A composite reverse osmosis membrane having a semipermeable bilayer polyamide composition comprising a base layer containing a rigid crosslinked aromatic polyamide and a top layer containing a flexible aliphatic polyamide is disclosed, the two layers in combination providing reduced salt passage in reverse osmosis desalination of brackish waters and of seawater.

The invention relates to a process for recovering methane from digester biogas or landfill gas. More specifically, the invention pertains to a method for producing biomethane that removes impurities from a compressed digester biogas with staged membrane modules of at least two different types, to produce a biomethane having at least 94% CH.sub.4, below 3% of CO.sub.2, and below 4 ppm of H.sub.2S.

The present inventive concept relates to a chemically modified anion exchange membrane and a method of preparing the same and, more particularly, an anion exchange membrane in which sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane are substituted with anion conductive groups such as an ammonium group, a phosphonium group, an imidazolium group, a pyridinium group and a sulfonium group, and a method of preparing an anion exchange membrane by chemically modifying sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane.

The present inventive concept relates to a chemically modified anion exchange membrane and a method of preparing the same and, more particularly, an anion exchange membrane in which sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane are substituted with anion conductive groups such as an ammonium group, a phosphonium group, an imidazolium group, a pyridinium group and a sulfonium group, and a method of preparing an anion exchange membrane by chemically modifying sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane.

The present disclosure describes compositions and methods for preparing membrane protein nanosheets and two-dimensional crystals. In particular, the methods employ a solvent. A mixture of a polymer and a membrane protein is solubilized in the solvent, applied to a substrate, and subsequently dried to form the nanosheet or two-dimensional crystal. Applicants have surprisingly found that the membrane proteins maintain their structure when exposed to solvents during the short processing time utilized.

The present disclosure describes compositions and methods for preparing membrane protein nanosheets and two-dimensional crystals. In particular, the methods employ a solvent. A mixture of a polymer and a membrane protein is solubilized in the solvent, applied to a substrate, and subsequently dried to form the nanosheet or two-dimensional crystal. Applicants have surprisingly found that the membrane proteins maintain their structure when exposed to solvents during the short processing time utilized.

A composite liquid filtration platform including a composite filtration medium featuring an electrospun polymeric nanofiber layer collected on a porous membrane. When in use, the porous membrane acts as a prefilter used upstream from the polymeric nanofiber layer to remove particles from a liquid stream flowing through the composite filtration structure. The nanofiber layer, positioned downstream from the porous membrane, is used as the retentive layer for critical filtration to provide biosafety assurance, and is responsible for capturing microorganisms like bacteria, mycoplasma or viruses. The composite liquid filtration platform provided herein exhibits permeability advantages over conventional porous membranes or nanofiber mats spun on coarse non-wovens.

A composite liquid filtration platform including a composite filtration medium featuring an electrospun polymeric nanofiber layer collected on a porous membrane. When in use, the porous membrane acts as a prefilter used upstream from the polymeric nanofiber layer to remove particles from a liquid stream flowing through the composite filtration structure. The nanofiber layer, positioned downstream from the porous membrane, is used as the retentive layer for critical filtration to provide biosafety assurance, and is responsible for capturing microorganisms like bacteria, mycoplasma or viruses. The composite liquid filtration platform provided herein exhibits permeability advantages over conventional porous membranes or nanofiber mats spun on coarse non-wovens.

Described are methods of membrane distillation for processing organic liquids, hydrophobic distillation membranes useful for membrane distillation methods, and methods of preparing the hydrophobic distillation membranes.

Described are methods of membrane distillation for processing organic liquids, hydrophobic distillation membranes useful for membrane distillation methods, and methods of preparing the hydrophobic distillation membranes.