Alternative Silica Sources in the Synthesis of Ordered Mesoporous Silica.

In this work, the influence of the use of alternative inexpensive silica sources on the structural, morphological and textural properties of MCM-41 like mesoporous materials to be used for biomedical applications has been investigated. The Liquid Crystal Template Method has been used to prepare the ordered mesoporous structured materials according to a novel composition starting from fumed silica or granular silica gel as alternative silica sources. The obtained materials have been characterized by X-ray Powder Diffraction, Transmission and Scanning Electron Microscopy, and nitrogen sorption, which showed for both samples the formation of the ordered hexagonal pore arrangement typical of a MCM-41 material. However, when using fumed silica, higher long-range hexagonal pore ordering as well as higher surface area have been obtained (1030 vs. 763 m²/g). For comparison, the features of a commercial silica mesostructured MCM-41 type have been investigated as well. Again, the silica fumed based sample has showed higher long-range hexagonal pore ordering, higher surface area and wall thickness. Preliminary stability studies on the fumed silica based material showed a decrease in the pore ordering at the end of the third year after the synthesis.