Silica-based monoliths with co-continuous structure were successfully prepared through a sol-gel process in the presence of a poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol) (F68). The triblock copolymer was compared to the classical PEG, in the formation of silica monoliths and was demonstrated to lead to co-continous structures in a wider composition range, presenting smaller through pores. Moreover, mesoporous structures templated at the sol-gel transition were assumed to occur at the surface of the silica skeleton while PEG exhibited no mesopore templating. (C) 2009 Elsevier Inc. All rights reserved.