Surface modification mechanism of magnesium oxysulfate whiskers via wet chemical method

Magnesium oxysulfate whisker（MOSW） was produced using magnesite and sulfuric acid as raw materials by hydrothermal method and further modified by taking zinc stearate as modifier via wet chemical method.The infiuences of the amount of modifier, slurry concentration, modification duration, modification temperature and the stirring rate on the surface modification were investigated. The effects of surface modification in functional groups, morphology and electron binding energies of surface elements of MOSW were characterized by Fourier transform infrared spectroscopy（FT-IR）, scanning electron microscopy（SEM） and X-ray photoelectron spectroscopy（XPS）. The mechanism of modification was analyzed by studying the microstructure model of the surface of MOSW, which was modified by zinc stearate. The results show that the coordination is generated by the Mg element and O in carboxylic ion of modifier, and the chemical bond could be obtained by modification. Moreover, the surface of MOSW bonds the molecules of zinc stearate, and it becomes rough. Then, the hydrophobicity of MOSW is also improved significantly. In addition, the 1s electron binding energies of Mg and O on the surface of MOSW decrease by1.2 and 0.2 eV, respectively.