On the basis of the above results, a possible mechanism for the
formation of MgO nanoparticles (CTAB-free samples) and nano-plates (CTAB-assisted samples) may be proposed (Fig. 4). In the ab-sence of CTAB, the following equilibrium was written in the
solution: Mg
2þ
þ2OH
MgðOHÞ
2
ðsÞ (1). As-prepared Mg(OH)2
was obeyed hydrothermal treatment at 180C and then calcination
at 450C to obtain nanosized MgO particles with severe agglomer-ation of tiny particles, as previously observed inFig. 2a. Thermal
energy is possibly sufficient to promote the sintering of MgO par-ticles, mainly leading to the formation of larger clusters.
In the presence of CTAB, the following equations could be writ-ten in the system consisting of Mg
2+
,OH
, and CTAB