Multilamellar vesicular silica with an adjustable mesoporosity

Abstract

Mesoporous silica is a promising material for applications such as catalysis, separation, or drug delivery. Especially multilamellar vesicular silica (MLVS) is interesting due to the high surface-to-volume ratio. MLVS synthesis by a cation-cationic co-surfactant templating route was reported earlier. By varying the molar ratio of DDAB/CTAB as structure-directing agents, the number of lamellae varied between 7 and 2. Nevertheless, the pore volume is low compared to typical mesoporous silica’s, e.g. SBA-15. Here, we aim to increase the mesoporosity of MLVS by optimizing the silica precursor concentration. Lowering the concentration causes an increase in the surface area and pore volume of the MLVS. As a consequence, it can be expected that the loading capacity will increase. Since mainly the template determines the MLVS particles’ size, the latter can be maintained whilst varying the amount of silica precursor. This ensures that the primary properties of the particles remain unchanged as well.