A graphene-based membrane and a method of producing the same are disclosed. The graphene-based membrane may include a graphene-polymer composite, wherein the graphene-polymer composite may consist of an amine functionalized graphene and a polymer containing an anhydride group as a linker for linking the amine functionalized graphene to the polymer. The graphene-based membrane may be constructed of a single-layer. A method may include reacting a polymer containing an anhydride with an amine functionalized graphene in presence of a solvent to form an intermediate product; and thermal imidizing the intermediate product to form a graphene grafted polymer composite for use in fabricating a graphene-based membrane.

The invention relates to a combined method for gentle molecular surface functionalisation of the very thin, selectively-acting separating layer which preferably consists of aromatic polyamides, polyurethanes and/or polyureas, of thin-film composite membranes for reverse osmosis (hyperfiltration) and for nanofiltration, subsequently collectively termed water-filtration membranes, in order to achieve a passive antifouling effect without impairing the selectivity of the water-selective separating layer made of polyamides and the water-permeability of the membrane.

An ultrafiltration/nanofiltration membrane with gas-tunable pore size is provided. This membrane comprises an active layer arranged between two porous support layers, wherein the active layer is formed of randomly arranged cellulose nanocrystals, wherein pores are defined in the active layer by the free spaces existing between the randomly arranged cellulose nanocrystals, and wherein chains of a CO.sub.2-responsive polymer are grafted on the surface of the cellulose nanocrystals. There are also provided methods for filtering a feed using the membrane, for tuning the apparent pore size/MWCO/charge of the membrane, for cleaning the membrane, and for manufacturing the membrane.

The present disclosure belongs to the technical field of porous membrane material preparation, and specifically relates to a reverse osmosis composite membrane with an ultrathin desalting layer and a preparation method thereof; the intermediate layer is introduced after modifying the polysulfone base membrane, the modified polysulfone base membrane support layer may strengthen the bonding to the desalting layer through a covalent bond, and the thickness of the desalting layer is reduced to be ?10 nm, so that the desalination rate of the membrane is not greatly affected while increasing the membrane flux. Compared with the membrane having a conventional thickness of the desalting layer, the water flux of the reverse osmosis composite membrane with an ultrathin desalting layer may be increased by about 0.5 times, while the desalination rate has a small change.

The present disclosure relates to a conjugated polyelectrolyte-grafted membrane, which is obtained by fixing a conjugated polyelectrolyte (CPE) capable of generating active oxygen under visible light irradiation to a membrane through crosslinking, and can remove contaminants in water, while reducing bio-fouling on the surface of the membrane, by generating active oxygen through a photocatalytic reaction of the conjugated polyelectrolyte (CPE), as well as to a method for manufacturing the same. The method for manufacturing a conjugated polyelectrolyte-grafted membrane includes the steps of: preparing a conjugated polyelectrolyte (CPE); coating a conjugated polyelectrolyte (CPE) on the surface of a membrane; and carrying out crosslinking of the conjugated polyelectrolyte (CPE) with the surface of the membrane.

Disclosed is a nanoporous membrane including a porous support layer and a selective layer. The selective layer, being deposited on a surface of the porous support layer, has an effective pore size smaller than that of the porous support layer and contains an array of polymeric nanoparticles that have on their surfaces a plurality of C(?O)XR groups. Also disclosed are methods of fabricating a nanoporous membrane described above and using the nanoporous membrane for separating a mixture that contains two solutes.

The present disclosure relates to semipermeable membranes based on acrylonitrile copolymers capable of adsorbing bacteria from fluids, methods of producing such membranes, and devices comprising such membranes.

The present disclosure relates to a scaling-resistant and yellowing-resistant composite reverse osmosis membrane and a preparation method thereof. By modifying the stability and yellowing of a coating of the reverse osmosis membrane, and grafting 2-(methacryloyloxy)ethyl)dimethyl-3-sulphoproyl) ammonium hydroxide (MEDSAH) and ethylene glycol methacrylate (EGMA) as amphoteric monomers and N-(isobutoxymethyl)acrylamide (IBMA) as yellowing-resistant particles on a surface of the reverse osmosis membrane using active polymerization, the present disclosure forms a three-network high-performance PMEDSAH/PEGMA/PIBMA composite coating. By active regulation of a polyamide (PA) layer through the three systems, the reverse osmosis membrane has high compatibility due to PMEDSAH, and stability, high hydrophilicity and anti-protein fouling property due to PEGMA, as well as yellowing-resistant property by coating PIBMA on the surface. The test results show that the reverse osmosis membrane prepared by the present disclosure has excellent stability and yellowing-resistant property. And the flux and salt rejection are also higher than those of the existing reverse osmosis membranes.

An article that can be used for biomaterial capture comprises (a) a porous substrate; and (b) borne on the porous substrate, a polymer comprising interpolymerized units of at least one monomer consisting of (1) at least one monovalent ethylenically unsaturated group, (2) at least one monovalent ligand functional group selected from acidic groups, basic groups other than guanidino, and salts thereof, and (3) a multivalent spacer group that is directly bonded to the monovalent groups so as to link at least one ethylenically unsaturated group and at least one ligand functional group by a chain of at least six catenated atoms.

The invention provides methods for preparing a polymer-grafted and functionalized nonwoven membrane adapted for use in separation processes. The invention further provides so-formed membranes as well as improved separation methods utilizing the membranes. The polymer-grafted and functionalized nonwoven membranes are particularly formed utilizing thermal grafting. In particular, an acrylate or methacrylate polymer can be grafted onto a nonwoven web comprising a plurality of polymeric fibers to form a plurality of polymer segments covalently attached to the polymeric fibers. Thermal grafting particularly can comprise using a thermal initiator and exposing the nonwoven web to heat to initiate polymerization of the acrylate or methacrylate monomer. The grafted polymeric fibers can be functionalized to attach at least one functional group adapted for binding to a target molecule to the polymer segments of the grafted polymeric fibers.