Separation of linear and branched alkane isomers via selective permeation through a composite membrane is disclosed. The separation layer in the composite membrane is fabricated from a blend of at least two different fluoropolymer compositions, A and B, in which composition A has a normal-alkane isomer permeability that is greater than composition B. Composition B has a normal alkane to branched-alkane isomer selectivity that is equal or greater than composition A. The separation layer in the composite membrane has a normal-alkane permeability that is greater than composition B and a normal-alkane to branched alkane isomer selectivity that is greater than composition A.

Methods and systems for the separation of isotopes from an aqueous stream are described as can be utilized in one embodiment to remove and recover tritium from contaminated water. Methods include counter-current flow of an aqueous stream on either side of a separation membrane. The separation membrane includes an isotope selective layer (e.g., graphene) and an ion conductive supporting layer (e.g., Nafion). An electronic driving force encourages passage of isotopes selectively across the membrane to enrich the flow in the isotopes.

The present disclosure relates to, inter alia, a modified surface comprising an optically active monomer, a polymeric material having a surface onto which the optically active monomer is covalently bound. In one aspect, a membrane comprising an optically active monomer, a poly(aryl sulfone) membrane having a surface onto which the optically active monomer is covalently bound. The present disclosure also relates to a method of modifying a surface, the method comprising applying sufficient energy to a surface to induce covalent bonding with an optically active monomer, and contacting the optically active monomer with the surface. In one aspect, a method of modifying a surface of a poly(aryl sulfone) membrane is disclosed. In another aspect, a method of synthesizing an optically active monomer is disclosed. In one aspect, a method of filtration of chiral compounds is disclosed.

Asymmetric membrane structures are provided that are suitable for various types of separations, such as separations by reverse osmosis. Methods for making an asymmetric membrane structure are also provided. The membrane structure can include at least one polymer layer. Pyrolysis can be used to convert the polymer layer to a porous carbon structure with a higher ratio of carbon to hydrogen.

Asymmetric membrane structures are provided that are suitable for various types of separations, such as separations by reverse osmosis. Methods for making an asymmetric membrane structure are also provided. The membrane structure can include at least one polymer layer. Pyrolysis can be used to convert the polymer layer to a porous carbon structure with a higher ratio of carbon to hydrogen.

Microstructures immersed in a liquid have multiple chambers and funnels oriented inwardly. The funnels generate differential motility for bacteria. Bacteria is therefore concentrated within the chamber, and effectively sequestered from the environment outside the microstructures. Multiple consecutive chambers and conical funnels allow more effective sequestration of bacteria. These microtraps offer biocontrol options alternative to pharmaceutical solution such as antibiotics.

A method for preparing a thin or thick film, including the aligning non-spherical seed crystals on a flat portion of at least one surface of the substrate such that an a-axis, a b-axis, and/or a c-axis are oriented according to a certain rule; and exposing the aligned seed crystals to a solution for enabling the growth of the seed crystals to thereby form and grow a film from the seed crystals using a secondary growing technique.

Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

Asymmetric membrane structures are provided that are suitable for hydrocarbon reverse osmosis of small hydrocarbons. Separation of para-xylene from ortho- and meta-xylene is an example of a separation that can be performed using hydrocarbon reverse osmosis. Hydrocarbon reverse osmosis separations can be incorporated into a para-xylene isomerization and recovery system in a variety of manners.

A method of treating an aqueous liquid. The method comprises providing an aqueous feed liquid comprising water and at least one solute to a first side of a membrane. A draw solution comprising water and a draw solute comprising at least one of a phosphazene compound and a triazine compound is provided to a second side of the membrane. At least a portion of the water of the aqueous feed liquid is osmosed across the membrane and into the draw solution to form a diluted draw solution comprising water and the draw solute. The water of the diluted draw solution is separated from the draw solute of the diluted draw solution to form a purified water product. Draw solutes comprising phosphazene compounds and draw solutes comprising triazine compounds are also disclosed, as are methods of forming the draw solutes.