Preparation of magnesium hydroxide nanoflowers from boron mud via anti-drop precipitation method

摘要

Using boron mud as the starting material, the flower-like magnesium hydroxide (MH) has been successfully prepared via anti-drop precipitation method. The effect of NH_3•H_2O concentration, aging time, and surfactant on the morphology of MH was investigated. The optimum precipitation conditions are dropping MgSO_4 solution in 5% NH_3•H_2O solution, with 3% polyethylene glycol as surfactant, aging for 30 min. XRD, SEM, FI-IR, and TG/DTA have been employed to characterize the as-prepared samples. XRD reveals that MH with high purity has the brucite structure. SEM images show that the flower-like MH exists in the form of mono-disperse well uniform spherical aggregation with diameter of 3-5 μm. TG/ DTA shows a total percentage of weight loss 33.6% with a well-defined endothermic peak near 381.3 ℃. corresponding to the decomposition of MH. Furthermore, it reports that the extremely fast primary nucleation is of significance for crystal growth of MH.