Morphology control of mesoporous silica particles

We demonstrate morphology dependence of mesoporous silica synthesized in acidic condition via the control of silica hydrolysis and condensation at 4 degrees C under quiescent acidic condition, and without using any organic cosolvents. Tetramethyl orthosilicates (TMOS) is used as a silica source and cetyltrimethylammonium chloride (CTAC) as the structure directing agent ( SDA). Straight fibers of different aspect ratio with pore channels aligned parallel to the fiber axis are synthesized by varying TMOS from the sols of molar compositions 0.17-0.32TMOS: 0.22CTAC: 9HCl: 100H(2)O. Curved morphologies such as discoids and spheres are prepared by controlling acidity in the sols of molar compositions 0.17TMOS: 0.22CTAC: 14-16HCl: 100H2O. The mesoporous silica particles show BET surface area of 1100-1400 cm3/g, and the mesopore diameter and mesopore volume are in the range of 2.2- 2.6 nm and 0.6-0.8 cm(3)/g, respectively.