The surfactant templated MCM-41 materials consists of hexagonally ordered cylindrical pores, where the pore sizes may be varied between 2 and 10 nm. (1,2) These framework-confined mesopores are usually the only mesopores reported to be present in MCM-41-type materials. For catalytic, biofiltration and chromatographic purposes it is important to have an easy access to the small framework-confined mesopores. Tanev et al.(3,4) have synthesized molecular sieves, denoted HMS, consisting of both framework-confined and textural mesopores where the latter originate from the voids between agglomerated silica particles. These textural mesopores are about one order of magnitude larger than the framework-confined mesopores and therefore allow a better access for guest molecules to the framework-confined mesopores. Furthermore, the small particles (<100 nm) reduce the flow time for guest molecules in the mesoporous channels, making the material more attractive for catalytic purposes. The HMS molecular sieves were prepared by using long-chain amines as the template. The same authors also used C_nTAB (n=8-18) as the template but did not achieve as high a textural porosity as for the amine. We hereby report the synthesis of mesoporous silica possessing both framework-confined and textural mesoporosity prepared using an ionic (S~+T~-) synthesis route with a total porosity similar to those of the HMS materials or higher.
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