Ion-selective separation by shock electrodialysis is performed by applying a voltage differential between electrodes across a porous medium to selectively draw a first species in a liquid toward at least one of the electrodes to a greater degree than a degree to which a second species in the liquid is drawn toward the same electrode. The voltage differential creates a shock in the charged-species concentration in the bulk volume of the liquid within pore channels of the porous medium, wherein the concentration of the first species in a depleted zone of the liquid bulk volume between the shock and the ion-selective boundary is substantially lower than the concentration of the second species in the liquid bulk volume between the shock and the first electrode. A dilute stream including the second species is extracted from the depleted zone separate from a concentrated stream including the first species.

Method for preparing a membrane from fibril cellulose includes supplying fibril cellulose dispersion on a filter layer, draining liquid from a fibril cellulose dispersion by the effect of reduced pressure through the filter layer that is impermeable to fibrils of the fibril cellulose but permeable to the liquid to form a membrane sheet on the filter fabric, applying heat on the opposite side of the membrane sheet to the membrane sheet while continuing draining of the liquid through the filter layer by pressure difference over the filter layer, and removing the membrane sheet from the filter layer as a freestanding membrane.

Provided are certain membranes useful in the filtration of liquids and removal of various contaminants therein. In certain aspects the membranes have as one component a polyamide such as Nylon 11 and/or Nylon 12. Also provided is methodology for manufacturing such membranes and their use in filtration and purification of liquids. Membranes of the disclosure thus prepared exhibit superior acid stability when compared to polyamide membranes prepared from Nylon 6 or Nylon 6,6.

The present invention relates to a composite semipermeable membrane including: a supporting membrane including a substrate and a porous supporting layer; and a separation functional layer disposed on the porous supporting layer, in which the separation functional layer includes: a crosslinked polyamide; and a hydrophilic polymer which is a polymer of a monomer having an ethylenically unsaturated group, and a surface of the separation functional layer has a ratio of the number of oxygen atoms to the number of nitrogen atoms (O/N ratio), both determined by X-ray photoelectron spectrometry, of 1.5-10, and a standard deviation of the O/N ratio of 0.15 or larger.

Cation exchange membranes and materials including silica-based ceramics, and associated methods, are provided. In some aspects, cation exchange membranes that include a silica-based ceramic that forms a coating on and/or within a porous support membrane are described. The cation exchange membranes and materials may have certain structural or chemical attributes (e.g., pore size/distribution, chemical functionalization) that, alone or in combination, can result in advantageous performance characteristics in any of a variety of applications for which selective transport of positively charged ions through membranes/materials is desired. In some embodiments, the silica-based ceramic contains relatively small pores (e.g., substantially spherical nanopores) that may contribute to some such advantageous properties. In some embodiments, the cation exchange membrane or material includes sulfonate and/or sulfonic acid groups covalently bound to the silica-based ceramic.

A bilayer electrospun membranes for treating hydraulic fracking wastewater via membrane distillation, and more particularly to bilayer electrospun membranes having an omniphobic layer to prevent low-surface tension solution wicking and an oleophobic antifouling surface to prevent foulant depositing on the membrane. Nanoparticles are decorated on the omniphobic surface through electrochemical interaction, which is coated with a fluorine monomer on the nanoparticles. A zwitterionic co-polymer is grafted using self-assembly between hydroxy groups on the antifouling surface generated by alkaline treatment and anchor segment epoxy groups on zwitterionic co-polymer.

Durable asymmetric composite membranes comprising of a film of cross-linked poly(ether ether ketone) adhered to a sheet of hydrophilicitized microporous polyolefin are disclosed. The membranes are suitable for use in the recovery or removal of water from feed streams where repeated clean-in-place protocols are required such as in the processing of dairy products. The membranes are also suitable for use in the preparation of durable asymmetric composite membranes with improved rejection characteristics.

A nanostructured composite membrane filter for rapid water purification and methods for preparing the nanostructured composite membrane filter are provided. The nanostructured composite membrane includes a silver layer having a plurality of silver functionalized nanofibers for disinfecting microorganisms of water, and a chemical modified layer having a plurality of chemical modified nanofibers for removing impurities from the water. The plurality of silver functionalized nanofibers includes a plurality of polyvinyl alcohol (PVA) nanofibers coated with polydopamine (PDA) and silver, and each of the plurality of chemical modified nanofibers includes a polymer matrix such as polyvinyl alcohol (PVA) and anionic polyelectrolytes such as poly (sodium styrenesulfonate) (PSSNa) for capturing metal ions of the water.

The present disclosure provides a porous polymeric membrane that is coated with a cross-linked polymerized monomer. The coating on the porous polymeric membrane has a charge when it is immersed in an organic liquid. The coated porous polymeric membrane, a filter utilizing the membrane, and a method for treating an organic liquid used for photoresist with the coated porous polymeric membrane to remove metal contaminants from the organic liquid are disclosed.

A method of making a filter, the resulting filter, and a method of using the filter to filter proteins from solution are described. The method includes contacting a porous, polymeric substrate with a transfer liquid comprising a solvent(s) and a charged polymeric solute. The transfer liquid and the polymeric substrate have a Hansen Solubility Parameter (“HSP”) distance of from about 10 to about 35. Contacting the polymeric substrate with the transfer solution causes the polymeric substrate to accept the charged polymeric solute by diffusion transfer, thereby yielding a functionalized filter medium. Removal of the transfer liquid from the polymeric substrate traps the charged polymeric solute on the surface of the polymeric substrate.