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 °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.

Figure optionsDownload high-quality image (132 K)Download as PowerPoint slideResearch highlights▶ Packing–filling method promotes homogeneous Si-PDMS composite membrane synthesis. ▶ Capillary support decreases transport resistance. ▶ Ultrathin homogenerous membrane possesses high iso-butanol flux.