Effect of surfactants with different ionizing properties on dispersion stability and PCMP properties of CeO2 nanoparticle polishing slurry

CeO2 nanoparticles have small particle size, quantum size effect and surface effect, which make the particles easy to agglomerate. How to restrain the agglomeration of particles is the key to the preparation of high-quality CeO2 polishing paste, and it is also a research hotspot in the field of fine powder. Therefore, this study is devoted to using different kinds of surfactants and their additives to improve the dispersion stability of Ce0.96Y0.02Pr0.02O2 polishing solution and the performance of photocatalysis-assisted chemical mechanical polishing (PCMP), including cationic surfactant (Cetyl trimethyl ammonium bromide, CTAB), anionic surfactant (Sodium dodecyl benzene sulfonate, SDBS) and Nonionic surfactant (Polyvinylpyrrolidone, PVP). The results of dispersion stability show that compared with CTAB and SDBS, the polishing solution containing 2.5 wt% PVP has the advantages of slow settling rate and high absorbance, and the improvement effect of dispersion stability is the best. In addition, the polishing properties of different surfactants in quartz glass photocatalysis-assisted chemical mechanical polishing were analyzed. The polishing solution prepared with PVP as dispersant has lower surface roughness (Ra:0.13 nm). However, it is worth noting that the material removal rate decreases after the addition of surfactant, which may be related to the lubrication of surfactant in polishing slurry. Through the test of the friction coefficient, it can be seen that the introduction of surfactant does reduce the friction coefficient of the polishing slurry, and then affect the improvement of material removal rate. Finally, it is proposed that the dispersion mechanisms of CTAB, SDBS and PVP are electrostatic stability, electrostatic stability and steric hindrance stability, respectively. The dispersion mechanism of different surfactants can provide a theoretical basis for researchers to optimize the polishing process and provide guidance for the selection of suitable surfactants.