A gas separation membrane comprising the following layers: (i) a porous support layer; and (ii) a discriminating layer comprising groups of the Formula (1): M(O).sub.x, wherein: M is a metal or metalloid atom; O is an oxygen atom; and x has a value of at least 4; optionally (iii) a layer which comprises a fluorinated polymer; and optionally (iv) optionally a protective layer; wherein: (a) the porous support layer (i) comprises less than 10 mg/m.sup.2 of monovalent metal ions; (b) the discriminating layer (ii) comprises a surface comprising at least 10 atomic % of M of Formula (1) groups, wherein M is as hereinbefore defined; and (c) when layer (iii) is present, layer (ii) is located between layers (i) and (iii).

Durable asymmetric composite membranes consisting essentially of a film of cross-linked sulfonated poly(ether ether ketone) adhered to a sheet of hydrophilicitized microporous poly(ethylene) are disclosed. The membranes have application in the recovery of water from feed streams where the ability to clean in situ is desirable, for example in dairy processing. Methods of preparing cross-linked sulfonated poly(ether ether ketone) suitable for use as the rejection layer and hydrophilicitized sheets of microporous poly(ethylene) suitable for use as the support layer of such membranes are also disclosed.

A system for manufacturing a membrane filter is provided. The system includes a radiation source operative to emit radiation that contacts discrete portions of a filter substrate so as to facilitate the formation of openings within the filter substrate, and a collimator disposed between the filter substrate and the radiation source and operative to restrict some of the radiation from contacting the filter substrate.

The present disclosure provides an etching mask, a method for manufacturing the same, a method for manufacturing a porous membrane using the same, a porous membrane, a fine dust blocking mask including the same, and a method for manufacturing a surface enhanced Raman scattering active substrate. In this connection, the etching mask includes an organic film; and a pattern layer disposed on the organic film, wherein the pattern layer has openings defined therein having a uniform size, wherein each of the openings includes a micro-scale or nano-scale hole.

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.

Methods that expand the properties of laser-induced graphene (LIG) and the resulting LIG having the expanded properties. Methods of fabricating laser-induced graphene from materials, which range from natural, renewable precursors (such as cloth or paper) to high performance polymers (like Kevlar). With multiple lasing, however, highly conductive PEI-based LIG could be obtained using both multiple pass and defocus methods. The resulting laser-induced graphene can be used, inter alia, in electronic devices, as antifouling surfaces, in water treatment technology, in membranes, and in electronics on paper and food Such methods include fabrication of LIG in controlled atmospheres, such that, for example, superhydrophobic and superhydrophilic LIG surfaces can be obtained. Such methods further include fabricating laser-induced graphene by multiple lasing of carbon precursors. Such methods further include direct 3D printing of graphene materials from carbon precurors. Application of such LIG include oil/water separation, liquid or gas separations using polymer membranes, anti-icing, microsupercapacitors, supercapacitors, water splitting catalysts, sensors, and flexible electronics.

The present invention relates to a hollow fiber membrane in which the thickness L of a spherical structure layer is 60-500 ?m (inclusive), the spherical structure layer has a first surface and a second surface, the average diameter Da.sub.1 of the spherical structure in a region Sa.sub.1 10 ?m or less from the first surface and the average diameter db.sub.2 of the spherical structure in a region Sb.sub.2 10-20 ?m from the second surface satisfy the relational expression Da.sub.1>db.sub.2, and the spherical structure satisfies certain parameters.

A process for preparing an ion-exchange membrane having a textured surface profile comprising the steps (i) and (ii): (i) applying a radiation-curable composition to a membrane in a patternwise manner; and (ii) irradiating and thereby curing the radiation-curable composition present on the membrane; wherein the radiation-curable composition comprises: a) 10 to 65 wt % of curable ionic compound(s) comprising one ethylenically unsaturated group; b) 3 to 60 wt % of crosslinking agent(s) comprising at least two ethylenically unsaturated groups and having a number average molecular weight below 800; c) 0 to 70 wt % of inert solvent(s); d) 0 to 10 wt % of free-radical initiator(s); and e) 0.5 to 25 wt % of thickening agent(s).

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.

One aspect of the disclosed is to provide a method of manufacturing a nanoporous multilayer graphene membrane, including a first step of oxidizing a surface of a multilayer graphene membrane, a second step of reducing the oxidized surface of the multilayer graphene to carry out reductive etching such that oxidized carbon atoms on the surface are naturally and randomly dispersed, and a third step of repeatedly performing a series of the first and the second steps until nanopores penetrating the multilayer graphene are formed.