Room temperature synthesis of Si-MCM-41 using polymeric version of ethyl silicate as a source of silica

Synthesis of mesoporous MCM-41 materials at room temperature using less expensive polymeric version of ethyl silicate (40 wt% SiO2) as a source of silica was established. The influence of crucial synthesis parameters such as molar ratios of H2O/NH4OH, NH4OH/SiO2 and CTMABr/SiO2 in gel on the quality of the phase formed was investigated. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and low temperature N2 adsorption–desorption isotherms have been employed to characterize the products. The magnitude of orderness, textural properties and thermal stability of the Si-MCM-41 samples prepared under identical judiciously pre-controlled synthesis conditions using ethyl silicate and conventional tetraethyl orthosilicate (TEOS) were assessed. Even though, ethyl silicate has proved to be suitable source for the preparation of MCM-41 at room temperature, there exists an optimum value of H2O/NH4OH for different NH4OH/SiO2 molar ratios in the gel. Changes in the morphology were observed when NH4OH/SiO2, H2O/NH4OH molar ratios in the gels were changed.