Capillary supported ultrathin homogeneous silicalite-poly(dimethylsiloxane) nanocomposite membrane for bio-butanol recovery

An ultrathin (300 nm) homogeneous silicalite-poly(dimethylsiloxane) (PDMS) nanocomposite membrane was fabricated on capillary support by a Packing-filling method. Firstly, silicalite-1 nano-crystals were deposited onto a porous alumina capillary support using dip-coating technique (packing); secondly, the interspaces among the nano-crystals were filled with PDMS phase (filling). No voids between nano-crystals and PDMS phase were observed by scanning electron microscopy (SEM), suggesting good zeolite-polymer adhesion. The membrane possesses very high flux (5.0-11.2 kg m(-2) h(-1)) and good separation factor (25.0-41.6) for the pervaporative recovery of iso-butanol from aqueous solution (0.2-3 wt.%) at 80 degrees C. Such properties offer great potential towards applications in fermentation-pervaporation coupled processes. The effects of feed temperature and concentration on the pervaporation performance of this nanocomposite membrane were investigated. (C) 2010 Elsevier B.V. All rights reserved.