A membrane based separation method is for the separation or enrichment of one or more unsaturated compounds from mixtures of chemically similar organic compounds having a different degree of unsaturation, using a membrane, such as an inorganic membrane, functionalized with a metal, such as silver. An inorganic membrane, preferably modified or grafted with an organic functional group, is further functionalized with a metal, such as silver, for use in the membrane based separation methods.

A filtration membrane coating comprising a hydrophilic polymer, a surfactant, and one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine. The hydrophilic polymer and surfactant form a thin primer layer which is also superhydrophilic. The primer layer improves flux, and enables improved adhesion of the one or more charged compounds, which form a charged dye layer on top of the primer layer when enhances rejection of charged divalent ions. The coating can be applied while the membrane is packaged in its final form, such as in a spiral wound or other configuration.

A filtration membrane coating comprising a hydrophilic polymer, a surfactant, and one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine. The hydrophilic polymer and surfactant form a thin primer layer which is also superhydrophilic. The primer layer improves flux, and enables improved adhesion of the one or more charged compounds, which form a charged dye layer on top of the primer layer when enhances rejection of charged divalent ions. The coating can be applied while the membrane is packaged in its final form, such as in a spiral wound or other configuration.

A membrane based separation method is for the separation or enrichment of one or more unsaturated compounds from mixtures of chemically similar organic compounds having a different degree of unsaturation, using a membrane, such as an inorganic membrane, functionalized with a metal, such as silver.

An inorganic membrane, preferably modified or grafted with an organic functional group, is further functionalized with a metal, such as silver, for use in the membrane based separation methods.

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.

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. In some cases, the support layer can comprise a gas permeable polymer and hydrophilic additive dispersed within the gas permeable polymer. In some cases, the selective polymer layer can comprise a selective polymer matrix and carbon nanotubes dispersed within the selective polymer matrix. 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.

In embodiments of the present disclosure, a CMS hollow fiber membranes may be prepared to have an ultrathin (e.g. 2 microns or less) separation layer. A precursor hollow fiber may be prepared as dual layer fibers having a thin sheath layer and a core layer. During pyrolysis, the sheath layer is transformed into an ultrathin separation layer. Porosity of the core layer substrate is well-maintained during pyrolysis, thereby enabling high permeance of the CMS hollow fiber membrane. Additionally, in some embodiments, the sheath layer of the precursor hollow fibers may be hybridized prior to pyrolysis. By hybridizing the sheath layer prior to pyrolysis, a CMS hollow fiber may having an improved separation factor, including for example increased carbon dioxide/methane selectivity, may be provided.

A filtration membrane coating comprising a hydrophilic polymer, a surfactant, and one or more charged compounds, each containing one or more sulfonate functionalities and one or more linkable functionalities selected from the group consisting of amine, monochlorotriazine, and dichlorotriazine. The hydrophilic polymer and surfactant form a thin primer layer which is also superhydrophilic. The primer layer improves flux, and enables improved adhesion of the one or more charged compounds, which form a charged dye layer on top of the primer layer when enhances rejection of charged divalent ions. The coating can be applied while the membrane is packaged in its final form, such as in a spiral wound or other configuration.

A thin film nanocomposite nanofiltration membrane or TFC-NF membrane includes an ultrafiltration support membrane coated with a trimesic acid coating layer. The trimesic acid coating layer is formed or self-assembled on the ultrafiltration support membrane by pouring an aqueous solution of a water soluble tertiary amine on the support membrane to form a first coating layer and then applying a solution of trimesolychloride on the first coating layer. In other words, the trimesic acid coating layer can be formed as a result of the liquid-liquid interface of the water soluble tertiary amine and the trimesolychloride. A total thickness of the TFC-NF membrane can be about 150 ?m. The thin film nanocomposite nanofiltration membrane can be free from MPD monomers.

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 ?m. The present invention also relates to processes of fabricating the composite polyamide reverse osmosis membrane.