以硫酸亚铁为原料,H2O2作锚固剂,在pH值6.0~6.5的异丙醇/水介质中制得了卡其色水性铝颜料,探讨了包覆机理和温度对水性铝颜料性能的影响.扫描电子显微镜,光学显微镜,X衍射和红外光谱表征结果说明:H2O2氧化金属铝形成的水铝石可吸引带相反电荷的氧化铁晶种或颗粒,锚固在铝粉表面形成包覆层.低温时吸引无定型颗粒占主导,温度升高吸引晶种诱导形成针铁矿的几率增大,结晶度增强.性能测试结果表明包覆温度为45 ℃时,针铁矿和无定型氧化铁共生均匀地沉积在铝表面,形成致密的包覆层,制得了具有显著耐腐蚀性的卡其色铝颜料.
The khaki waterborne aluminum pigments were prepared in isopropyl alcohol/water media at 6-6.5 pH value,using ferrous sulfate as precursor and H2O2 as anchoring agent.The encapsulated mechanism and the effect of temperature on the aluminum property were discussed.Scanning electron microscopy,optical microscopy,X-ray diffraction and infrared spectroscopy results show that the diaspore form on the aluminum flakes surface by H2O2 oxidizing,and the amorphous iron oxide particles with opposite charge can combine with diaspore by mutual attraction.Perhaps the diaspore induces the iron oxide in the solution to form goethite anchored on the aluminum surface and then form a dense coating layer.At low temperature,the electrostatic attraction of amorphous iron oxide dominates.As the temperature rising,the proportion of goethite is increased,and the crystallinity is enhanced.The performance test prove that goethite and amorphous iron oxide evenly deposits on the aluminum surface together to form a dense coating layer at 45 ℃,and thus gives the khaki aluminum pigments excellent corrosion resistance performance.
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