Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membrane can include a support layer, and a selective polymer layer disposed on the support layer. The selective polymer layer can include a selective polymer matrix (e.g., hydrophilic polymer, a cross-linking agent, an amino compound, a CO.sub.2-philic ether, or a combination thereof), and optionally graphene oxide dispersed within the selective polymer matrix. The membranes can be used to separate carbon dioxide from hydrogen. Also provided are methods of purifying syngas using the membranes described herein.

Provided herein are gas permeable membranes comprising an amine-containing selective layer on top of a gas permeable polymer support as well as methods of making and using thereof. The membranes are useful for the separation of CO.sub.2 from N.sub.2-containing gases.

Provided is a facilitated CO.sub.2 transport membrane having improved CO.sub.2 permeance and improved CO.sub.2 selective permeability. The facilitated CO.sub.2 transport membrane includes a separation-functional membrane comprising a hydrophilic polymer gel membrane which contains a CO.sub.2 carrier and a CO.sub.2 hydration catalyst, wherein the hydrophilic polymer is a copolymer including a first structural unit derived from an acrylic acid cesium salt or an acrylic acid rubidium salt and a second structural unit derived from vinyl alcohol. More preferably, the CO.sub.2 hydration catalyst has catalytic activity at a temperature of 100° C. or higher.

The present invention relates to a composite separation membrane that is applicable to carbon dioxide separation and recovery processes. The composite separation membrane includes a coating layer composed of graphene oxide and a bile acid or its salt on a porous polymer support. The composite separation membrane of the present invention, which includes a coating layer composed of graphene oxide and a bile acid or its salt, has both high carbon dioxide permeability and high selectivity for carbon dioxide over nitrogen, hydrogen or methane gas, is free of surface defects, and maintains a stable structure without deterioration of its performance even after long-term use. Due to these advantages, the composite separation membrane of the present invention can be applied to industrial fields involving carbon dioxide separation and recovery processes. The present invention also relates to a method for manufacturing the composite separation membrane.

New carbon nanomaterials, preferably titanium carbide-derived carbon (CDC) nanoparticles, were embedded into a polyamide film to give CDC/polyamide mixed matrix membranes by the interfacial polymerization reaction of an aliphatic diamine, e.g., piperazine, and an activated aromatic dicarboxylate, e.g., isophthaloyl chloride, supported on a sulfone-containing polymer, e.g., polysulfone (PSF), layer, which is preferably previously prepared by dry/wet phase inversion. The inventive membranes can separate CO.sub.2 (or other gases) from mixtures of CO.sub.2 and further gases, esp. CH.sub.4, based upon the generally selective nanocomposite layer(s) of CDC/polyamide.

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 are described that may include aligned carbon nanotubes coated with an inorganic support layer and a polymeric matrix. Methods of membrane fabrication are described that may include coating an aligned carbon nanotube array with an inorganic support layer followed by infiltration with a polymeric solvent or solution. The support carbon nanotube membrane may have improved performance for separations such as desalination, drug delivery, or pharmaceuticals.

Provided are a CO.sub.2 gas separation membrane, a method for manufacturing the same, and a carbon dioxide gas separation membrane module including the same, the CO.sub.2 gas separation membrane including: a first layer (A) containing at least one alkali metal compound selected from the group consisting of an alkali metal carbonate, an alkali metal bicarbonate and an alkali metal hydroxide, and a first resin in which a polymer having a carboxyl group has been crosslinked; a second layer (B) containing at least one of the alkali metal compounds, and a second resin having a structural unit derived from a vinyl ester of a fatty acid; and a hydrophobic porous membrane (C).

Methods of making a poly(propylenimine) (PPI) sorbent, a PPI sorbent, structures including the PPI sorbent, methods of separating CO.sub.2 using the PPI sorbent, and the like, are disclosed.

A membrane including a polymer substrate having pore channels and a metal-organic framework disposed on the polymer substrate. Methods of producing the membrane are described. Methods of separating gases using the membrane are also provided.