脂肪醇聚氧乙烯醚羧酸钠改性纳米氢氧化镁性能研究

Study on modification of nano-sized magnesium hydroxide by sodium fatty alcohol polyoxyethylene ether carboxylate

以六水硝酸镁、氢氧化钠为原料,脂肪醇聚氧乙烯醚羧酸钠为改性剂,采用直接沉淀法一步合成改性纳米氢氧化镁,用沉降体积实验确定改性剂的最佳用量为氢氧化镁质量的0.2%,通过红外光谱(FT-IR)、X射线衍射(XRD)、透射电镜(TEM)、表观密度对改性前后的样品进行表征。结果表明:该方法可以使改性剂吸附在氢氧化镁颗粒表面,使氢氧化镁表面由亲水性变为亲油性,提高了氢氧化镁在有机介质中的分散稳定性。与未改性的氢氧化镁样品相比,改性后纳米氢氧化镁衍射峰主峰强度提高,结晶性更好,团聚程度降低,表观密度减小。

Surface modified nano-sized mgnesium hydroxide was prepared by direct precipitation method with magnesi- um nitrate hexahydrate and sodium hydroxide as raw materials,and sodium fatty alcohol polyoxyethylene ether carboxylate as modifying agent. The optimum dosage of modifying agent was 0.2% of the mass of magnesium hydroxide, which was confirmed by sediment volume experiment. Modified and unmodified samples were characterized by fourier transform infrared spectroscopy （ FT - IR ） , X - ray diffraction （ XRD ） , transmission electron microscope （ TEM ） , and tap density test. Results indicated that sodium fatty alcohol polyoxyethylene ether carboxylate was adsorbed onto the surface of magnesium hydroxide nano-particles changing the hydrophilic surface into hydrophobic surface and improving the dispersion stability in organic medium. Compared to unmodified magnesium hydroxide, the main XRD diffraction peak of nano-sized magnesium hydroxide was strengthened showing better crystalline, lower agglomeration, and smaller tap density after modified.