Green synthesis of the excellent magnesium oxysulfate whiskers under controlled reaction conditions

Magnesium oxysulfate (MgSO4·5Mg(OH)2·3H2O, abbreviated as 153MOS) whiskers with high aspect ratio, high purity, and favorable dispersibility without the sector-like whiskers has been prepared via a simple hydrothermal method. In this method, only MgSO4·7H2O and Mg(OH)2 is used as the starting raw materials without by-products detected in the final production, which can decrease the cost and reduce the discharge of pollutant. The diameter and length of the whiskers is 0.1-0.7 μm and 70-150 μm, respectively. In addition, the molar ratio of MgSO4·7H2O to Mg(OH)2, reaction temperature, reaction time, and the solid content of Mg(OH)2 have influence on the purity, structure, and morphology of the 153MOS whiskers. This 153MOS whiskers obtained in this research may be further used in the polymer matrix composites as reinforcing materials, flame retardant, and composite materials additive.