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Organic–inorganic hybrid silica membranes were prepared from 1, 2 bis (triethoxysilyl)ethane (BTESE) by sol–gel processing at temperatures as low as 100°C, followed by solid-phase HCl-assisted post-treatment to tune the silica network by reducing the pore size. The Brunauer–Emmett–Teller (BET) surface area, thermogravimetric (TG) and positron annihilation lifetime (PAL) showed reduced pore sizes and a densified network structure of BTESE powder after the HCl-assisted treatment. The HCl-assisted treatment increased the permeance ratios of both He-to-N2 and He-to-C3H8, while the permeance of He was decreased. During the pervaporation (PV) dehydration of a 90wt% (wt%) isopropanol (IPA) aqueous solution at 75°C, a BTESE membrane fired at 100°C with HCl treatment showed a stable PV water flux of 2.46kgm−2 h−1 and a separation factor of 3960 for more than 80h, confirming the successful preparation of BTESE membranes at low firing temperatures. The BTESE-derived silica networks were successfully and easily controlled by this novel HCl-assisted post-treatment. [ABSTRACT FROM AUTHOR]

Solvents purification mainly used in pharmaceutical field such as acetone and methyl ethyl ketone (MEK) were performed through hybrid silica membranes and from binary and multi-components mixtures. Two hybrid silica membranes—zirconia doped bis(triethoxysilyl)methane and bis(triethoxysilyl)ethane (BTESE)—were studied. Flux, permeance, and separation factor were evaluated depending on temperature, composition, and number of organic compounds in the feed. Dehydration tests of acetone were operated at 30 and 45 °C following by acetone and MEK purification at 50 °C from multi-components hydro-organic mixtures where hydrophilic compounds (water, methanol) but also hydrophobic (dichloromethane (DCM) and/or toluene) were present. Results showed that the presence of Zr nanoparticles affected flux and improved selectivity in the case of dehydration. Experiments related to acetone and MEK purification, revealed a mass transfer alteration and a decrease of performance, from 99 to 97 wt% and from 98 to 95 wt% respectively, when the number of compounds in the initial feed grown up and more precisely, in the presence of DCM and toluene thus highlighting a possible coupling effect. [ABSTRACT FROM AUTHOR]