Preparation of Raspberry-Like Nanocomposite Microspheres Based on Soap-Free Cationic Latex and Nano-SiO₂ Particles

Abstract

Raspberry-like nanocomposite microspheres with polymer core and nano-SiO₂ particles shell structure were fabricated by a simple mixture process of soap-free cationic poly-styrene-acrylate latex and nano-SiO₂ particles. The raspberry-like structured microspheres were formed due to the electrostatic interaction between positive charged cationic latex and negative charged nano-SiO₂ particles. Effects of pH on the surface zeta potential of the polymer latex and nano-SiO₂ particles were studied. Effect of nano-SiO₂ content to the stability of nanocomposite microspheres was investigated. TEM observation shows that when the pH of both the cationic emulsion and nano-SiO₂ sol is 3, stable raspberry-like nanocomposite microspheres with 10 wt% nano-SiO₂ content can be obtained, the nano-SiO₂ particle is distributed on the surface of the nanocomposite microspheres.

Keywords:

• Nano-SiO₂
• Nanocomposite microsphere
• Raspberry-like cationic latex