Nanofiltration of aqueous solutions or other water-based fluids in various applications, such as desalination, dialysis, seawater purification, for example, may be enhanced through precisely controlling a filtration cutoff within graphene oxide nanofilters. By initially compressing and constraining the stacked thickness of multiple graphene oxide layers deposited between porous substrates, the interlayer gap size, and thus, the filtration cutoff may be adjusted and optimized.

In a first aspect, the present disclosure relates to a method for forming a diamond membrane, comprising: providing a substrate having an amorphous dielectric layer thereon, the amorphous dielectric layer comprising an exposed surface, the exposed surface having an isoelectric point of less than 7, preferably at most 6; seeding diamond nanoparticles onto the exposed surface; growing a diamond layer from the seeded diamond nanoparticles; and removing a portion of the substrate from underneath the diamond layer, the removed portion extending at least up to the amorphous dielectric layer, thereby forming the diamond membrane over the removed portion.

A method for producing a wet-laid nonwoven fabric for a semipermeable membrane supporting body, the method comprising: performing papermaking according to a wet papermaking method by using a fiber slurry containing a synthetic fiber as a main constituent fiber; drying the fiber slurry; subsequently subjecting the dried sheet to hot press processing two times by using a heat calender apparatus, wherein the hot press process temperature in the second treatments is adjusted to be higher by 10 C. or more than the hot press processing temperature in the first treatment, while treating the dried sheet by using a hard nip heat calender apparatus equipped with a combination of a metal roll and a metal roll for at least one time of the hot press processing; and thereby obtaining a wet-laid nonwoven fabric for a semipermeable membrane supporting body.

The present invention relates to a composite membrane for gas separation and/or nanofiltration of a feed stream solution comprising a solvent and dissolved solutes and showing preferential rejection of the solutes. The composite membrane comprises a separating layer with intrinsic microporosity. The separating layer is suitably formed by interfacial polymerization on a support membrane. Suitably, at least one of the monomers used in the interfacial polymerization reaction should possess concavity, resulting in a network polymer with interconnected nanopores and a membrane with enhanced permeability. The support membrane may be optionally impregnated with a conditioning agent and may be optionally stable in organic solvents, particularly in polar aprotic solvents. The top layer of the composite membrane is optionally capped with functional groups to change the surface chemistry. The composite membrane may be cured in the oven to enhance rejection. Finally, the composite membrane may be treated with an activating solvent prior to nanofiltration.

The invention relates to a high-strength hollow fiber zeolite membrane and its preparation method, characterized in that the support of the high-strength zeolite membrane has a multi-channel hollow fiber configuration. The preparation method comprises first preparing a crystal seed solution, then immersing the dry support with the multi-channel hollow fiber configuration in the crystal seed solution, and extracting and drying the support to obtain a crystal-seeded support; and finally placing the crystal-seeded support in a zeolite membrane synthetic fluid, performing hydrothermal synthesis, and taking out, washing and drying the product to obtain the high-strength hollow fiber zeolite membrane. The multi-channel hollow fiber support can provide high mechanical property, which greatly reduces the depreciation rate of the hollow fiber zeolite membrane equipment during use. Meanwhile, the multi-channel hollow fiber zeolite membrane prepared by the Invention possesses high loading density of permeation flux and membrane module and can reduce the production cost and improve the separation efficiency significantly, and thus lays the foundation for promoting the industrial application of the hollow fiber zeolite membrane.

Described are filtration membranes that include a porous fluoropolymer membrane and thermally stable ionic groups; filters and filter components that include these filtration membranes; methods of making the filtration membranes, filters, and filter components; and method of using a filtration membrane, filter component, or filter to remove unwanted material from fluid.

Nanofiltration of aqueous solutions or other water-based fluids in various applications, such as desalination, dialysis, seawater purification, for example, may be enhanced through precisely controlling a filtration cutoff within graphene oxide nanofilters. By initially compressing and constraining the stacked thickness of multiple graphene oxide layers deposited between porous substrates, the interlayer gap size, and thus, the filtration cutoff may be adjusted and optimized.

A method of deionizing saline water by contacting the saline water with a diffusion barrier to remove at least a portion of divalent ions to form deionized water, in order to desalinate the deionized water without scale formation, and a method of fabricating the diffusion barrier. Various embodiments of the diffusion barrier, the method of fabricating thereof, and the method of deionizing the saline water are provided.

The present invention relates to a composite membrane for nanofiltration of a feed stream solution comprising a solvent and dissolved solutes and showing preferential rejection of the solutes. The composite membrane comprises a thin polymeric film formed by interfacial polymerization on a support membrane. The support membrane is further impregnated with a conditioning agent and is stable in polar aprotic solvents. The composite membrane is optionally treated in a quenching medium, where the interfacial polymerization reaction can be quenched and, in certain embodiments, membrane chemistry can be modified. Finally the composite membrane is treated with an activating solvent prior to nanofiltration.

A gas separation membrane comprising the following layers: (i) a porous support layer; and (ii) a discriminating layer comprising groups of the Formula (1): M(O).sub.x, wherein: M is a metal or metalloid atom; O is an oxygen atom; and x has a value of at least 4; optionally (iii) a layer which comprises a fluorinated polymer; and optionally (iv) optionally a protective layer; wherein: (a) the porous support layer (i) comprises less than 10 mg/m.sup.2 of monovalent metal ions; (b) the discriminating layer (ii) comprises a surface comprising at least 10 atomic % of M of Formula (1) groups, wherein M is as hereinbefore defined; and (c) when layer (iii) is present, layer (ii) is located between layers (i) and (iii).