Formation of ordered macropores and templated nanopores in silica sol-gel system incorporated with EO-PO-EO triblock copolymer

Silica gels with well-defined co-continuous gel skeletons and pore in the micrometer range have been prepared using a poly(ethylene oxide-propylene oxide-ethylene oxide (EO-PO-EO)) triblock copolymer. Being essentially independent of the micrometer-range structure, the mesopore exhibited narrow distributions around an identical median size and its volume was correlated well to the concentration of triblock copolymer. Small-angle neutron scattering of wet, dried and heat-treated gels revealed that the mesopore structure had been already templated at the sol-gel transition, and was preserved or even enhanced during the removal of solvent and carbonaceous constituents. (C) 2001 Elsevier Science B.V. All rights reserved.