A membrane modification method for improving liquid membrane separation of carbon dioxide (CO.sub.2) includes grafting an organic substance containing an amine group on a porous membrane material, and loading water into pore channels of the porous membrane material to prepare a supported liquid membrane for a gas mixture separation experiment of CO.sub.2. In the method, the amine group is introduced through chemical grafting to make the water being alkaline when used as membrane liquid. Compared with an alkaline solution as the membrane liquid, the method can avoid the loss of active alkaline substances and increase the permeation flux of CO.sub.2.

A membrane modification method for improving liquid membrane separation of carbon dioxide (CO.sub.2) includes grafting an organic substance containing an amine group on a porous membrane material, and loading water into pore channels of the porous membrane material to prepare a supported liquid membrane for a gas mixture separation experiment of CO.sub.2. In the method, the amine group is introduced through chemical grafting to make the water being alkaline when used as membrane liquid. Compared with an alkaline solution as the membrane liquid, the method can avoid the loss of active alkaline substances and increase the permeation flux of CO.sub.2.

Embodiments described herein relate generally to graphene oxide membranes for fluid filtration and more specifically to graphene oxide membranes having tunable permeability, rejection rate, and flux. Some embodiments of the graphene oxide membranes disclosed herein are characterized as having a flux of at least about 2.5×10.sup.−4 gallons per square foot per day per psi with a 1 wt % lactose solution at room temperature, and a lactose rejection rate of at least 50% with a 1 wt % lactose solution.

This disclosure relates to CO.sub.2-philic crosslinked polyethylene glycol membranes useful for natural gas purification processes. Also provided are methods of using the membranes to remove CO.sub.2 and H.sub.2S from natural gas.

A composite polyamide reverse osmosis membrane comprising a polyamide layer; where the polyamide layer has a thickness in the range of 50-250 nm, and large open spaces (i.e., free volumes); where the open spaces are defined by a ratio of water flux, J.sub.w, (gfd) divided by the average surface roughness, Ra, (nm) of the polyamide layer; wherein the composite polyamide reverse osmosis membrane has the ratio of J.sub.w/Ra>0.35 gfd/nm when tested at 65 psi, using an aqueous solution containing 250 ppm of NaCl; and a microporous support with a thickness ranging from 100-150 μm. The present invention also relates to processes of fabricating the composite polyamide reverse osmosis membrane.

Embodiments described herein relate generally to durable graphene oxide membranes for fluid filtration. For example, the graphene oxide membranes can be durable under high temperatures non-neutral pH, and/or high pressures. One aspect of the present disclosure relates to a filtration apparatus comprising: a support substrate, and a graphene oxide membrane disposed on the support substrate. The graphene oxide membrane has a first lactose rejection rate of at least 50% with a first 1 wt % lactose solution at room temperature. The graphene oxide membrane has a second lactose rejection rate of at least 50% with a second 1 wt % lactose solution at room temperature after the graphene oxide membrane is contacted with a solution that is at least 80° C. for a period of time.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membranes can comprise a support layer, and a selective polymer layer disposed on the support layer. The selective polymer layer can comprise a selective polymer matrix and carbon nanotubes dispersed within the selective polymer matrix. The carbon nanotubes can comprise multi-walled carbon nanotubes wrapped in a hydrophilic polymer, such as polyvinylpyrrolidone or a copolymer thereof, such as poly(1-vinylpyrrolidone-co-vinyl acetate). The membranes can exhibit selective permeability to gases. As such, the membranes can be for the selective removal of carbon dioxide and/or hydrogen sulfide from hydrogen and/or nitrogen.

An article having a nanoporous membrane and a nanoporous graphene sheet layered on the nanoporous membrane. A method of: depositing a layer of a diblock copolymer onto a graphene sheet, and etching a minor phase of the diblock copolymer and a portion of the graphene in contact with the minor phase to form a nanoporous article having a nanoporous graphene sheet and a nanoporous layer of a polymer. A method of: depositing a hexaiodo-substituted macrocycle onto a substrate having a Ag(111) surface; coupling the macrocycle to form a nanoporous graphene sheet; layering the graphene sheet and substrate onto a nanoporous membrane with the graphene sheet in contact with the nanoporous membrane; and etching away the substrate.

This disclosure relates to CO.sub.2-philic crosslinked polyethylene glycol membranes useful for natural gas purification processes. Also provided are methods of using the membranes to remove CO.sub.2 and H.sub.2S from natural gas.

This disclosure relates to CO.sub.2-philic crosslinked polyethylene glycol membranes useful for natural gas purification processes. Also provided are methods of using the membranes to remove CO.sub.2 and H.sub.2S from natural gas.