Synthesis of mesoporous MSU-X materials using inexpensive silica sources

MSU-X materials are a family of ordered mesoporous silica obtained through an assembly mechanism between nonionic poly(ethylene oxide)-based surfactants and silica precursors. Until now, among many advantages, the main drawback of this synthesis was the cost of the silica source, a silicon alkoxide that prevented any application where large amounts of material are required. We report that a new two-step synthesis pathway implying first the stabilization of a microemulsion made of both nonionic surfactants and a silica source and then the silica condensation through a fluoride-helped catalysis can be extended to cheaper silica sources than the silicon alkoxide usually used. Both sodium silicate or colloidal silica lead to sodium- and fluoride-free materials that exhibit exactly the same structures and properties as those previously reported [Boissiere et al. J. Chem. Sec. Chem. Commun. 1999, 20, 2047]. In addition, with the process occurring in slightly acidic aqueous medium, at moderate temperatures, and in open-air containers, the use of both surfactant and low-cost silica reagents opens up the field of large-scale preparation for the mesoporous MSU-X silica.