The natural carbon cycle provides inexpensive sources for highly versatile building blocks in the development of new nanostructured materials for energy technology and environmental applications. In this work the chemical similarity and the structural difference of graphene oxide (GO) and of a natural biopolymer (HAL) have been exploited to fabricate stable and homogenous carbon-based membranes with enhanced water permeability, as shown in Fig. 1. From the chemical point of view, both GO and HAL consist of a carbon backbone functionalized with oxygen-containing moieties (i.e carboxylic acids, phenols, and epoxy groups), which make them highly dispersible in water at neutral and basic pH. However, GO dispersions consist of 2D layers with monoatomic thickness, while dispersed HAL macromolecules have a 3D brunched structure. Due to their chemical resemblance, HAL macromolecules can easily intercalate GO sheets during membrane formation. After annealing at 120 ºC, HAL macromolecules introduce disorder in the GO layers staking, making the membrane more permeable to water molecules. This feature together with a good water/ethanol perm-selectivity makes GO-HAL membranes promising devices for alcohol dehydration. This work was made possible by H2020-MSCA-RISE-2014, project number 645551.

Vittorio Boffa is Associate Professor at the Department of Chemistry and Bioscience, Aalborg University, Denmark. His primary research interests are nanofiltration ceramic membranes, graphene oxide membranes, and photocatalytic membranes. He has been introduced to inorganic membranes at Twente University (Enschede, The Netherlands) where he received his PhD degree in 2008, by defending a thesis on niobia-silica gas-separation membranes. After working for nearly three years (2008-2010) at Turin University (Turin, Italy), in a project concerning the extraction of biopolymers from urban waste, he moved to Aalborg University, where he has been involved in few national and European projects on the development of new ceramic membranes for water purification and micropolutants abatement.