Nanomaterials Enhanced membranes and Processes for water and energy challenges
Membranes are fundamental elements for many industrial processes such as water desalination and water purification plants, but their usage is also widespread in fuel cells, batteries and “blue energy” harvesting systems exploiting the selective passage of ionic chemical species for energy generation and storage. Notwithstanding their large technological relevance, currently employed membranes suffer from many drawbacks and a further breakthrough in this field would require the use of innovative materials and in some cases complete membrane redesign. Among relevant challenges affecting actual membranes technology and calling for innovative solutions in terms of new materials and processes, we can mention: reduction of membrane fouling, scaling-up, increasing flux/reducing pressure, even pores size distribution in the membrane (all pores having similar size), increasing membrane resistance (mechanical, thermal and chemical resistance) and lifetime, and enhance membrane selectivity. In recent years, several studies highlighted that nanomaterials have the potential to achieve a breakthrough in membranes performances, solving most of the above-mentioned weaknesses. In particular, the classes of nanomaterials that have attracted most of the research attention at the laboratory scale for both environmental and energy applications can be classified as follows: (i) two dimensional materials such as graphene, graphene oxide, hexagonal boron nitride and transition metal dichalcogenides (TMDs) (ii) artificial water channels (carbon nanotubes and other 1D systems) (iii) nanostructured polymers and oxides (iv) zeolites and (v) metal organic frameworks (MOF).