Morphology Control of Mesoporous Silica Particles Using Bile Acids as Cosurfactants

Morphology control and tuning of nanomaterials are crucial to determine their properties and applications. Solutions based on different synthetic methodologies have been proposed, and in general they required variation of several parameters. Here, a new facile and cost-effective bottom-up strategy to control the morphology of mesoporous silica particles is presented. Specifically, catanionic templating systems composed of bile acids and CTAB enable the production of submicrometer MCM-41 particles of various shapes, high porosity, and remarkable features. The variation of a single component, the bile acid, leads to the preparation of particles with different morphologies. For instance, small (<500 nm) well-separated hexagonal platelets and twisted rods, with tunable aspect ratio and chiral pore channels, were prepared. Experiments aimed at elucidating the role of the bile acids showed that the control of shape is due to the specific interactions between bile acids and CTAB.