Nano Archive

Rattle-type silica colloidal particles prepared by a surface-protected etching process

Zhang, Qiao and Ge, Jianping and Goebl, James and Hu, Yongxing and Lu, Zhenda and Yin, Yadong (2009) Rattle-type silica colloidal particles prepared by a surface-protected etching process. Nano Research, 2 (7). pp. 583-591. ISSN 1998-0124 (Print) 1998-0000 (Online)

[img]
Preview
PDF
747Kb

Official URL: http://www.springerlink.com/content/l622hum6lq1911...

Abstract

This paper explores the capability of the “surface-protected etching” process for the creation of rattle-type SiO2@void@SiO2 colloidal structures featuring a mesoporous silica shell and a mesoporous movable silica core. The surface-protected etching process involves stabilization of the particle surface using a polymer ligand, and then selective etching of the interior to form hollow structures. In this paper, this strategy has been extended to the formation of rattle-like structures by etching SiO2@SiO2 core shell particles which are synthesized by a two-step sol gel process. The key is to introduce a protecting polymer of polyvinylpyrrolidone (PVP) to the surface of both core and shell in order to tailor their relative stability against chemical etching. Upon reacting with NaOH, the outer layer silica becomes a hollow shell as only the surface layer is protected by PVP and the interior is removed, while the core remains its original size thanks to the protection of PVP on its surface. This process can be carried out at room temperature without the need of additional templates or complicated heterogeneous coating procedures. The etching process also results in the rattle-type colloids having mesoscale pores with two distinct average sizes. In our demonstration of a model drug delivery process, such mesoporous structures show an interesting two-step elution profile which is believed to be related to the unique porous rattle structures.

Item Type:Article
Subjects:Physical Science > Nanophysics
Physical Science > Nano objects
Material Science > Nanochemistry
Material Science > Nanostructured materials
Divisions:Faculty of Engineering, Science and Mathematics > School of Physics
Faculty of Engineering, Science and Mathematics > School of Chemistry
ID Code:8359
Deposited By:JNCASR
Deposited On:01 May 2010 10:40
Last Modified:01 May 2010 10:40

Repository Staff Only: item control page