Chementator: A promising nanosieve for dehydrating solvents and biofuels  

Although nanoporous silica membranes are promising systems for the molecular separation of gases and liquids, they lack microstructural stability in the presence of water at temperatures as low as 60°C. Prolonged exposure to water causes hydrolysis, resulting in the formation of large, non-selective pores and cracks in the membrane. On the other hand, polymeric membranes are less prone to damage by water, but are unable to operate at high temperatures. A hybrid membrane, which combines the advantages of ceramics and polymers, has been developed by researchers at the University of Twente (Enschede, Netherlands; edlinks.chemengonline.com/7370-566). In collaboration with the University of Amsterdam and the Energy Research Center of the Netherlands (ECN; Petten; edlinks.chemengonline.com/7370-567), the Twente scientists have shown that the new membrane can be used to dehydrate 95 wt.% n-butanol, without a significant drop in selectivity after continuous exposure to 150°C for 1.5 yr. In contrast, inorganic silica deteriorated within weeks at 95°C, according to professor Andre ten Elshof, professor at Twente’s Dept. of Inorganic Materials Science. In the new membrane (diagram), some of the ceramic links (Si – O –…