Abstract: Various systems and methods relating to two-dimensional materials such as graphene. A membrane include a cross-linked graphene platelet polymer that includes a plurality of cross-linked graphene platelets. The cross-linked graphene platelets include a graphene portion and a cross-linking portion. The cross-linking portion contains a 4 to 10 atom link. The cross-linked graphene platelet polymer is produced by reaction of an epoxide functionalized graphene platelet and a (meth)acrylate or (meth)acrylamide functionalized cross-linker.

Abstract: Perforated graphene sheets can be used in forming separation membranes. Separation membranes of the present disclosure, which can be used in gas separation processes in some embodiments, can include one or more layers of perforated graphene and one or more layers of another membrane material. Methods for separating a gas mixture can include contacting a gas mixture with the separation membranes, and transiting one or more of the gases through the perforated graphene so as to affect separation.

Abstract: Two-dimensional materials, particularly graphene-based materials, having a plurality of apertures thereon can be formed into enclosures for various substances and introduced to an environment, particularly a biological environment (in vivo or in vitro). One or more selected substances can be released into the environment, one or more selected substances from the environment can enter the enclosure, one or more selected substances from the environment can be prevented from entering the enclosure, one or more selected substances can be retained within the enclosure, or combinations thereof. The enclosure can for example allow a sense-response paradigm to be realized. The enclosure can for example provide immunoisolation for materials, such as living cells, retained therein.

Abstract: Perforated graphene and other perforated two-dimensional materials can be used in hemodialysis membranes and blood filtration membranes for selective removal of components from blood in vivo and ex vivo. The membranes are useful in hemodialysis and hemofiltration techniques to provide improved patient care. Hemodialysis systems can include a hemodialysis membrane formed from perforated graphene or another perforated two-dimensional material disposed upon a porous support structure. Hemofiltration systems can include one or more and preferably two or more blood filtration membrane formed from perforated graphene or another perforated two-dimensional material disposed upon a porous support structure. Methods for performing hemodialysis can involve exposing blood from a patient to a hemodialysis membrane formed from a perforated two-dimensional material. Ex vivo dialysis techniques can be performed similarly.

Abstract: A method for making a nanoporous membrane is disclosed. The method provides a composite film comprising a two-dimensional material layer and a polymer layer, and then bombarding the composite film with energetic particles to form a plurality of pores through at least the two-dimensional material layer. The nanoporous membrane also has a two-dimensional material layer with a plurality of apertures therethrough and a polymer film layer adjacent one side of the graphene layer. The polymer film layer has a plurality of enlarged pores therethrough, which are aligned with the plurality of apertures. All of the enlarged pores may be concentrically aligned with all the apertures. In one embodiment the two-dimensional material layer is graphene.

Abstract: Multi-layer sheets of graphene-based material having a plurality of pores extending therethrough are described herein. Methods for making the sheets include exposing a graphene-based material comprising multilayer graphene having from 5 to 20 layers of graphene to a particle beam having an ion energy of at least about 1500 eV to create damage tracks in the graphene sheets. The damage tracks in the graphene sheets are then exposed to a chemical etchant, such as an oxidant to define pores through the stacked graphene sheets. Production of the damage tracks and etching of the damage tracks can take place while the graphene is disposed on a substrate.

Abstract: Structures comprising a first sheet of perforated two-dimensional material and a first plurality of spacer elements disposed between a surface of the first sheet of perforated two-dimensional material and at least one of a surface of a structural substrate and a surface of a second sheet of perforated two-dimensional material are disclosed, as well as related methods. The structures may further comprise a structural substrate, a second plurality of spacer elements, additional sheets of perforated two-dimensional material in direct contact with the first and/or said second sheet of perforated two-dimensional material and/or relief features in the surface of the structural substrate.