University of California, Berkeley,
Keywords: polymers, membranes
Summary:Graphene oxide has emerged as a two-dimensional nanomaterial with exceptional morphological, mechanical, electrical, chemical, and biological properties. I will discuss the promise of innovatively using graphene oxide as building blocks to form a new type of membranes for water purification. Some exciting results from our ongoing research on graphene oxide membranes made by layer-stacking and bonding of graphene oxide nanosheets will be presented. Compared with todays widely used polymeric membranes, graphene oxide membranes can be fabricated with inexpensive carbon materials by facile methods and demonstrate many unique transport phenomena. For example, a cross-linked graphene oxide membrane exhibits unique rejection properties to uncharged organic species (~ 85%) and ionic species (~6%). Besides, despite a stronger affinity between graphene oxide and foulants, the graphene oxide coating showcases its efficacy at preventing severe membrane fouling and thus providing a promising strategy to substantially enhance energy yield of pressure retarded osmosis process. Overall, graphene oxide membranes exhibit many unique properties and hold great promise as a new class of multifunctional, environment-friendly, high-performance, low-cost membranes for water purification and reuse.