Synthesis and Characterization of Large Pore MSU-Type Mesoporous Silica

The syntheses and characterization of mesoporous silica obtained by neutral polyoxiethylene surfactants are reported. Syntheses were carried out according to a previously-reported interfacial approach based on a slowrate not-catalyzed tetraethylortosilicate (TEOS) hydrolysis but using different organic phases. Synthesis systems are constituted by a two-level biphasic emulsion and mesoporous silica particles grow at the interface of the organic (upper) and the inorganic (lower) regions. The newly-formed particles migrate because of the gravity force to the bottom of the synthesis vessel, far from the upper silica-feeding solution. Typical particle size is at the nanometer scale. Solids with very large mesopores, high pore volume and specific surface SBET up to 400 m²/g are obtained at room temperature starting from synthesis systems not including a mineralizing agent such as H+, OH– or F-ions.