Synthesis of mesoporous silica fibers and discoids endowed with circular pore architecture using disodium trioxosilicate as silica source

We describe the synthesis of mesoporous silica fibers and discoids using disodium trioxosilicate (Na2SiO3 center dot 9H(2)O), a convenient silica source with cetyltrimethylmmonium chloride (CTAC) as a structure directing agent under acidic condition. The molar composition of the synthesis sol is 1Na(2)SiO(3) center dot 9H(2)O:1.5CTAC:28HCl:729H(2)O. The fibers and discoids, both p6mm, hexagonal, are obtained at room temperature and 70 degrees C, respectively. The particles are mesoporous single-crystal like with hexagonally organized pores and possess a circular architecture with pore channels running around the fiber or discoid axis endowing self-sealed-type structure to the particles. For fibers and discoids, the BET surface areas are 1330 m(2)/g and 1250 m(2)/g, mesopore diameters are 2.4 nm and 2.5 nm, and pore volumes are 0.93 cm(3) and 0.96 cm(3)/g, respectively. (C) 2008 Elsevier Inc. All rights reserved.