Background
Since their discovery in the late 1970s mesoporous silicas have attracted much attention due to their unique ordered pore structures, very high specific surface areas and range of morphologies that can be synthesised for examples spheres rods, discs and powders. Unlike traditional porous silicas, mesoporous silicas exhibit unusually ordered pores due to the nanotemplating approach applied during synthesis. Over the past 30 years a plethora of mesoporous silicas (SBA 15, SBA 16 MCM 41, 48 etc.) have been synthesised with a wide ranging pore geometries (Hexagonal, Cubic etc.) and particle morphologies e.g Discs, Spheres, Rods etc.
Figure 1 below illustrates some of the morphological qualities of mesoporous silica (MS) and porous silica spheres (PSS). PSS are spherical particles with quasi ordered porosity. Recent developments in manufacturing of mesoporous silica which allow production at a kg scale has allowed mesoporous silica to move from blue skies research laboratories into more advanced application driven research.
Mesoporous silicas with uniform and tailorable pore dimensions and high surface areas, are currently being employed in a number of advanced applications that include: