Abstract: Magnesium ammonium phosphate (MAP) was prepared by inverse microemulsion method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and thermal analysis (TG-DSC).The results show that MAP prepared by inversed microemulsion method is narrower and smaller in size.MAPs with different crystal forms were obtained by different methods.Cetyl trimethyl ammonium bromide as a surfactant to prepare a magnesium ammonium phosphate has the smallest particle size distribution.Sodium dodecyl benzenesulfonate as a surfactant to prepare a magnesium ammonium phosphate has the smallest particle size and the best thermal stability.

Key words: Magnesium ammonium phosphate (MAP) was prepared by inverse microemulsion method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR) and thermal analysis (TG-DSC).The results show that MAP prepared by inversed microemulsion method is narrower and smaller in size.MAPs with different crystal forms were obtained by different methods.Cetyl trimethyl ammonium bromide as a surfactant to prepare a magnesium ammonium phosphate has the smallest particle size distribution.Sodium dodecyl benzenesulfonate as a surfactant to prepare a magnesium ammonium phosphate has the smallest particle size and the best thermal stability.