Characterization of the Porous Structure of SBA-15

Abstract

SBA-15 ordered mesoporous silicas were synthesized using the method reported by Zhao et al. The structures of these materials were characterized using powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), and nitrogen adsorption. The samples were found to exhibit structural properties similar to those reported earlier. Our study confirmed that the size of primary mesopores of SBA-15 can be tailored by the choice of synthesis temperature and that SBA-15 exhibits a significant amount of disordered micropores and small mesopores. The volume and size of these complementary pores were found to be dependent to some extent on the synthesis/aging temperature. It was shown that the washing of as-synthesized SBA-15 in water or ethanol was accompanied by an appreciable structural shrinkage and led to the removal of a significant part of the polymeric template. Therefore, washing needs to be avoided if one wants to isolate SBA-15 without appreciable loss of the template. It was confirmed that water-washed SBA-15 samples have fully accessible primary mesopores. Ethanol-washed samples also were found to exhibit accessible porosity. Despite an appreciable content of the template in the water-and ethanol-washed samples, their pore sizes were usually larger than those of the calcined materials. The observed structural properties of SBA-15 and their dependence on the synthesis temperature and washing were attributed to the changes in the degree of penetration of the poly(ethylene oxide) chains of the triblock copolymer template within the siliceous walls of SBA-15.

MALDI-TOF-MS analysis of small molecules using modified mesoporous material SBA-15 as assisted matrix

“…The isotherms and the corresponding pore size distribution curves (obtained by Barrett-Joyner-Halenda (BJH) method) are shown in Figure 2. The isotherm of SBA-15-8QSi was type IV (IUPAC classification) with H1 hysteresis loops, which are typical isotherm patterns of mesoporous materials with 2D-hexagonal symmetry [32]. As expected from the sharp condensation steps in the region of p/p 0 ϭ 0.6 -0.8 in the isotherms, the SBA-15-8QSi material exhibited a very narrow BJH pore size distribution curve centered at 7.2 nm.…”

Synthesis and Characterization of Mesoporous Silica McM-41 and Sba-15 From Power Plant Bottom Ash

“…The both isotherms were similar to those reported in the literatures which are type IV. The sharpness of adsorption branches indicate the narrow pore size distribution [17]. Table 1 …”

Mesoporous silica SBA‐15 functionalized with acidic deep eutectic solvent: A highly active heterogeneous N‐formylation catalyst under solvent‐free conditions

“…[16][17][18] Nanostructured mesoporous silica matrices, in particular, SBA-15 are attractive candidates as heterogeneous catalysts for various organic transformations due to their large surface area, narrow pore size distribution and a tunable pore diameter. [19][20][21][22][23][24] On the other hands, adsorbed or covalently bonded organic functional groups, especially ionic liquids at the surface of nanostructured mesoporous silica matrices have been widely researched because of the many applications of these composite materials. [24][25][26][27] Deep eutectic solvents DESs are the most attractive and effective precursor for immobilization on the solid support for the several advantages such as ease of preparation, available from bulk renewable resources, and especially economic considerations.…”