CeO2基抛光粉在水介质中很容易沉淀,为提高CeO2料浆的抛光能力,氧化铈基抛光粉被表面改性。所用改性剂有六偏磷酸钠、十二烷基硫酸钠、十六烷基三甲基溴化铵、谷氨酸。用红外光谱分析仪、XRD、扫描电镜、激光粒度分析仪、Zeta电位、热重分析等对CeO2改性前后的物相组成、结构、颗粒大小、分散性、悬浮性和改性剂对CeO2的包裹率等进行表征,结果表明,阴离子改性剂十二烷基硫酸钠、阳离子改性剂十六烷基三甲基溴化铵和无机盐改性剂六偏磷酸钠能明显改善CeO2在水介质中的悬浮稳定性,两性离子改性剂谷氨酸对提高CeO2的悬浮稳定性的作用不明显;改性剂没有改变CeO2的物相组成和结构,仅粘附于CeO2的颗粒表面。CeO2悬浮液动力学试验表明,六偏磷酸钠对CeO2的黏附力最强,十六烷基三甲基溴化铵和十二烷基硫酸钠次之,氨基酸最弱。对玻璃材料的研磨试验结果表明,改性的CeO2颗粒(包裹体)有比较好的抛光效果,对玻璃材料去除率(MRR)的差异可能与改性剂的包裹率有关。在生产上,可以选用六偏磷酸钠作为CeO2基抛光粉的改性剂,且包裹率以不大于1.5%(质量分数)为宜。
CeO2 powder is very easy to precipitate in aqueous medium. To improve the polishing performance of CeO2 slurry, the ceria oxide particles were surface modified with six partial sodium ( ( NaPO3 )6 ), twelve sodium alkyl sulfate ( Cj2 H25 NasO4 ), sixteen alkyl three methyl bromide (CTMAB) and glutamic acid ( C5 H9 NO4 ). The compositions, structures, particles size, dispersibility, suspension and encapsulation rate of the modifier to CeO2 particles were characterized by Fourier transform infrared spectroscopy (FTIR), XRD, scanning electron microscopy, laser particle size analyzer, zeta potential meas- urement and TGA- DTA spectrum,respectively. The results indicated that anionic modifier CI2HzsNaSO4, cationic modifier CTMAB and inorganic salt modifier ( NaPO3 ) 6 can significantly improve the suspension stability of CeO2 in aqueous medium, the amphoteric modifier C5 n9 NO4 can not. The modifiers don' t change the phase composition and structure of the CeO2 parti- cles; they only adhere to the surface of the CeO: particles. The dynamics test of CeO2 suspension indicated that the adhesion force between (NaPO3 )6 and CeO: was the strongest in the four kinds of modifiers, CTMAB and C12 H25 NaSO4 were the second strongest, C5 H9 NO4 is the weakest. Then the mechanical polishing performance of the modified ceria oxide particles on glass substrate was investigated. Then,the mechanical polishing performance of the modified ceria particles on glass substrate was investigated. Experimental results showed that the modified ceria particles exhibited much better surface quality than unmodi- fied ceria particles,the difference of the glass material removal rate (MRR) may be relationship with the package rate. In pro- duction, (NaPO3)6 can be chosen as modifier of CeOz polishing powder, and it would be appropriate that the package rate is less than 1.5%.