Direct observation of the shape evolution of MgO whiskers in a solution system

MgO whiskers are chemically synthesized by a facile route based on the calcination of precursor whiskers, magnesium carbonate hydrate, which are prepared by the precipitation reaction between magnesium chloride and sodium carbonate solution. The obtained samples are systematically investigated by X-ray diffraction and scanning electron microscopy (SEM). The present results indicate that MgO samples are in a high purity, the morphology of whiskers is well-shaped and structurally uniform. The shape evolution of the precursor whiskers is investigated by the analysis of SEM results. Furthermore, the concentration effect on the final morphology has also been studied. The formation mechanism of whiskers is proposed, which is helpful for us to understand the shape evolution and provides guidance for the morphology control of other whiskers in a solution system. (c) 2006 Elsevier B.V. All rights reserved.