Langmuir, Vol.28, No.33, 12334-12340, 2012
Preparation of Mesoporous/Macroporous Materials in Highly Concentrated Emulsions Based on Cubic Phases by a Single-Step Method
A novel and simple single-step method for the preparation of meso/macroporous silica materials is described, which consists in templating in highly concentrated emulsions with a cubic liquid crystal in the continuous phase. Tetraethyl orthosilicate (TEOS) was solubilized in the aqueous continuous phase of highly concentrated emulsions stabilized by C-12(EO)(8) and a PEO-PPO-PEO block copolymer nonionic surfactant, with a cubic liquid crystalline phase of the Fd3m type. The resulting silica materials were characterized by small-angle X-ray scattering, nitrogen sorption and transmission electron microscopy. The results showed that a dual pore size distribution was obtained, consisting of mesopores in the nanometer range and macropores between 1 and 5 mu m. These dual meso/macroporous silicas with bimodal pore size distribution can possess specific surface areas higher than 400 m(2)/g.