Water permeable membranes and methods of preparation are described. The water permeable membrane can comprise a porous support, and a polyamide layer comprising a crosslinked polyamide on a surface of the porous support, wherein the polyamide layer further comprises nanoparticles and a hydrophilic additive, and wherein the hydrophilic additive covalently bonds to the crosslinked polyamide. The crosslinked polyamide can be interfacially polymerized on the porous support. Methods for desalinating water, performing dialysis, or performing pervaporation using the water permeable membranes are disclosed.

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.

Disclosed is the preparation of composite membranes formed by a tailored selective chemical modification of an ultra-thin nanoporous surface layer of a semi-crystalline mesoporous poly (aryl ether ketone) membrane with graded density pore structure. The composite separation layer is synthesized in situ on the poly (aryl ether ketone) substrate surface and is covalently linked to the surface of the semi-crystalline mesoporous poly (aryl ether ketone) membrane. Hollow fiber configuration is the preferred embodiment of forming the functionalized the poly (aryl ether ketone) membranes. Composite poly (aryl ether ketone) membranes of the present invention are particularly useful for a broad range of fluid separation applications, including organic solvent ultrafiltration and nanofiltration to separate and recover active pharmaceutical ingredients.

A method for preparation of conductive polymer/carbon nanotube (CNT) composite nanofiltration (NF) membrane and the use thereof. This conductive polymer/CNT composite NF membrane is obtained by polymerizing conductive polymer into a CNT membrane and then in-situ cross-linking with glutaraldehyde under acidic condition. The synthetic method for the conductive polymer/CNT composite NF membrane is simple and has no need of expensive equipment. The prepared membrane has controllable membrane structure and possesses superior electrical conductivity and electrochemical stability. The membrane can couple with electrochemistry for electrically assisted filtration. With the electrical assistance, the membrane can achieve improved ion rejection performance while retaining high permeability by enhancement of membrane surface charge density, which alleviates the permeability-selectivity trade-off. Furthermore, the electrically assisted NF membrane filtration can also enhance the removal for small molecular organic pollutants.

Embodiments described herein relate generally to durable graphene oxide membranes for fluid filtration. For example, the graphene oxide membranes can be durable under high temperatures non-neutral pH, and/or high pressures. One aspect of the present disclosure relates to a filtration apparatus comprising: a support substrate, and a graphene oxide membrane disposed on the support substrate. The graphene oxide membrane has a first lactose rejection rate of at least 50% with a first 1 wt % lactose solution at room temperature. The graphene oxide membrane has a second lactose rejection rate of at least 50% with a second 1 wt % lactose solution at room temperature after the graphene oxide membrane is contacted with a solution that is at least 80° C. for a period of time.

New carbon nanomaterials, preferably titanium carbide-derived carbon (CDC) nanoparticles, were embedded into a polyamide film to give CDC/polyamide mixed matrix membranes by the interfacial polymerization reaction of an aliphatic diamine, e.g., piperazine, and an activated aromatic dicarboxylate, e.g., isophthaloyl chloride, supported on a sulfone-containing polymer, e.g., polysulfone (PSF), layer, which is preferably previously prepared by dry/wet phase inversion. The inventive membranes can separate CO.sub.2 (or other gases) from mixtures of CO.sub.2 and further gases, esp. CH.sub.4, based upon the generally selective nanocomposite layer(s) of CDC/polyamide.

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.

A method for preparing a durably hydrophilic and uniform-pore ultrafiltration membrane is disclosed herein. Chemical reactions between the functional groups and the active bonds of the molecular chains in the membrane materials are initiated perform the grafting of hydrophilic chains on the polymer chains under conventional dissolution conditions of the polymer membrane material (dissolution with synchronized hydrophilization), so as to realize durable hydrophilization of the membrane materials. The resulting hydrophilized polymer solution (a nascent-state membrane) is introduced into a coagulation bath to initiate a crosslinking reaction among the hydrophilic chains. The resulting crosslinking serves to synergistically regulate subsequent phase separation and membrane formation (phase separation under synergistic crosslinking).

The invention relates to the field of biomimetic membranes with artificial water channels, notably the use thereof in the context of the production and management of drinking water. The present invention relates to a biomimetic membrane with artificial water channels, the method of synthesis thereof, as well as the use thereof for desalination of brackish water and seawater, production of ultra-pure water or filtration of contaminants.

A spiral wound membrane module is suitable for use with high temperature water that may also have a high pH, for example steam injection produced water. The module uses a membrane with a polyphenylene sulfide (PPS) backing material. The feed spacer of the module may be made from polyphenylene sulfide (PPS) or ethylene chlorotrifluoroethylene (ECTFE). The permeate carrier may be made of a woven nylon (i.e. nylon 6, 6) fabric coated with high temperature epoxy. The core tube and anti-telescoping device may be made of polysulfone. In some examples, the module may be used at a temperature of up to 130° C. Optionally, the module may be used at a pH of 9.5 or more. In a filtration method, the module may be operated at a pressure in the range of 150 to 450 psi. The module may be operated at a generally constant pressure.