包覆型Fe_2O_3/SiO_2复合颜料的制备及其性能

Preparation and Properties of Fe_2O_3/SiO_2Composite Red Pigment

采用溶胶--凝胶法制备了均匀分散于醇/水体系中的Fe2O3/SiO2微纳米复合粒子。通过色差分析、扫描电子显微镜、红外光谱分析、酸溶率测试等研究了反应温度、催化剂浓度、硅/铁质量比等工艺因素对包膜效果和色度的影响。结果表明,得到的最优工艺条件是:反应温度为30℃,催化剂氨水的浓度为0.75mol/L,硅铁质量比为0.265∶1,反应时间为6h。在最优工艺条件下,可以得到SiO2膜均匀致密包覆的氧化铁红颗粒,其色度值均得到提升;Fe2O3/SiO2复合粒子置于稀盐酸56h后,Fe3+析出量仅为0.08%。并分析了包覆过程中静电作用和化学键作用机理,证实包覆形态的决定性作用。

The micro-sized/nano-sized particles of Fe2 O3/SiO2 composite evenly in alcohol/water system were prepared by a sol- gel method. The effects of parameters （i. e. , reaction temperature, catalyst concentration and silica/hematite （SiO2/Fe203） mass ratio） on the surface modification and chromaticity of the Fe203/SiO2 composite particles were investigated by chromatic difference analysis, scanning electron microscopy, infrared spectroscopy and acid resistance test, respectively. The results show that the optimal conditions are reaction temperature of 30 ℃, catalyst concentration of ammonia solution of 0. 75 tool/L, silica/hematite ratio of 0. 265.＇1 and reaction time of 6h. Under the optimal condition, hematite particles can be coated with homogeneous and compact silica, and the chromaticity values of the coated composite particles can be improved. The quantity of dissolved Fe3＋ is 0. 08% after Fe2 O3/SiO2 composite particles are in diluted hydrochloric acid for 56 h. In addition, the elec- trostatic effect and the chemical bonding mechanism of the coating process were also analyzed.