Methods of making membrane elements for fluid or gas filtration, comprising applying feed or reject spacers, or intermediate spacers, or fold line protection strips, or end support strips directly to a membrane sheet, or to a substrate material which are subsequently applied to a membrane sheet, which thereby avoids contamination from directly printed adhesives, inks, or polymers, or damage from heat or radiation damage to the membrane sheet during direct application of spacers or patterns to the surface of the membrane sheet, thereby avoiding utilization of conventional feed spacer mesh materials. Membrane sheets and spiral wound filtration elements having spacers applied to defined regions of the sheet, in some embodiments having spacers mounted on substrates with different material properties, e.g., stiffness, than the underlying membrane.

A pervaporation membrane formed on a porous support containing a composition encompassing a polysiloxane, a crosslinker and a catalyst are disclosed and claimed. Also disclosed are the fabrication of membranes which exhibit unique separation properties, and their use in the separation of organic volatiles from biomass and/or organic waste, including butanol, ethanol, and the like.

Disclosed herein are membranes comprising: porous substrate; and two or more graphene oxide (GO) sheets disposed on the porous substrate, each GO layer comprising a plurality of GO flakes, each GO flake comprising a planar graphene structure with oxygen moieties extending therefrom, wherein the membrane, when a pressure from 10 bar to 50 bar of transmembrane pressure is applied from 1 hour to 48 hours, has an aqueous flux wherein the aqueous flux changes by 5% or less while the pressure is applied. The membranes can also include an intercalating agent disposed between the two or more GO sheets, the intercalating agent interacting with each GO sheet, wherein the intercalating agent provides a non-covalent stabilization of the two or more GO sheets. Also disclosed herein are methods of making and using the same and systems for implementing the same.

Methods of making membrane elements for fluid or gas filtration, comprising applying feed or reject spacers, or intermediate spacers, or fold line protection strips, or end support strips directly to a membrane sheet, or to a substrate material which are subsequently applied to a membrane sheet, which thereby avoids contamination from directly printed adhesives, inks, or polymers, or damage from heat or radiation damage to the membrane sheet during direct application of spacers or patterns to the surface of the membrane sheet, thereby avoiding utilization of conventional feed spacer mesh materials. Membrane sheets and spiral wound filtration elements having spacers applied to defined regions of the sheet, in some embodiments having spacers mounted on substrates with different material properties, e.g., stiffness, than the underlying membrane.

The present disclosure relates to nanochannel plates for use in reverse osmosis systems and methods of their manufacture. An example nanochannel plate includes a first surface and an opposing second surface. The first surface and the second surface are parallel to a major flat of the nanochannel plate. The nanochannel plate also includes a plurality of channels. At least one channel includes a carbon nanotube having a first end opening proximate to the first surface and a second end opening proximate to the second surface. Optionally, a core portion of the carbon nanotube could be configured to transport water from the first surface to the second surface or vice versa. Optionally, the core portion of the carbon nanotube has a core diameter of less than or equal to 0.7 nanometers.

Spacers may be attached onto a membrane by a method in which adjacent ones of the spacers are spaced apart from one another with spacings that are accurate to a very fine tolerance. In the method, adjacent ones of the spacers may be attached to one another via lateral members so as to fix the relative spacing between the spacers. The spacers arranged with the fixed spacing may be attached to a transparent substrate via one or more intermediate layers, and thereafter, the lateral members may be severed. Afterwards, a surface of each of the spacers facing away from the transparent substrate may be coated with an adhesive layer. The spacers may be pressed against a membrane so as to attach the spacers to the membrane via the adhesive layer. After being attached to the membrane, the spacers may be detached from the transparent substrate.

Disclosed is a statistical copolymer that includes both zwitterionic repeat units and hydrophobic repeat units, and a filtration membrane that contains a selective layer formed of the statistical copolymer. Also disclosed are methods of preparing the above-described filtration membrane.

The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a precursor polymer is pyrolyzed to form a carbon molecular sieve membrane that is then exposed to a conditioning atmosphere comprised of a target permeate gas molecule such as ethylene when the membrane is desired to separate it from a light hydrocarbon gas stream. The exposure to the ethylene desirably occurs prior to the CMS permeance and selectivity combination substantially changing (e.g., within 5 days) of cooling from the pyrolyzing temperature. The CMS membranes have shown an improved combination of selectivity and permeance as well as stability and are useful to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.

The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a polyimide precursor polymer is pyrolyzed to form a carbon molecular sieve membrane by heating, in a furnace, said polyimide precursor polymer to a final pyrolysis temperature of 600 C to 700 C at a pyrolysis heating rate of 3 to 7 C/minute from 400 C to the final pyrolysis temperature, the final pyrolysis temperature being held for a pyrolysis time of at most 60 minutes in a non-oxidizing atmosphere. In a particular embodiment, the cooling rate from the pyrolysis temperature is accelerated by methods to remove heat. The CMS membranes have shown an improved combination of selectivity and permeance as well as being particularly suitable to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.

Disclosed is a statistical copolymer that includes both zwitterionic repeat units and hydrophobic repeat units, and a filtration membrane that contains a selective layer formed of the statistical copolymer. Also disclosed are methods of preparing the above-described filtration membrane.