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.

A hybrid type filtration structure for filtering liquid includes a first active layer, a porous supporting layer and a permeable layer. The first active layer has a first nano pore inner wall of which a function group included compound is combined with. The porous supporting layer has a plurality of pores and is disposed under the first active layer. The permeable layer is disposed under the porous supporting layer. The porous supporting layer includes a plurality of lipid bilayers having membrane protein inside of the pore, a molecule of water selectively passes through the membrane protein. The first nano pore passes through the first active layer vertically. The first nano pore and the pore are connected with each other through which liquid flows.

Membranes suitable for use in membrane distillation are provided. Such membranes may include nano-fibrous layers with adjustable pore sizes. The membranes may include a hydrophobic nano fibrous scaffold and a thin hydrophilic protecting layer that can significantly reduce fouling and scaling problems.

A proton exchange solid support includes a porous polymer network including a polymer. The polymer includes a tetravalent boron-based acid group in a side chain of the polymer, and the tetravalent boron-based acid group includes a boron atom having a negative formal charge. A cation is ionically linked to the boron atom.

Provided are membranes useful for electrochemical or fuel cells. A membrane may be formed of or include a sulfonated polymer whereby the sulfonated polymer is covalently or ionically associated with a multi-nitrogen containing heterocyclic molecule. The resulting membranes possess excellent ion conductivity and selectivity.

A periodic mesoporous organosilica (PMO) nanoparticle functionalized nanocomposite membrane (NCM) for membrane distillation, the NCM including: polymer fibers such as polyetherimide fibers aggregated into a matrix; and hydrophobic PMO nanoparticles disposed on the polymer fibers. The PMO nanoparticles include a framework connected by organic groups and pentafluorophenyl groups. Good membrane flux and anti-fouling was demonstrated. Membranes can be prepared by electrospinning.

The present invention relates to synthetic membranes and use of these synthetic membranes for isolation of volatile organic compounds and purification of water. The synthetic membrane includes a hydrophobic polymer layer located on a polymeric membrane support layer. The invention includes a method of isolating volatile organic compounds with the synthetic membrane by contacting a volatile organic mixture with the hydrophobic polymer layer of the synthetic membrane and removing volatile organic compounds from the polymeric membrane support layer of the synthetic membrane by a process of pervaporation. The invention also includes a method of purifying water with the synthetic membrane by contacting an ionic solution with the hydrophobic polymer layer of the synthetic membrane and removing water from the polymeric membrane support layer of the synthetic membrane by a process of reverse osmosis. The invention also relates to methods of isolating non-polar gases by gas fractionation.

An improved method for concentrating dispersions of graphene oxide, coating a substrate with a layer of a graphene oxide solution, and producing a supported graphene membrane stabilised by controlled deoxygenation; and graphene-based membranes that demonstrate ultra-fast water transport, precise molecular sieving of gas and solvated molecules, and which show great promise as novel separation platforms.

A functionalized nonwoven substrate and methods for preparing the same are described. The functionalized substrates are useful in selectively filtering and removing biological materials, such as biocontaminates, from biological samples.

Poly(amino acids) having hydrophilic side groups may be grafted onto active surfaces of polyamide composite membranes so as to confer fouling resistance. Polylysine, polyhistidine, polyarginine and their blends with polyglutamic acid may be grafted to membrane surfaces via amide linkages or via peroxide-induces bonding, modifying membrane surfaces behavior towards foulants.