Synthesis of rod-like mesoporous silica using mixed surfactants of cetyltrimethylammonium bromid and cetyltrimethylammonium chloride as templates

Using sodium silicate as precursors and mixed surfactants of cetyltrimethylammonium bromide (CTAB) and cetyltrimethylammonium chloride (CTAC) as templates, rod-like mesoporous silica with hexagonal appearance were synthesized by controlling the pH value of solution during hydrolysis of ethylacetate. Results showed that at a molar ratio of 9:1 (CTAB to CTAC), regular rod-like shapes were obtained, and that with the decrease of the molar ratio of CTAB to CTAC (from 9:1 to 5.5:4.5), the amount and length of rod-like mesoporous silica decreased, but the amount of irregular particles increased. The diffraction peaks obtained with XRD were assigned to hexagonal symmetry. Type IV adsorption isotherm and an HI hysteresis loop were observed in N-2 adsorption-desorption curves. (C) 2003 Elsevier Science B.V. All rights reserved.