摘要：以苦卤和氨水为原料,硬脂酸镧为改性剂,采用常温一步直接沉淀法制备疏水性氢氧化镁纳米粒子;用扫描电子显微镜、傅里叶红外光谱、热重分析、X射线衍射、疏水性分析等手段对所得产物进行表征分析并进行疏水性测试。结果表明,在合成的过程中,硬脂酸镧通过化学反应改变了氢氧化镁的表面性质,改性后的Mg(OH)₂为非极性,可漂浮在水面,表现为疏水性;硬脂酸镧并未改变Mg(OH)₂的晶型,但是在X射线衍射中出现La(OH)₃的杂质峰;硬脂酸根离子吸附在Mg(OH)₂纳米粒子表面,使其表面有机化,同时提高了分散性和热稳定性。

关键词： 氢氧化镁；硬脂酸镧；疏水性

Abstract：Hydrophobic magnesium hydroxide(Mg(OH)₂) nano-particles were prepared visa the one-step direct precipitation method by using brine(MgCl₂·6H₂O) and ammonia as raw materials,lanthanum stearate as surface modifier at room temperature.The product was analyzed by SEM,FTIR,TG,XRD and hydrophobic test.The results show that the particles surface is changed from hydrophilic to hydrophobic through the reaction between lanthanum stearate and Mg(OH)₂.The modified Mg(OH)₂ is nonpolar and can float over the water.Its performance shows hydrophobic.Lanthanum stearate does not change the crystal form of Mg(OH)₂.But the impurity peak of La(OH)₃ emerges in XRD.Stearic acid iron organizes the surface of Mg(OH)₂ by adsorbing on it.The dispersibility and thermal stability are improved at the same time.

Keywords：magnesium hydroxide；lanthanum stearate；hydrophobic property