Calcium sulfate crystals with microrod morphology have been synthesized by a simple hydrothermal process using calcium oxide and sodium sulfate as the raw materials. X-ray diffraction, scanning electron microscopy and infra-red spectrum have been used to characterize the calcium sulfate crystals with microrod morphology. The calcium sulfate crystals with microrod morphology possess orthorhombic CaSO4 phase and the diameter and length are 500 nm-10 μm and 10-100 μm, respectively. The hydrothermal temperature and reaction time play essential roles on the formation and size of the calcium sulfate crystals with microrod morphology. The nucleation and crystalline growth process are proposed to explain the formation and growth of the calcium sulfate crystals with microrod morphology.
Keywords: Calcium sulfate crystals, microrods, growth conditions, electron microscopy, biomineralization, microemulsion, diffractometer, monochromatized, hydrothermal process, submicroscale particles, metastable, microrod powders, hydrothermal conditions, hydroxylate, IR