The object of the present invention is polyphenylene oxide based film with crystalline nanoporous phases with surface area equal to or greater than 30 m2/g, preferably greater than 100 m2/g, and a procedure for the attainment thereof.

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.

A raw material solution concentration system that has: a first unit for obtaining a concentrated raw material solution and a diluted induction solution by bringing a raw material solution containing a solvent and a solute into contact with an induction solution containing an induction solute through a forward osmosis membrane and transferring the solvent in the raw material solution into the induction solution and the induction solute in the induction solution into the raw material solution; and a second unit for performing a freeze-dry treatment on the concentrated raw material solution and obtaining a further-concentrated product.