不同改性方式对沉淀白炭黑性能的影响

Effect of different modification methods on properties of precipitated silica

以水玻璃为硅源、硫酸为沉淀剂传统化学沉淀法制备白炭黑,探索原位改性和后处理改性的效果;采用扫描电子显微镜、激光粒度分析仪、X射线衍射仪、热分析仪、傅里叶变换红外吸收光谱分析改性前后样品的形貌、团聚体粒径、结构及改性效果;采用N2吸附测试、DBP值测试对改性前后空间结构度进行表征。结果表明:原位改性比后处理改性工艺效果更好,干燥后聚集体粒子平均粒径15.59μm;改性后白炭黑表面Si—OH的强度减小,疏水性增强,BET值为112.7 m2/g,吸油值为3.44 m L/g,具有较大的比表面积和空间结构度。

Silica was prepared by traditional chemical precipitation method using water glass as silicon source and sulfuric acid as precipitant. The modification effect of two processes the in-situ modification preparation and the post-treatment modification was studied. The morphology, size,structure and the modification effect of the modified samples were characterized by scanning electron microscopy, laser particle size analyzer, X-ray diffractometer, thermal analyzer and Fourier transform infrared absorption spectroscopy. N_2 adsorption test and DBP test were used to characterize the degree of space structure.The results show that the modification in-situ modification process is better than the post-treatment process. The average particle size of the aggregated particles after drying is 15.59 μm. The infrared spectra shows that the strength of Si—OH on the modified silica surface is decreased and the hydrophobicity is enhanced. The BET value is 112.7 m^2/g and the oil absorption is 3.44 mL/g which indicates that the sample has a high specific surface area and spatial structure.