Ren Qingli1£¬Luo Qiang2£¬Chen Shoutian3£¬Wu Hongcai4
(1.School of Technical Physics,Xidian¡¡University,Xi'an 710071,China; 2.The First Department,The Second Artillery Institute of Engineering,Xi'an 710025,China;3.School of Electrical Engineering,Xi'an Jiaotong University,Xi'an 710049,China;4.School of Electronics and Information Engineering,Xi'an 710049,China£©
Abstract:Mg£¨OH)2 and Mg£¬Al-hydrotalcite Mg6Al2£¨OH£©16CO3·4H2O samples were prepared by liquid method£®XRD and TEM micrographies reveal that both Mg(OH)2 and Mg£¬Al-hydrotalcite are nanocrystalline with acicular morphology£® Moreover,Mg(OH)2 nanocrystalline can be obtained under the reaction temperature of either low 30¡æ or high 190¡æ£»Mg£¬Al-hydrotalcite nanocrystalline can be prepared in the reaction temperature range from 45¡æ to 150¡æ£® With the temperature raising from 35¡æ to 45¡æ£¬ the chemical reaction result is finished from Mg(OH)2 to Mg6Al2(OH)16CO3·4H2O£» and with the temperature raising from 170¡æ to 190¡æ,the chemical reaction result is finished from Mg6Al2(OH)16CO3·4H2O to Mg(OH)2£®It is also proposed that the first changing is related with the formation of the amorphous Mg£¨OH£©2 precipitation£¬ which facilitates the diffusion of the Al3+of £ÛAl13(OH)32]7+ and CO2-3 in the amorphous Mg(OH)2 precipitation£» and the second changing is caused from the destruction of the physical structure condition£¬ which reserves the crystal water in the middle layer of Mg£¬Al-hydrotalcite£®
Keywords:Mg,Al-hydrotalcite;Mg£¨OH)2;acicular nanocrystalline;making mechanism