Abstract

The hydrolytic sol–gel polymerization of a variety of molecular precursors with a “rigid” geometry 1,4-C₆H₄[Si(OMe)₃]₂1 and a “flexible” geometry (MeO)₃Si-(CH₂)₁₀-Si(OMe)₃2 was investigated varying the nature of the catalyst, the temperature and the length of ageing. The reactions were performed using ionic and non-ionic catalysts. The ionic ones were a nucleophile [tetrabutylammonium fluoride (TBAF)] or acid (HCl) and the non-ionic one was dimethylaminopyridine (DMAP). The solvent was THF. In all cases, the length of ageing had a minor effect on the level of condensation at silicon atoms of the different xerogels. Only a small increase was observed. In contrast, the specific surface area, the porosity and the pore size were highly dependent on the length of ageing. The longer ageing times favoured the formation of mesoporous solids with high specific surface areas and narrow pore size distribution.