Ordered Structure Analysis of Prepared Mesoporous Silica Using Small Angle X-Ray Scattering

Abstract

Ordered pores structure analysis of mesoporous silica materials using a template of poly(ethylene oxyde)-poly(propylene oxide)-poly(ethylene oxide), PEO-PPO-PEO, triblock copolymer or Pluronics in numerous synthesis conditions has been conducted. Two different length of hydrophilic chain of Pluronics, i.e., P123 (EO 20 PO 70 EO 20) and F127 (EO 106 PO 70 EO 106), produced two different fine pore structures, which were basically hexagonal and cubic. A highly ordered pore structure, confirming with many Bragg peaks, was clearly obtained with the lattice parameters in nanometer scale from analyzing the synchrotron small angle X-ray scattering (SAXS) data. Meanwhile, the surface area and pores size of mesoporous silica determined by nitrogen absorption clearly support the analysis of SAXS data, presenting a complete information of pore order characteristics. This paper shows how the synthesis parameters, such as length of hydrophilic chains, silica precursor concentration, Al:Si ratio and synthesis methods, are related to the structure and order of the pores formed. The SAXS patterns show that the pore order increases with increasing concentration of sodium silicate and decreases with longer sonication time.

Rifampicin adsorption and release study using Santa Barbara amorphous-16 modified Al (SBA-16-Al) for a drug delivery system

“…Previous research has been conducted to study the properties of the MSN nanostructures using small-angle X-ray scattering (SAXS) and one of the applications for radioactive drug delivery. 16,17 From the SAXS characterization study on SBA-16-Al which was carried out previously, it was observed that the synthesized SBA-16-Al is an MSN that has pores in the uniform mesoporous order, a threedimensional cubic Im3m structure, and has a high specic surface area, up to 1000 m 2 g −1 . Mesoporous silica nanomaterial with a high specic surface area and large pore volume will provide a high drug-loading capacity, 18,19 thus lowering the frequency of drug administration.…”