Composition and morphology of the thermal decomposition products of 3Mg(OH)2•MgCl2•8H2O nanowires

The thermal decomposition of 3Mg(OH)(2)center dot MgCl2 center dot 8H(2)O (318MHCH) nanowires synthesized fromagglomerated Mg(OH)(2) microspheres was investigated. The influence of heating rate and temperature on the composition and morphology of the products was investigated. Thermogravimetric-differential scanning calorimetry, field-emission scanning electron microscopy, high-resolution transmission electron microscopy, and X-ray diffraction showed that increasing the heating rate from 1 to 20 degrees C/min promoted the escape of crystalline water from the 318MHCH nanowires. 318MHCH nanowires were dehydrated stepwise to 310MHCH porous nanowires from room temperature to 320 degrees C, and then to MgO cubic nanoparticles from 420 to 700 degrees C. The nanowires retained their one-dimensional morphology, until the phase changed to MgO. The immediate collapse of the one-dimensional structure was attributed to the presence of Mg-O/Cl chains. (C) 2016 Chinese Society of Particuology and Institute of Process Engineering, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.