The disclosure provides a porous polymeric membrane having ionizable nitrogen functional groups at least at its surface, wherein such groups are associated with a hydroxide anion. The membranes are useful in the purification of polar solvents such as water and alcohols and are capable of removing trace amounts of anionic contaminants such as halides, phosphates, nitrates, nitrites, sulfites, and sulfates.

The present invention relates to a method for recovering a rare metal salt, the method including: an acid treatment step of obtaining a rare metal-containing acidic aqueous solution by bringing a material including a monovalent rare metal and a polyvalent rare metal into contact with an acidic aqueous solution; a separation step of obtaining permeated water including the monovalent rare metal and non-permeated water including the polyvalent rare metal from the rare metal-containing acidic aqueous solution by using a nanofiltration membrane satisfying the condition (1); and a concentration step of obtaining non-permeated water having a higher concentration of the monovalent rare metal and permeated water having a lower concentration of the monovalent rare metal than that of the permeated water in the separation step, by using a reverse osmosis membrane.

The present invention relates to a method for recovering a rare metal salt, the method including: an acid treatment step of obtaining a rare metal-containing acidic aqueous solution by bringing a material including a monovalent rare metal and a polyvalent rare metal into contact with an acidic aqueous solution; a separation step of obtaining permeated water including the monovalent rare metal and non-permeated water including the polyvalent rare metal from the rare metal-containing acidic aqueous solution by using a nanofiltration membrane satisfying the condition (1); and a concentration step of obtaining non-permeated water having a higher concentration of the monovalent rare metal and permeated water having a lower concentration of the monovalent rare metal than that of the permeated water in the separation step, by using a reverse osmosis membrane.

Synthesis, fabrication, and application of nanocomposite polymers in different form (as membrane/filter coatings, as beads, or as porous sponges) for the removal of microorganisms, heavy metals, organic, and inorganic chemicals from different contaminated water sources.

A forward osmosis membrane for seawater desalination and a method for preparing the same. The forward osmosis membrane has a composite membrane structure including a nonwoven fabric layer; a hydrophilic polymer layer; and a polyamide layer. The hydrophilic polymer layer formed on the nonwoven fabric layer facilitates an inflow of water from the feed water to the draw solution to enhance flux and realize high water permeability in the direction of osmosis. The polyamide layer not only secures contamination resistance and chemical resistance but also minimizes the back diffusion of salts of the draw solution in the direction of reverse osmosis. Hence, the forward osmosis membrane of the present invention is greatly useful for desalination of high-concentration seawater.

The present invention relates to a method for producing a polyelectrolyte complex (PEC) membrane having a predetermined porosity via salt dilution induced phase separation, in which a liquid polymer solution (P) containing polyanions (A) and polycations (C) dissolved in an aqueous medium at an overcritical salt concentration is exposed to an aqueous medium.

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 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.

A gas separation membrane, a method for making the gas separation membrane, and a method for using the gas separation membrane are provided. An exemplary gas separation membrane includes a polyether-block-polyamide (PEBA) matrix and a cross-linked network including functionalized polyhedral oligomeric silsesquioxane (POSS) nanoparticles dispersed through the PEBA matrix.

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.