Whether it be desalination or purification, the use of membrane filtration is essential to secure safe water sources worldwide. Graphene has the potential to revolutionise separation technology as it is exceptionally thin yet ultra-strong, ideal properties for a membrane to possess. Much of the early graphene membrane research has focused on producing membranes made from just a single sheet of graphene. These are made permeable by engineering tiny pores into the graphene sheet, quite difficult to do consistently and on a large scale.

Here at the NanoCentre, Dr. Luke Sweetman and Prof’s Shapter, Lewis and Ellis are developing multi-layer graphene oxide membranes made by simply vacuum filtering suspensions of graphene oxide. These membranes have the ability to control the passage of ions or molecules, however, their ability to survive in turbulent water for the long-term is of concern. Thus, we have been looking into new methods to covalently cross-link these membranes in order to improve their long-term stability without compromising performance. We also aim to investigate the use of these membranes to sequester isotopes found in nuclear waste with our collaborators at ANSTO. Graphene oxide suspensions have already been shown to quickly remove radioactive material from water, so by incorporating them into a membrane it may be possible to remove these problematic materials using simple filtration techniques.

Post by Dr Luke Sweetman, Postdoc with Professor Amanda Ellis