A method for making a graphene membrane includes applying a suspension of graphene platelets in a fluid onto a porous substrate, and applying a pressure differential to force the fluid through the substrate to yield a filtered fluid while retaining the graphene platelets on the substrate. The graphene platelets and the substrate form the graphene membrane.

A thin micro-porous membrane sheet and filtering device using it is presented. The membrane sheet includes a thin porous metal sheet of thickness between 20 and 200 μm with a porous ceramic coating of thickness less than 25 μm on at least one of its surfaces. The porous metal sheet has mean pore sizes at micro and sub-micrometer level and has a surface substantially free of pores greater than 10 micrometers. The ceramic coating layer may be made of particles with a mean particle size in a range of 10 to 300 nm and contains certain sintering promoters. The ceramic coating is sintered with the metal sheet in non-oxidizing environment at lower temperatures than typical ceramic membranes. The thin membrane sheet is used to filter fine particulates from micrometers to nanometers from a liquid or gas stream. The thin membrane sheet may be assembled into a filter device having high surface area packing density and straight mini-flow channels.

A drying method for a separation membrane includes supplying a gas for drying to the separation membrane so that a value obtained by dividing the difference between a maximum value and a minimum value of a flow rate of the gas for drying on a membrane surface of the separation membrane by the minimum value of the flow rate is less than or equal to 15%. The gas for drying is less than or equal to 40 degree C. and contains a water-soluble gas that has a solubility in 1 cm.sup.3 of water of greater than or equal to 0.5 cm.sup.3 in conditions of 40 degree C. and 1 atmosphere.

A method for preparing a nanofiltration membrane and a nanofiltration membrane prepared therefrom, the method comprising the following steps: dissolving a polymer in a solvent to prepare a polymer solution, and curing the polymer solution on a support material to form a base membrane; sequentially applying a first liquid-phase solution and a second liquid-phase solution on the base membrane to form a nascent membrane; densifying the nascent membrane by using a solution that contains an alkaline substance; processing the densified nascent membrane by using a solution that contains an acidic substance; and obtaining the nanofiltration membrane after post-processing and drying.

There is provided a semi-permeable membrane comprising: at least two two-dimensional (2D) heterostructure layers of; and a polyelectrolyte layer between each 2D heterostructure layer of the at least two 2D heterostructure layers. There is also provided a method of preparing the membrane comprising: mixing a 2D heterostructure solution and a polyelectrolyte solution to form a mixture; and vacuum filtering the mixture onto a substrate to form the membrane.

A polyamide (PA) nanofiltration (NF) membrane and a preparation method thereof by regeneration from a scrapped microfiltration (MF) membrane are provided. The method adopts a cleaning-repairing-interfacial polymerization upgrading strategy, where, sodium hypochlorite and oxalic acid are used for deeply cleaning a scrapped MF membrane. PDA is used as a repairing agent to construct a reaction platform on the membrane surface, and finally a reaction system of piperazine and trimesoyl chloride (TMC) are used to form a PA NF membrane with a PA active layer. The repairing can construct a coating with a given thickness and prominent hydrophilicity on the membrane surface, which provides favorable base membrane conditions for upgrading and preparing an NF membrane.

The present invention relates to a separator membrane having a hierarchical structure, a production method therefor and a xylene separation method using same, and to: a separator membrane having a hierarchical structure comprising mesopores, the separator membrane having mesopores introduced inside a microporous zeolite separator membrane, thereby being thin, having less defects and exhibiting high xylene permeation and separation performance; a production method therefor; and a xylene separation method using same.

Disclosed are a light-driven filtration antibacterial composite membrane and a preparation method and use thereof. The method for preparing the light-driven filtration antibacterial composite membrane includes: mixing dichloromethane and N,N-dimethylformamide to obtain a first solution; adding PCL particles to the first solution, and stirring until being uniform to obtain an electrospinning solution; adding a ZIF-8 powder to the electrospinning solution, and ultrasonically dispersing for at least 1 hour to obtain a PCL/ZIF-8 spinning solution; spraying the PCL/ZIF-8 spinning solution onto a PPCL@PDA/TAEG men-blown membrane to obtain the light-driven filtration antibacterial composite membrane.

Ion exchange membranes obtainable by curing a composition comprising: (a) a monomer comprising an aromatic group and at least one polymerisable ethylenically unsaturated group; (b) a photoinitiator which has an absorption maximum at a wavelength longer than 380 nm when measured in one or more of the following solvents at a temperature of 23° C.: water, ethanol and toluene; and (c) at least one co-initiator.

Disclosed are compositions that may be useful for forming synthetic membranes, methods of forming membranes therefrom, and membranes. In an embodiment, a membrane comprises a free hydrophilic polymer comprising a polyoxazoline, and a polyurethane, the polyurethane comprising a backbone comprising the reaction product of a diisocyanate, a polymeric aliphatic 5 diol, and optionally a chain extender.