A separation membrane includes a membrane comprising a polymer, characterized in that a functional layer is formed on the surface in one side of the membrane, the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface of the preceding functional layer is 0.1% (by atomic number) or more but not more than 10 (% by atomic number), and the peak area percentage of carbon derived from ester group measured by the electron spectroscopy for chemical analysis (ESCA) on the surface opposite to the functional layer is not more than 10 (% by atomic number). A separation membrane module suffering from little sticking of organic matters, proteins, platelets and so on is provided with the separation membrane as a built-in membrane.

The present invention relates to an anti-fouling, semi-permeable membrane comprising a porous support layer, a thin film composite (TFC) layer formed on a surface of the support layer, and a cross-linked polyvinyl alcohol (PVA) layer formed on top of the TFC layer, wherein the cross-linked PVA layer is the reaction product of PVA and a cross-linking agent, said cross-linking agent being a polybasic acid comprising three or more acid groups or precursors thereof. The obtained membrane shows a high water flux and a low roughness suitable for an effective membrane notable for feed solution having a tendency of fouling the membrane.

A method of using a system includes injecting a liquid mixture from a reservoir to an upper cell; stirring the liquid mixture in the upper cell using a stirrer; separating a first organic constituent from the liquid mixture by absorbing the first organic constituent of the liquid mixture at a first peripheral section of a membrane thereby causing a retentate comprising a second organic constituent and a solvent to reside in the upper cell; desorbing the first organic constituent of the liquid mixture at a second peripheral section of the membrane to obtain a first organic constituent permeate vapor; receiving the first organic constituent permeate vapor in a third feed line of a lower cell; receiving the retentate in a second feed line of the upper cell; and sending the retentate to the reservoir via the second feed line.

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.