Fractal nature of non-spherical silica particles via facile synthesis for the abrasive particles in chemical mechanical polishing

摘要

Non-spherical silica particles (NSSPs) have shown great advantages in chemical mechanical polishing (CMP) as abrasive particles. Due to their novel shapes, the material removal rate (MRR) is enhanced dramatically. In this paper, we propose a facile approach to synthesize NSSPs with verified effectiveness in polishing test and considerable potential in industrial production. In our experiments, zinc acetate was introduced into the traditional Stober system as morphology controller to form peanuts shaped NSSPs, whose sizes were investigated with the concentration of ammonium hydroxide, water and Zn(Ac)(2). Results show that the novel shapes of NSSPs originate from the overlap of fractal spherical silica particles in the early stage of Stober reaction. Hereafter, by studying the structure of NSSPs by transmission electron microscope (TEM) and electron scattering, the fractal nature of NSSPs has been revealed, demonstrating a similar result compared with small angle X-ray scattering (SAXS). To our knowledge, this is the first study on the effect of divalent ions on the Stober system and is the first attempt to interpret the fractal nature of amorphous materials by electron scattering. (C) 2016 Elsevier B.V. All rights reserved.