Organosilica Multilamellar Vesicles with Tunable Number of Layers and Sponge-Like Walls via One Surfactant Templating

Organosiliceous multilamellar vesicles (MLVs) have been prepared with a high yield (>90%) and at mild conditions, through a single-templating approach by using Pluronic P85 as a structure directing agent and 1,2-bis(triethoxysilyl)ethane (BTEE) as an organosilica source. The obtained vesicles have diameters of 100-200 nm and possess sponge-like walls with the mesopore size centered at 6 nm. The number of layers can be adjusted from 7 to 1 by changing the synthesis pH value from 4.8 to 5.2. The specific surface area and pore volume of organosilica MLVs are as large as 695 m(2)/g and 2.10 cm(3)/g, respectively. Moreover, a transformation from the hexagonal mesostructure obtained at pH 4.2 to multilamellar (pH 4.8-5.2) and unilamellar vesicles (pH 5.5) is observed. The organosilica MLVs with controlled wall thickness, hierarchical porosity, and interconnected sponge-like walls are promising candidates for applications in nanoreactors, selective sorption, and controlled release.