Nanoparticle Halos Mechanism in Stabilizing of Colloidal Suspensions: Polymeric Binder and Dispersant Effects

Abstract

Dispersion behavior of colloidal Al₂O₃ aqueous suspensions was investigated in the presence of highly charged CeO₂ nanoparticles and polymeric additives. It was found that among the investigated parameters, ceria nanoparticles concentration had the highest significant effect on the stability of Al₂O₃-CeO₂ suspensions. However, the low influence of dispersant concentration may be due to significant role of ceria nanoparticles stabilizing alumina microspheres by “nanoparticle halo” formation. The stabilization of the bidispersed suspensions was also evidenced by scanning electron microscopy and elemental analysis of the sediment layers after three weeks.

Keywords:

• Al₂O₃
• CeO₂
• nanoparticle halo
• polymeric binder
• polymeric dispersant

Acknowledgments

The authors wish to thank Sahand University of Technology (SUT) for financial support of this work. Also, thank is extended to coworkers and technical staff in the Institute of Polymeric Materials, Nanostructure Materials Research Center (NMRC) and Chemical Engineering Department of SUT, especially Dr. S. Shafiee for help during various stages of this work.

Notes

^a Fibrona, Tehran, Iran.

^b Advanced Nano Technologies Pty. Ltd., Welshpool, Western Australia, Australia.

^c E. Merck, D 6100 Darmstadt, Germany.

^d R.T. Vanderbilt Co., Norwalk, CT, USA.

^e Shahid Ghazi Pharmaceutical Co, Tabriz, Iran.