Long-term pervaporation performance of microporous methylated silica membranesElectronic Supplementary Information (ESI) available: details of the sol synthesis; GPC and NMR measurements; and additional SEM micrographs. See http://www.rsc.org/suppdata/cc/b4/b401496k/

The incorporation of methyl groups in microporous silica membranes was proven to enhance the service time in the dehydration of a butanol-water mixture at 95 degrees C from a few weeks to more than 18 months with a water flux of about 4 kg m(-2) h(-1) and a selectivity between 500 and 20 000.