The present specification provides a composition comprising a material of Chemical Formula 1: ##STR00001##
having a molecular weight of 500,000 to 700,000 where R1 and R2 are the same as or different from each other, and each independently is hydrogen, deuterium, or an alkyl group, and n is from 10,000 to 20,000, for forming a reverse osmosis membrane protective layer, a method for preparing a reverse osmosis membrane using the same, a reverse osmosis membrane and a water-treatment module.

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 invention aims to improve the separation selectivity for light gases such as hydrogen and helium. The gas separation membrane according to the present invention includes a porous support layer and a separation functional layer containing a cross-linked polyamide and laid on the porous support layer, wherein: the separation functional layer has a protuberance structure containing a plurality of protrusions and recesses; randomly selected 20 of the protrusions on the surface of the separation functional layer indented under a load of 3 nN and observed in pure water at 25° C. by atomic force microscopy give an average deformation of 5.0 nm or more and 10.0 nm or less; and they give a standard deviation of the deformation of 5.0 nm or less.

A high-performance thin-film composite polyamide membrane upcycled from a substrate fouled with a biopolymer and a preparation method thereof are provided. The method includes fouling the substrate preferably with the biopolymer to obtain a composite of the substrate and a biopolymer foulant layer; then immersing the composite into a first solution formed by dissolving a polyamine monomer in water, followed by taking the composite out of the first solution and removing excess droplets from a surface of the composite; then immersing the composite treated in the previous step into a second solution formed by dissolving an acyl chloride monomer in n-hexane for interfacial polymerization to form a rejection layer on the surface of the composite; and after completion of the reaction, taking the composite out of the second solution, followed by drying and heat treatment, to obtain the target polyamide membrane.

The purpose of the present invention is to provide a composite semipermeable membrane whose water permeability is hard to decline even when exposed to high temperature environment for a long period of time, a spiral wound separation membrane element using the composite semipermeable membrane, and a method for producing the same. Another purpose of the invention is to provide a method for evaluating water permeation performance of a composite semipermeable membrane, which method evaluates whether the water permeability of a composite semipermeable membrane is likely to decline due to heat, by a simple evaluation method. The composite semipermeable membrane having a skin layer that includes a polyamide resin, the skin layer being placed on a porous support and having an elastic modulus of 100 MPa or more, calculated by AFM force curve measurement in water.

A curable composition comprising the components (i) 0 to 60 wt % non-ionic crosslinker(s); (ii) 20 to 85 wt % curable ionic compound(s) comprising an anionic group and at least one ethylenically unsaturated group; (iii) 15 to 45 wt % solvent(s); (iv) 0 to 10 wt % of photoinitiator(s); and (v) 2 to 45 wt % of structure modifier(s); wherein the molar ratio of component (v):(ii) is 0.25 to 0.65. The compositions are useful for preparing membranes for (reverse) electrodialysis.

A composite molecular sieve membrane, preparation method and use thereof are provided in the embodiments. The composite molecular sieve membrane includes a support layer and a molecular sieve membrane layer, wherein the support layer is a high-porosity and porous ceramic which is made of nano- or submicron ceramic powder materials or ceramic material precursors prepared through an electrospinning process. The high-porosity and porous ceramic, is adjustable from 40% to 83%. The composite molecular sieve membrane of the embodiments uses the porous ceramic prepared through an electrospinning process as the support layer, and the support layer has a flat and continuous surface, high porosity, uniform and adjustable pore sizes, low-tortuosity pore channels, and high mechanical strength; the flux of the composite molecular sieve membrane is increased, besides, the seed crystals can attach effectively due to the fibrous pore channels of the support layer, ensuring the adhesion amount of seed crystals.

The present invention relates to a thin film composite forward osmosis membrane with a polyethylene porous support, and a thin film composite forward osmosis membrane which is low cost, has excellent durability and chemical resistance, and outstanding performance (water flux and specific salt flux) may be provided in the present invention.

A separation membrane, suitably for oil and water separation. The membrane including a porous substrate layer and an active layer arranged over at least a part of the substrate layer. The active layer includes a hydrophilic agent and a superhydrophilic agent. Also described is a method of producing the separation membrane and a drain valve comprising the membrane.

A separation membrane, such as for pressure-assisted oil and water separation. The membrane includes a porous substrate layer and an active layer arranged over at least a part of the substrate layer. The active layer is at least partially crosslinked and comprises a superhydrophilic agent. Also described is a method of producing the separation membrane and a drain valve comprising the membrane.