization behaviors of nanosized MgO particles from magnesium alkoxides.
Crystallization behaviors of nanosized MgO particles from magnesium alkoxides.
复制标题
DOI：
10.1016/s0021-9797(03)00034-1
复制
发表时间：
2003-03
影响因子：
9.9
通讯作者：
H. Jung;Jung‐Kun Lee;Jin-Young Kim;K. Hong
中科院分区：
文献类型：
--
作者：
H. Jung;Jung‐Kun Lee;Jin-Young Kim;K. Hong
采用热重分析、傅立叶变换红外光谱、X射线粉末衍射和透射电子显微镜研究了烷氧基大小对醇镁（甲醇镁和乙醇镁）热分解行为和MgO结晶行为的影响。随着烷基尺寸的增加，分解温度降低，并且所得的醇盐前体的MgO结晶增强。在惰性N2气氛中，乙醇镁的分解温度约为260°C，比甲醇镁的分解温度低约70°C。MgO颗粒从乙醇盐中结晶的程度也显著高于甲醇盐。这一结果是解释的醇盐的O R键强度。利用Kissinger方法计算了醇镁的热分解活化能，发现醇镁的热分解活化能与烷基的大小有关。甲醇镁和乙醇镁的活化能分别为161±23和130±24 kJ/mol。
The effects of the size of the alkoxy group on the thermal decomposition behavior of magnesium alkoxides (magnesium methoxide and ethoxide) and the crystallization behavior of MgO was investigated using thermogravimetry, Fourier-transformed infrared spectroscopy, X-ray powder diffraction, and transmission electron microscopy. As the size of the alkyl group increased, the decomposition temperature decreased and resultant MgO crystallization of the alkoxide precursor was enhanced. In an inert N2atmosphere, the decomposition temperature of magnesium ethoxide was about 260°C, which was lower than that of magnesium methoxide by approximately 70°C. The degree of the crystallization of MgO particles from the ethoxide was also significantly higher than that of the methoxide. This result is explained in terms of the OR bonding strength of the alkoxide. With use of the Kissinger method, the activation energy for the thermal decomposition of magnesium alkoxide was found to be dependent on the size of the alkyl group. The activation energies were 161±23 and 130±24 kJ/mol for the magnesium methoxide and the magnesium ethoxide, respectively.