Synthesis and characterisation of pore-expanded mesoporous silica materials

Mesoporous silicas are synthesised using 1,3,5-trimethylbenzene (TMB) and heptanes as pore expanders. Small-angle X-ray diffraction and N₂ adsorption-desorption isotherms at 77 K were used to characterise the pore structure of the prepared materials. The porosity increased with the added TMB amount for samples using TMB as a pore expander and a total pore value of 2.48 cm³/g was obtained, representing an increase by a factor of 2.4 as compared with mesoporous silica without TMB addition. For samples with heptanes as a pore expander, the pore volume increased with synthesis temperature. The mesoporous silica synthesised at 52°C had a total pore volume of 2.38 cm³/g.