Described embodiments include a graphene membrane film for solvent purification and related method, and a solvent purification system using same. The graphene membrane film for solvent purification is formed having a plurality of stacked graphene plate-shaped flakes, and at least one pair of the plurality of stacked graphene plate-shaped flakes comprises a physical bond or a chemical bond connecting layers. The graphene membrane film for solvent purification is produced by preparing a graphene oxide dispersion liquid by dispersing graphene oxide in distilled water; confining the graphene oxide dispersion liquid between a pair of substrates; and applying heat and pressure to the graphene oxide dispersion liquid between the substrates to perform a hydrothermal reaction to concurrently thermally reduce the graphene oxide and bind graphenes. Due to lipophilic surface property and fine pores, size exclusion separation and hydrophilic-lipophilic component separation through polarity may be realized, and thus is usable in fine chemistry fields.

Nanofiltration of aqueous solutions or other water-based fluids in various applications, such as desalination, dialysis, seawater purification, for example, may be enhanced through precisely controlling a filtration cutoff within graphene oxide nanofilters. By initially compressing and constraining the stacked thickness of multiple graphene oxide layers deposited between porous substrates, the interlayer gap size, and thus, the filtration cutoff may be adjusted and optimized.

A graphene oxide membrane with a controllable interlayer spacing, a preparation method and use thereof are provided. The preparation method provides of infiltrating a graphene oxide membrane in an aqueous solution A of salt to swell, thereby obtaining the graphene oxide membrane with the controllable interlayer spacing. The aqueous solution A of salt is a solution containing metal cation, and the concentration of the metal cation in the aqueous solution A is from 0.25-2.5 mol/L. The application can precisely control the size of the interlayer spacing of the graphene oxide membrane in the range of 1114 , and the variable range of this spacing can be controlled to within 0.61 . The graphene oxide membrane with the controllable interlayer spacing of the application has excellent mechanical strength, which remains a complete membrane state after 5 hours of infiltration. The preparation process is simple and easy to be operated, and the obtained graphene oxide membrane has a function of screening and filtering smaller ions, and thus has a good application prospect.

Nanofiltration of aqueous solutions or other water-based fluids in various applications, such as desalination, dialysis, seawater purification, for example, may be enhanced through precisely controlling a filtration cutoff within graphene oxide nanofilters. By initially compressing and constraining the stacked thickness of multiple graphene oxide layers deposited between porous substrates, the interlayer gap size, and thus, the filtration cutoff may be adjusted and optimized.

A method for increasing the thickness of a sheet of CNTs (146, 147, 246, 346), comprising: providing a wet sheet of CNTs, wherein the sheet of CNTs is either a continuous sheet of CNTs or a portion of sheet of CNTs, wherein the wet sheet of CNTs is the result of applying a process for manufacturing a sheet of CNTs; separating the wet sheet of CNTs from any filter or support element; drying the wet sheet of CNTs (146, 147, 246, 346) by applying heat (15, 25, 35) from a heat source (12, 22, 32). A method for manufacturing a continuous sheet of CNTs, comprising: in a container (41) filled with a liquid solution (42) comprising CNTs at certain concentration, submerging a vacuum tank (43) having a lower surface forming a grillage; moving an elongated filtering membrane (44) along the lower surface of the vacuum tank (43) while vacuum is applied on the elongated filtering membrane (44) in such a way that in the surface of the filtering membrane (44) opposed to the surface in contact with the lower surface of the vacuum tank (43) CNTs are deposited forming a continuous sheet of CNTs (45) of constant thickness; taking the filtering membrane (44) together with the continuous sheet of CNTs (45) out of the container (41); washing the continuous sheet of CNTs (55) disposed on the filtering membrane or on a support element (54) in a second container (51) filled with cleaning solution (52); taking the continuous sheet of CNTs (55) together with the filtering membrane or the support element (54) out of the second container (51); separating the continuous sheet of CNTs (55) from the filtering membrane or the support element (54); drying the continuous sheet of CNTs (55) by applying the method for increasing the thickness of a sheet of CNTs.

Disclosed is a method for the production of a porous polymer membrane suitable for liquid filtration or analyte capture, comprising the steps of: providing a flowable composition (100) on a substrate (220) the composition including at least: photo-activatable monomer molecules, photo activation initiator molecules and photo-activation quencher molecules; providing one or more pulses (L) of laser light at at least one focal point in the composition of sufficient energy to locally polymerise the composition; moving the or each focal point relative to the previously polymerised composition in a continuous or stepwise predetermined manner to a multiplicity of further positions; and repeating the pulse(s) at those further positions such that a three dimensional matrix of the composition is polymerised leaving unpolymerized areas of a size equivalent to conventional polymer membrane pores.

A method for controlling fiber cross-alignment in a nanofiber membrane, comprising: providing a multiple segment collector in an electrospinning device including a first and second segment electrically isolated from an intermediate segment positioned between the first and second segment, collectively presenting a cylindrical structure, rotating the cylindrical structure around a longitudinal axis proximate to an electrically charged fiber emitter; electrically grounding or charging edge conductors circumferentially resident on the first and second segment, maintaining intermediate collector electrically neutral; dispensing electrospun fiber toward the collector, the fiber attaching to edge conductors and spanning the separation space between edge conductors; attracting electrospun fiber attached to the edge conductors to the surface of the cylindrical structure, forming a first fiber layer; increasing or decreasing rotation speed of the cylindrical structure to alter the angular cross-alignment relationship between aligned nanofibers in adjacent layers, the rotation speed being altered to achieve a target relational angle.

During a first stage of a priming procedure, a priming fluid is conveyed into a spinning membrane separator via a filtrate outlet port so as to convey air out of the spinning membrane separator via an inlet port and a retentate outlet port of the spinning membrane separator. During an optional second stage of the priming procedure, the priming fluid is conveyed into the spinning membrane separator via the inlet port so as to convey air out of the spinning membrane separator via the retentate outlet port. A rotor positioned within a housing of the spinning membrane separator may be rotated with respect to the housing during the first and second stages to force air from within the rotor into an annulus defined between the rotor and the housing for more complete priming of the spinning membrane separator.

A process for preparing a composite membrane comprising the steps: a) applying a radiation-curable composition to a porous support; b) irradiating the composition present on the support, thereby forming a gutter layer of cured polymer; c) forming a discriminating layer on the gutter layer; and d) applying a radiation-curable composition to the discriminating layer and irradiating that composition, thereby forming a protective layer on the discriminating layer; wherein one or both of the radiation-curable compositions applied in steps a) and d) comprise a photo acid generator having an absorbency coefficient ? at 313 nm of more than 1?10.sup.4 mol.sup.?1*cm.sup.?1. Also claimed are composite membranes and gas separation cartridges comprising the membranes.

The invention is an improved method of making a carbon molecular sieve (CMS) membrane in which a polyimide precursor polymer is pyrolyzed to form a carbon molecular sieve membrane by heating, in a furnace, said polyimide precursor polymer to a final pyrolysis temperature of 600 C to 700 C at a pyrolysis heating rate of 3 to 7 C/minute from 400 C to the final pyrolysis temperature, the final pyrolysis temperature being held for a pyrolysis time of at most 60 minutes in a non-oxidizing atmosphere. In a particular embodiment, the cooling rate from the pyrolysis temperature is accelerated by methods to remove heat. The CMS membranes have shown an improved combination of selectivity and permeance as well as being particularly suitable to separate gases in gas streams such methane from natural gas, oxygen from air and ethylene or propylene from light hydrocarbon streams.