Embodiments described herein relate generally to graphene oxide membranes for fluid filtration and more specifically to graphene oxide membranes having tunable permeability, rejection rate, and flux. Some embodiments of the graphene oxide membranes disclosed herein are characterized as having a flux of at least about 2.5×10.sup.−4 gallons per square foot per day per psi with a 1 wt % lactose solution at room temperature, and a lactose rejection rate of at least 50% with a 1 wt % lactose solution.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membranes can comprise a support layer, and a selective polymer layer disposed on the support layer. In some cases, the support layer can comprise a gas permeable polymer and hydrophilic additive dispersed within the gas permeable polymer. In some cases, the selective polymer layer can comprise a selective polymer matrix and carbon nanotubes dispersed within the selective polymer matrix. The membranes can exhibit selective permeability to gases. As such, the membranes can be for the selective removal of carbon dioxide and/or hydrogen sulfide from hydrogen and/or nitrogen.

Embodiments described herein relate generally to graphene oxide membranes for fluid filtration and more specifically to graphene oxide membranes having tunable permeability, rejection rate, and flux. Some embodiments of the graphene oxide membranes disclosed herein are characterized as having a flux of at least about 2.510.sup.4 gallons per square foot per day per psi with a 1 wt % lactose solution at room temperature, and a lactose rejection rate of at least 50% with a 1 wt % lactose solution.

Embodiments described herein relate generally to durable graphene oxide membranes for fluid filtration. For example, the graphene oxide membranes can be durable under high temperatures non-neutral pH, and/or high pressures. One aspect of the present disclosure relates to a filtration apparatus comprising: a support substrate, and a graphene oxide membrane disposed on the support substrate. The graphene oxide membrane has a first lactose rejection rate of at least 50% with a first 1 wt % lactose solution at room temperature. The graphene oxide membrane has a second lactose rejection rate of at least 50% with a second 1 wt % lactose solution at room temperature after the graphene oxide membrane is contacted with a solution that is at least 80 C. for a period of time.

Membranes, methods of making the membranes, and methods of using the membranes are described herein. The membranes can comprise a gas permeable support layer, optionally an inorganic layer disposed on the support, and a selective polymer layer disposed on the inorganic layer. In some cases, the selective polymer layer can comprise an amine-containing polymer and an amino acid salt dispersed within the amine-containing polymer. In other cases, the selective polymer layer comprises a sterically hindered amine-containing polymer, such as a sterically hindered derivative of polyvinylamine. The membranes can be used, for example, to separate gaseous mixtures, such as flue gas.

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.

This invention provides a new high selectivity stable facilitated transport membrane comprising a polyethersulfone (PES)/polyethylene oxide-polysilsesquioxane (PEO-Si) blend support membrane, a hydrophilic polymer inside the pores on the skin layer surface of the PES/PEO-Si blend support membrane; a hydrophilic polymer coated on the skin layer surface of the PES/PEO-Si blend support membrane, and metal salts incorporated in the hydrophilic polymer coating layer and the skin layer surface pores of the PES/PEO-Si blend support membrane, and methods of making such membranes. This invention also provides a method of using the high selectivity stable facilitated transport membrane comprising PES/PEO-Si blend support membrane for olefin/paraffin separations such as propylene/propane and ethylene/ethane separations.

A filter medium including: a porous first support; nanofiber webs respectively stacked at the upper and lower parts of the first support, and made of a plurality of nanofibers of which the diameters have a standard deviation of 300 nm or less; and a porous second support interposed between the first support and the nanofiber web. The filter medium is implemented by fibers having uniform diameters, and thus is easily manufactured to have a predetermined pore diameter and simultaneously has excellent uniformity of the pore diameters, thereby having excellent filtering efficiency and being more suitable when selectively separating specific objects. Backwashing is enabled at uniform pressure during backwashing such that high cleaning power is obtained. The filter medium has excellent water permeability and excellent mechanical strength so as to minimize the shape and structural deformation and damage of the filter medium.

A composition of five parts by mass of chitosan and one part graphene oxide is suspended in water. The composition may be used to form filtration layers of any size or shape and may be reinforced by additional layers. The composition may be used to construct a large filtration apparatus of any size or shape and may be used to form highly resilient, antimicrobial structures and surfaces for a variety of applications.

A composition of five parts by mass of chitosan and one part graphene oxide is suspended in water. The composition may be used to form filtration layers of any size or shape and may be reinforced by additional layers. The composition may be used to construct a large filtration apparatus of any size or shape and may be used to form highly resilient, antimicrobial structures and surfaces for a variety of applications.