Methods and systems for producing and using multi-layer composite co-polyimide membranes, one method for producing including preparing a microporous or mesoporous membrane support material for coating; applying a sealing layer to the membrane support material to prevent intrusion into the membrane support material of co-polyimide polymer; applying a first permselective co-polyimide layer atop and in contact with the sealing layer; and applying a second permselective co-polyimide layer atop and in contact with the first permselective co-polyimide layer.

An acidic gas separation membrane sheet causes an acidic gas to selectively permeate therethrough. The acidic gas separation membrane sheet includes a first porous layer, a hydrophilic resin composition layer, and a second porous layer in this order. A second peel strength between the second porous layer and the hydrophilic resin composition layer is less than a first peel strength between the first porous layer and the hydrophilic resin composition layer. An average value of the second peel strength is within a range of greater than or equal to 5 N/m and less than or equal to 500 N/m.

A monolayer membrane containing gelling polymer particles having at least one of a basic functional group and an acidic functional group, and having a thickness of less than 5 μm. A composite having a porous carrier and gelling polymer particles having at least any one of a basic functional group and an acidic functional group and filling up the surface pores of the porous carrier. The invention can provide a novel material capable of efficiently separating an acid gas from a mixed gas.

The present invention relates to a continuous process for preparing permselective hollow fiber membranes being suitable e.g. for hemodialysis, hemodiafiltration and hemofiltration of blood which comprises a two-stage drying and tempering treatment of the hollow fiber membranes. According to a further aspect, the invention relates to a continuous process for drying permselective hollow fiber membranes on-line. The invention also relates to devices for on-line drying of permselective hollow fiber membranes.

A method for making a graphene membrane includes applying a suspension of graphene platelets in a fluid onto a porous substrate, and applying a pressure differential to force the fluid through the substrate to yield a filtered fluid while retaining the graphene platelets on the substrate. The graphene platelets and the substrate form the graphene membrane.

There is provided a semi-crystalline polymer membrane, the membrane being a single-layer membrane and su-perwettable without provision of a coating or additives. There is also provided a method of forming the membrane comprising: depositing a solution on a substrate surface, the solution comprising a semi-crystalline polymer to form a nascent membrane; spraying a fluid on the nascent membrane; and immersing the nascent membrane in a non-solvent to form the semi-crystalline polymer membrane. In preferred embodiments, the fluid sprayed on the nascent membrane is selected from compressed air, water, a mixture of ethanol and water, or a solid suspension of ethanol/water/sodium chloride.

The disclosure relates to superhydrophobic membranes and methods of making and using such membranes. Polydimethylsiloxane (PDMS) substrate is formed on sandpaper such that the PDMS substrate has a surface texture replicating the opposite impression of the sandpaper texture. Separately, a PVDF solution is prepared and disposed on the PDMS substrate. The PVDF substrate and liquid film combination are transferred to a solution of deionized water mixed with 2-propanol to form a PVDF film on the PDMS substrate. The PVDF film-PDMS substrate is transferred to a second DI water bath, after which the PVDF film is detached from the PDMS substrate. The PVDF film is then washed and dried, to yield a superhydrophobic PVDF membrane having the texture of sandpaper.

The disclosure relates to superhydrophobic membranes and methods of making and using such membranes. Polydimethylsiloxane (PDMS) substrate is formed on sandpaper such that the PDMS substrate has a surface texture replicating the opposite impression of the sandpaper texture. Separately, a PVDF solution is prepared and disposed on the PDMS substrate. The PVDF substrate and liquid film combination are transferred to a solution of deionized water mixed with 2-propanol to form a PVDF film on the PDMS substrate. The PVDF film-PDMS substrate is transferred to a second DI water bath, after which the PVDF film is detached from the PDMS substrate. The PVDF film is then washed and dried, to yield a superhydrophobic PVDF membrane having the texture of sandpaper.

A method for preparing a high-selectivity lithium-magnesium separation membrane includes: (1) preparing an aqueous phase mixture containing aqueous phase monomer, crown ethers or aza-macrocycles, acid acceptor, surfactant and water; (2) preparing an organic phase mixture containing organic phase monomer, and organic solvent that is incompatible with water; (3) contacting the supporting membrane with the aqueous phase mixture to obtain an aqueous phase monomer-adsorbed supporting membrane; (4) contacting the aqueous phase monomer-adsorbed supporting membrane with an organic phase mixture for an interfacial polymerization reaction; and (5) placing a nascent membrane obtained into a drying oven and heat-treating the membrane to obtain a lithium-magnesium separation membrane. The present method is simple in preparation process, mild in preparation conditions, easy to scale up, and easy to realize industrial production. The prepared high-selectivity lithium-magnesium separation membrane is large in permeation flux, high in lithium-magnesium selectivity and good in long-term operation stability.

The separations membrane system includes a substrate, a microporous layer, and a selective layer. The microporous layer may be disposed over the substrate. The selective layer may be disposed over the microporous layer, thereby sandwiching the microporous layer between the selective layer and the substrate. The microporous layer includes a thermoplastic material. The selective layer includes a polyamide structure of 2,2-Dimethyl-1,3-propanediamine and/or 1,3,5-Benzenetricarbonyl chloride.