Using as-Synthesized Mesoporous Silica as New Capturer and Releaser

Submit Manuscript | http://medcraveonline.com composition and relative regular geometric structure. For example these micelles occluded in the as-synthesized mesoporous silica such as MCM-41 are the unique resource, since they are distributed in the spoke-like configuration to form numerous sub-nanometer gaps between them and the silica walls, and these inherent chemical and geometric properties are very difficult, if not impossible, to be duplicated by other methods [3]. For this reason, it is necessary to utilize these template micelles orientated inside the channel. We had reported a simple approach previously: the as-made ordered mesoporous materials with template occluded in the pores were utilized as the specific support and manually ground with guest precursor salts such as magnesium acetate. And this mixture was then calcined to form high dispersion of guest species like MgO, performing the guest dispersion and the template removal at one step [4]. As the consequence, a solvent-free technique was employed for fast modification of mesoporous materials. Copper, chromium and iron oxide species could be highly dispersed in SBA-15 by manually grinding the corresponding precursor salts and the host, followed by calcinations for the first time. This method is more effective to spontaneously disperse oxide species onto SBA-15 than impregnation. Besides, Cr(VI) species dominate in the mixing sample while Cr(III) species dominate in the impregnation one. In the temperature programmed surface reaction of nitrosamines, the sample prepared by solvent-free method showed a higher catalytic activity than the impregnation one [5]. This method finely exploits the weak interaction of inorganic-organic hybrids to achieve spontaneous infiltration of guest species in the occluded pores of the as-made mesoporous materials so as to be a powerful means to fabricate guest-host composites. More importantly, this method hints a possibility to take advantage of the confined space between silica wall and template aggregates [4,6].