Disclosed herein are nanoporous membranes for separating a target substance from a non-target substance in a fluid medium and methods of making and use thereof. The nanoporous membranes comprise a 2D material permeated by a first and second population of pores; wherein the average pore diameter of the first population of pores is greater than or equal to the van der Waals diameter of water and less than the average size of the non-target substance in the fluid medium; wherein the average pore diameter of the second population of pores is greater than or equal to the average size of the non-target substance in the fluid medium; and wherein substantially all of the second population of pores are substantially blocked by a polymer via size-selective interfacial polymerization; such that the nanoporous membrane allows for transport of the target substance through the nanoporous membrane via the first population of pores.

Devices and methods for controlling molecular transport are disclosed herein. The devices include a membrane having a plurality of nanochannels extending therethrough. The membrane has an inner electrically conductive layer and an outer dielectric layer. The outer dielectric layer creates an insulative barrier between the electrically conductive layer and the contents of the nanochannels. At least one electrical contact region is positioned on a surface of the membrane. The electrical contact region exposes the electrically conductive layer of the membrane for electrical coupling to external electronics. When the membrane is at a first voltage, molecules flow through the nanochannels at a first release rate. When the membrane is at a second voltage, charge accumulation within the nanochannels modulates the flow of molecules through the nanochannels to a second release rate that is different than the first release rate. Methods of fabricating devices for controlling molecular transport are also disclosed herein.

Method for making a porous graphene layer of a thickness of less than 100 nm with pores having an average size in the range of 5-900 nm, includes the following steps: providing a catalytically active substrate catalyzing graphene formation under chemical vapor deposition conditions, the catalytically active substrate in or on its surface being provided with a plurality of catalytically inactive domains having a size essentially corresponding to the size of the pores in the resultant porous graphene layer; chemical vapor deposition using a carbon source in the gas phase and formation of the porous graphene layer on the surface of the catalytically active substrate. The pores in the graphene layer are in situ formed due to the presence of the catalytically inactive domains.

Provided is a method for making a porous graphene layer of a thickness of less than 100 nm, including the following steps: providing a catalytically active substrate, said catalytically active substrate on its surface being provided with a plurality of catalytically inactive domains having a size essentially corresponding to the size of the pores in the resultant porous graphene layer; and chemical vapour deposition and formation of the porous graphene layer on the surface of the catalytically active substrate;. The catalytically active substrate is a copper-nickel alloy substrate with a copper content in the range of 98 to less than 99.96% by weight and a nickel content in the range of more than 0.04-2% by weight, the copper and nickel contents complementing to 100% by weight of the catalytically active substrate.

The invention, belonging to the field of membrane technology, presents a method for the direct growth of ultrathin porous graphene separation membranes. Etching agent, organic solvent and polymer are coated on metal foil, and then they are calcined at high temperature in absence of oxygen; after removal of metal substrate and reaction products, single-layered or multi-layered porous graphene membranes are obtained. Alternatively, the dispersion or solution of etching agent is coated on metal foil, on which a polymer film is then overlaid. The obtained sample is subsequently calcined at high temperature in absence of oxygen; after removal of metal substrate and reaction products, single-layered or multi-layered porous graphene membranes are obtained. The method involved in this invention is simple and highly efficient, and allows direct growth of ultrathin porous graphene separation membranes, without needing expensive apparatuses, chemicals and graphene raw material. Additionally, the graphene membranes prepared with this method have controlled pore size, ultrahigh water flux and strong resistance to irreversible fouling.

There is provided a multi-layered membrane comprising a top layer, a bottom layer, and a spacer layer; wherein said spacer layer is interposed between said top layer and said bottom layer; wherein said top layer, said bottom layer and said spacer layer are each independently composed of one or more selective layers, each selective layer comprising a 2D material; wherein said spacer layer comprises at least one channel for receiving a fluid; wherein said bottom layer comprises a hole with an area in the range of 1 μm.sup.2 to 1 mm.sup.2; and wherein said hole is capable of being in fluid communication with said at least one channels of said spacer layer.

There is also provided a method to synthesize the top layer of a multi-layered membrane as disclosed herein, methods for separating a plurality of ions or molecules in a fluid stream, a device comprising a multi-layered membrane as disclosed herein, and use of the method or the device as disclosed herein in osmotic power generation.

There is provided a system and method for angstrom confinement of trapped ions. The method including: receiving water molecules and ionic compounds in a first reservoir, an angstrom confinement assembly is positioned between the first reservoir and a second reservoir, the angstrom confinement assembly defining angstrom conduits; and repeatedly applying an electric field across a first electrode and a second electrode, the first electrode on a same side of the angstrom confinement assembly as the first reservoir and the second electrode on a same side of the angstrom confinement assembly as the second reservoir, the electric field applied such that, when the electric field is applied, positive ions of the ionic compounds are induced to flow through the angstrom conduits, and wherein, when the electric field is not applied, water molecules flow into the angstrom conduits due to capillary forces to confine the positive ions in the angstrom conduits.

A microfluidic assembly can include a first microchannel substrate defining one or more first microchannels, a second microchannel substrate defining one or more second microchannels. The assembly can further include a membrane positioned between the first and second microchannel substrates and comprising a first polymeric layer, a second polymeric layer, and one or more graphene layers disposed between the first and second polymeric layers. At least a portion of the first microchannels can overlap at least a portion of the second microchannels such that, when a first fluid is present in the first microchannels and a second fluid is present in the second microchannels, the first fluid and the second fluid contact opposite sides of the membrane.

A perfluorocarbon-free membrane composed of a non-perfluorocarbon material having a first side and a second side opposite of the first side. The perfluorocarbon-free membrane also includes a plurality of pores, each having an inlet and outlet and each passing through the non-perfluorocarbon material so that each pore provides fluidic communication between the first and second sides of the non-perfluorocarbon material. A portion of the non-perfluorocarbon material extends over the inlet and outlet of each the plurality of pores so that a cross-sectional area of the inlets and outlets in a direction of the extension of the non-perfluorocarbon material is smaller than a cross-sectional area of the respective pore in the direction of the extension of the non-perfluorocarbon material. The perfluorocarbon-free membrane does not include a hydrophobic perfluorocarbon coating.

A structure and method for carbon capture, e.g., in flue gas. An oxygen-terminated crown pore in graphene can be provided. Exposed carbon atoms on the pore edge can be bonded with oxygen to make a crown pore. When the CO.sub.2 is inside the pore, the electrostatic interaction becomes attractive because the positively charged carbon atom in CO.sub.2 is now exposed to negatively charged oxygen atoms on the crown pore edge. A favorable interaction between CO.sub.2 and the crown pore can be expected.