Preparation of magnesium oxide whiskers by sintering of basic magnesium sulfate

Magnesium oxide whiskers were prepared by precursor sintering method using low-priced magnesium sulfate and sodium hydroxide as raw materials. Firstly, a single phase of the precursor basic magnesium sulfate [MgSO4-5 Mg(OH)2-2 H2O] with good crystallization and fibrous shape was produced by normal temperature reaction and hydrothermal crystallization using magnesium sulfate and sodium hydroxide as raw materials. The precursor was decomposed slowly at low temperature to maintain the whisker shape by controlling its decomposition rate, and then sintered at high temperature to obtain well-sintered, uniformly dispersed magnesium oxide whiskers with large aspect ratio.

The products were characterized by SEM and XRD, and the magnesium oxide whiskers were sintered magnesium oxide nanoparticles with diameters ranging from 0.2 to 1.5 μm and length-to-diameter ratios ≥50. The process was proved to be simple, easy and mild, which provided an effective and feasible new way for the industrial production of magnesium oxide whiskers.