Processing effects in self-organized mesoporous silica materials

The mesoporous silica MCM-41 materials with different pore sizes had been synthesized under three synthetic conditions. The processing effects were due to hydrolysis and condensation of tetraethyl orthosilicate (TEOS), concentrations of inorganic counter-ions and reaction temperature. A higher concentration of inorganic counter-ions can lead to a thinner electrical double layer of surfactant micelles and smaller nanopore size under acidic conditions. More condensation and less charge density of silicate oligomers in basic medium resulted in the larger size of the mesopore. In addition, the largest pore size could be obtained upon the hydrothermal treatment.