A polysulfone membrane is modified so that monomers are grafted onto the surface of the membrane. The polysulfone membranes can be grafted by contacting the membrane with a grafting solution and exposing the membrane to electromagnetic radiation, typically within the ultraviolet portion of the spectrum. The monomers that are grafted are typically anionic or cationic. The grafted membranes can be used for filtering impurities, such as positively and negatively charged particles, from a liquid. Anionic membranes provide improved filtration of negatively charged impurities, while cationic membranes provide improved filtration of positively charged impurities.

Provided is a method for preparing a defect-free DDR molecular sieve membrane. Sigma-1 molecular sieve is used as an inducing seed crystal to prepare and obtain a continuous and compact DDR molecular sieve membrane on the surface of a porous ceramic support. An ozone atmosphere or an external field assisted technology is used to remove a template in the pores of the molecular sieve membrane at a low temperature. The invention avoids the formation of intercrystal defects and cracks, an activated DDR molecular sieve membrane has a good selectivity for separating CO2, and the membrane preparation time is significantly reduced.

The present disclosure describes membrane compositions and methods for preparing membrane compositions. In particular, the methods employ a layer-by-layer approach to membrane preparation. The membrane compositions provide significantly enhanced membrane performance over existing commercial membranes, particularly in terms of permeability and selectivity.

A monovalent selective ion exchange membrane is disclosed. The membrane includes a polymeric microporous substrate, a cross-linked ion-transferring polymeric layer on a surface of the substrate, and a charged functionalizing layer covalently bound to the ion-transferring layer. A method of producing a monovalent selective cation exchange membrane is also disclosed. The method may include chemically adsorbing a styrene intermediate layer to a cross-linked ion-transferring polymeric layer on a surface of a polymeric microporous substrate, chlorosulfonating the styrene intermediate layer to attach a sulfonyl chloride group layer, aminating the sulfonyl group layer to attach an amine group layer, and functionalizing the amine group layer with a charged compound layer to produce the cation exchange membrane. Water treatment systems including the monovalent selective cation exchange membrane and methods of facilitating water treatment including providing the monovalent selective cation exchange membrane are also disclosed.

A monovalent selective ion exchange membrane is disclosed. The membrane includes a polymeric microporous substrate, a cross-linked ion-transferring polymeric layer on a surface of the substrate, and a charged functionalizing layer covalently bound to the ion-transferring layer by an acrylic group. A method of producing a monovalent selective cation exchange membrane is also disclosed. The method may include chemically adsorbing an acrylic intermediate layer comprising a chlorosulfonated methacrylate group to a cross-linked ion-transferring polymeric layer on a surface of a polymeric microporous substrate, aminating the chlorosulfonated methacrylate group to attach an amine group layer, and functionalizing the amine group layer with a charged compound layer to produce the cation exchange membrane. Water treatment systems including the monovalent selective cation exchange membrane and methods of facilitating water treatment including providing the monovalent selective cation exchange membrane are also disclosed.

A superhydrophobic polypropylene porous film, including a polypropylene porous film substrate, titanium dioxide layers and a surface modifier layer, is disclosed. The titanium dioxide layers are deposited on the surface of the polypropylene porous film substrate by atomic deposition technology; a surface modifier is coated on the titanium dioxide layers; hydrophobic bonds are formed between the titanium dioxide layers and the surface modifier layer; the superhydrophobic polypropylene porous film has a water contact angle greater than 150 degrees, a rolling angle less than 10 degrees, an aperture of 0.1-0.4 μm, a porosity of 50%-80%, a tensile strength of 30-50 MPa, and an elongation at break of 10%-30%. The superhydrophobic polypropylene porous film maintains the chemical resistance, rigidity, and porosity of the polypropylene porous film, and has superhydrophobic properties and a good separation effect after working for 80 hours, thus greatly increasing the service life, and reducing operation costs and working costs in a membrane distillation process.

The present disclosure describes membrane compositions and methods for preparing membrane compositions. In particular, the methods employ a layer-by-layer approach to membrane preparation. The membrane compositions provide significantly enhanced membrane performance over existing commercial membranes, particularly in terms of permeability and selectivity.

A method for making a gas separation membrane comprises dissolving and mixing poly(ether-b-amide) (Pebax) copolymer and acrylate-terminated polyethylene glycol oligomers (PEGDA) in a solvent, casting the polymer solution into a mold, removing the solvent to form a film, adding a photoinitiator to the film and irradiating the film with ultraviolet radiation to induce crosslinking of the PEGDA in the film, producing XLPEGDA, and submerging the film after exposure in a crosslinking solution to form crosslinked Pebax (XLPebax) in the film, wherein the crosslinking solution comprises one of a diisocyanate, a diisocyanate derivative and a combination of a diiscyanate and a diisocyanate derivative.

Described herein are articles for separating gases. The article includes a selective layer consisting of a crosslinked amorphous fluorinated copolymer containing one or more types of fluorinated ring monomers, with crosslinking between the fluorinated copolymer chains. The crosslinking improves the mechanical properties of the fluoropolymer, thereby permitting use of polymer types which would otherwise be excessively brittle. The resulting crosslinked polymer membranes have superior selectivity and reliability performance compared with previous compositions known to the art. Methods for making and using the article described are also provided.

To provide a composite semipermeable membrane having high water permeability and separability.

Provided is a composite semipermeable membrane which is for water treatment and comprises a microporous support membrane and a polymerized liquid crystal thin film, the composite semipermeable membrane being characterized in that a polymerized liquid crystal represents a smectic structure.