Pure, simple and green synthesis of magnesium oxysulphate whiskers through hydrothermal reaction

One-dimensional magnesium oxysulphate MgSO4·5Mg(OH)2·2H2O (abbreviated as 152MOS) with a high aspect ratio was prepared through the hydrothermal reaction route without granular fragments observed in the final products. Those parameters such as molar ratio of MgSO4·7H2O to NaOH solution, reaction temperature, reaction time, and dropping order between MgSO4·7H2O and NaOH that can influence the morphology, purity, and structure of 152MOS whiskers were taken into consideration. The results indicated that the high purity 152MOS whisker with a length of 170–210 μm can be obtained at 200°C for 15 h in an oven when dropping NaOH into MgSO4 with the molar ratio of 1:1.5. The product characteristics were investigated by X-ray diffraction, Fourier transform-infrared, thermogravimetry, and scanning electron microscopy.