Provided are composite articles having a membrane and a porous substrate, where the porous substrate has the membrane disposed thereon. The membrane has two layers, where the first layer has the second layer disposed thereon, and each layer has a plurality of polymer chains with a plurality of silicon-oxygen groups and a plurality of silicon-carbon groups. The first layer has a silicon to oxygen ratio of about 4:1 to about 1:1.25 and a silicon to carbon ratio of about 1:2 to about 1:10, and the second layer has a silicon to oxygen ratio of about 1:1 to about 1:2 and a silicon to carbon ratio of about 2:1 to about 10:1. At least a portion of the polymer chains of the second layer am crosslinked. The composite articles may be used in gas separation methods. Also provided are methods of making the composite articles and devices utilizing the composite articles.

Provided are composite articles having a membrane and a porous substrate, where the porous substrate has the membrane disposed thereon. The membrane has two layers, where the first layer has the second layer disposed thereon, and each layer has a plurality of polymer chains with a plurality of silicon-oxygen groups and a plurality of silicon-carbon groups. The first layer has a silicon to oxygen ratio of about 4:1 to about 1:1.25 and a silicon to carbon ratio of about 1:2 to about 1:10, and the second layer has a silicon to oxygen ratio of about 1:1 to about 1:2 and a silicon to carbon ratio of about 2:1 to about 10:1. At least a portion of the polymer chains of the second layer am crosslinked. The composite articles may be used in gas separation methods. Also provided are methods of making the composite articles and devices utilizing the composite articles.

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 feed containing methane and nitrogen gas is processed in a three-stage membrane system, each stage of which is selective for methane over nitrogen. The methane enriched permeate from the first stage is removed as product gas. The methane-depleted residue from the second stage is purified in second and third cascaded stages to provide second and third permeates and second and third residues. The third stage permeate is recycled to the feed.

A feed containing methane and nitrogen gas is processed in a three-stage membrane system, each stage of which is selective for methane over nitrogen. The methane enriched permeate from the first stage is removed as product gas. The methane-depleted residue from the second stage is purified in second and third cascaded stages to provide second and third permeates and second and third residues. The third stage permeate is recycled to the feed.

Polymer-based membranes and methods for fabricating membranes are described. The methods include forming a casting solution featuring a polyvinylidene fluoride (PVDF)-based solvent and a polyvinylpyrrolidone (PVP)-based modifying agent, dispersing the casting solution to form a first element, generating a plurality of active sites on a surface of the first element, and forming a polymer-based membrane by exposing the surface of the first element to a fluorosilane composition to form a fluorosilane layer on the surface, where the fluorosilane composition includes a silane compound having at least one alkyl substituent that includes between 9 and 21 fluorine atoms.

Polymer-based membranes and methods for fabricating membranes are described. The methods include forming a casting solution featuring a polyvinylidene fluoride (PVDF)-based solvent and a polyvinylpyrrolidone (PVP)-based modifying agent, dispersing the casting solution to form a first element, generating a plurality of active sites on a surface of the first element, and forming a polymer-based membrane by exposing the surface of the first element to a fluorosilane composition to form a fluorosilane layer on the surface, where the fluorosilane composition includes a silane compound having at least one alkyl substituent that includes between 9 and 21 fluorine atoms.

The disclosure provides a bifunctional composite membrane, a preparation method and use thereof, and a method for removing a plasticizer in liquor. The bifunctional composite membrane includes a supporting membrane and a dense layer which covers a surface of the supporting membrane, wherein the supporting membrane includes a filtering membrane and an adsorbent, and the adsorbent is dispersed in a pore structure of the filtering membrane.

Disclosed herein are rolled-membrane microfluidic diffusion devices and corresponding methods of manufacture. Also disclosed herein are three-dimensionally printed microfluidic devices and corresponding methods of manufacture. Optionally, the disclosed microfluidic devices can function as artificial lung devices.

A composite porous membrane contains at least one porous base layer and at least one uniaxially stretched coating layer located on at least one side surface of the porous base layer. For example, the composite porous membrane comprises at least one porous base layer and at least one nanofiber-like non-polyolefin polymer porous layer oriented along the transverse stretching direction of the composite porous membrane and located on one or two side surfaces of the porous base layer, or the composite porous membrane comprises a biaxially stretched polypropylene porous base layer and a uniaxially stretched coating layer located on at least one side surface of the porous base layer. The composite porous membrane is coated with a coating solution prior to transversely stretching. The nanofiber-like non-polyolefin polymer porous layer may reduce cracking of the composite porous membrane in the machine direction.