A filtration membrane comprising cellulose fibres, the membrane having a pore size distribution such that the modal pore diameter is between 10 nm and 25 nm and/or wherein less than 5% of the pore volume comprises pores of greater than 40 nm and having a total porosity greater than 30%.

A method of enhancing hydrophilicity of a hydrophobic polymer material includes pre-treating the hydrophobic polymer material, comprising treating the hydrophobic polymer material with a first atmospheric pressure plasma discharge in a first atmosphere. The first atmosphere includes ammonia to obtain a pre-treated polymer material. The method includes treating the pre-treated polymer material with a second atmospheric pressure plasma discharge in a second atmosphere in which an aerosol of a carboxylic acid is introduced. A substrate is provided as well, the substrate including a hydrophobic polymer material having a modified interface, wherein the modified interface includes carboxylic functional groups grafted on the hydrophobic polymer material, the modified interface having a contact angle with water, which, measured after immersion in water at 20? C. for 3 days, is at least 25? less than a contact angle with water of the hydrophobic polymer material.

A low cost, high selectivity asymmetric polyimide/polyethersulfone (PES) blend hollow fiber membrane, a method of making the membrane and its use for a variety of liquid, gas, and vapor separations such as deep desulfurization of gasoline and diesel fuels, ethanol/water separations, pervaporation dehydration of aqueous/organic mixtures, CO.sub.2/CH.sub.4, CO.sub.2/N.sub.2, H.sub.2/CH.sub.4, He/CH.sub.4, O.sub.2/N.sub.2, H.sub.2S/CH.sub.4, olefin/paraffin, iso/normal paraffins separations, and other light gas mixture separations. The polyimide/PES blend hollow fiber membrane is fabricated from a blend of a polyimide polymer and PES and showed surprisingly unique gas separation property with higher selectivities than either the polyimide hollow fiber membrane without PES polymer or the PES hollow fiber membrane without PES polymer for gas separations such as for H.sub.2/CH.sub.4, He/CH.sub.4, H.sub.2S/CH.sub.4, CO.sub.2/CH.sub.4 separations.

Durable asymmetric composite membranes consisting of a film of cross-linked poly(ether ether ketone) adhered to a sheet of hydrophilic microporous poly(ethylene) are disclosed. The membranes are suitable for use in the recovery or removal of water from feed streams where repeated clean-in-place protocols are required such as in the processing of dairy products.

The present invention belongs to the technical field of membrane-based water treatment and relates to a novel guanidine-based composite nanofiltration (NF) flat-sheet membrane, and a preparation method and application thereof. The present invention provides a method for preparing a guanidine-based composite NF flat-sheet membrane, where a dense separation layer is formed on the surface of a polyethersulfone ultrafiltration membrane through polymerization reaction between the amino group of 1,3-diaminoguanidine and the acyl chloride group of trimesoyl chloride. Under suitable reaction conditions, the guanidine-based composite NF membrane obtained according to the present invention enables effective separation of multivalent ions over a wide pH range, with a rejection rate of over 96% for 1000 ppm of MgSO.sub.4 solution, and can operate continuously and stably in a mixed ions solution with a wide pH.

Methods of producing an ion exchange membrane support are disclosed. The methods include saturating a polymeric microporous substrate with a charged monomer solution comprising at least one functional monomer, a cross-linking agent, and an effective amount of at least one photopolymerization initiator and polymerizing the at least one functional monomer by exposing the saturated polymeric microporous substrate to ultraviolet light under conditions effective to cross-link the at least one functional monomer and produce the ion exchange membrane support. Methods of producing a monovalent selective ion exchange membrane are also disclosed. The methods include functionalizing an exterior surface of the ion exchange membrane support with a charged compound layer, drying the ion exchange membrane support and soaking the ion exchange membrane support in a solution comprising an acid or a base for an amount of time effective to produce the monovalent selective ion exchange membrane.

The present disclosure provides a gas separation membrane using a ladder-structured polysilsesquioxane in which organic functional groups are attached to a long siloxane chain and a method for fabricating the same. In accordance with the present disclosure, a free-standing ladder-structured polysilsesquioxane-based membrane with various functional groups can be fabricated for gas separations. The performance of the gas separation membrane can be controlled through a variety of combinations of the organic functional groups linked to the siloxane chain. In addition, by controlling the molecular structure of the gas separation membrane through mixing of the ladder-structured polysilsesquioxane with an amine compound or conventional glassy or rubbery polymers or through thermal/UV-curing, the permeability and selectivity of the gas separation membrane can be controlled selectively.

This invention discloses a method for preparing an antibacterial and dust-removal membrane. The method comprises the following steps: depositing a layer of nano-ZnO on the immersed membrane surface as the seed crystal with the atomic layer deposition instrument (ALD instrument); vertically immersing the membrane covered with nano-ZnO layer in a hydrothermal reactor filled with crystal growth solution, heating it for a period of time, taking the membrane out and cooling it to the room temperate, and removing it from the substrate; finally, heating this membrane in a drier, and purging it with nitrogen to remove the paraffin within the membrane pore to obtain the porous membrane with nano-ZnO arrays growing on the surface.

Provided is a technique for fabricating a novel thin membrane with a starting material such as a biocompatible compound that is not easily processible into a membrane, particularly a technique for fabricating a novel thin membrane of a composition that is gradually polymerized from a membrane surface into the membrane in the cross sectional direction of the membrane, and having, for example, different structures on the front and back of the membrane. The technique includes the steps of preparing a solution of a starting material compound; forming a thin membrane of the solution on a base material surface; and forming the organic polymer thin membrane through a polymerization reaction caused by irradiating the exposed surface of the thin membrane with a plasma or an electron beam.

A method is provided for fabricating a nanopore in a membrane. The method includes: applying an electric potential across the membrane, where value of the electric potential is selected to induce an electric field which causes a leakage current across the membrane; monitoring current flow across the membrane while the electric potential is being applied; detecting an abrupt increase in the leakage current across the membrane; and removing the electric potential across the membrane in response to detecting the abrupt increase in the leakage current.