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 dry phase inversion process is performed on the polyimide membrane.

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 present invention generally relates to polymeric membrane materials formed, at least in part, from monomeric material selected from 2,3,3,3-tetrafluoropropene (CF.sub.3CF═CH.sub.2, HFO-1234yf) or trans-1,3,3,3-tetrafluoropropene (CF.sub.3CH═CFH, HFO-1234ze), and to membrane preparations and uses thereof in water desalination, filtration, membrane distillation, pervaporation, and selective gas separation.

A porous membrane is made from a poly(phenylene ether) copolymer containing 10 to 40 mole percent repeat units derived from 2-methyl-6-phenylphenol and 60 to 90 mole percent repeat units derived from 2,6-dimethylphenol; and a block copolymer containing backbone or pendant blocks of poly(C.sub.2-4 alkylene oxide). The porous membrane is made by dissolving the poly(phenylene ether) copolymer in a water-miscible polar aprotic solvent to form a membrane-forming composition; and phase-inverting the membrane forming-composition in a first non-solvent composition to form the porous membrane. A method of making a hollow fiber by coextrusion through a spinneret having an annulus and a bore, includes coextruding the membrane-forming composition through the annulus, and a first non-solvent composition through the bore, into a second non-solvent composition to form the hollow fiber.

A separation module that includes a porous membrane, where the porous membrane includes a poly(phenylene ether) copolymer containing 10 to 40 mole percent repeat units derived from 2-methyl-6-phenylphenol and 60 to 90 mole percent repeat units derived from 2,6-dimethylphenol; and a block copolymer containing backbone or pendant blocks of poly(C.sub.2-4 alkylene oxide). The separation module can be used in devices for wastewater treatment, water purification, desalination, separating water-insoluble oil from oil-containing wastewater, membrane distillation, sugar purification, protein concentration, enzyme recovery, dialysis, liver dialysis, or blood oxygenation.

Microporous membranes comprising a single integral layer having first and second microporous surfaces; and, a porous bulk between the microporous surfaces, wherein the bulk comprises at least a first region and a second region; the first region comprising a first set of pores having outer rims, prepared by removing introduced silica dissolvable nanoparticles, the first set of pores having a first controlled pore size, and a second set of pores connecting the outer rims, the second set of pores having a second controlled pore size, and a polymer matrix supporting the first set of pores, wherein the first controlled pore size is greater than the second controlled pore size; the second region comprising a third set of pores prepared by phase inversion, the third set of pores having a third controlled pore size, filters including the membranes, and methods of making and using the membranes, are disclosed.

Process for making a membrane M comprising the following steps: a) preparing a copolymer C, wherein said copolymer C comprises blocks of at least one polyarylene ether A and blocks of polyalkylene oxide PAO, wherein the content of polyethyleneoxide in copolymer C is 30 to 90% by weight and wherein copolymer C is prepared in a solvent L to yield solution S; b) providing a dope solution D comprising at least one polymer P; c) mixing solution S and dope solution D; d) preparing a membrane by bringing the mixture of solution S and dope solution D into contact with at least one coagulating agent.

A hydrophobic-oleophilic and hollow fiber composite membrane includes hollow tubular braids and surface separation layers coated on the outer surfaces of the hollow tubular braids. Membrane-forming polymers in the surface separation layers are polyvinylidene fluoride, and all other components are hydrophobic ingredients, including graphene. A preparing method includes preparing hollow tubular braids by two-dimensional braided technique using polyester filaments, wherein the hollow tubular braids are used as the reinforcements. The method further includes mixing polyvinylidene fluoride, hydrophobic pore-forming agent, and the rest of solvent to prepare a casting solution of surface separation layer. The method further includes pre-treatment processing of the reinforcements; and coating the casting solution of surface separation layer on the outer surface of the processed reinforcements through a spinning spinneret to form a primary membrane. The reinforcements are replaced by the primary after post-processing, and repeating the coating process.

Embodiments of the present disclosure provide for polystyrene-b-polyethylene oxide (PS-b-PEO) block copolymer nanoporous membranes, methods of making a PS-b-PEO block copolymer nanoporous membrane, methods of using PS-b-PEO block copolymer nanoporous membranes, and the like.

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 dry phase inversion process is performed on the polyimide membrane.