Formation of highly ordered mesoporous silica materials adopting lyotropic liquid crystal mesophases

Mesoporous silica materials have been synthesised in strongly acidic media at pH = 1.3 using high concentrations of a non- ionic surfactant (Brij 76) as a structure- directing agent. Well- defined ordered mesoporous silicas with hexagonal (H-I), lamellar (L-infinity) and solid phase (S) structure have been prepared at room temperature according to the lyotropic liquid crystalline mesophases of Brij 76. At high temperature (60°C), highly ordered cubic (Ia3d), cubic (Im3m) and 3-d hexagonal (p6(3)/mmc) nanostructured materials have been produced. The synthesised materials were studied by powder X- ray diffraction (XRD), the Brunauer- Emmett-Teller (BET) method for nitrogen adsorption/ desorption isotherms and surface area measurements. Transmission electron microscopy (TEM), XRD and TEM patterns for all materials show well- defined long- range porous architectures. It was found that BET surface area values of the nanostructured materials are reduced upon increasing the temperature of synthesis