By having a coating layer, this composite semipermeable membrane has fouling resistance easily maintainable before and after contact with acid, and enables stable operation over a long period of time. This composite semipermeable membrane comprises a porous support layer, a separation function layer arranged on the porous support layer, and a coating layer arranged on the separation function layer, wherein the separation function layer contains a crosslinked aromatic polyamide which is a polycondensate of polyfunctional aromatic amines and polyfunctional aromatic acid chloride, and the coating layer contains an aliphatic polymer having the structure (I) in the description.

Methods and formulations for antimicrobial and anti-biofouling coating comprising: a hollow round colloidal structure, comprising: an active polymer shell; and an active or inert core; wherein the active polymer shell comprises one and more polymers with antimicrobial and anti-biofouling activities selected from the group consisting of polyethylenimine (PEI), functionalized chitosan (CHI), polyquaternium, poly(diallyldimethylammonium chloride) (PDDA) and polyhexamethylene biguanide (PHMD); wherein the active or inert core contains one and more disinfectants, biocides, fragrances or inert solvent; and wherein the hollow round colloidal structure is stable for at least 3 months.

A membrane for fuel cells, such as PEM and/or AEM fuel cells and/or electrolyzers is disclosed. Such a membrane (e.g., an anion conducting membrane) may include: crosslinked ionomer comprising two types of functional groups: a first type of functional groups forming crosslinking bonds between two ionomer chains; and a second type of functional groups comprising ion conducting functional groups. In some embodiments, the crosslinking bonds may not include the ion conducting functional groups. A catalyst coated membrane (CCM) is also disclosed. In such case the membrane may further include at least one catalyst layer attached to at least one side of the membrane to form the catalyst coated membrane (CCM). The at least one catalyst layer may include catalyst nanoparticles and crosslinked ionomer of the catalyst layer comprising two types of functional groups.

Described herein is a filtration media comprising: (i) a first filtration medium comprising an anion exchange nonwoven substrate, wherein the anion exchange nonwoven substrate comprises a plurality of quaternary ammonium groups; and (ii) a second filtration medium comprising a functionalized microporous membrane wherein the functionalized microporous membrane comprises a plurality of guanidyl groups; wherein the first filtration medium is positioned upstream of the second filtration medium.

A method for fabricating calcite channels in a nanofluidic device is described. A porous membrane is attached to a substrate. Calcite is deposited in porous openings in the porous membrane attached to the substrate. A width of openings in the deposited calcite is in a range from 50 to 100 nanometers (nm). The porous membrane is etched to remove the porous membrane from the substrate to form a fabricated calcite channel structure. Each channel has a width in the range from 50 to 100 nm.

A separation membrane (10) of the present disclosure includes: a separation functional layer (30) composed of a polyamide containing, as a monomer unit, at least one selected from the group consisting of piperazine and a piperazine derivative; and a coating (40) covering the separation functional layer (30) and containing a polymer having a repeating unit represented by the following formula (1). In the formula (1), N.sup.+ is a nitrogen atom constituting a quaternary ammonium cation, and R.sup.1 and R.sup.2 are each independently a substituent containing a carbon atom bonded to the nitrogen atom.

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A separation membrane (10) of the present disclosure includes: a separation functional layer (30) composed of a polyamide; and a coating (40) covering the separation functional layer (30) and containing a polymer having a repeating unit represented by the following formula (1). In the formula (1), N.sup.+ is a nitrogen atom constituting a quaternary ammonium cation, and R.sup.1 and R.sup.2 are each independently a substituent containing a carbon atom bonded to the nitrogen atom.

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An article having a nanoporous membrane and a nanoporous graphene sheet layered on the nanoporous membrane. A method of: depositing a layer of a diblock copolymer onto a graphene sheet, and etching a minor phase of the diblock copolymer and a portion of the graphene in contact with the minor phase to form a nanoporous article having a nanoporous graphene sheet and a nanoporous layer of a polymer. A method of: depositing a hexaiodo-substituted macrocycle onto a substrate having a Ag(111) surface; coupling the macrocycle to form a nanoporous graphene sheet; layering the graphene sheet and substrate onto a nanoporous membrane with the graphene sheet in contact with the nanoporous membrane; and etching away the substrate.

The present invention provides among other things a silver nanoparticle-coated membrane that reduces biofouling. The membranes exhibit extended antimicrobial properties that prevents the buildup that causes biofouling, which in turn prolongs the life of the membranes. The membranes may be reverse osmosis membranes, microfiltration membranes, ultrafiltration membranes, nanofiltration membranes, or any other membrane suitable for liquid processes.

Compositions and processes for fabricating filter units containing carbon-based materials, including but not limited to activated carbon and charcoal powders are disclosed. The powders are embedded within a polymeric porous network, including but not limited to methylcellulose, that is crosslinked with citric acid to create the functioning units. These units can be used to filter out specific molecules from any solution. They can also be allowed to absorb certain molecules and then release these molecules when they are contacted with another solution. The absorption and release of different molecules can be performed simultaneously. By controlling the properties of the polymeric network, such as the chemical properties of the network, the pore sizes and porosity, and the degree of crosslinking, the absorption and release rates of different molecules can be adjusted. In order to selectively control the transport of small molecules with certain sizes, the units can be enclosed in dialysis membranes with different molecular weight cut-offs to limit the size of molecules that can be absorbed and/or filtered by the unit based on their molecular weight.