Polymer-based membranes and methods for fabricating membranes are described. The methods include forming a casting solution featuring a polyvinylidene fluoride (PVDF)-based solvent and a polyvinylpyrrolidone (PVP)-based modifying agent, dispersing the casting solution to form a first element, generating a plurality of active sites on a surface of the first element, and forming a polymer-based membrane by exposing the surface of the first element to a fluorosilane composition to form a fluorosilane layer on the surface, where the fluorosilane composition includes a silane compound having at least one alkyl substituent that includes between 9 and 21 fluorine atoms.

The present invention relates to a hydrophilic separation membrane polymer composition containing a sulfonated graphene oxide and a sulfonated carbon nanotube, and a hydrophilic separation membrane fabricated therefrom. A hydrophilic separation membrane according to the present invention has the advantage of being very high in water permeability and excellent in anti-fouling properties.

The present invention relates to a process for the production of asymmetric cellulose hollow fibres and the use of such fibres in the production of asymmetric carbon hollow fibre membranes (CHFMs). In particular, the present invention provides a facile and scalable process for the preparation of asymmetric CHFMs by direct pyrolysis of polymeric precursors without the need for complex pre-pyrolysis treatment steps to prevent pore collapse. The present invention also relates to the use of asymmetric CHFMs prepared according to said process in the separation of hydrogen gas from a mixed gas source, especially in the separation of hydrogen from CO.sub.2 in the steam-methane reforming reaction.

A method of separating gas and a method of making a gas separation membrane. The method of separating gas includes flowing a gas stream through a membrane, in which the membrane comprises a crosslinked mixture of a poly(ether-b-amide) copolymer and an acrylate-terminated poly(ethylene glycol) according to formula (I) or formula (II); and separating the gas stream via the membrane. ##STR00001##
In formulas (I) and (II), each n is of from 2 to 30; and each R is independently —H or —CH.sub.3.

A method of preparing a membrane comprising the steps of: a) mixing together a membrane-forming polymer, a water-soluble polyetheramine, and a solvent, said mixture containing no component which will react chemically with the polyetheramine; and b) casting said mixture to form the polymer into a solid membrane.

The present disclosure relates to a microporous hollow fiber filter membrane having a large inner diameter and a thin wall. The fiber can be used for sterile filtration of liquids or removal of particles from liquids. The disclosure further relates to a method for producing the membrane and a filter device comprising the membrane.

The disclosure provides a method for preparing a hollow fiber membrane by melt spinning-stretching and selective swelling, including: preparing a nascent hollow fiber by melt spinning in an inert gas protective atmosphere by using an amphiphilic block copolymer as a film forming material, and stretching the nascent hollow fiber in the cooling process, a stretch rate being controlled at 200-540 mm/min, and a stretch ratio being controlled at 150-600%; immersing the obtained hollow fiber in a swelling solvent, and treating the hollow fiber in a water bath at 65° C. for 1 h; and then transferring the hollow fiber into a long-chain alkane solvent, treating the hollow fiber at the same temperature for 1-12 h, and after the completion of the treatment, immediately taking out the hollow fiber and drying the hollow fiber to obtain the hollow fiber membrane with a bicontinuous porous structure. By combining the melt spinning-stretching and the selective swelling, the method of the disclosure can synchronously and continuously improve the permeability and selectivity of the hollow fiber membrane. The treatment in the long-chain alkane solvent can make the polar chain excessively enriched on the surface of the membrane migrate inward, thereby improving the performance of the hollow fiber membrane.

The present disclosure provides a liquid membrane conveying apparatus for preparing a porous membrane includes a transmission unit and a carrier unit. The carrier unit conveys a liquid membrane into a gelling solution by the entrainment of the transmission unit. The carrier unit includes a first carrier and a second carrier. The first carrier and the second carrier respectively contact with opposite edges of the liquid membrane along a conveying direction of the liquid membrane. The consistency of the pores on the two surfaces of the porous membrane is improved by using the liquid membrane conveying apparatus.

A preparation method of separation membrane is provided. First, a polyimide composition including a dissolvable polyimide, a crosslinking agent and a solvent is provided. The dissolvable polyimide is represented by formula 1: ##STR00001## wherein B is a tetravalent organic group derived from a tetracarboxylic dianhydride containing aromatic group, A is a divalent organic group derived from a diamine containing aromatic group, A′ is a divalent organic group derived from a diamine containing aromatic group and carboxylic acid group, and 0.1≤X≤0.9. The crosslinking agent is an aziridine crosslinking agent, an isocyanate crosslinking agent, an epoxy crosslinking agent, a diamine crosslinking agent, or a triamine crosslinking agent. A crosslinking process is performed on the polyimide composition. The polyimide composition which has been subjected to the crosslinking process is coated on a substrate to form a polyimide membrane. A wet phase inversion process is performed on the polyimide membrane.

The invention provides a method of producing multi-walled carbon nanotube blended polyvinylidene fluoride (MWCNTs/PVDF) membranes for membrane distillation (MD) treatment of saline water using non-solvent induced phase separation (NIPS), said method including mixing two solvents with different solubility parameters and the use of a dual coagulation bath system to control the formation of membrane pore structures and enhance surface hydrophobicity whereby blended PVDF membranes are produced for application in MD processes.