Facile preparation of ultra-large pore mesoporous silica nanoparticles and their application to the encapsulation of large guest molecules.
Pore-enlarged mesoporous silica nanoparticles (MSNs) were prepared directly from as-prepared MSNs through a new, simple method using divalent Ca or Mg salts as both efficient silica etching reagents and as ion exchangers in methanolic solution under mild conditions. The resultant MSNs became almost template-free simultaneously during this etching process. The pore-enlarged MSNs, referred to as Ca-MSN or Mg-MSN, maintained their original hexagonal pore symmetry and particle sizes, but several ultra-large mesopores were generated inside and outside the MSNs together with regular mesopores having expanded pore dimension of around 4-5 nm. The average pore diameters for ultra-large pores were 47.5 nm for Ca-MSN and 52.4 nm for Mg-MSN. The generation of ultra-large pores can be regarded as the collapse of several mesopores into an ultra-large pore. Both Ca-MSN and Mg-MSN were good sorbents for positively charged porphyrin molecules. Additionally, these ultra-large pore MSNs exhibited better adsorption ability than calcined MSN for large proteins and antibodies, such as bovine serum albumin (BSA) and immunoglobulin G (IgG).
Department of Chemistry and Protein Research Center for Bio-Industry, Hankuk University of Foreign Studies , Yongin 449-791, Korea.
Hye-Seon
HS
Shin
Yong-Kyung
YK
Hwang
Seong
S
Huh
D021621:Imaging, Three-Dimensional; D009682:Magnetic Resonance Spectroscopy; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D036103:Nanotechnology / Q000379:methods*; D016062:Porosity; D012822:Silicon Dioxide / Q000737:chemistry*; D055672:Static Electricity; D013818:Thermogravimetry; D014961:X-Ray Diffraction
D012822:Silicon Dioxide