Cross-linked Graphene Oxide Films for Separation Processes

Membranes comprising graphene oxide sheets and associated filter media and methods are provided. In some embodiments, a membrane may comprise graphene oxide sheets that have undergone one or more chemical treatments. The chemical treatment(s) may impart beneficial properties to the membrane, such as a relatively small d-spacing, compatibility with a broad range of environments, physical stability, and charge neutrality. For example, the graphene oxide sheets may undergo one or more chemical treatments that form chemical linkages between at least a portion of the graphene oxide sheets in the membrane. Such chemical linkages may impart a small d-spacing, broad compatibility, and/or allow relatively thick membranes to be formed. In certain embodiments, the graphene oxide sheets may undergo one or more chemical treatment that imparts relative charge neutrality to the membrane by altering the ionizability of certain functional groups. Graphene oxide membranes, described herein, can be used for a wide range applications.