(中南大学 化学化工学院，长沙 410083)
摘 要: 采用分步液相沉积法在片状铝粉表面包覆SiO2与Fe2O3双层薄膜制备了具有金属光泽的彩色铝粉，以彩度与光泽度为主要评价指标，探讨Fe2O3用量与pH值对铝粉包覆效果的影响，利用原子力显微镜(AFM)、扫描电子显微镜(SEM)和X射线衍射(XRD)等手段对包覆前后的铝粉进行表征。结果表明：当SiO2包覆量为20%(质量分数)时，随着Fe2O3膜厚的增加，铝粉颜色由浅黄→金黄→红黄过渡，光泽度下降；当m(Fe2O3):m(SiO2):m(Al)= 0.75:0.2:1时，铝粉具有良好的彩度与光泽度，铝粉表面粗糙度由5.05 nm增大到20.6 nm；反应过程pH值对Fe2O3包覆效果有重要影响，pH值宜控制在3.9~4.0；表面活性剂PVP的加入有利于提高Fe2O3膜层与SiO2和Al基体的结合力，从而提高颜色稳定性。
关键字: 片状铝粉；表面包覆；氧化铁；彩度；光泽度
Fe2O3/SiO2/Al by liquid deposition
（School of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China）
Abstract:The colored aluminum flake powder with metallic luster was prepared by encapsulating SiO2 and Fe2O3 double-layer film via step liquid-phase deposition method. Using the chromaticity and gloss as the main targets, the influence of Fe2O3 amount and pH value on the coating effect was studied. The unencapsulated and encapsulated aluminum powders were characterized by AFM, SEM and XRD. The results show that when the amount of SiO2 is 20% (mass fraction), with the increase of Fe2O3 amount, the aluminum powder changed colors from pale-yellow to golden-yellow, and then to red-yellow, and the gloss is reduced. Under the condition of m(Fe2O3):m(SiO2):m(Al)= 0.75:0.2:1, the encapsulated sample has good chromaticity and gloss synchronously, and the surface roughness of the aluminum powder increases from 5.05 nm to 20.6 nm. Furthermore, pH value should be controlled between 3.9 to 4.0. The addition of PVP is helpful to improve the color stability property of the aluminum powder, the Fe2O3 film is firmly combined with SiO2 and Al.
Key words: flake aluminum powder; surface coating; ferric oxide; chromaticity; gloss
