Novel fabrication of monodispersed peanut-type celestine particles using Sr-EDTA chelating precursors

Novel monodispersed peanut-type SrSO4 (celestine) particles have been prepared using a facile precipitation reaction of Sr-EDTA chelating precursors at ambient temperature. The as-formed products were studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen absorption–desorption and differential scanning calorimetry–thermogravimetry (DSC–TG) measurement. The monodispersed SrSO4 particles with an average length of 1.7 μm and an aspect ratio of 1.4 appear unusual peanut-type morphology. These SrSO4 particles have a relatively large Brunauer–Emmett–Teller (BET) surface area of about 20.9 m2 g−1 and contain mesopores with a mean pore size of about 34.3 nm. The SrSO4 particles exhibit an excellent thermal stability from room temperature to 1400 °C with a structural transformation at 1158.3 °C. The growth mechanism of the monodispersed peanut-type celestine particles was discussed to obtain a better understanding on their formation process.