Electrospun poly(acrylic) acid (PAA)/poly(vinyl) alcohol PVA nanofibers and integrated filtration membranes generated therefrom are disclosed herein. The membranes are suitable for use in selectively removing heavy metals such as lead and cadmium from water. The surface of the nanofibers is preferably functionalized with one or more chelating agents. The membranes have a high removal efficiency and adsorption capacity with well-distributed high-density heavy metal adsorption sites with strong binding affinities for targeted heavy metals.

Methods and apparatus for forming apertures in a solid state membrane using dielectric breakdown are provided. In one disclosed arrangement a plurality of apertures are formed. The membrane comprises a first surface area portion on one side of the membrane and a second surface area portion on the other side of the membrane. Each of a plurality of target regions comprises a recess or a fluidic passage opening out into the first or second surface area portion. The method comprises contacting all of the first surface area portion of the membrane with a first bath comprising ionic solution and all of the second surface area portion with a second bath comprising ionic solution. A voltage is applied across the membrane via first and second electrodes in respective contact with the first and second baths comprising ionic solutions to form an aperture at each of a plurality of the target regions in the membrane.

A thin film composite membrane (TFC) includes an active layer on a support. The active layer includes at least 8 barrier layers of star-polymers each having at least three linear polymers attached at a central core. Each of the barrier layers has a thickness between 5 and 50 nm, and the barrier layers have alternating charge.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membranes can comprise a gas permeable support layer, an inorganic layer disposed on the support, the inorganic layer comprising a plurality of discreet nanoparticles having an average particle size of less than 1 micron, and a selective polymer layer disposed on the inorganic layer, the selective polymer layer comprising a selective polymer having a CO.sub.2:N.sub.2 selectivity of at least 10 at 57 C. In some embodiments, the membrane can be selectively permeable to an acidic gas. The membranes can be used, for example, to separate gaseous mixtures, such as flue gas.

A structure, and methods of making the structure are provided in which the structure can include: a membrane having a first layer and a second layer, the first layer comprising polymer chains formed with coordination complexes with metal ions, and the second layer consisting of a porous support layer formed of polymer chains substantially, if not completely, lacking the presence of metal ions. The structure can be an asymmetric polymeric membrane containing a metal-rich layer as the first layer. In various embodiments the first layer can be a metal-rich dense layer. The first layer can include pores. The polymer chains of the first layer can be closely packed. The second layer can include a plurality of macro voids and can have an absence of the metal ions of the first layer.

The filtration material includes a supporting layer, a first selective layer disposed on the supporting layer, and a second selective layer disposed on the first selective layer. The first selective layer includes a polyimide and an ionic polymer intertwined with the polyimide. In particular, the polyimide includes at least one repeat unit having a structure represented by Formula (I)

##STR00001##

wherein A.sup.1 is

##STR00002##

A.sup.2 is

##STR00003##

R.sup.1 and R.sup.2 are independently H, CF.sub.3, OH, Br, Cl, F, C.sub.1-6 alkyl group, or C.sub.1-6 alkoxy group; and X and Y are independently single bond, O, CH.sub.2, C(CH.sub.3).sub.2, or NH.

Provided is an interfacial polymerization process for preparation of a highly permeable thin film composite membrane, which can be used for nanofiltration, or forward or reverse osmosis, for use with tap water, seawater and brackish water, particularly for use with brackish water at low energy conditions. The process includes contacting a porous support membrane with an aqueous phase containing a polyamine and a flux enhancing combination, which includes a metal chelate additive containing a bidentate ligand and a metal atom or metal ion and a dialkyl sulfoxide, to form a coated support membrane, and applying an organic phase containing a polyfunctional acid halide to the coated support membrane to interfacially polymerize the polyamine and the polyfunctional acid halide to form a discrimination layer of the thin film composite membrane. Also provided are the membranes prepared by the methods and reverse osmosis modules containing the membranes.

The invention includes compositions comprising curable imidazolium-functionalized poly(room-temperature ionic liquid) copolymers and homopolymers. The invention further includes methods of preparing and using the compositions of the invention. The invention further includes novel methods of preparing thin, supported, room-temperature ionic liquid-containing polymeric films on a porous support. In certain embodiments, the methods of the invention avoid the use of a gutter layer, which greatly reduces the overall gas permeance and selectivity of the composite membrane. In other embodiments, the films of the invention have increased gas selectivity and permeance over films prepared using methods described in the prior art.

A porous filter includes a porous laminate in which a plurality of biaxially stretched porous sheets made of PTFE are stacked. The Gurley number G and the bubble point B (kPa) of the porous laminate satisfy the following expressions (1) and (2):

log G>3.710.sup.3B0.8(1)

log G<4.910.sup.3B+0.45(2).

Provided are a functional polymer membrane including: a surface layer; and an anion exchange membrane or a cation exchange membrane, in which the surface layer contains a polymer which includes a cross-linked structure having, in a cross-linking unit, an ionic group with a charge opposite to a charge of an ionic group included in at least one of the anion exchange membrane or the cation exchange membrane; a production method thereof, and a stack or a device provided with a polymer functional membrane.