Structural Investigations of AMS-n Mesoporous Materials by Transmission Electron Microscopy

A novel synthesis route for mesoporous silicates using anionic surfactants has been recently reported. It was advanced that materials synthesized using anionic surfactants and aminosilane groups as co-structure directing agents led to the synthesis of highly ordered, novel mesoporous materials with unprecedented structural properties. Here we present an in-depth high-resolution transmission electron microscopy (HRTEM) investigation on the structural characteristics of these novel mesoporous solids denoted AMS-n (anionic mesoporous silicas). These materials show increased order in comparison with conventional mesoporous structures as a result of the long-range periodicity of structural modulations. Structural defects formed in these materials are investigated using electron diffraction (ED) and Fourier transform (FT) diffractograms. In addition we present a new cubic mesostructure AMS-8 (space group Fd3m). These new materials show promising new pore connectivities and morphologies making them ideal for applications ranging from catalysts' supports to gas separation, and from nanodevices to drug delivery.