碱式硫酸镁晶须的分子式为xMgSO4?yMg(OH)2?zH2O，是一种人工合成具有一定长径比的无机功能材料。作为填充剂，可提高材料的抗拉强度等机械性能，也可以起到阻燃的作用。在NH4+-NH3缓冲体系，用常压一步法制备长度为10~30 μm，直径为0.05~0.3 μm，长径比为30~150的MgSO4?5Mg(OH)2?3H2O晶须。采用XRD、SEM、TG、TEM对产品进行表征，结合表征结果对反应浓度、反应温度、反应时间和陈化时间等影响因素进行研究。对碱式硫酸镁的生成机理进行第一性原理分析，碱式硫酸镁晶须生长习性符合位错螺旋生长机制。采用缓冲体系稳定溶液酸碱性，降低反应溶液的非理想性，可以使晶体在非受迫情况下定向生长，为进一步工业应用，实现低能耗生产碱式硫酸镁晶须提供了重要参考。

The molecular formula of basic magnesium sulfate whisker is xMgSO4?yMg(OH)2?zH2O, which is a synthesized inorganic functional material with a certain aspect ratio. As a filler, basic magnesium sulfate whiskers can improve the mechanical properties such as tensile strength of the material, and also play a role of flame retardant. In the NH4+-NH3 buffer system, MgSO4?5Mg(OH)2?3H2O whiskers with length of 10 μm to 30 μm, diameter of 0.05 μm to 0.3 μm, and an aspect ratio of 30 to 150 were prepared in a one-step process at atmospheric pressure. The products were charcaterized by XRD, SEM, TG, TEM, and the influencing factors such as reaction concentration, reaction temperature, reaction time and aging time were studied combination with the characterization results. The first-principle analysis of the formation mechanism shows that the growth habit of basic magnesium sulfate whiskers accord with the dislocation spiral growth mechanism. The buffer system stabilizes the acidity and basicity of the solution and reduces the non-ideality of the reaction solution. It can make the crystals grow under unforced conditions. Basic magnesium sulfate whiskers provide an important reference for further industrial applications and the realization of low-energy-consumption production.