A method for producing a nano-porous membrane with one or up to four graphene layers, pores in the membrane having an average pore size in the range of 0.2-50 or 0.3-10 nm, wherein the method involves the following steps: a) generation of a contiguous, essentially non-porous membrane with one or up to four graphene layers; b) distributed point wise defect creation in the non-porous membrane with one or up to four graphene layers by way of irradiation; c) generation and successive growth of the pores at the defects generated in step b) by thermal annealing in the gas phase, e.g. under 02 at a temperature in the range of 250° C. to less than 400° C.

The present invention relates to ultrathin polymer nanofilm and its composite membrane, its method of preparation. Composite membranes are produced via interfacial polymerization of diamine (or polyamine) monomer (or polymer) and trimesoyl chloride. After IP, post-treatment of washing nascent nanofilm with sufficient volume of solvent and drying at room temperature for 10-30 s followed by annealing at 70-100° C. for 1-10 min is developed. This washing step removes remaining TMC in organic phase and stops further growth of polyamide nanofilm. Ultrathin nanofilm composite membrane gives high water permeance (up to 61.3 Lm.sup.−2h.sup.−1bar.sup.−1) with high rejection of Na.sub.2SO.sub.4 (up to 99.3%) by maintaining relatively low rejection of MgCl.sub.2 (up to 27.7%) and NaCl (up to 11.9%) tested under 5 bar pressure at 25 (±1) ° C. with 2 g/L feed solution.

The present disclosure provides a method for treating the surface of a microporous polymeric membrane, comprising immersing a microporous polymeric membrane in a liquid; and applying ultrasonic waves to the microporous polymeric membrane immersed in the liquid.

Compositions and methods directed to the production of single layer, highly porous, free-standing polytetrafluoroethylene (PTFE) membranes having macro-textured surfaces are provided. The macro-textured surfaces are due to the presence of macroscopic nodal aggregates within the membrane that are connected by fibrils The membranes have high porosity, high airflow, and a bulk density less than 1.0 g/cm3. Articles comprising the porous, single layer PTFE membranes are also provided.

A method for producing a crystalline film comprising zeolite and/or zeolite-like crystals on a porous substrate is described. The method has the steps of: providing a porous support; modifying at least a surface of the top-layer of said porous support by treatment with a composition having one or more cationic polymer(s); rendering at least the outer surface of said porous support hydrophobic by treatment with a composition having one or more hydrophobic agent(s); subjecting said treated porous support to a composition having zeolite and/or zeolite-like crystals thereby depositing and attaching zeolite and/or zeolite-like crystals on said treated porous support, and growing a crystalline film of zeolite and/or zeolite-like crystals on said treated porous support and calcination. Crystalline films find use in a variety of fields such as in the production of membranes, catalysts etc.

The present disclosure relates, according to some embodiments, to systems, apparatus, and methods for fluid purification (e.g., water) with a ceramic membrane. For example, the present disclosure relates, in some embodiments, to a cross-flow fluid filtration assembly comprising (a) membrane housing comprising a plurality of hexagonal prism shaped membranes (b) an inlet configured to receive the contaminated fluid and to channel a contaminated fluid to the first end of the plurality of hexagonal prism shaped membranes, and (c) an outlet configured to receive a permeate released from the second end of the plurality of hexagonal shaped membranes. The present disclosure also relates to a cross-flow fluid filtration module comprising a fluid path defined by a contaminated media inlet chamber, a fluid filtration assembly positioned in a permeate chamber and a concentrate chamber.

Provided is a porous membrane including polytetrafluoroethylene and/or modified polytetrafluoroethylene having a small pore diameter, thin film thickness, high porosity, and high strength; and a method for manufacturing the same. The porous membrane including polytetrafluoroethylene and/or modified polytetrafluoroethylenehas bubble point of isopropyl alcohol according to JIS K3832 of 600 kPa or more, and tensile strength according to JIS K6251 of 90 MPa or more.

Hollow fiber membranes, membrane contactors, and related production and use methods. The asymmetric hollow fiber membranes include a porous substrate having a multiplicity of pores and including at least one semi-crystalline thermoplastic polyolefin (co)polymer. A skin layer including at least one polydiorganosiloxane polyoxamide copolymer overlays the porous substrate. The skin layer is less porous than the porous substrate and forms an outer surface of the asymmetric hollow fiber membrane, while the porous substrate forms an inner surface of the hollow fiber membrane. The skin layer is preferably nonporous.

The present invention relates to a method for producing ceramic gas-separation membranes, which comprises depositing, by means of inkjet printing, water-based inks that form layers of a gas separation membrane. More specifically, the method comprises at least the following steps forming a porous support (i) compatible with a functional separation layer; depositing on the support (i), by means of inkjet printing, at least one functional separation layer (ii) formed by at least two inks, and depositing at least one porous catalytic activation layer (iii) on the functional separation layer (ii); and performing at least one heat treatment, which produces sintering. The functional separation layer (ii) is deposited in a manner to produce a surface with fadings, patterns, or combinations thereof he invention also relates to a gas separation membrane produced using the described method.

A polymer electrolyte membrane according to the present invention has a cluster diameter of 2.96 to 4.00 nm and a converted puncture strength of 300 gf/50 μm or more. The polymer electrolyte membrane according to the present invention has a low electric resistance and an excellent mechanical strength.